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No study so far has tested a beverage containing glutamine 2 h before anesthesia in patients undergoing surgery. The aim of the study was to investigate: 1) the safety of the abbreviation of preoperative fasting to 2 h with a carbohydrate-L-glutamine-rich drink; and 2) the residual gastric volume (RGV) measured after the induction of anesthesia for laparoscopic cholecystectomies. Randomized controlled trial with 56 women (42 (17-65) years-old) submitted to elective laparoscopic cholecystectomy. Patients were randomized to receive either conventional preoperative fasting of 8 hours (fasted group, n = 12) or one of three different beverages drunk in the evening before surgery (400 mL) and 2 hours before the initiation of anesthesia (200 mL). The beverages were water (placebo group, n = 12), 12.5% (240 mOsm/L) maltodextrine (carbohydrate group, n = 12) or the latter in addition to 50 g (40 g in the evening drink and 10 g in the morning drink) of L-glutamine (glutamine group, n = 14). A 20 F nasogastric tube was inserted immediately after the induction of general anesthesia to aspirate and measure the RGV. Fifty patients completed the study. None of the patients had either regurgitation during the induction of anesthesia or postoperative complications. The median (range) of RGV was 6 (0-80) mL. The RGV was similar (p = 0.29) between glutamine group (4.5 [0-15] mL), carbohydrate group (7.0 [0-80] mL), placebo group (8.5 [0-50] mL), and fasted group (5.0 [0-50] mL). The abbreviation of preoperative fasting to 2 h with carbohydrate and L-glutamine is safe and does not increase the RGV during induction of anesthesia.
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Nutr Hosp. 2011;26(1):86-90
S.V.R. 318
Safety of oral glutamine in the abbreviation of preoperative fasting;
a double-blind, controlled, randomized clinical trial
D. Borges Dock-Nascimento1, J. E. D Aguilar-Nascimento2, C. Caporossi2, M. Sepulveda Magalhães
Faria2, R. Bragagnolo3, F. Stephan Caporossi3and D. Linetzky Waitzberg4
1Department of Food and Nutrition. Federal University of Mato Grosso. Cuiabá. Brazil. 2Department of Surgery. Federal
University of Mato Grosso. Cuiabá. Brazil. 3Multidisciplinary Team. Julio Muller Hospital. Federal University of Mato
Grosso. Cuiabá. Brazil. 4Department of Gastroenterology. São Paulo University. São Paulo. Brazil.
Introducción: Ningún estudio hasta el momento ha
investigado una bebida que contiene glutamina 2 h antes
de la anestesia en pacientes sometidos a cirugía.
Objetivos: El objetivo del estudio fue investigar: 1) la
seguridad de la abreviación del ayuno preoperatorio para
2 h con una bebida conteniendo carbohidratos y L-gluta-
mina, y 2) el volumen gástrico residual (RGV), medido
después de la inducción de la anestesia en colecistecto-
mías laparoscópicas.
Métodos: Ensayo controlado aleatorizado con 56 muje-
res (42 (17-65) años) sometidas a colecistectomía laparoscó-
pica electiva. Las pacientes fueron aleatorizadas para reci-
bir ayuno preoperatorio convencional de 8 horas (grupo
ayuno, n = 12) o una de tres bebidas diferentes tomadas la
noche antes de la cirugía (400 ml) y también 2 horas antes
del inicio de la anestesia (200 ml). Las bebidas eran agua
(grupo placebo n = 12), 12,5% (240 mOsm/l) maltodextrina
(grupo carbohidrato, n = 12) o carbohidrato además de 50 g
(40 g la noche anterior y 10 g por la mañana) de L-gluta-
mina (grupo glutamina, n = 14). Una sonda nasogástrica 20
F fue insertada inmediatamente después de la inducción de
la anestesia general para aspirar y medir el RGV.
Resultados: Cincuenta pacientes completaron el estu-
dio. Ninguno de los pacientes han presentado regurgita-
ción durante la inducción de la anestesia ni complicacio-
nes postoperatorias. La mediana (variación) del RGV fue
de 6 (00-80) mL. El RGV fue similar (p = 0,29) entre el
grupo glutamina (4,5 [0-15] mL), el grupo carbohidrato
(7,0 [0,80] mL), grupo placebo (8,5 [0-50] mL), y grupo
ayuno (5,0 [0-50] mL).
