Comparison of 9 mg of intrathecal plain and hyperbaric bupivacaine both with fentanyl for cesarean delivery. Spinal anesthesia for cesarean section: comparative study between isobaric and hyperbaric bupivacaine associated to morphine. Transient neurologic symptoms after spinal anaesthesia using isobaric 2% mepivacaine and isobaric 2% lidocaine. Intrathecal hypobaric versus hyperbaric bupivacaine with morphine for cesarean section. A comparative study of isobaric and hyperbaric solution of bupivacaine for spinal anaesthesia in caesarean section. The incidence of transient neurologic symptoms (TNS) after spinal anaesthesia in patients undergoing surgery in the supine position. Hyperbaric lidocaine 5% versus hyperbaric bupivacaine 0.5%.
We randomized 76 parturients to a double-blinded trial to receive spinal anesthesia with either hyperbaric or plain bupivacaine 9 mg with fentanyl 20 microg for elective cesarean delivery. A combined spinal-epidural technique was used. The onset and duration of anesthesia (absence of pinprick sensation), analgesia (absence of sharp sensation to pinprick), and absence of cold sensation and motor block were measured until recovery from the motor block. No major differences were seen in onset or duration of anesthesia between the groups. Motor block, however, vanished faster when hyperbaric bupivacaine was used (P < 0.05). The level of anesthesia (no pinprick sensation) required for painless operation was at dermatome T5. At this time, the absence of cold sensation ranged from dermatome T1 to C3. The median time for the anesthesia to reach dermatome T5 was 10 min. Cervical spread of pinprick anesthesia was noted in six patients, and five needed supplementary analgesics during surgery (not significant between the groups). Maternal satisfaction was good. Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution.
                Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution. Bupivacaine preparations, plain or with glucose, are frequently used in the clinical practice. Blockade upper level is determined by local anesthetic spread in the CSF. This study aimed at comparing isobaric and hyperbaric bupivacaine in patients submitted to spinal anesthesia for Cesarean section.
                In this prospective, randomized and double-blind study 60 patients submitted to spinal anesthesia for Cesarean section were distributed in two groups: IB - (0.5% isobaric bupivacaine, 12.5 mg) and HB - (0.5% hyperbaric bupivacaine, 12.5 mg). After monitoring, venous puncture was performed followed by hydration with lactated Ringers solution. Spinal puncture was paramedially performed at L3-L4 interspace with 27G Quincke needle. Following the CSF dripping, morphine (100 microg) and bupivacaine were separately injected at the speed of 1 ml. 15 s(-1). With the patient back to supine position, two parameters were recorded: onset time (absence of sensitivity in L3) at 1-minute intervals as well as motor and sensory block after 20 minutes. All patients were kept with preanesthetic blood pressure levels until umbilical cord clamping, and if necessary, ephedrine was administered. Neonates were evaluated by Apgars score at 1 and 5 minutes. Sensory and motor blocks were also evaluated at PACU 120 minutes after local anesthetic injection.
                Groups were homogeneous. Onset time: Group IB (1', 50") and HB (1', 33"), with no statistical difference. Motor and sensory block at twenty minutes showed no significant difference. Ephedrine consumption: IB (11.83 mg) and HB (14.17 mg), showed also no statistical difference. PACU motor block evaluation showed significant differences.
                We concluded that 12.5 mg isobaric and hyperbaric bupivacaine associated to morphine (100 microg) in spinal anesthesia for Cesarean section in term pregnant women are effective and present similar profiles. Transient Neurological Symptoms (TNS) syndrome following subarachnoid anaesthesia was initially associated with hyperbaric lidocaine 50 mg/ml, but has also been reported with most local anaesthetics, including hyperbaric mepivacaine 40 mg/ml. The aim of this study was to determine the incidence of TNS after subarachnoid anaesthesia using isobaric mepivacaine 20 mg/ml and isobaric lidocaine 20 mg/ml.
                Eighty patients of both sexes, ASA class I-II, scheduled for elective minor orthopaedic surgery under subarachnoid anaesthesia, were prospectively included and randomly allocated to receive 40-60 mg of either isobaric mepivacaine 20 mg/ml (Group M) or isobaric lidocaine 20 mg/ml (Group L). Patients were evaluated on the first postoperative day by one investigator unaware of the grouping, looking for symptoms suggestive of TNS, such as pain or dysaesthesias in the buttocks or lower limbs with or without back pain.
