human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 
    Output:
    
agent
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 .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 
    Output:
    