Conclusión: La abreviación del ayuno preoperatorio
para 2 h con carbohidratos y L-glutamina es seguro y no
aumenta el RGV durante la inducción de la anestesia.
(Nutr Hosp. 2011;26:86-90)
Palabras clave: Colecistectomía. Ayuno preoperatorio.
Glutamina. Volumen gástrico residual. Estudio controlado
Introduction: No study so far has tested a beverage con-
taining glutamine 2 h before anesthesia in patients under-
going surgery.
Objectives: The aim of the study was to investigate: 1)
the safety of the abbreviation of preoperative fasting to 2 h
with a carbohydrate-L-glutamine-rich drink; and 2) the
residual gastric volume (RGV) measured after the induc-
tion of anesthesia for laparoscopic cholecystectomies.
Methods: Randomized controlled trial with 56 women
(42 (17-65) years-old) submitted to elective laparoscopic
cholecystectomy. Patients were randomized to receive
either conventional preoperative fasting of 8 hours
(fasted group, n = 12) or one of three different beverages
drunk in the evening before surgery (400 mL) and 2 hours
before the initiation of anesthesia (200 mL). The beverages
were water (placebo group, n = 12), 12.5% (240 mOsm/L)
maltodextrine (carbohydrate group, n = 12) or the latter
in addition to 50 g (40 g in the evening drink and 10g in the
morning drink) of L-glutamine (glutamine group, n = 14).
A 20 F nasogastric tube was inserted immediately after
the induction of general anesthesia to aspirate and mea-
sure the RGV.
Results: Fifty patients completed the study. None of the
patients had either regurgitation during the induction of
anesthesia or postoperative complications. The median
(range) of RGV was 6 (0-80) mL. The RGV was similar
(p = 0.29) between glutamine group (4.5 [0-15] mL), car-
bohydrate group (7.0 [0-80] mL), placebo group (8.5 [0-
50] mL), and fasted group (5.0 [0-50] mL).
Conclusion: The abbreviation of preoperative fasting
to 2 h with carbohydrate and L-glutamine is safe and does
not increase the RGV during induction of anesthesia.
(Nutr Hosp. 2011;26:86-90)
Key words: Cholecystectomy. Preoperative fasting. Gluta-
mine. Residual gastric volume. Randomized controlled study.
Correspondence: Jose E. Aguilar-Nascimento.
Department of Surgery. Federal University of Mato Grosso.
Rua Estevao de Mendonça, 81, apto. 801.
78043-300 Cuiabá. Brazil.
Recibido: 22-VII-2010.
1.ª Revisión: 15-IX-2010.
Aceptado: 22-IX-2010.
The main reason for traditional 8 hours of preopera-
tive fasting is to reduce the volume and acidity of stom-
ach contents, thus decreasing the risk of regurgitation
and aspiration recognized as Mendelson’s syndrome.1
In the 1980s, it was already known that gastric empty-
ing of water and other noncaloric fluids followed an
extremely fast exponential curve in volunteers.2,3 Vari-
ous randomized controlled studies4-6 and a meta-
analyse7in adults scheduled for elective surgery have
consistently documented that oral intake of water and
other clear fluids up to 2 h before induction of anesthe-
sia does not increase gastric volume or acidity. The use
of carbohydrate-rich beverage in the immediate preop-
erative period is not only safe, but may also reduce the
catabolic stress response to surgery and thus enhance
postoperative recovery.8,9 The use of additional meta-
bolic conditioning agents such as glutamine may be of
potential benefit to patients undergoing surgery. Gluta-
mine is a conditionally essential amino acid, which
improves both gastrointestinal perfusion and immune
function,10 and possesses a multiple beneficial systemic
function.11 A beverage containing glutamine in addi-
tion to carbohydrate may, therefore, provide additional
benefits to surgical patients, beyond carbohydrate
loading alone. One study has shown that gastric empty-
ing time for beverages containing glutamine is approx-
imately 160 minutes in healthy volunteers.12 However
no study so far has tested this solution in patients
undergoing surgery offered two hours before anesthe-
sia. The aim of the study was to investigate: 1) the
safety of the abbreviation of preoperative fasting to 2 h
with a carbohy drate-L-glutamine-rich drink; and 2) the
residual gastric volume (RGV) measured after the
induction of anesthesia for laparoscopic cholecystec-
Materials and methods
A group of 56 adult women (median age = 42 (17-
65) years-old) scheduled to undergoing elective
laparoscopic cholecystectomy at Santa Rosa Hospital,
Cuiabá, Brazil were eligible for inclusion in this trial.