                TNS symptoms were observed in three patients (7.5%) of Group M and in one patient (2.5%) of Group L, without statistically significant differences between the groups. Symptoms had an abrupt onset and relief, lasted from 45 min to 24 h, and had a complete resolution without sequelae. The only statistically significant difference between groups was longer motor blockade in Group M (P=0.0031).
                In this study TNS was associated with isobaric mepivacaine 20 mg/ml, with an incidence of 7.5%, and with isobaric lidocaine 20 mg/ml, with an incidence of 2.5%, in patients having orthopaedic procedures in the supine position. Both hyper- and hypobaric solutions of bupivacaine are often combined with morphine to provide subarachnoid anesthesia for cesarean section. Differences in the baricity of subarachnoid solutions influence the intrathecal distribution of anesthetic drugs and would be expected to influence measurable clinical variables. We compared the effects of hyper- and hypobaric subarachnoid bupivacaine with morphine to determine whether one has significant advantages with regard to intraoperative anesthesia and postoperative analgesia in term parturients undergoing elective cesarean section. Thirty parturients were randomized to receive either hyper- or hypobaric bupivacaine (15 mg) with morphine sulfate (0.2 mg). Intraoperative outcomes compared included extent of sensory block, quality of anesthesia, and side effects. Postoperative outcomes, including pain visual analog scale scores, systemic analgesic requirements, and side effects, were monitored for 48 h. Sedation effects were quantified and compared using Trieger and digit-symbol substitution tests. We detected no differences in sensory or motor block, quality of anesthesia, quality of postoperative analgesia, incidence of side effects, or psychometric scores. Both preparations provide highly satisfactory anesthesia for cesarean section and effective postoperative analgesia. Implications: Dextrose alters the density of intrathecal bupivacaine solutions and is thought to influence subarachnoid distribution of the drug. We randomized parturients undergoing cesarean section to one of two often used spinal bupivacaine preparations, hypobaric and hyperbaric. We detected no differences in clinical outcomes between groups. Though hyperbaric solution of bupivacaine following intrathecal injection had satisfactory spread of analgesia, it regressed rapidly with more side effects. Isobaric bupivacaine seemed to provide a slow regression of analgesia with fewer undesirable effects except for its inadequate spread of analgesia. As a result, if the dosages as well as the time of administration of isobaric solution are well adjusted, we believe that it is safe and reliable with an excellent level of analgesia for caesarean section. The incidence of TNS after spinal anaesthesia is a problem. Especially the use of hyperbaric lidocaine in patients placed in the lithotomy position during surgery has been associated with a high incidence of TNS. The present study was performed to investigate whether TNS is present more frequently in patients undergoing surgery in the supine position with use of hyperbaric lidocaine compared with hyperbaric bupivacaine.
                Seventy patients were included and randomised to receive either hyperbaric lidocaine or hyperbaric bupivacaine. All patients were contacted on the first and third postoperative days by an anaesthesiologist blinded to the local anaesthetic used. The patients were asked about symptoms of TNS, pain not associated with the operation area, and asked to grade the complaints after a verbal analogue score from 0 to 10.
                We found a total of ten patients who showed signs of TNS. There were nine patients in the lidocaine group (26%) who showed signs of TNS compared to only one patient in the bupivacaine group (3%) (P<0.01). The average score of TNS complaints was 3.5. A total of 13 patients (19%) complained of back pain. There were no significant differences with regard to which local anaesthetic was used. The average score of back pain was 3.3.
                TNS is a significant problem in patients having spinal anaesthesia with hyperbaric lidocaine compared to hyperbaric bupivacaine, both in the supine position. For day-case surgery, TNS would start after dismissal from hospital. The use of hyperbaric lidocaine is therefore questionable, even though these problems are of an order that the majority of patients would still choose spinal anaesthesia for future operations.
The criteria for conversion to general anaesthesia should be clearly defined in future research. This review found that intrathecal hyperbaric bupivacaine had a more rapid onset of sensory blockade at the T4 level than isobaric bupivacaine. It may also result in less need for conversion to general anaesthesia and supplemental analgesia. However, due to the rarity of this outcome, variability in the dose, use of adjuvant drugs and differences in the technique used for regional anaesthesia the evidence is weak. Any apparent advantage of hyperbaric bupivacaine needs to be confirmed in larger randomized trials. There were no differences in the adverse effects studied.