title: The Impact of Food Viscosity on Eating Rate, Subjective Appetite, Glycemic Response and Gastric Emptying Rate Does adding milk to tea delay gastric emptying? Ultrasound to confirm gastric tube placement in prehospital management. Role of caloric content on gastric emptying in humans. Ultrasonography and gastric emptying in children: validation of a sonographic method and determination of physiological and pathological patterns Gastric Sonography in the Fasted Surgical Patient: A Prospective Descriptive Study Ultrasound assessment of gastric volume in critically ill patients Intra- and Interrater Reliability of Ultrasound Assessment of Gastric Volume The effect of lipid droplet size on satiety and peptide secretion is intestinal site-specific. Effect of Metoclopramide on Gastric Fluid Volumes in Diabetic Patients Who Have Fasted before Elective Surgery Correlation between simultaneous scintigraphic and ultrasonographic measurement of gastric emptying in patients with type 1 diabetes mellitus. Gastric Sonography in the Severely Obese Surgical Patient: A Feasibility Study Validation of a Mathematical Model for Ultrasound Assessment of Gastric Volume by Gastroscopic Examination
abstract: Underst and ing the impact of rheological properties of food on postpr and ial appetite and glycemic response helps to design novel functional products . It has been shown that solid foods have a stronger satiating effect than their liquid equivalent . However , whether a subtle change in viscosity of a semi-solid food would have a similar effect on appetite is unknown . Fifteen healthy males participated in the r and omized cross-over study . Each participant consumed a 1690 kJ portion of a st and ard viscosity ( SV ) and a high viscosity ( HV ) semi-solid meal with 1000 mg acetaminophen in two separate sessions . At regular intervals during the three hours following the meal , subjective appetite ratings were measured and blood sample s collected . The plasma sample s were assayed for insulin , glucose-dependent insulinotropic peptide ( GIP ) , glucose and acetaminophen . After three hours , the participants were provided with an ad libitum pasta meal . Compared with the SV meal , HV was consumed at a slower eating rate ( P = 0.020 ) , with postpr and ial hunger and desire to eat being lower ( P = 0.019 and P<0.001 respectively ) while fullness was higher ( P<0.001 ) . In addition , consuming the HV result ed in lower plasma concentration of GIP ( P<0.001 ) , higher plasma concentration of glucose ( P<0.001 ) and delayed gastric emptying as revealed by the acetaminophen absorption test ( P<0.001 ) . However , there was no effect of food viscosity on insulin or food intake at the subsequent meal . In conclusion , increasing the viscosity of a semi-solid food modulates glycemic response and suppresses postpr and ial satiety , although the effect may be short-lived . A slower eating rate and a delayed gastric emptying rate can partly explain for the stronger satiating properties of high viscous semi-solid foods BACKGROUND Many preoperative fasting guidelines suggest that hot tea or coffee with milk added should be considered similar to solid food , allowing an interval of 6 h before commencing anaesthesia . There is little evidence to support these instructions , with recent guidelines undecided on the issue . This study aim ed to establish whether there was a clinical ly significant delay in gastric emptying associated with adding a modest amount of milk to tea . METHODS This r and omized controlled crossover study was conducted in 10 healthy volunteers . The  paracetamol absorption technique and real-time ultrasound measurement of the cross-sectional area of the gastric antrum were used to assess gastric emptying after ingestion of 300 ml of black tea or 300 ml of tea with milk ( 250 ml black tea plus 50 ml of full fat milk ) . RESULTS The mean difference in the time to reach the peak paracetamol concentration ( tmax ) was -8 min [ 95 % confidence interval ( CI ) -23.1 to 7 ] in favour of tea with milk . Ultrasound assessment indicated that the geometric mean of the half-time to gastric emptying ( T₁/₂ ) after tea without milk was 22.7 ( 95 % CI 12.7 - 40.9 ) min and after tea with milk 23.6 ( 95 % CI 13.5 - 41.0 ) min ( ratio 1.04 ) ( 95 % CI 0.47 - 2.29 ) . CONCLUSIONS This study demonstrated no difference in gastric emptying times when a modest amount of milk was added to tea . These findings suggest that it may be acceptable to allow patients to add a small quantity of milk to their tea or coffee and follow the same fasting restrictions applied to clear fluids BACKGROUND In emergency medicine , the gastric tube ( GT ) has many purpose s , however in prehospital setting s , the only indication is gastric decompression . To date , there is lack of recommendation on the diagnostic methods to verify correct GT placement in prehospital . The aim of this study is to estimate diagnostic accuracy of  ultrasound  in confirming gastric tubes placement in a