Exclusion criteria were: American Society of Anesthe-
siologists (ASA) score above II, diabetes mellitus,
pregnancy, age above 65 years old, renal or hepatic
failure, gastroesophageal reflux, acute cholecystitis,
use of corticosteroids up to 6 months previously, and
any noncompliance or violation on the assigned proto-
col of preoperative fasting. The local ethics committee
approved the study, and all patients gave written
informed consent before randomization.
Three patients were excluded before randomization
due to refusal to participate (1) or age above 65 years-
old (2). Patients were randomized to receive either con-
ventional preoperative fasting of 8 hours (fasted group,
n =12) or one of three different beverages to be drunk
in the evening before surgery (400 mL) and 2 hours
before the initiation of anesthesia (200 mL). The bever-
ages were water (placebo group, n = 14), 12.5% (240
mOsm/L) maltodextrine (Nidéx®, Nestlé, São Paulo,
Brazil) (carbohydrate group, n = 12) or the latter in
addition to 50 grams (40 g in the evening drink and 10 g
in the morning drink 2 hours before the induction of
anesthesia) of L-glutamine (Resource Glutamine®,
Nestlé, São Paulo Brazil (glutamine group, n = 15).
Osmolarity of the beverage containing L-glutamine
was either 639.2 mOsm/L (evening drink, 400 mL) or
219.8 mOsm/L (morning drink, 200 mL).
Preoperative protocol
All patients received both oral and written informa-
tion about the protocol at the outpatient clinic. The
assignment was done by randomized numbers arranged
by a computer. Operations were scheduled to begin at
7:00 AM The evening before operation patients were
free to ingest solid food until 11:00 PM. The patients
belonging to the three groups of abbreviation of fasting
were told to ingest the beverage at 11:00 PM (400 mL)
and at 5:00 AM (200 mL), and be at the hospital admis-
sion unit at 6:00 AM.
Intraoperative protocol
A 20 F nasogastric tube was inserted immediately
after the induction of anesthesia to aspirate and mea-
sure the gastric contents. Placement of the nasogastric
tube was checked by a stethoscope positioned over the
epigastric region followed by a bolus injection of 10-20
cc of air. Patients were submitted to general anesthesia
without epidural blockage and received a single dose of
1 g of intravenous cefazolin.
Outcome variable and statistical analysis
Sample size was calculated supposing a mean differ-
ence of 3 mL (based on a pilot study) in the RGV and
with a standard deviation of 2 mL. Therefore a number of
11 cases per group were estimated to attain 80% power.
The main endpoint of the study was the RGV. Gastric
contents regurgitation during induction of anesthesia was
a secondary endpoint. Comparison of RGV among
groups was done by Kruskal-Wallis test. A 5% level was
adopted for significance. Data were presented as either
median (range) or mean ± SD as appropriate. All analysis
were done by SPSS statistical software v 10.0.
The flowchart of the randomized trial is presented
in figure 1. Three patients were excluded due to either
Glutamine in preoperative fasting 87Nutr Hosp. 2011;26(1):86-90
88 D. Borges Dock-Nascimento et al.Nutr Hosp. 2011;26(1):86-90
being aged (2) or refused to participate (1). After ran-
domization three others were ruled out due to either
have not correctly ingested the beverage (one in glut-
amine group and one in placebo group) or cancella-
tion of the surgery (one case in placebo group). There-
fore, 50 patients completed the study. There was no
difference in demographic and biochemical data
between groups (table I). None of the patients had
regurgitation during the induction of anesthesia.
