[Compression stockings as prevention of hypotension in Cesarean section during spinal anesthesia]. Prevention of hypotension following spinal anaesthesia for elective caesarean section by wrapping of the legs. Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload. Ephedrine and phenylephrine for avoiding maternal hypotension due to spinal anaesthesia for caesarean section. Effects on uteroplacental and fetal haemodynamics. Prevention of hypotension during spinal anaesthesia for caesarean section. Leg elevation and wrapping in the prevention of hypotension following spinal anaesthesia for elective caesarean section. The use of thromboembolic deterrent stockings and a sequential compression device to prevent spinal hypotension during caesarean section. Thromboembolic deterrent stockings fail to prevent hypotension associated with spinal anaesthesia for elective caesarean section. Influence of volume preloading on uteroplacental and fetal circulation during spinal anaesthesia for caesarean section in uncomplicated singleton pregnancies. Hemodynamic effects of spinal anesthesia and simultaneous intravenous bolus of combined phenylephrine and ephedrine versus ephedrine for cesarean delivery. Spinal anaesthesia for caesarean section: comparison of infusions of phenylephrine and ephedrine. A reevaluation of the role of crystalloid preload in the prevention of hypotension associated with spinal anesthesia for elective cesarean section. Colloid vs. crystalloid preloading to prevent maternal hypotension during spinal anesthesia for elective cesarean section. Glycopyrronium and hypotension following combined spinal-epidural anaesthesia for elective Caesarean section in women with relative bradycardia. Evaluation of pre-emptive intramuscular phenylephrine and ephedrine for reduction of spinal anaesthesia-induced hypotension during Caesarean section. Lumbar wedge versus pelvic wedge in preventing hypotension following combined spinal epidural anaesthesia for caesarean delivery. Hypotension following combined spinal-epidural anaesthesia for Caesarean section. Left lateral position vs. tilted supine position. Spinal or epidural anaesthesia for elective caesarean section? A Swedish experience. Effect of delayed supine positioning after induction of spinal anaesthesia for caesarean section. Effectiveness of intravenous ephedrine infusion during spinal anaesthesia for caesarean section based on maternal hypotension, neonatal acid-base status and lactate levels. Maternal cardiovascular consequences of positioning after spinal anaesthesia for Caesarean section: left 15 degree table tilt vs. left lateral. Combined spinal epidural anaesthesia for caesarean section: a randomised comparison of Oxford, lateral and sitting positions. Crystalloid preload versus rapid crystalloid administration after induction of spinal anaesthesia (coload) for elective caesarean section. Sequential compression device with thigh-high sleeves supports mean arterial pressure during Caesarean section under spinal anaesthesia. Reduction in spinal-induced hypotension with ondansetron in parturients undergoing caesarean section: a double-blind randomised, placebo-controlled study. Hemodynamic effects of a right lumbar-pelvic wedge during spinal anesthesia for cesarean section. Prospective, randomized trial comparing general with spinal anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace. Prophylactic intravenous bolus ephedrine for elective Caesarean section under spinal anaesthesia. Preoperative dextrose does not affect spinal-induced hypotension in elective Cesarean section. Prevention of hypotension after spinal anesthesia for cesarean section: dextran 40 versus lactated Ringer's solution. Effect of crystalloid and colloid preloading on uteroplacental and maternal haemodynamic state during spinal anaesthesia for caesarean section. Prophylactic ephedrine and hypotension associated with spinal anesthesia for cesarean delivery. Prevention of hypotension after spinal anesthesia for cesarean section: six percent hetastarch versus lactated Ringer's solution. Comparison of prophylactic angiotensin II versus ephedrine infusion for prevention of maternal hypotension during spinal anesthesia. [Preload during spinal anesthesia for cesarean section: comparison between crystalloid and colloid solutions.]. Neurologic activity of infants following anesthesia for cesarean section. Re-evaluation of i.m. ephedrine as prophylaxis against hypotension associated with spinal anaesthesia for Caesarean section. Warm or cold saline for volume preload before spinal anaesthesia for caesarean section? The effect of prophylactic glycopyrrolate on maternal haemodynamics following spinal anaesthesia for elective caesarean section. Prevention of hypotension by a single 5-mg dose of ephedrine during small-dose spinal anesthesia in prehydrated cesarean delivery patients. Hemodynamic effects of simultaneous administration of intravenous ephedrine and spinal anesthesia for cesarean delivery. Prophylactic phenylephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery. Rapid administration of crystalloid preload does not decrease the incidence of hypotension after spinal anaesthesia for elective caesarean section. Fluid loading to reduce abnormalities of fetal heart rate and maternal hypotension during epidural analgesia in labour. Manual displacement of the uterus during Caesarean section. General versus spinal anaesthesia for elective caesarean sections: effects on neonatal short-term outcome. A prospective randomised study. Glycopyrrolate reduces nausea during spinal anaesthesia for caesarean section without affecting neonatal outcome. Comparison of pentastarch and Hartmann's solution for volume preloading in spinal anaesthesia for elective caesarean section. Hydroxyethylstarch 10% is superior to Ringer's solution for preloading before spinal anesthesia for Cesarean section. [Practice of spinal anesthesia in a developing country: usefulness of vascular preloading with a 7.5% hypertonic saline solution].
Inflatable splints and wrapping of the legs have been shown to be effective against hypotension during spinal anaesthesia for Caesarean section. The aim of this study was to investigate if compression stockings could have a similar effect. Thirty healthy mothers scheduled for elective Caesarean section were randomised to have either compression stockings or no stockings on before spinal anaesthesia. The stockings had a pressure effect of 54 mmHg. The women were preloaded with 20 ml isotonic NaCl one hour preoperatively. Hypotension was defined as either a decrease in systolic blood pressure to 80% of preoperative values or systolic blood pressure under 100 mmHg. Blood pressure was measured every second minute, and ephedrine 5 mg was given in the presence of hypotension. Two patients were excluded in the control group. There were no differences in demographic data, extension of blockade, and spinal injection to delivery time. Nine patients in the group with stockings had either no fall in blood pressure or a fall in blood pressure corrected with only 5 mg ephedrine. In the control group the corresponding number was four patients (p < 0.12). Ephedrine dose between zero and 20 minutes and total ephedrine dose was significantly lower in the group with stockings than in the control group (p < 0.038). Five patients in the control group experienced nausea, no patients in the study group had nausea (p < 0.013). In conclusion, compression stockings stabilised the blood pressure during Caesarean section in spinal anaesthesia and led to a significant smaller need for ephedrine. Twenty-four parturients undergoing elective Caesarean section were allocated randomly to have the legs wrapped with elasticated Esmarch bandages immediately following spinal anaesthesia or to serve as controls. Significant hypotension (systolic arterial pressure less than 100 mm Hg and less than 80% of baseline value) was treated with i.v. ephedrine in 5-mg boluses. Leg wrapped patients had a significantly (P = 0.0033) lower incidence (16.7%) of hypotension than controls (83.3%). Only two patients in the leg wrapped group required ephedrine compared with 10 in the control group. Systolic arterial pressure was significantly (P less than 0.05) less in control subjects at 4, 5 and 6 min following spinal injection. No patient in the leg wrapped group became hypotensive following removal of the elasticated bandages. We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. Maternal uterine circulation was measured using Doppler ultrasound in 11 parturients before and after spinal anaesthesia. There was a lower incidence of severe hypotension in the ephedrine group compared with the fluid group (35% vs. 65%, p = 0.04), although the incidence of moderate hypotension was similar. Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section. The effects of i.v. vasopressors on Doppler velocimetry of the maternal uterine and placental arcuate arteries and the fetal umbilical, renal and middle cerebral arteries were studied during spinal anaesthesia in 19 healthy parturients undergoing elective caesarean section. Fetal myocardial function was investigated at the same time by M-mode echocardiography. The patients were randomized into two groups, to be given either ephedrine or phenylephrine as a prophylactic infusion supplemented with minor boluses if systolic arterial pressure decreased by more than 10 mmHg from the control value. Both the vasopressors restored maternal arterial pressure effectively. The ephedrine group showed no significant differences in any of the Doppler velocimetry recordings relative to the baseline values, but during the phenylephrine infusion the blood flow velocity waveform indices for the uterine and placental arcuate arteries increased significantly and vascular resistance decreased significantly in the fetal renal arteries. Healthy fetuses seem to tolerate these changes in uteroplacental circulation well, however, since the Apgar scores for the newborns and the acid-base values in the umbilical cord were within the normal range in both groups. The results suggest that some caution is required when selecting the specific vasopressor agent, the dosage and the mode of administration for the treatment of maternal hypotension secondary to spinal anaesthesia for caesarean section. Twenty-six parturients scheduled to receive spinal anaesthesia for caesarean section were randomized to receive either isotonic saline 750 ml plus 20 ml/kg (group A) or 750 ml plus 500 ml (group B) before subarachnoid administration of bupivacaine 13 mg. Ephedrine 0.15 mg/kg i.v. followed by an infusion 0.4 mg.kg(-1) h(-1) were then administered in group B. In both groups ephedrine 10 mg/min i.v. was given if the mean arterial blood pressure decreased more than 10 mmHg. Despite the fluid preload and large doses of ephedrine noted {median (range), group A 30 mg (10-80), group B 92 mg (25-194)}, hypotension, sometimes accompanied by nausea, still occurred. Mean maternal arterial was significantly lower in group A than in group B 5-10 min after induction of spinal anaesthesia (P < 0.05). There was no difference in the frequency of nausea or vomiting, Apgar score, or pH in umbilical cord blood. One neonate in group A and 2 in group B were acidotic. In conclusion, a reduced volume loading could be compensated with an increased ephedrine administration after induction of spinal anaesthesia, without increasing the incidence of hypotension or other maternal or neonatal complications. However, the fluid volumes and/or ephedrine doses used were not sufficient to prevent hypotension altogether. Ninety-seven parturients undergoing elective Caesarean section were allocated randomly to have their legs elevated to approximately 30 degrees on pillows or elevated and wrapped with elasticated Esmarch bandages or neither (controls) following spinal anaesthesia. All patients received intravenous crystalloid (20 ml.kg-1 over 20 min) prior to spinal injection and were placed in the left lateral tilt position. Significant hypotension was treated with intravenous ephedrine in 5 mg bolus doses. Leg wrapping resulted in a significant reduction in the incidence of postspinal hypotension in comparison to the control group (18% compared to 53%, p = 0.004). This represents a five-fold reduction in the likelihood of postspinal hypotension (odds ratio 5.3, 95% CI 1.7-16.3). Leg elevation alone did not significantly reduce the incidence of hypotension (39%). There was no significant difference in the time of onset of hypotension between the groups. For those patients requiring ephedrine, there was no significant difference in mean dose requirements between the groups. The use of leg compression immediately postspinal provides a simple means of reducing the accompanying hypotension and should be used more widely. Hypotension is a common side effect of spinal anaesthesia for caesarean section. We have performed a randomised, controlled study to determine the efficacy of a sequential compression device (SCD) (Kendall) in combination with thromboembolic deterrent (TED) stockings (Kendall) to reduce the incidence of hypotension in this setting. Within 20 min of spinal injection, there was no statistically significant difference in the incidence of hypotension (defined as less than 100 mmHg and less than 80% of baseline blood pressure) (TED/SCD group 65%, control 80%, P = 0.12). However, there was a trend for those receiving TED/SCD prophylaxis to require less ephedrine to maintain normotension than the control group (median TED/SCD 3 mg, control 6 mg, P = 0.08). The administration of ephedrine deviated from protocol on a total of 46 occasions (2.3% of recordings). To try to reduce the influence of this, we reinspected our data using time to first episode of hypotension with a Kaplan-Meier survival analysis. This showed that the instantaneous risk (hazard) of developing hypotension was 1.8 (95% CI: 1.1-2.9) times higher in controls than those receiving TED/SCD prophylaxis (P = 0.02). Despite demonstrating some benefit of TED/SCD prophylaxis to prevent hypotension, we do not consider that the magnitude of this benefit warrants their routine use. This study was carried out to determine whether the use of thrombo-embolic deterrent (TED) stockings, in combination with an intravenous crystalloid preload, would prevent hypotension following spinal anaesthesia for caesarean section. Fifty parturients undergoing elective caesarean section under spinal anaesthesia were randomly allocated into two groups. TED stockings were applied to the study group 1 h before spinal anaesthesia but none were applied to the control group. Both groups received a crystalloid preload of 15 ml kg(-1) over 15 min before spinal injection. Significant hypotension, defined as an absolute value of systolic arterial pressure (SAP) of less than 90 mmHg and a decrease of more than 20% from baseline SAP was treated with 3 mg bolus of ephedrine as required. The difference in SAO between the two groups was not statistically significant. In the control group, 80% of parturients required ephedrine as opposed to 56% in the TED group; a difference that was also not statistically significant. Effects of volume preloading during spinal anaesthesia for elective caesarean section on maternal blood pressure, feto-maternal circulation and fetal outcome.
                In a pilot study a randomised trial was performed in 22 healthy women with uncomplicated, singleton pregnancies at 36-40 weeks of gestation undergoing elective caesarean section under spinal anaesthesia. In the low volume group (group A) patients received 150 ml of crystalloid solution for preloading, in the high volume group (group B) they were given 15 ml/kg of crystalloid solution for preloading before the initiation of spinal anaesthesia. Maternal blood pressure was monitored intermittently. Hypotension was defined as a decrease in systolic pressure to less than 80% of the baseline value. The Doppler flow evaluation consisted of measurements from the uterine artery at the placental site, fetal umbilical artery and fetal middle cerebral artery. Pulsatility indices were derived before and after fluid preloading, and when spinal anaesthesia was established. The neonatal outcome was assessed by Apgar scores, arterial acid base status and neurologic and adaptive capacity scores (NACS).
                The incidence of maternal hypotension in both groups was 45.5% (n = 10); 3 cases occurred in group A compared to 7 cases in group B (n.s.). There was no evidence that the high dose volume is useful in preventing maternal hypotension. The pulsatility indices of uterine arteries, umbilical arteries and middle cerebral arteries were not altered. Statistical analysis showed no changes in neonatal outcome concerning umbilical arterial pH, Apgar score and NACS (n.s.) between groups A and B.
                Our preliminary results suggest that high dose crystalloid volume preloading has no preventive function in the avoidance of maternal hypotension in healthy parturients undergoing elective caesarean section under spinal anaesthesia, and shows no harmful effects on neonatal outcome as long as maternal hypotension is corrected immediately. However, the statistical significance may reflect the small sample size, and larger series are needed before changing the current management.
                Copyright 2002 S. Karger AG, Basel Hypotension following spinal anesthesia for cesarean delivery can produce adverse maternal symptoms and neonatal acid-base effects. Single-agent prophylaxis, most notably with ephedrine, does not reliably prevent spinal anesthesia-induced hypotension; recently, however, the prophylactic use of phenylephrine with ephedrine as an infusion was observed to be effective. We postulated that this combination, when given as an intravenous bolus for prophylaxis and rescue treatment, could be similarly effective.
                Forty-three term parturients were randomized to receive a bolus of ephedrine 10 mg +/- phenylephrine 40 microg (groups E and EP, respectively) simultaneously with spinal anesthesia. Hypotension was defined as a systolic blood pressure below 100 mmHg or a decrease of 20% from a baseline value. Rescue boluses comprised of ephedrine 5 mg +/- phenylephrine 20 microg.
                For groups E and EP, respectively, the incidence of hypotension was 80% vs. 95% (P=0.339), with the mean number of rescue boluses being 3.85+/-3.7 and 3.05+/-1.7 and the mean umbilical artery pH being 7.246+/-0.081 vs. 7.244+/-0.106. All comparisons were not significant (NS).