prehospital setting . METHOD This was a prospect i ve multicentre study conducted in two French towns ( Marseille and Grasse ) over a one-year period from May 2010 to May 2011 . RESULTS One hundred and thirty patients were included in the study with an M/F sex ratio of 77/53 and a mean age of 55.7±19.8 years . The GT position was confirmed by ultrasound , with direct visualization in the gastric area in 116 of the 130 patients . In 14 cases , the ultrasound  failed to visualize the tip of the GT ; these results were due in 2 cases to gas interposition and in 12 cases the GT was shown by final X-ray to be located in the end of the oesophagus . Direct visualization by ultrasound thus has a sensitivity of 98.3 % [ 94 - 99.5 ] and a specificity of 100 % [ 75.7 - 100 ] , a positive predictive value of 100 % and a negative predictive value of 85.7 % , Youden 's index of 0.98 . GT size affects ultrasound visualization ; the larger the GT , the easier it is to see . CONCLUSION Bedside ultrasound thus appears to constitute an effective and reliable diagnostic procedure for confirming correct gastric tube placement in prehospital setting 1 . This study examined the effects of caloric content ( caloric density and the nature of calories ) on the rate of gastric emptying using the double-sampling gastric aspiration technique . Four test meals of 600 ml ( glucose , 0.1 kcal ml-1 ; pea and whey peptide hydrolysates , both 0.2 kcal ml-1 ; milk protein , 0.7 kcal ml-1 ) were tested in six healthy subjects in r and om order on four separate occasions . 2 . The glucose solution was emptied the fastest with a half-time of 9.4 + /- 1.2 min ( P < 0.05 ) and the milk protein the slowest with a half-time of 26.4 + /- 10.0 min ( P < 0.05 ) ; the pea peptide hydrolysate and whey peptide hydrolysate solutions had half-times of emptying of 16.3 + /- 5.4 and 17.2 + /- 6.1 min , respectively . The rates of gastric emptying for the peptide hydrolysate solutions derived from different protein sources were not different . 3 . Despite the lower rate of gastric emptying for the milk protein solution , the rate of caloric delivery to the duodenum during the early phase of the gastric emptying process was higher than that for the other three solutions ( 46.3 + /- 6 , 63.5 + /- 22 , 62.5 + /- 19 and 113.8 + /- 25 cal min-1 kg-1 for the glucose , pea peptide hydrolysate , whey peptide hydrolysate and milk protein meals , respectively ; P < 0.05 ) . The caloric density of the test solutions was linearly related to the half-time of gastric emptying ( r = 0.96 , P < 0.05 ) as well as to the rate at which calories were delivered to the duodenum ( r = 0.99 , P < 0.001 ) . 4 . This study demonstrates that the rate of gastric emptying is a function of the caloric density of the ingested meal and that a linear relationship exists between these variables . Furthermore , the nature of the calories seems to play a minor role in determining the rate of gastric emptying in humans Background The association between gastric emptying and gastro-esophageal reflux ( GER ) has been widely recognised from scintigraphic studies . Objective A prospect i ve study to ( a ) vali date US as a means of measuring gastric emptying , ( b ) determine physiological patterns of gastric emptying and ( c ) measure gastric emptying in symptomatic refluxers . Material s and methods Three cohorts were studied : ( a ) Ten babies in whom gastric emptying was measured by US and scintigraphy ; ( b ) gastric emptying in 330 asymptomatic children aged between 15 days and 10 years to determine physiological variations ; and ( c ) gastric emptying in 552 children with GER , manifesting as vomiting or cardiorespiratory problems . Results US and scintigraphic techniques showed general concordance in 90 % of cases . In the remaining 10 % , discordant results were related to overlapping of duodenum and stomach during scintigraphy and shadowing of the gastric antrum by air during US . Tremendous variations were induced by change of feed volume or type of formula , underlining the need for a st and ardised procedure . Twenty-two percent of cases showed a peculiar ' plateau ' which differed significantly from the physiological patterns . Most of these babies had esophagitis or acute life-threatening events . Conclusions Investigation of gastric emptying seems to be a key element in the assessment of children with ' pathological ' GER .  