There were neither deaths nor postoperative compli-
The median (range) of RGV was 6 (0-80) (mean =
10.6) mL. Comparisons showed that the RGV was simi-
lar (p = 0.29) between glutamine group (median = 4.5 [0-
15], mean = 4.9) mL), carbohydrate group (median = 7.0
[0-80], mean = 12.6 mL), placebo group (media = 8.5 [0-
50], mean = 12.9 mL), and fasted group (median 5.0 [0-
50], mean = 12.1 mL). This can be seen in figure 2.
The findings showed that the abbreviation of preop-
erative fasting for 2 hours with carbohydrate and L-
glutamine-rich drink was safe and was not associated
with complications during the induction of anesthesia.
Furthermore the RGV was similar in either fasted
patients or in groups treated with abbreviation of pre-
operative fasting to 2 h. This is most relevant since this
is the first study in the surgical setting that compared
RGV with a group drinking a beverage containing glut-
amine 2 h before anesthesia. The data suggest that this
new ingredient to abbreviate preoperative fasting is
safe thus encouraging further studies.
After an overnight fast, the stomach is almost never
completely empty and the RGV in healthy volunteers
can range from 0 to 95ml with a mean of 27 mL.12 Vari-
ous techniques are available to study gastric emptying,
Fig. 1.—Flowchart of
the randomization.
Asessed for elegibility
(n = 56)
(n = 53)
(n = 50)
(n = 50)
Placebo group
(n = 12)
Placebo group
(n = 12)
Fasted group
(n = 12)
Fasted group
(n = 12)
Carbohydrate group
(n = 12)
Carbohydrate group
(n = 12)
Glutamine group
(n = 14)
Glutamine group
(n = 14)
Fasted group
(n = 12)
Carbohydrate group
(n = 12)
Glutamine group (n = 15)
1 excluded - non compliance
with the protocol
Placebo group
(n = 14)
2 excluded due to
cancellation of surgery;
or non-compliance with
the protocol
Randomized (n = 53)
Excluded (n = 3):
2 were over 65 years old
1 refused to participate
Glutamine in preoperative fasting 89Nutr Hosp. 2011;26(1):86-90
all of them having specific advantages and disadvan-
tages. Since the introduction of radionuclide gastric
emptying tests, considerable improvement has been
achieved in both methodology and operational equip-
ment, and scintigraphy has become the “gold standard”
for measurements of gastric emptying in research and
in the clinical setting.13 Recently magnetic resonance
image has been also used.12 While room to criticism
may exist in connection with the accuracy of this
method, other studies have also reported its useful
application at the surgical unit.14,15 Moreover, the data
showed that all groups including glutamine group had
similar RGV at induction of anesthesia.
Another importance of these findings is that it keeps
opened the gate for testing other nutrients for abbrevia-
tion of preoperative fasting in addition of carbohy-
drate-rich beverages. The use of L-glutamine associ-
ated with carbohydrate beverage may theoretically
accelerate postoperative recovery by improving glu-
cose metabolism and insulin requirements,16 reduce
anti-oxidative and anti-inflammatory response,17 and as
a result reduce postoperative complications11,18 and
mortality.11 Insulin resistance as a result of prolonged
fasting may be also reduced. Insulin resistance is a
mark of metabolic response to both prolonged fasting
and trauma.9Further studies are necessary to confirm
all these benefits associated to the abbreviation of pre-
operative fasting with beverages containing L-gluta-
The present findings allow us to conclude that the
abbreviation of preoperative fasting to 2 h with carbo-
hydrate and L-glutamine is safe and does not increase
the RGV during induction of anesthesia.
1. Mendelson CL. The aspiration of stomach contents into the
lungs during obstetric anesthesia. Am J Obstet Gynecol 1946;
52: 191-205.
2. Erskine L, Hunt JN. The gastric emptying of small volumes
given in quick succession. J Physiol 1981; 313: 335-341.
3. Brener W, Hendrix TR, McHugh PR (1983) Regulation of the
gastric emptying of glucose. Gastroenterology 85: 76-82.
4. Phillips S, Hutchinson S, Davidson T. Preoperative drinking
does not affect gastric contents. Br J Anaesth 1993; 70: 6-9.