                The combination of ephedrine and phenylephrine given as an intravenous bolus at the doses selected is not superior to ephedrine alone in preventing or treating hypotension in healthy parturients undergoing cesarean delivery. Maternal cardiovascular changes and neonatal acid-base status were assessed in 29 healthy women undergoing elective lower segment Caesarean section under spinal anaesthesia. The patients were allocated randomly to one of three groups to receive an i.v. infusion of one of the following: ephedrine 1 mg min-1 (group E1: n = 10), ephedrine 2 mg min-1 (group E2: n = 9), or phenylephrine 10 micrograms min-1 (group P: n = 10). Invasive arterial pressure was monitored continuously and if hypotension occurred (defined as a 20% decrease from baseline, taken after i.v. preload administration), bolus doses of either ephedrine (6 mg in groups E1 and E2) or phenylephrine (20 micrograms in group P) were given. Only four patients became hypotensive in group E2, compared with eight patients in group E1 and nine patients in group P. The total time that the patients remained hypotensive was greatest in group P (P < 0.005), less in group E1 and least in group E2. Neonatal Apgar scores and acid-base profiles were similar in all three groups. In this study, an infusion of phenylephrine 10 micrograms min-1 with bolus doses of 20 micrograms was shown to be significantly less effective in maintaining systolic arterial pressure within 20% limits of baseline compared with an infusion of ephedrine 1 or 2 mg min-1 with bolus doses of 6 mg. Hypotension after spinal anesthesia for cesarean section remains a common and serious complication despite the use of uterine displacement and volume preloading. The current study revaluated the role of crystalloid volume preloading in this context.
                In a two-stage open sequential design, patients presenting for elective repeat cesarean section were allocated to receive either no preload or 20 ml/kg crystalloid administered over 15-20 min before spinal anesthesia. Hypotension was defined as a decrease in systolic pressure to less than 100 mmHg and to less than 80% of baseline value, and the study was designed to detect a 20% difference in the incidence of hypotension between the groups, with statistical significance at the 10% (alpha = 0.1) level, one-tailed.
                One hundred forty patients were studied. Hypotension occurred in 43 (55%, 95% CI 43.4-66.4) preloaded and 44 (71%, 95% CI 58-81.8) unpreloaded subjects, a difference in incidence of 16% (95% CI 0.04-31.6), which was statistically significant. There were no significant differences in the severity, timing, or duration of hypotension; the dose requirement for ephedrine; or the clinical and biochemical status of neonates between the groups. The only difference seen was a lower mean base excess (-3.4, SD 2.81 mM-1) in the neonates of hypotensive mothers compared to neonates of nonhypotensive mothers (-2.4, SD 1.99 mM-1).
                The study confirms that hypotension associated with spinal anesthesia for cesarean section cannot be eliminated by volume preloading in the supine wedged patient. The relatively small reduction in incidence of hypotension challenges our perception of the value of crystalloid preload. Though volume preload in the elective cesarean section is advocated, the requirement for a mandatory administration of a fixed volume before spinal anesthesia for urgent cases has been abandoned. Hypotension associated with spinal anesthesia for cesarean section is still a clinical problem. Colloid solutions seem preferable to crystalloid solutions for preloading. In most studies the overall rate of hypotension is reported. Few studies have, however, investigated the maternal and neonatal consequences of different levels of maternal hypotension.
                In this randomized, double-blinded study 110 patients presenting for elective cesarean section received either 1000 ml acetated Ringer's solution or 1000 ml 3% dextran 60 solution immediately before spinal anesthesia. The effect on overall hypotension, clinically significant hypotension (hypotension associated with maternal discomfort defined as nausea, retching/vomiting, dizziness or chest symptoms) and severe hypotension (systolic arterial pressure <80 mmHg) was studied.
                Dextran reduced the incidence of overall hypotension from 85 to 66% (P=0.03), reduced the incidence of clinically significant hypotension from 60 to 30% (P=0.002) and reduced the incidence of severe hypotension from 23 to 3.6% (P=0.004) compared to Ringer's solution. There were neither differences in neonatal outcome between treatment groups nor between neonates grouped after severity of maternal hypotension.
                Clinically significant hypotension seems to be a more suitable outcome variable than overall hypotension. The protective effect of the colloid solution increased with increased severity of hypotension. The ability of glycopyrronium to reduce the severity of hypotension following subarachnoid block in parturients with a relative bradycardia was evaluated in a double-blind randomised controlled study. Women with a resting heart rate of < or = 80 beat x min(-1) presenting for elective Caesarean section were randomly allocated to receive either glycopyrronium 2 microg x kg(-1) or normal saline intravenously once positioned for combined spinal-epidural anaesthesia. Following spinal injection of 2.6 ml hyperbaric bupivacaine 0.5% and fentanyl 15 microg, women randomly allocated to the saline group were given 6 mg ephedrine so that all parturients received some prophylaxis against hypotension other than the fluid preload. Further ephedrine and fluid boluses were administered if mean arterial pressure fell 20% or more from resting values. Using a sequential analysis technique, analysis after the first 20 subjects indicated the study should be stopped, with no difference in ephedrine requirements or hypotension between the groups. We conclude that pretreatment with glycopyrronium 2 microg x kg(-1) is no more effective than 6 mg ephedrine in preventing hypotension following subarachnoid block in parturients with relatively low resting heart rates. Pre-emptive intramuscular (i.m.) vasopressors were evaluated in 108 patients undergoing elective Caesarean section under spinal anaesthesia, assigned to four groups in a randomized, double-blind, placebo-controlled study. Group 1 received pre-emptive phenylephrine 4 mg i.m., group 2 received phenylephrine 2 mg i.m., group 3 received ephedrine 45 mg i.m., while controls received an i.m. injection of saline, all given immediately after induction of spinal anaesthesia. Hypotension was defined as a 25% decrease in mean arterial pressure (MAP). Rescue intravenous (i.v.) boluses of ephedrine were given if the patient was hypotensive or reported nausea, vomiting or dizziness. The incidence of hypotension was 33% in the phenylephrine 4 mg group compared with 70% in the control and phenylephrine 2 mg groups (P=0.03), and 48% in the ephedrine 45 mg group. The phenylephrine 4 mg and ephedrine 45 mg groups had a significantly lower percentage reduction in MAP (-21 (SD 14)% and -22 (14)%) compared with controls (-32 (18)%, P=0.04). They also had a lower total dose of rescue i.v. ephedrine (15.7 (15.7) mg and 15.8 (15.6) mg) compared with controls (28.8 (20.6) mg, P=0.02). We conclude that pre-emptive i.m. phenylephrine 4 mg and ephedrine 45 mg reduce the severity of hypotension and the total dose of rescue i.v. ephedrine during spinal anaesthesia for Caesarean section. Aortocaval compression is a major cause of maternal hypotension. A randomised controlled clinical trial was designed to compare two wedged supine positions for prevention of hypotension following combined spinal epidural anaesthesia for caesarean delivery. Sixty parturients undergoing elective caesarean delivery were randomly assigned to two different wedged supine positions. After the completion of subarachnoid injection, parturients were placed with either a wedge under the right pelvis (group P pelvic wedge) or under the right lumbar region (group L, lumbar wedge). Systolic blood pressure and heart rate were recorded every minute for 20 minutes from the subarachnoid injection. Hypotension, defined as systolic blood pressure <100 mmHg or 80% of the baseline, was treated with intravenous ephedrine 5 mg. The incidence of hypotension, ephedrine use and neonatal Apgar scores and umbilical arterial pH were recorded. The incidence of hypotension was significantly higher in group P than that in group L (23/30 [77%] vs. 14/30 [47%], P=0.016). Systolic blood pressure decreased significantly in both groups at seven, eight and nine minutes (P < 0.001); moreover it was lower at seven, eight and nine minutes in group P than in group L (P < 0.01). Heart rate did not change significantly in either group. There were no significant differences between the two groups for Apgar score and umbilical arterial pH. A lumbar wedge is more effective than a pelvic wedge in preventing hypotension following combined spinal epidural anaesthesia for caesarean delivery, although it does not eliminate hypotension. Eighty-seven pregnant mothers undergoing elective Caesarean section were randomly allocated either to the full left lateral position (n = 45) or to the supine position with 12 degrees left lateral tilt (n = 42) after a combined spinal-epidural (CSE) in the sitting position and an initial 2 min in the full right lateral position. Fewer mothers were hypotensive while in the study position [29 (64%) in lateral group vs. 38 (90%) in the tilted supine group; p = 0.03]. Mothers in the lateral group tended to become hypotensive after turning them back to the tilted supine position immediately before surgery; hence the number of mothers who were hypotensive from the insertion of the CSE until delivery were similar [36 (80%) vs. 38 (90%)]. Mothers in the lateral group needed a lower dose of ephedrine to treat their hypotension while in their study position (median (interquartile range [range]) 6 (0-12 [0-36]) mg vs. 12 (6-18 [0-36]) mg, respectively; p = 0.04) but ephedrine requirements were similar overall (12 (6-12 [0-36]) mg vs. 12 (6-18 [0-36]) mg), respectively. The full left lateral position reduces the incidence of early hypotension compared with the tilted supine position with tilt, and makes it easier to treat. Ninety seven women undergoing elective lower segment caesarean section were randomly divided into two groups, group 1 received spinal anaesthesia with hyperbaric bupivacaine and group 2 received mepivacaine 20 mg/ml with adrenaline 5 microg/ml via an epidural catheter. All patients were given a preload of Ringer acetate and Macrodex prior to onset of anaesthesia. Ephedrine 5 mg was given if the systolic blood pressure fell below 100 mmHg. There was a small (<30%) but significant (P<0.01) fall in blood pressure in both groups of women. Six women in the epidural group required supplemental analgesics during the operation compared to only 1 patient in the spinal group (P<0.01). Muscle relaxation was judged to be inadequate in 3 patients in the spinal group and in 5 patients in the epidural group. One patient in the spinal group had a characteristic post-spinal headache lasting 3 days. The injection-delivery time was shorter (P<0.01) in the spinal group compared to the epidural group. The Apgar scores at 1 and 5 min were similar in both groups. The results from our study suggest that spinal anaesthesia is a good alternative to epidural anaesthesia for elective caesarean section. A fall in blood pressure, which is equally possible in both groups of patients, should be prevented by adequate fluid preload and treated immediately by intravenous ephedrine. The study tested the hypothesis that the incidence of hypotension during spinal anaesthesia for caesarean section is less in parturients who remain in the sitting position for 3 min compared with parturients who are placed in the modified supine position immediately after induction of spinal anesthesia.