US is a safe and cheap alternative to scintigraphy for the assessment of gastric emptying BACKGROUND : Aspiration pneumonia remains a serious anesthetic-related complication . A reliable diagnostic tool to assess gastric volume is currently lacking . We recently demonstrated that gastric sonography can provide reliable qualitative and quantitative information about gastric content and volume in healthy volunteers . In the current study , we performed a prospect i ve qualitative and quantitative analysis of the gastric antrum in 200 fasted patients undergoing elective surgery . METHODS : A st and ardized gastric scanning protocol was applied before anesthetic induction . Patients were classified following a 3-point grading system based solely on qualitative sonographic assessment of the antrum in the supine and right lateral decubitus positions . RESULTS : Eighty-six patients were classified as grade 0 ( empty antrum ) ; 107 patients as grade 1 ( minimal fluid volume detected only in the right lateral decubitus position ) ; and 7 patients were classified as grade 2 ( antrum clearly distended with fluid visible in both supine and lateral positions ) . The 3-point grading system correlated with total gastric fluid volume as predicted by a previously reported mathematical model . Essentially grade 0 corresponds to a completely empty stomach , grade 1 corresponds to negligible fluid volumes ( 16 ± 36 mL ) within normal ranges expected for fasted patients , and grade 2 correlates with significantly higher predicted gastric fluid volumes ( 180 ± 83 mL ) beyond previously reported “ safe ” limits . One patient with a grade 2 antrum had an episode of significant regurgitation of gastric contents on emergence from anesthesia . CONCLUSION : We propose a 3-point grading system based exclusively on qualitative sonographic assessment of the gastric antrum that correlates well with predicted gastric volume . This grading system could be a promising “ biomarker ” to assess perioperative aspiration risk . Before it can be applied widely to clinical practice , this diagnostic tool needs to be further vali date d and characterized Purpose To assess the feasibility and validity of ultrasonographic measurement of gastric antral cross-sectional area ( usCSA ) in critically ill patients to predict gastric volume and the use of computed tomography ( CT ) as a reference to measure gastric volume . Method This single-center , prospect i ve , cross-sectional study included 55 critically ill patients who had an abdominal CT scan . usCSA measurements were performed within the hour preceding the CT scan .  Gastric volumes were measured on the CT scan using semiautomatic software . The feasibility rate , performing conditions ( % “ good ” and “ poor ” ) , internal and external validity of antral usCSA measurements , performed by an ICU physician , were assessed to predict gastric volume . Results Antral usCSA measurements were feasible in 95 % of cases and were positively correlated with gastric volume measured by the CT scan when performed in “ good ” conditions ( 65 % ) ( r = 0.43 ) . There was good reproducibility of measurements ( intraclass correlation coefficient of 0.97 , CI 95 % 0.96–0.99 ) and there was clinical ly acceptable agreement between measurements performed by radiologists and intensivists ( bias −0.12 cm2 ) . The receiver operating characteristic curve identified a cutoff value of 3.6 cm2 that discriminated an “ at-risk stomach ” ( volume > 0.8 mL/kg ) at a sensitivity of 76 % and a specificity of 78 % . Conclusions Ultrasonographic measurement of antral CSA is feasible and reliable in the majority of critically ill patients . This technique could be useful to manage critically ill patients at risk of aspiration or with enteral feeding Background : Gastric sonography can provide information about gastric content and volume that can help determine aspiration risk at the bedside . The primary objective of this study is to assess the intrarater and interrater reliability of a previously vali date d method of gastric volume assessment based on gastric antral area . The secondary objective is to evaluate the agreement between two different methods to measure gastric antral area . Methods : Three independent raters performed a st and ardized gastric ultrasound assessment in healthy subjects who had been r and omly allocated to ingest a predetermined volume of clear fluid ( apple juice ) from 0 to 400 ml . Each rater measured the gastric antral area , using twice the two-diameter method and twice the free-tracing method . The rater order was allocated at r and om and raters were unaware of the volume ingested and of one-another ’s measurements . The Guidelines for Reporting Reliability and Agreement Studies were followed for conducting and reporting this study . Results : Twenty-two volunteers were studied . Ultrasound assessment of antral cross-sectional area and volume was found to have “ nearly perfect ” intrarater and interrater reliability ( correlation coefficient > 0.8 ) with maximum differences within 13 % . A Bl and –Altman analysis suggests that the free-tracing method and the two-diameter method are essentially equivalent , within a clinical ly acceptable level of agreement . Conclusions : Ultrasound assessment of gastric volume by clinical anesthesiologists is highly reproducible with high intrarater and interrater reliability . The free-tracing method to measure antral cross-sectional area is equivalent to the two-diameter method BACKGROUND & AIMS : Infusion of fat into the small intestine induces satiety . Reducing fat droplet size accelerates