5. Maltby JR, Koehli N, Ewen A et al. Gastric fluid volume, pH,
and gastric emptying in elective inpatients. Influences of nar-
Table I
Demographic and biochemical data of the study population
Variable Fasted Placebo Carbohydrate Glutamine p
Age (years)42 (19-65) 44 (17-63) 34 (17-62) 45 (22-65) 0.46
BMI (kg/m2)26.5 (20.4-31.2) 27 (20.4-33.3) 24.7 (23.3-29.1) 22.8 (19.2-29.1) 0.10
Serum glucose (mg/dl)* 88.1 ± 4.9 82.6 ± 8.4 83.8 ± 10.8 85.5 ± 11.5 0.75
Hemoglobin (g/dl)* 13.6 ± 1.1 12.4 ± 0.9 12.4 ± 1.0 13.2 ± 1.3 0.10
Creatinine (mg/dl)* 0.64 ± 0.84 0.69 ± 0.21 0.73 ± 0.23 0.67 ± 0.98 0.72
SGOT (u/l)* 17.3 ± 5.0 23.8 ± 9.6 20.8 ± 4.1 17.5 ± 3.6 0.31
SGPT (u/l)* 19 ± 55 23.6 ± 9.3 22.8 ± 12.2 16.3 ± 4.3 0.27
ASA (n; %)
I 8 (66.6) 7 (58.3) 8 (72.7) 8 (57.1) 0.84
II 4 (33.3) 5 (41.6) 3 (27.2) 6 (42.8)
* = Mean ± SD.
= Median (range).
SGOT: serum glutamic-oxalacetic transaminase.
SGPT: serum glutamic-pyruvate transaminase.
ASA: American Society of Anesthesiologists score.
Fig. 2.—Gastric residual volume in the four groups. Data ex-
press the median, variation, and interquartile range (p = 0.29).
Black dots are outliers.
N = 12 12 12 14
Placebo Fasted Carbohydrate Glutamine
Gastric Residual Volume (mL)
90 D. Borges Dock-Nascimento et al.Nutr Hosp. 2011;26(1):86-90
cotic–atropine premedication, oral fluid, and ranitidine. Can J
Anaesth 1988; 35: 562-566.
6. Maltby JR, Lewis P, Martin A et al. Gastric fluid volume and
pH in elective patients following unrestricted oral fluid until
three hours before surgery. Can J Anaesth 1991; 38: 425-429.
7. Brady M, Kinn S, Stuart P. Preoperative fasting for adults to
prevent perioperative complications. Cochrane Database Syst
Rev 2003; (4): CD004423.
8. Hausel J, Nygren J, Thorell A et al. Randomized clinical trial of
the effects of oral preoperative carbohydrates on postoperative
nausea and vomiting after laparoscopic cholecystectomy. Br J
Surg 2005; 92: 415-421.
9. Faria MS, Aguilar-Nascimento JE, Pimenta OS et al. Preopera-
tive fasting of 2 hours minimizes insulin resistance and organic
response to trauma after video-cholecystectomy: A random-
ized, controlled, clinical trial. World J Surg 2009; 33: 1158-
10. Roth E. Non nutritive effects of glutamine. J Nutr 2008; 138:
11. Wischmeyer PE. Glutamine: role in critical illness and ongoing
clinical trials. Curr Opin Gastroenterol 2008; 24: 190-197.
12. Lobo DN, Hendry PO, Rodrigues G et al. Gastric emptying of
three liquid oral preoperative metabolic preconditioning regi-
mens measured by magnetic resonance imaging in healthy
adult volunteers: A randomized double-blind, crossover study.
Clin Nutr 2009; 28:636-641.
13. Hellstrom PM, Gryback P, Jacobsson H. The physiology of
gastric emptying. Best Prac Res Clin Anaesth 2006; 20: 397-
14. Henriksen MG, Hessov I, Dela F et al. Effects of preoperative
oral carbohydrates and peptides on postoperative endocrine
response, mobilization, nutrition and muscle function in
abdominal surgery. Acta Anaesthesiol Scand 2003; 47: 191-
15. Hutchinson A, Maltby JR, Reid CR. Gastric fluid volume and
pH in elective in-patients. Part I: Coffee or orange juice versus
overnight fast. Can J Anaesth 1988; 35: 12-15.