                Spinal anaesthesia was induced with the woman in the sitting position using 2.8 ml hyperbaric bupivacaine 0.5% at the L(3-4) or L(2-3) interspace. Ninety-eight patients scheduled for elective caesarean section under spinal anaesthesia were randomised to assume the supine position on an operating table tilted 10 degrees to the left (modified supine position) immediately after spinal injection (group 0, n=52) or to remain in the sitting position for 3 min before they also assumed the modified supine position (group 3, n=46). Isotonic saline 2-300 ml was given intravenously over 15 min before spinal injection followed by 15 ml/kg over 15-20 min after induction of spinal anaesthesia. If the systolic blood pressure decreased to less than 70% of baseline or to less than 100 mmHg or if there was any complaint of nausea, ephedrine was given in 5 mg boluses intravenously every 2 min.
                The blood pressure decreased significantly in both groups following spinal injection (P<0.001). Blood pressure variations over time differed significantly between the two groups (P<0.05). However, the incidence of maternal hypotension before delivery was similar in the two groups. The difference was caused by the time to the blood pressure nadir being significantly shorter in group 0 compared with group 3 (9.1+/-4.5 min vs. 11.7+/-3.7 min, P<0.01). Similar numbers of patients received rescue with ephedrine before delivery: 35 (67%) in group 0 vs. 26 (57%) in group 3 (NS). The mean total dose of ephedrine before delivery was 10.9 mg in group 0 vs. 9.2 mg in group 3 (NS). There were no differences in neonatal outcome between the two groups.
                At elective caesarean section, a 3-min delay before supine positioning does not influence the incidence of maternal hypotension after induction of spinal anaesthesia in the sitting position with 2.8 ml of bupivacaine 0.5% with 8% dextrose. Maternal cardiovascular changes and neonatal acid-base status, including lactate levels, were assessed in 30 healthy women undergoing elective caesarean section under spinal anaesthesia. Patients were allocated randomly to receive IV ephedrine infusion (n = 15) (5 mg.min(-1) immediately after the spinal injection or bolus administration of IV ephedrine (n = 15) (10 mg) in case of development of hypotension. Maternal and neonatal blood pressure, heart rate and acid-base status including lactate levels were compared between the groups. Systolic blood pressure in the bolus group was significantly lower when compared to the infusion group. Nausea was observed in one patient (6%) in the infusion group and nausea and vomiting were observed in 10 patients (66%) in the bolus group. Although umbilical arterial pH values were significantly lower in the bolus group, lactate levels were similar In conclusion, ephedrine infusion prevented maternal hypotension, reduced the incidence of nausea and vomiting and led to improved umbilical blood pH during spinal anaesthesia for caesarean section. Sixty healthy women undergoing elective Caesarean section were randomly allocated to either a measured 15 degrees left table tilt position (n = 31) or full left lateral position (n = 29) for a 15-min period after spinal blockade. Arm and leg blood pressure, ephedrine requirements, symptoms, fetal heart rate, cord gases and Apgar scores were recorded. Mean ephedrine requirements and incidence of hypotension were similar in the two groups. Arm systolic arterial pressure over time was similar in both groups, but leg systolic arterial pressure over time was significantly lower in the tilt group (p < 0.001); the mean leg systolic arterial pressure was lower for all 15 sequential recordings in the tilt group, reaching statistical significance (p < 0.05) at 4, 5, 6 and 8 min. Differences in maternal nausea, vomiting and bradycardia and fetal outcome were not statistically significant. Following spinal anaesthesia, even a true 15 degrees left table tilt position is associated with aortic compression. Maternal position during induction of intrathecal anaesthesia for caesarean section influences block height and haemodynamic stability. In a randomised study of 90 women presenting for elective caesarean section using combined spinal-epidural anaesthesia, three positions were compared--the Oxford position (group O), the right lateral to supine wedged (group R) and the sitting to supine wedged (group S). Hyperbaric bupivacaine 12.5 mg with fentanyl 12.5 microg was injected intrathecally using a needle-through-needle CSE technique. Intravenous ephedrine 6 mg was given every minute that systolic blood pressure fell below 80% of baseline. Time required for block height to reach T5 as assessed by light touch, was similar in the three groups. There were no significant differences in blood pressure although ephedrine requirements were less in group R. There were no significant differences in the incidence of maternal nausea and vomiting or in neonatal outcome as assessed by Apgar scores and umbilical cord blood gas analysis. Although the study failed to show any significant differences in block height between the groups, no women in group O had a block above T2 compared with three in group R and three in group S. Current methods of crystalloid preload administration prior to spinal anaesthesia for elective caesarean section are relatively ineffective in preventing hypotension. This study examined the relevance of the timing of the fluid administered. Fifty women were randomly allocated to receive either 20 ml x kg(-1) of crystalloid solution during 20 minutes prior to induction of spinal anaesthesia (preload), or an equivalent volume by rapid infusion immediately after induction (coload). Significantly more patients in the coload group did not require vasopressor therapy pre-delivery (P=0.047). The coload group required a lower median dose (P=0.03) and a lower median number (P=0.04) of ephedrine doses for the treatment of maternal hypotension pre-delivery. There was no between-group difference in either the total cumulative dose, or in the total number of doses of ephedrine. Neonatal outcomes among the two groups were similar. Rapid crystalloid administration after, rather than over 20 minutes before the induction of spinal anaesthesia for elective caesarean section, may be advantageous in terms of managing maternal blood pressure prior to delivery. This study investigated the use of a Sequential Compression Device (SCD) with thigh-high sleeves and a preset pressure of 50 mm Hg that recruits blood from the lower limbs intermittently, as a method to prevent spinal hypotension during elective Caesarean section. Possible association of arterial pressure changes with maternal, fetal, haemodynamic, and anaesthetic factors were studied.
                Fifty healthy parturients undergoing elective Caesarean section under spinal anaesthesia were randomly assigned to either SCD (n=25) or control (n=25) groups. A standardized protocol for pre-hydration and anaesthetic technique was followed. Hypotension was defined as a decrease in any mean arterial pressure (MAP) measurement by more than 20% of the baseline MAP. Systolic (SAP), MAP and diastolic (DAP) arterial pressure, pulse pressure (PP), and heart rate (HR) were noted at baseline and every minute after the spinal block until delivery.
                A greater than 20% decrease in MAP occurred in 52% of patients in the SCD group vs 92% in the control group (P=0.004, odds ratio 0.094, 95% CI 0.018-0.488). There were no significant differences in SAP, DAP, HR, and PP between the groups.