fat digestion , but the effect on satiety after ileal fat infusion is not known . The aim of the study was to compare the effects of fat emulsions differing in droplet size ( fine , coarse ) infused in either duodenum or ileum on satiety , gastric emptying and peptide secretion . METHODS In a r and omized single-blind crossover study 15 healthy volunteers received , after intubation with a nasoileal tube  , 4 different treatments on 4 consecutive days . After consumption of a liquid meal , 6 g of fine or coarse fat emulsion was infused into duodenum or ileum . Study parameters were satiety , gastric emptying and gut peptides . These parameters were statistically evaluated using ANCOVA . RESULTS In the duodenum , Fine emulsion significantly reduced hunger , increased fullness , delayed gastric emptying , but did not affect peptide secretion versus Coarse . In the ileum , Fine emulsion did not affect hunger , fullness , or gastric emptying , but significantly increased peptide secretion versus Coarse . CONCLUSIONS Compared to larger fat droplets , smaller droplets significantly affect satiety , gastric emptying and gut peptide release , but with the effect being dependent on the intestinal location of fat delivery . DUTCH TRIALREGISTER : NTR1515 Background : Diabetes-induced gastroparesis is believed to increase fasting gastric fluid volume before elective surgery . Metoclopramide is routinely administered preoperatively to reduce gastric fluid volume in these patients . This study compared nondiabetic controls to non – insulin-dependent and insulin-dependent diabetics to determine the effect of metoclopramide , administered before surgery , on gastric volumes in patients who fasted before surgery . Methods : Control and diabetic patients fasted preoperatively before receiving either placebo or 10 mg intravenous metoclopramide 20 min before induction of anesthesia . After intubation , a gastric tube was placed , and stomach contents were aspirated with volumes compared among the groups . Results : Both groups of diabetic patients were older than the control group , and insulin-dependent patients had a higher incidence of comorbidities compared with the non – insulin-dependent group .  Fasting blood sugar and hemoglobin A1C values were higher in both insulin-dependent and non – insulin-dependent patients . Gastric fluid volumes were similar in control , non – insulin-dependent , and insulin-dependent patients ( 8.0 ± 2.6 vs. 9.6 ± 4.1 vs. 17.7 ± 2.5 ml , respectively ) . In insulin-dependent diabetic patients , metoclopramide decreased gastric volume compared with placebo treatment ( 17.7 ± 2.5 vs. 7.8 ± 2.9 ml ; P = 0.027 ) . After stratification , a sub population of patients with poorly controlled diabetes , regardless of type , were identified to have increased gastric residual volumes . Conclusion : In elective surgical patients who have fasted before surgery  , gastric volumes are minimal , even in diabetics with severe neuropathic symptoms . Metoclopramide prophylaxis to reduce gastric volumes seems to be unnecessary unless the patient has a prolonged history of poor blood glucose control OBJECTIVE To compare scintigraphic measurements of total stomach emptying of a semisolid meal with ultrasonographic measurements of changes in antral area as estimates of antral emptying in type 1 diabetic patients . METHODS Eleven patients with insulin-dependent diabetes mellitus were studied with simultaneous measurements of  gastric emptying  by scintigraphy and ultrasonography . Patients were imaged immediately after ingestion ( time 0 ) and every 15 minutes over 120 minutes . The gastric emptying rate was expressed as percent reduction in antral cross-sectional area from 15 to 90 minutes after meal ingestion . RESULTS Ultrasonographic measurements showed a postpr and ial maximal antral area at 15 minutes , continuously decreasing with time , and reaching a plateau 45 to 90 minutes after the end of meal ingestion , whereas the scintigraphic counts attained their maximum immediately after the meal and began to fall thereafter . Between 15 and 90 minutes , the residual radioactivity and antral ultrasonographically measured distension curves were concordant . The curves then showed a tendency toward deviation for the last 15 minutes ( median , 51 % versus 59 % at 105 minutes and 40 % versus 57 % at 120 minutes , respectively ) . A strong significant correlation could be seen between the ultrasonographic gastric emptying rate and scintigraphic half-time values ( r = -0.94 ; P < .001 ) . Comparing scintigraphic and ultrasonographic half-time values showed a systematic measurement error of 9.9 minutes and a r and om measurement error of 18.6 minutes . CONCLUSIONS The use of st and ardized real-time ultrasonography to determine the gastric emptying rate of semisolid meals in diabetic patients , with the use of the change in gastric antral cross-sectional area in a single section of the stomach 15 and 90 minutes postpr and ially , offers a valid method for clinical practice BACKGROUND : Gastric ultrasonography allows qualitative and quantitative assessment of gastric contents and volume in nonobese subjects . In this study , we sought to determine the feasibility of gastric ultrasound in severely obese patients ( body mass index [ BMI ] ≥35 kg/m2 ) . We defined feasibility as the ability to identify a full cross section of the gastric antrum in at least 80 % of subjects when imaged in the right lateral decubitus position . METHODS : This was a prospect i ve cohort study on fasted surgical patients with BMI > 35 kg/m2 . The primary outcome measure was the feasibility of gastric sonography .  