16. Déchelotte P, Hasselmann M, Cynober L et al. L-alanyl-L-
glutamine dipeptide-supplemented total parenteral nutrition
reduces infectious complications and glucose intolerance in
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... The 20 studies identified by our search regarding clear liquids intake and gastric volumes did not report any event of aspiration or regurgitation. [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84] The studies were of Low, or Very Low level of evidence. In eight studies, after overnight fasting, one group received water to consume medications and the other, received between 100 and 500 mL water till 2 hours before induction of anaesthesia. ...
... [75] Other studies which compared residual gastric volumes and pH after consumption of different kinds of liquids showed comparable gastric volumes and pH (LOE-Very Low to Low). [76][77][78][79][80][81][82] In a study assessing gastric volumes by gastroscopic aspiration after consumption of 200 mL water, the patients fasted for 40 to 75 min had gastric volumes similar to those fasted for 80-150 min (LOE-Moderate). [83] An earlier meta-analysis also concluded that there was no evidence that patients given liquid (including water, coffee, fruit juice, clear liquids and other drinks, e.g., isotonic drink, carbohydrate drink) 2-3 h prior to surgery had increased incidence of aspiration or regurgitation (LOE-High). ...
... [85] Similarly, comparable residual gastric volumes were found between overnight fasting patients and those receiving 100-500 mL clear liquids 2 h before surgery in other studies conducted in patients scheduled for elective surgical procedures (LOE-Very Low to Low). [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84] ...
... Giving adult patients carbohydrate drinks before surgery has been shown to be as safe as fasting from midnight while significantly reducing postoperative complications associated with prolonged preoperative fasting (Breuer-P. et al., 2006;Dock-Nascimento et al., 2011;Gustafsson et al., 2008). Furthermore, several clinical trials have shown consumption of a carbohydrate drink does not delay gastric emptying or affect gastric acidity and is safe in patients undergoing elective surgery without increasing aspiration risks (Dock-Nascimento et al., 2011;Gustafsson et al., 2008;Hellström, Samuelsson, Al-Ani, & Hedström, 2017;Yagci et al., 2008). ...
... et al., 2006;Dock-Nascimento et al., 2011;Gustafsson et al., 2008). Furthermore, several clinical trials have shown consumption of a carbohydrate drink does not delay gastric emptying or affect gastric acidity and is safe in patients undergoing elective surgery without increasing aspiration risks (Dock-Nascimento et al., 2011;Gustafsson et al., 2008;Hellström, Samuelsson, Al-Ani, & Hedström, 2017;Yagci et al., 2008). ...
Aim and objective To evaluate current evidence to determine whether oral preoperative carbohydrate drinks shorten hospital stays, reduce insulin resistance and/or improve postoperative discomfort for patients undergoing abdominal or cardiac surgery. Background Criticisms of standard preoperative fasting have forced practitioners to explore new ways of preparing patients for theatre. Consequently, the use of preoperative carbohydrate drinks prior to elective surgery has gained momentum. Current evidence regarding the efficacy of this treatment has been inconsistent and contradictory which prompted a review of the current literature. Design A systematic review of Randomised Clinical Trials (RCTs). Methods In accordance with Prisma guidelines, the review incorporated a systematic, comprehensive search of English language only texts published between 2001‐2018. The search focused on five databases (MEDLINE, EMBASE, CINAHL, British Nursing Index and ASSIA). Reference lists of relevant systematic reviews and studies located were also hand‐search for eligibility and further references. All randomised control trials (RCTs) investigating the effect of preoperative carbohydrate drinks on adult patients undergoing cardiac or abdominal surgery were included. The review excluded RCTs conducted on patients with type 1 or 2 diabetes mellitus and patients under the age of 18. Result The review included 22 RCT's with a total sample of 2065 patients across thirteen countries. Nine different types of surgery were identified. No significant reductions in hospital stay were noted in 8 of the ten trials. Preoperative carbohydrate drinks significantly reduced insulin resistance and improved postoperative discomfort especially in patients undergoing laparoscopic cholecystectomy. No definite conclusion regarding the impact of preoperative carbohydrate drinks on gastric volume and gastric pH were noted. Similarly, no adverse events such as pulmonary aspiration were reported. Conclusion Preoperative carbohydrate drinks were found to be safe and can be administered up to 2 hours before surgery. Such drinks were also found to reduce insulin resistance and improve postoperative discomfort especially in patients undergoing laparoscopic cholecystectomy. However, there is insufficient evidence to definitively conclude what impact they have on length of hospital stay. Relevance to Clinical Practice Patients undergoing surgery are often required to fast from midnight, while in some extreme cases patients are fasted for up to 24 hours prior to surgery. The main purpose of asking patients to undergo this prolonged fasting is to reduce the risk of aspiration. However, there is a general consensus that this traditional practice is out‐of‐date, and it is often associated with postoperative complications. On the other hand, current evidence suggests oral intake of fluids up to 90 ‐ 180 minutes prior to surgery is safe and consumption of a preoperative carbohydrate drinks does not delay gastric emptying or affect gastric acidity. This article is protected by copyright. All rights reserved.