                SCD use in conjunction with vasopressor significantly reduced the incidence of a 20% reduction of MAP. Subarachnoid block is the preferred method of anaesthesia for caesarean section, but is associated with hypotension and bradycardia, which may be deleterious to both parturient and baby. Animal studies suggest that in the presence of decreased blood volume, 5-HT may be an important factor inducing the Bezold Jarisch reflex via 5-HT3 receptors located in intracardiac vagal nerve endings. In this study, we evaluated the effect of ondansetron, as a 5-HT3 receptor antagonist, on the haemodynamic response following subarachnoid block in parturients undergoing elective caesarean section.
                Fifty-two parturients scheduled for elective caesarean section were randomly allocated into two groups. Before induction of spinal anaesthesia Group O (n=26) received intravenous ondansetron 4 mg; Group S (n=26) received normal saline. Blood pressure, heart rate and vasopressor requirements were assessed.
                Decreases in mean arterial pressure were significantly lower in Group O than Group S from 14 min until 35 min. Patients in Group O required significantly less vasopressor (P=0.009) and had significantly lower incidences of nausea and vomiting (P=0.049).
                Ondansetron 4 mg, given intravenously 5 min before subarachnoid block reduced hypotension and vasopressor use in parturients undergoing elective caesarean section.
                Copyright © 2011 Elsevier Ltd. All rights reserved. Aortocaval compression is a major cause of maternal hypotension. A randomized controlled trial was designed to determine the effectiveness of a mechanical intervention using a right lumbar-pelvic wedge in preventing hypotension after spinal anesthesia for cesarean delivery.
                Eighty healthy women undergoing elective cesarean section were randomly allocated immediately after spinal blockade to either a lumbar-pelvic wedge positioned under the right posterior-superior iliac crest (Wedge group, n=40) or the complete supine position (Supine group, n=40). Hemodynamic values, vasopressor consumption and adverse effects were collected during the surgical procedure. Hypotension was defined as a reduction in systolic blood pressure of 25% from baseline. Patient allocation, management and data collection were performed by a single unblinded anesthetist.
                There was no difference in the incidence of hypotension between the two groups (42.5% vs. 50%, P=0.51). During the first 5 min, blood pressure decreased less in the Wedge group. There were significant differences in median [interquartile range] vasopressor requirements between the Wedge group and the Supine group (1 [0-2] vs. 3 [1-4] mg, P<0.01) and in nausea during the procedure (6 vs. 22 patients, P<0.01).
                In our study population the use of right lumbar-pelvic wedge was not effective in reducing the incidence of hypotension during spinal anesthesia for cesarean section. Patients in whom the wedge was used had higher systolic blood pressure values during the first 5 min of anesthesia and fewer episodes of nausea. The risk of hypotension remains substantial.
                Copyright © 2011 Elsevier Ltd. All rights reserved. There are no randomized studies on neonatal outcome after spinal versus general anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace. This study examined both markers of neonatal hypoxia and maternal hemodynamics.
                Seventy patients were randomized to general (n = 35) or spinal anesthesia (n = 35). The general anesthesia group received thiopentone, magnesium sulfate, and suxamethonium intravenously before intubation, followed by 50% nitrous oxide in oxygen, 0.75-1.5% isoflurane, and morphine after delivery. The target end-tidal partial pressure of carbon dioxide (Pco2) was 30-34 mmHg. The spinal anesthesia group received 1.8 ml hyperbaric bupivacaine plus 10 microg fentanyl at the L3-L4 interspace. Heart rate and blood pressure were measured at specific time points. Hypotension was treated with ephedrine. Maternal arterial and neonatal umbilical arterial blood gas samples were taken at delivery. Resuscitation requirements were recorded.
                In both groups, hemodynamic measures remained within acceptable limits. Spinal anesthesia patients required more ephedrine (13.7 vs. 2.7 mg). Maternal Paco2 was lower in the spinal group (28.9 vs. 32.4 mmHg). One-minute Apgar scores were lower after general anesthesia. Base deficit was greater (7.13 vs. 4.68 mEq/l) and neonatal umbilical arterial pH was lower (7.20 vs. 7.23) after spinal anesthesia. Post hoc analysis showed that if maternal diastolic blood pressure on admission was greater than 110 mmHg, neonatal umbilical arterial base deficit was greater after spinal anesthesia. There was no difference in the number of patients with Apgar scores less than 7 at 1 or 5 min or umbilical arterial pH less than 7.2 or in the requirements for resuscitation.
                In preeclamptic patients with a nonreassuring fetal heart trace, spinal anesthesia for cesarean delivery was associated with a greater mean neonatal umbilical arterial base deficit and a lower median umbilical arterial pH. The clinical significance remains to be established. Maternal hemodynamics were similar and acceptable with either anesthetic technique. To evaluate the efficacy and optimal dose of prophylactic intravenous ephedrine for the prevention of maternal hypotension associated with spinal anaesthesia for Caesarean section.
                After patients had received an intravenous preload of 0.5 L of lactated Ringer's solution, spinal anaesthesia was administered in the sitting position with hyperbaric bupivacaine 2.5 mL 0.5% combined with 25 microg fentanyl. A total of 68 patients were randomized to receive a simultaneous 2 mL bolus intravenously of either 0.9% saline (Group C, n = 20), ephedrine 6 mg (Group E-6, n = 24), or ephedrine 12 mg (Group E-12, n = 22). Further rescue boluses of ephedrine 6 mg were given if systolic arterial pressure fell to below 90 mmHg, greater than 30% below baseline, or if symptoms suggestive of hypotension were reported.
                There was a significantly higher incidence of hypotension in Group C (60% patients) compared to Group E-12 (27%), but not in Group E-6 (50%). The 95% Confidence Interval for the difference in proportions between Groups C and E-12 was 6-60%, P < 0.05. Fewer rescue boluses of ephedrine were required in Group E-12 compared with Group C (1.8 +/- 1.2 vs. 3.3 +/- 2.1, P < 0.05). There were no significant differences in the incidence of maternal nausea or vomiting, or of neonatal acidaemia between groups.
                A prophylactic bolus of ephedrine 12 mg intravenously given at the time of intrathecal block, plus rescue boluses, leads to a lower incidence of hypotension following spinal anaesthesia for elective Caesarean section compared to intravenous rescue boluses alone. To determine if preoperative intravenous dextrose affects the incidence and ease of treatment of spinal-induced hypotension in parturients having elective Cesarean section under spinal anesthesia.
                In this prospective, double-blind study, following informed consent, 119 ASA I, II parturients for elective Cesarean section were randomized to receive intravenously either dextrose 5% in normal saline (Group D) or normal saline (Group NS) at 125 ml x hr(-1) for two hours prior to delivery. Following a bolus of 15 ml x kg(-1) normal saline iv, spinal anesthesia was induced with hyperbaric bupivacaine 0.75%, fentanyl and morphine. Hypotension (systolic blood pressure <100 mm Hg or >20% decrease) was treated with fluids and/or vasopressor. Data collected: demographics, blood glucose concentrations (fasting, time of spinal, delivery), blood pressure (baseline, one minute intervals from spinal to delivery), neonatal Apgar scores, umbilical blood gas analyses, glucose and lactate concentrations.
                There was no difference between the two groups in the rate of hypotension (P = 0.272). All parturients who experienced hypotension received fluids, and there was also no difference between the groups in vasopressor requirement [mean dose of ephedrine: Group D = 21.6 mg (95% CI 15.1-28.2), Group NS = 16 mg (95% CI 12.0-20.5)].
                The routine administration of dextrose 5% at a rate of 5.22 g x hr(-1) preoperatively does not affect the hypotension rate, or make it easier to treat. This study was designed to compare the efficacy of 10% dextran 40 with lactated Ringer's (LR) solution in reducing the incidence and severity of hypotension after spinal anesthesia for Cesarean section.
                Sixty ASA grade I patients scheduled for Cesarean section were randomized into two groups in a double-blind fashion to receive either 500 ml of dextran 40 or 1000 ml of LR solution prior to induction of spinal anesthesia.