Secondary outcomes included the distribution of antral grade following an existing 3-point grading system . In addition , the antral cross-sectional area ( CSA ) and gastric volumes in this cohort were compared with historical data from a published study in nonobese individuals . Time to image capture , antral wall thickness , and depth of the antrum are also reported . RESULTS : Sixty patients ( BMI range 35.1–68.7 ) were studied . The antrum was identified in 95 % of subjects in the right lateral decubitus ( 95 % CI , 0.86–0.99 ) and 90 % of subjects in the supine position . Definition of antral grade ( 0–2 ) was possible in 88.3 % ( 95 % CI , 0.77–0.95 ) of cases . As expected , antral grade correlated with antral CSA and gastric volumes ( P < 0.0001 ) . When compared with historical data , our results suggest that severely obese patients have a larger baseline CSA and gastric volume than nonobese patients ( P < 0.001 ) but a similar gastric volume per unit of weight ( P = 0.141 ) . CONCLUSIONS : Gastric ultrasound assessment is feasible in fasted severely obese subjects . Our data also suggest that obese individuals present larger antral size and gastric volume than their nonobese counterparts INTRODUCTION : Pulmonary aspiration of gastric contents is a serious perioperative complication . Previous models of ultrasound gastric volume assessment are preliminary and have not been vali date d by an external “ gold st and ard . ” In the present study we propose a more accurate model based on prospect i ve data obtained from 108 patients undergoing bedside gastric sonography and upper gastrointestinal endoscopy ( UGE ) .  METHODS : Patients undergoing elective UGE were r and omized to ingest one of 6 predetermined volumes of apple juice after an 8-hour fasting period  . A cross-sectional area of the antrum in the right lateral decubitus position ( Right lat CSA ) was measured by a blinded sonographer following a st and ardized scanning protocol . Gastric fluid was subsequently suctioned under gastroscopic vision during UGE performed by a blinded gastroenterologist and measured to the nearest milliliter . RESULTS : Data from 108 patients suggest that a previously reported model tends to overestimate gastric volume particularly at low volume states . A new best fit mathematical model to predict gastric fluid volume based on measurements of Right lat CSA is presented . This new model built on a more accurate gold st and ard can be used to estimate gastric volumes from 0 to 500 mL , in nonpregnant adults with body mass index < 40 kg/m2 . CONCLUSIONS : We report a new prediction model to assess gastric fluid volume using st and ard 2-dimentional bedside ultrasound that has several advantages over previously reported models
target: Taking knee arthroplasty as an example , patients deemed at low risk of experiencing outcomes such as postoperative pain or chronic pain  may receive intra-articular local anaesthesia infiltration ;  patients at medium risk may obtain additional analgesia via a saphe-nous nerve catheter ; and patients at high risk may also receive nerve blocks and anti-hyperalgesics .
  pain and function after fast-track hip and knee arthroplasty .
  catastrophizing , response to experimental heat stimuli , and post-cesarean section pain .
  In 1946 , Mendelson 1 showed that pulmonary complications and death could arise in pregnant women because of aspiration of gastric contents .
  Since then , prevention of aspiration of gastric contents has contributed significantly to a decrease in maternal deaths .
  Warner and colleagues 2 demonstrated in a large series from the Mayo Clinic that no aspiration occurred in pregnant or post-partum women ( probably because of the routine use of prophylactic measures ) , while both its occurrence and severity were significant in emergency procedures .
background: formation of large informatic data bases , or clinical quality registries , linking preoperative and intraoperative clinical data , imaging , genomics , and cancer and drug prescription data bases .
  References 1 Fischer HB , Simanski CJ , Sharp C , et al. A procedure-specific systematic review and consensus recommendations for postoperative analgesia following total knee arthroplasty .
  Postoperative pain management : number-needed-to-treat approach versus procedure-specific pain management approach .