... In order to minimise acute blockage of the respiratory system, aspiration pneumonia, and Mendelson syndrome under anaesthesia, routine preoperative fasting is always administered before elective surgery (12) . ...
... Accumulated evidences have showed that shortening of the fasting interval will not decrease the pH, or increase the volume of gastric contents related to perioperative complications [7,8]. Moreover, it could alleviate both preoperative [9] and postoperative [10,11] discomfort (e.g. ...
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Background To evaluate the impact of oral carbohydrate-rich (Ch-R) supplement taken 2 hours before an elective caesarean delivery (CD) on maternal and neonatal perioperative outcomes. Methods Ninety pregnant women undergoing elective CD were randomized into the Ch-R group, placebo group and fasting group equally. Participants’ blood was drawn at three time points, before intervention, immediately after and 1 day after the surgery to measure maternal and neonatal biochemical indices. Meanwhile women’s perioperative symptoms and signs were recorded. Results Eighty-eight pregnant women were finally included in the study. Women who had drunk Ch-R supplement had lower postoperative insulin level (β = − 3.50, 95% CI − 5.45 to − 1.56), as well as postoperative HOMA-IR index (β = − 0.74, 95% CI − 1.15 to − 0.34), compared with women who had fasted. Additionally, neonates of mothers who were allocated in the Ch-R group also had a higher glucose level, compared with neonates of mothers in the fasting group (β = 0.40, CI 0.17 to 0.62). Conclusion Oral Ch-R solution administered 2 hours before an elective CD may not only alleviate maternal postoperative insulin resistance, but also comfort women’s preoperative thirst and hunger, compared to fasting. Additionally, it may increase neonatal glucose level as well. Trial registration Chinese Clinical Trial Registry, ChiCTR2000033163 . Data of Registration: 2020-5-22.
... routinely fasted for 12 hours. 3 The preoperative fasting can persist up to a total of 12 to 20 hours based on the patients' operation order, operation duration, and the start time for postoperative feeding. Studies have revealed that gluconeogenesis begins, insulin resistance appears, lipolysis-proteolysis reactions occur, and blood glucose level increases during 12-hour fasting. ...