                The incidence of hypotension was 16 in 30 (53.3%) in the LR solution group and 8 in 30 (26.7%) in the dextran group (P < 0.05). The required dose of ephedrine for treatment of hypotension was significantly greater in the LR solution group than in the dextran group (15.5 mg versus 3.2 mg, P < 0.05). Neonatal outcome, as determined by Apgar score, was good and similar in both groups.
                We concluded that 500 ml of dextran 40 is more effective than 1000 ml of lactated Ringer's solution in reducing the incidence of hypotension induced by spinal anesthesia. We have studied the effects of crystalloid 1 litre (lactated Ringer's) or colloid 0.5 litre (hydroxyethyl starch) preloading in 26 healthy parturients undergoing elective Caesarean section under spinal anaesthesia. Maternal placental uterine artery circulation was measured using a pulsed colour Doppler technique with simultaneous measurement of maternal haemodynamics. A high incidence of maternal hypotension was observed during spinal anaesthesia in the crystalloid group (62%) but the incidence was lower in the colloid group (38%). Central venous pressure was increased significantly in both groups after preload but decreased shortly after induction of spinal anaesthesia to baseline values. The mean pulsatility index (PI) in the uterine arteries did not change during preload or spinal block. A surprising finding was the widespread variation and some high values for the uterine artery PI after spinal anaesthesia. These individual increases in PI were transient and always returned to baseline values within 2 min. These results suggest that preloading with either solution is ineffective in preventing maternal hypotension and that changes in maternal heart rate, systolic arterial pressure and central venous pressure during spinal anaesthesia were not associated with rapid individual increases in uteroplacental vascular resistance. These changes seemed not to have any major effect, however, on the clinical condition of the newborn, as assessed by Apgar scores and umbilical artery pH values. Hypotension commonly accompanies induction of spinal anesthesia for cesarean section. To determine whether intravenous ephedrine prophylaxis would benefit prehydrated obstetrical patients presenting for elective cesarean section, we studied 30 patients randomly assigned to one of three experimental groups. All patients were preloaded with crystalloid (15 ml/kg), given spinal anesthesia and positioned with left uterine displacement (LUD). During induction, all patients received a 2 ml intravenous bolus and intravenous infusion of the study drug or placebo. The control group (n=10) received a saline bolus and saline infusion, the bolus group (n=10) received an ephedrine bolus (10 mg) and a saline infusion and the infusion group (n=10) received a saline bolus and a two-stage ephedrine infusion (20 mg over 12 min). After induction of anesthesia, systolic blood pressure decreased in the first 5 min in all groups. Hypotension occurred in 6/10 control patients, 5/10 bolus patients and 5/10 infusion patients. The amount of supplemental ephedrine required to treat hypotension did not differ among groups. Although the efficacy of ephedrine prophylaxis for hypotension associated with spinal anesthesia for elective cesarean section cannot be established by the small number of patients studied, this practice does not appear to be clinically relevant at the doses studied. This study was designed to determine whether preoperative administration of 6% hetastarch decreases the incidence and severity of hypotension after spinal anesthesia for cesarean section. Forty nonlaboring ASA class I and II women having nonurgent cesarean sections were randomized to receive either 500 mL of 6% hetastarch plus 1 L lactated Ringer's solution (LR) (n = 20), or 2 L of LR (n = 20) prior to induction of spinal anesthesia. Hypotension occurred in 45% of patients who received hetastarch vs 85% of those who received only LR (P < 0.05), and minimum systolic blood pressure was lower in the LR group than in the hetastarch group (85 +/- 12 vs 93 +/- 12 mm Hg [mean +/- SD]; P < 0.05). In addition, the LR group had a higher maximum heart rate (115 +/- 17 vs 104 +/- 16 bpm), a shorter mean time to hypotension (7 +/- 4 vs 10 +/- 7 min), and required more 5-mg doses of ephedrine for treatment of hypotension (0 vs 2 [median]; P < 0.05) than the hetastarch group. Neonatal outcome, as determined by Apgar scores and cord blood gas analyses, was good and similar in both groups. We conclude that 6% hetastarch plus LR is more effective than LR alone and that its routine use before spinal anesthesia for cesarean section should be considered. Our purpose was to study the efficacy of ephedrine versus angiotensin II prophylactic infusions to counter maternal hypotension that occurs during spinal anesthesia at cesarean delivery.
                Healthy pregnant women undergoing elective repeat cesarean delivery at term with spinal anesthesia were randomized either to a control group (n = 10) or to one of two prophylactic infusion groups: angiotensin II (n = 10) or ephedrine (n = 10). Prophylactic infusions were titrated to a maternal diastolic blood pressure 0 to 10 mm Hg above baseline. Maternal and fetal blood samples for angiotensin II levels and acid-base status were obtained. Student's t test, chi 2, and analysis of variance were used.
                Mean arterial pressures were maintained after spinal anesthesia in the ephedrine and angiotensin II groups but decreased (p < 0.05) in the control group. Maternal angiotensin II levels rose with angiotensin II infusions but were unaltered in the other groups. Umbilical artery and vein angiotensin II levels were unaltered by angiotensin II infusions. Mean umbilical artery blood pH was lower (p < 0.05) in the ephedrine group than in the angiotensin II and control groups.
                In the healthy term fetus there is an advantage in using angiotensin II to maintain maternal blood pressure during regional anesthesia. Maternal hypotension is the most common complication following spinal anesthesia for cesarean section. This study aimed at comparing the incidence of hypotension and the need for vasopressors in patients submitted to cesarean section under spinal anesthesia following preload with either crystalloid or colloid (modified fluid gelatin).
                Participated in this prospective study 50 term pregnant patients, physical status ASA I, submitted to cesarean section under spinal anesthesia. Patients were randomly allocated into two groups receiving preload as follows: Crystalloid group, 10 mL.kg-1 lactated Ringer; Colloid group, 10 mL.kg-1 colloid (modified fluid gelatin). Control blood pressure was defined as the mean of three successive systolic blood pressure (SBP) values. SBP was measured at 1-minute intervals and 0.2 mg intravenous bolus of metaraminol was administered for SBP decrease above 10% of control blood pressure, and 0.4 mg bolus of the same drug for SBP decrease above 20% of control. Apgar score was evaluated after delivery and umbilical artery blood was sent for analysis. Modified Student's t test was used for statistical analysis and p < 0.05 was considered statistically significant.
                Hypotension 10% (100% and 100% of patients); hypotension 20% (72% and 72% of patients), nausea (4% and 8% of patients); vasopressor consumption (1.67+/- 0.89 mg and 1.88 +/- 0.74 mg) and umbilical artery pH (7.25 +/- 0.04 and 7.26 +/- 0.04), in Crystalloid and Colloid groups, respectively, were similar.
                In the conditions of this study, colloid (modified fluid gelatin) was equivalent to crystalloid (lactate Ringer) in preventing or decreasing the incidence of hypotension in patients submitted to cesarean section under spinal anesthesia. Elective cesarean section was performed in a consecutive series of 30 patients with full-term pregnancies who were not in labor. Epidural (lidocaine, 1.5 per cent, with epinephrine, 1:200,000) and general anesthesia (thiopental, nitrous oxide-oxygen, succinylcholine infusion) was used alternately. Neonatal acid-base values and Apgar scores showed no significant difference between the two anesthetic groups, and most infants were vigorous at birth. The neurologic recoveries of the infants showed no significant difference between the two groups. In the group receiving epidural anesthesia, there was a significant correlation between maternal hypotension and weak rooting and sucking reflexes of the infants during the first two days. All infants of high-risk obstetric patients in the series, independent of anesthetic technique used, had abnormal neurologic activity, as evidenced by either depression of muscle tone and the reflexes or all the tested variables. Neurologic assessment as followed in this series is a sensitive indicator of the effects of fetal stress factors acting during cesarean section. To assess the safety and efficacy of 37.5 mg ephedrine i.m. in preventing hypotension associated with spinal anaesthesia for Caesarean section.
                In a double-blind randomised controlled study, 40 patients (20 in each group) were given either 37.5 mg ephedrine or placebo i.m. The following parameters were recorded: (i) blood pressure; (ii) heart rate; (iii) ephedrine i.v. supplementation; (iv) umbilical venous blood gases and neonatal Apgar scores.
                The incidence of hypertension in the study group was 30% compared with 20% for the control group (P:NS). There was no difference in mean highest blood pressure or mean highest heart rate between the groups. The incidence of hypotension was lower but not significantly lower in the study group (50%) than in the control group (80%) (P:NS). However, the incidence of delayed hypotension was only 10% in the study group patients compared with 50% in the control group patients (P < 0.05).
                Giving 37.5 mg ephedrine i.m. prior to spinal anaesthesia was not associated with reactive hypertension or tachycardia. Intramuscular ephedrine provided more sustained cardiovascular support than intravenous ephedrine. In this study, we compared the effect of prophylactic administration of warm and cold saline against spinal anaesthesia induced hypotension in parturients undergoing elective caesarean section. One hundred and thirteen parturients with singleton pregnancies received an i.v. infusion of isotonic saline 20 mL x kg(- 1)during the 15 min before spinal injection followed by 10 mL x kg(- 1)during the 20 min after spinal injection. Fifty-seven patients were allocated to the warm saline group (37 degrees C) and 56 to the cold saline group (21 degrees C). Discomfort in the infusion arm was less in the warm saline group (P<0.01), whereas the incidence of shivering was similar in the two groups. Following induction of spinal anaesthesia, blood pressures were significantly higher in the cold saline infusion group compared to the warm saline group (P<0.05). However, the group mean difference in mean arterial pressure was only about 5 mmHg, and the amount of ephedrine administered and the incidence of clinical significant hypotension did not differ between groups. In conclusion, the temperature of the fluid used for i.v. preload and maintenance at caesarean section under spinal anaesthesia is not clinically important. We conducted a randomised controlled trial to compare the severity of hypotension and ephedrine requirements following spinal anaesthesia for elective caesarean section in women pretreated with either i.v. glycopyrrolate 4.0 microg/kg (group G) or saline (group S). Data were analysed using sequential analysis which allowed us to terminate the study after data from 40 patients had been analysed (20 in each group). There were no differences between the two groups in the severity of hypotension (mean +/- SD decrease from baseline 35 +/- 14% in group G and 29 +/- 15% in group S) or ephedrine requirements (15 +/- 11 mg in group G and 18 +/- 12 mg in group S). Intra-operative heart rate increased by a greater amount in group G than in group S (58 +/- 26% vs 35 +/- 21% mean +/- SD;P = 0.002) and there was a greater incidence of dry mouth (75% vs 15%;P = 0.0006) but no difference in the incidence of nausea and vomiting (30% vs 50%;P = 0.33). Pretreatment with glycopyrrolate did not confer an advantage in this study. To evaluate the effectiveness of prophylactic ephedrine for the prevention of hypotension associated with spinal anesthesia, 50 parturients undergoing cesarean delivery received either ephedrine 5 mg or saline IV in a double-blinded fashion immediately after the induction of spinal anesthesia. Spinal anesthesia was performed with hyperbaric bupivacaine 6.6 mg combined with sufentanil 3.3 microg as part of a combined spinal-epidural technique. All patients received 1000 mL of lactated Ringer's solution and 500 mL of hydroxyethylstarch 6% before the spinal injection. Additional ephedrine boluses (5 mg) were administered IV when the systolic blood pressure or heart rate decreased by more than 30% from baseline values, when systolic blood pressure became <100 mm Hg, or when patients complained of nausea or feeling faint. The height of the block was equal in the groups; however, more patients in the placebo group were found to develop hypotension (58% vs 25%, P < 0. 05). Only 2 (8%) patients in the ephedrine group developed hypotension with systolic blood pressure values <90 mm Hg, whereas 10 patients (42%) in the saline group experienced hypotension of this severity (P < 0.05). In addition, there was a higher incidence of nausea in the placebo-treated patients. The total amount of ephedrine administered did not differ between groups. These findings suggest that the incidence and severity of hypotension are significantly reduced by the IV administration of a prophylactic dose of 5 mg ephedrine in patients receiving small-dose spinal anesthesia for cesarean delivery.
                Ephedrine is the drug most often used to correct hypotension during spinal anesthesia for cesarean delivery in healthy patients. A single IV dose of 5 mg decreases the occurrence and limits the severity of hypotension in prehydrated subjects receiving a small-dose spinal local anesthetic-opioid combination. To evaluate the hemodynamic effects of an intravenous (IV) ephedrine bolus given simultaneously with spinal anesthesia for cesarean delivery.
                Randomized, prospective, double-blind study.
                Tertiary-care academic medical center.
                40 ASA physical status I and II nonlaboring women undergoing elective cesarean delivery of term, uncomplicated, singleton pregnancies.
                After a 10 mL/kg IV lactated Ringers bolus given over 15 minutes, patients simultaneously received an IV dose of 2 mL (10 mg) ephedrine or 2 mL saline, and an intrathecal dose of 12 mg (1.6 mL 0.75%) bupivacaine with 10 microg of fentanyl. Hypotension, defined as a 20% decrease in mean arterial pressure (MAP), was treated with 10-mg IV doses of ephedrine.
                Hemodynamic (heart rate and MAP) and non-invasive thoracic impedance (cardiac index, stroke index, and systemic vascular resistance index) measurements at baseline and at 1-minute intervals until the time of delivery. Total fluid, supplemental ephedrine, and Apgar scores were recorded. Data were evaluated using analysis of variance (ANOVA), ANOVA for repeated measures, and Mann-Whitney U-tests where appropriate, with p < 0.05 considered significant.
                Significant changes from baseline in MAP, systemic vascular resistance index, heart rate, and cardiac index were observed in both groups after spinal anesthesia. However, there were no differences between the ephedrine and saline groups in the incidence and severity of change from the baseline. The overall incidence of hypotension was 70% in both groups. No difference in total fluid or supplemental ephedrine use was observed.
                10 mg of IV ephedrine given at the time of spinal anesthesia, and after a 10 mL/kg lactated Ringers fluid bolus, does not diminish the incidence or severity of hypotension in parturients undergoing cesarean delivery. In a randomized, double-blinded, controlled trial, we investigated the prophylactic infusion of IV phenylephrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Immediately after intrathecal injection, phenylephrine was infused at 100 microg/min (n = 26) for 3 min. From that point until delivery, phenylephrine was infused at 100 microg/min whenever systolic arterial blood pressure (SAP), measured each minute, was less than baseline. A control group (n = 24) received IV bolus phenylephrine 100 microg after each measurement of SAP <80% of baseline. Phenylephrine infusion decreased the incidence (6 [23%] of 26 versus 21 [88%] of 24; P < 0.0001), frequency, and magnitude (median minimum SAP, 106 mm Hg; interquartile range, 95-111 mm Hg; versus median, 80 mm Hg; range, 73-93 mm Hg; P < 0.0001) of hypotension compared with control. Heart rate was significantly slower over time in the infusion group compared with the control group (P < 0.0001). Despite a large total dose of phenylephrine administered to the infusion group compared with the control group (median, 1260 microg; interquartile range, 1010-1640 microg; versus median, 450 microg; interquartile range, 300-750 microg; P < 0.0001), umbilical cord blood gases and Apgar scores were similar. One patient in each group had umbilical arterial pH <7.2. Prophylactic phenylephrine infusion is a simple, safe, and effective method of maintaining arterial blood pressure during spinal anesthesia for cesarean delivery.
                In patients receiving spinal anesthesia for elective cesarean delivery, a prophylactic infusion of phenylephrine 100 microg/min decreased the incidence, frequency, and magnitude of hypotension with equivalent neonatal outcome compared with a control group receiving IV bolus phenylephrine. Twenty parturients undergoing elective Caesarean section were allocated randomly to receive crystalloid preload 20 ml kg-1 over either 20 min or 10 min before spinal anaesthesia. Significant hypotension (systolic arterial pressure less than 100 mm Hg and less than 80% of baseline value) occurred in six of the 10 patients in the 20-min preload group and seven of 10 patients in the 10-min preload group (ns). Both groups had a significant (P less than 0.05) increase in central venous pressure during the preload period. The mean central venous pressure in the 10-min group was 11.9 mm Hg (range 6-19 mm Hg), which was significantly greater (P less than 0.05) than that in the 20-min group (mean 7.3 mm Hg, range 2-13 mm Hg). Three patients in the 10-min group had clinically unacceptable increases in central venous pressure. This study has demonstrated that rapid administration of crystalloid preload before spinal anaesthesia did not decrease the incidence or severity of hypotension, and questions the role of crystalloid preload. Fetal heart rate (FHR) was recorded and maternal blood pressure measured in 104 patients in whom lumbar epidural analgesia was induced in labour. Fifty-one patients received an intravenous load of 11 of Hartmann's solution immediately before the epidural injection. This infusion significantly reduced the incidence of abnormalities of FHR from 34% to 12% and of maternal hypotension from 28% to 2%. We did not study mothers with pre-eclampsia and hypertension, but we conclude that there is a strong case for preloading all other mothers in whom lumbar epidural analgesia is induced in labour. Ninety ASA 1 and 2 pregnant women with term singleton pregnancies and no maternal and fetal complications, scheduled for elective or emergency Caesarean section, were randomly allocated to group LT (15 degrees left lateral table tilt, n = 45) and group MD (leftward manual displacement, n = 45). Subarachnoid block was established with a 25-gauge spinal needle at the L3-L4 interspace using 1.5 ml of 0.5% hyperbaric bupivacaine. A median sensory level of T6 was observed in both groups but the incidence of hypotension was markedly lower in group MD when compared to group LT (4.4% vs 40%; p < 0.001) with a significant reduction in mean (SD) ephedrine requirement (6 (0) vs 11.3 (4.9) mg; p < 0.001). The mean (SD) fall in systolic blood pressure was 28.8 (7.3) mmHg in group LT and 20 (12.7) mmHg in group MD. The time to maximum fall in systolic blood pressure was similar in both groups (4.5 min). We conclude that manual displacement of the uterus effectively reduces the incidence of hypotension and ephedrine requirements when compared to 15 degrees left lateral table tilt in parturients undergoing Caesarean section. To compare neonatal short-term outcome in patients who underwent spinal, general anaesthesia and conversion from spinal to general anaesthesia.
                One hundred seventy-nine pregnant women undergoing elective caesarean section were allocated randomly to general (n=89) or spinal anaesthesia (n=90) and compared with 63 patients who required conversion to general anaesthesia. Umbilical cord artery pH, Apgar score as well as its individual parameter and need for assisted ventilation were evaluated.
                No differences were found in pH values (p=0.35), while the need for assisted ventilation differed significantly (p=0.001). The rate of depressed newborns was 1.1% in the spinal group, 25.9% in the general group and 12.7% in the conversion group with a significant difference for all comparisons. At 5-min, all newborns were vigorous. At 1 min, a higher score for each parameter was found in spinal group with respect to general group, while 'activity', 'grimace' and 'respiration' showed a higher score in conversion group than in general group. At 5 min, a difference was found only for 'activity'.
                All kinds of anaesthesia seem to be safe, but loco-regional blockade shows more advantages on the neonatal outcome also when a conversion is necessary. We have tested the hypotheses that glycopyrrolate, administered immediately before induction of subarachnoid anaesthesia for elective Caesarean section, reduces the incidence and severity of nausea, with no adverse effects on neonatal Apgar scores, in a double-blind, randomized, controlled study. Fifty women received either glycopyrrolate 200 micrograms or saline (placebo) i.v. during fluid preload, before induction of spinal anaesthesia with 2.5 ml of 0.5% isobaric bupivacaine. Patients were questioned directly regarding nausea at 3-min intervals throughout operation and asked to report symptoms as they arose. The severity of nausea was assessed using a verbal scoring system and was treated with increments of i.v. ephedrine and fluids. Patients in the group pretreated with glycopyrrolate reported a reduction in the frequency (P = 0.02) and severity (P = 0.03) of nausea. Glycopyrrolate also reduced the severity of hypotension, as evidenced by reduced ephedrine requirements (P = 0.02). There were no differences in neonatal Apgar scores between groups. We studied 160 patients undergoing elective Caesarean section under spinal anaesthesia who received a preloading volume of 15 ml kg-1 of 10% pentastarch in 0.9% saline, or Hartmann's solution, in a prospective, randomized, double-blind study. We compared the incidence of spinal-induced hypotension in each group. Hypotension was defined as a decrease in systolic arterial pressure to less than 70% of baseline values or < or = 90 mm Hg, whichever was the greater. The groups were comparable in physical characteristics and there was no serious morbidity. Fetal outcome was similar in both groups. Significantly more patients in the Hartmann's group (n = 38, 47.5%) developed hypotension than in the pentastarch group (n = 10, 12.5%) (P < 0.0001). Linear regression analysis showed that the only significant variable was type of fluid used. Blood glucose concentrations were not related to the presence of hypotension. We conclude that starches may be suitable for preloading in Caesarean section under spinal anaesthesia and provide an alternative to the aggressive use of vasoconstrictors. To compare the preloading effect of 500 ml hydroxyethylstarch (HES) 10% with 1 L Lactated Ringer's solution (LR).
                In 40 healthy women undergoing elective Cesarean section HES, 500 ml (n = 20), or LR, IL (n = 20), was administered during 10 min before spinal anesthesia. The incidence of hypotension, (systolic blood pressure < 80% of baseline and < 100 mm Hg), and the amount of ephedrine used to treat it were compared. Also, the incidence of nausea and/or vomiting were recorded. Neonatal outcome was assessed using Apgar scores and umbilical venous and arterial blood gases.
                The incidence of hypotension was higher in the LR than in HES group (80% vs 40%). Mean minimum systolic blood pressure was lower in the LR than in the HES group (86.1 +/- 12.7 mm Hg vs 99.6 +/- 9.7 mm Hg P < 0.05). Systolic blood pressure < 90 mmHg occurred in two of 20 patients (10%) who received HES vs 11 of 20 patients (55%) who received LR (P < 0.05). More doses of ephedrine were required to treat hypotension in the LRthan in the HES group (35.3 +/- 18.4 mg vs 10.6 +/- 8.6 mg; P < 0.05). The incidence of nausea and/or vomiting was lower in the HES than in the crystalloid group. Neonatal outcome was good and similar in both groups.
                Preloading patients undergoing elective Cesarean section with 500 ml HES 10%, decreases the incidence and severity of spinal-induced hypotension more than preloading with 1 L of LR solution. To assess the efficacy of hypertonic saline for prevention of arterial hypotension in patients undergoing spinal anaesthesia in Niger.
                Prospective, randomized, double-blinded study.
                Fifty adults undergoing scheduled surgery under spinal anaesthesia, allocated either to a hypertonic saline group (HSG) or a isotonic saline group (ISG).
                Over the 15 min prior to anaesthesia, 100 mL of 7.5% saline were infused in patients of HSG, and 100 mL of 0.9% saline in those of ISG respectively. Spinal anaesthesia was performed at the L3-L4 or L4-L5 interspace using either lidocaine 5%, or bupivacaine 0.5% or a mixture of both supplemented with fentanyl. Arterial pressure (AP) and heart rate (HR) were measured the day before surgery, prior to and after spinal anaesthesia, thereafter every 5 min over 30 min and every 10 min thereafter until completion of surgery. Hypotension (30% decrease of systolic AP control value was treated with 500 mL of Ringer lactate solution and in case of failure with ephedrine (5-30 mg i.v.). An isolated bradycardia (HR < 60 b.min-1) was treated with atropine (0.5-1 mg i.v.).
                Hypotension occurred in two out of 24 patients of the HSG and eight out of 24 of the ISG (P < 0.05). The mean infused volumes of Ringer lactate solution were 387 +/- 218 mL vs 623 +/- 318 mL respectively (P < 0.05). Ephedrine and/or atropine were not required in HSG, however in 7 out of the 24 patients of the ISG. Adverse clinical effects did not occur.
                Hypertonic saline prevents efficiently the occurrence of hypotension during spinal anaesthesia. Considering its ease of preparation, the lack of adverse effects, in patients not suffering arterial hypertension or congestive heart failure, and low cost, hypertonic saline is well adapted for use in a developing country, if isotonic solutions are not available.
While interventions such as colloids, ephedrine, phenylephrine or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension during spinal anaesthesia for caesarean section. No conclusions can be drawn regarding rare adverse effects due to the relatively small numbers of women studied.
[Note: The 89 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]