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Purpose: The aim of this study is to investigate the effects of preoperative oral intake of liquid carbohydrate on postoperative stress parameters (blood glucose, insulin resistance, cortisol, noradrenaline, and adrenaline levels) in patients who underwent laparoscopic cholecystectomy. Design: This is an experimental study with intervention and control groups. Methods: The sample consisted of 68 patients who underwent laparoscopic cholecystectomy (control group = 33; intervention group = 35). Twelve-hour preoperative fasting was applied to the patients in the control group in accordance with the clinical routine. Clear oral liquid carbohydrate (400 mL; 12.5 g/100 mL maltodextrin, 50 kcal/100 mL, pH 5.0) was administered to the patients in the intervention group at the preoperative second hour. Blood samples were taken from the patients at the preoperative 2nd and postoperative 2nd and 24th hours, and their blood glucose, insulin resistance, cortisol, noradrenaline, and adrenaline levels were measured. Results: Preoperative oral intake of carbohydrate had no effect on blood glucose (P > .05) but decreased insulin resistance at the postoperative 24th hour (P = .044; intervention and control group: 3.62 ± 3.44 to 8.16 ± 12.57 respectively) and cortisol level at the postoperative 2nd hour (P = .005; intervention and control group: 15.16 ± 6.53 mg/dl to 20.14 ± 7.49 mg/dl, respectively). In all of the three measurements, we found that the noradrenaline level of the patients in the intervention group was higher than the value of those in the control group (319.80 ± 301.49 pg/mL to 211.65 ± 141.11 pg/mL [P = .450]; 361.40 ± 213.50 pg/mL to 216.13 ± 114.53 [P = .001]; 268.40 ± 164.04 pg/mL to 196.00 ± 83.33 pg/mL [P = .026], respectively). Preoperative oral intake of liquid carbohydrate had no effect on postoperative adrenaline level (P > .05). Conclusions: Oral intake of liquid carbohydrate given at the preoperative 2nd hour decreased postoperative stress response through insulin resistance and cortisol.
... Fifty human subjects aged 17 -65 years old ingested a carbohydrate/ glutamine (50 grams of glutamine) supplement less than 20 hours prior to elective bowel surgery and no adverse Veterinary Science Research | Volume 02 | Issue 01 | June 2020 Distributed under creative commons license 4.0 effects were observed. The authors concluded that this amount of acute glutamine supplementation was safe during pre-operative "fasting" and subsequent surgery [94] . Elderly men and women (69 + 8.8 years) ingesting 0.5 g/ kg supplemental glutamine had no increase in plasma ammonia levels, although these subjects did have increased serum urea and creatinine (within the normal range) that were deemed not clinically relevant 95 (Galera et al. 2010). ...
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In some species of growing mammals glutamine is an essential amino acid that, if inadequate in the diet, is needed for normal growth and development. It is thus sometimes considered to be a conditionally essential amino acid in some species. A review of studies that have measured L-glutamine concentrations ([glutamine]) in horses demonstrates that plasma [glutamine] has routinely been reported to be much lower (~330 µmol/L) than in other mammals (> 600 µmol/L). Plasma [glutamine] represents the balance between intestinal transport into the blood after hepatic first pass, tissue synthesis and cellular extraction. The hypothesis is proposed that sustained low plasma [glutamine] represents a chronic state of sub-optimal glutamine intake and glutamine synthesis that does not meet the requirements for optimum health. While this may be without serious consequence in feral and sedentary horses, there is evidence that provision of supplemental dietary glutamine ameliorates a number of health consequences, particularly in horses with elevated metabolic demands. The present review provides evidence that glutamine is very important (and perhaps essential) for intestinal epithelial cells in mammals including horses, that horses with low plasma [glutamine] represents a sub-optimal state of well-being, and that horses supplemented with glutamine exhibit physiological and health benefits.
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These practice guidelines are a modular update of the “Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures.” The guidance focuses on topics not addressed in the previous guideline: ingestion of carbohydrate-containing clear liquids with or without protein, chewing gum, and pediatric fasting duration.
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Background Preoperative carbohydrate loading is an important element of the enhanced recovery after surgery (ERAS) paradigm in adult patients undergoing elective surgery. However, preoperative carbohydrate loading remains controversial in terms of improvement in postoperative outcomes and safety. We conducted a Bayesian network meta-analysis to evaluate the effects and safety of different doses of preoperative carbohydrates administrated in adult patients after elective surgery. Methods MEDLINE (PubMed), Web of Science, EMBASE, EBSCO, the Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure (CNKI) were searched to identify eligible trials until 16 September 2022. Outcomes included postoperative insulin resistance, residual gastric volume (RGV) during the surgery, insulin sensitivity, fasting plasma glucose (FPG), fasting serum insulin (Fin) level, the serum levels of C-reactive protein (CRP), postoperative scores of pain, patients’ satisfaction, thirst, hunger, anxiety, nausea and vomit, fatigue, and weakness within the first 24 h after surgery and the occurrences of postoperative infection. The effect sizes were estimated using posterior mean difference (continuous variables) or odds ratios (dichotomous variables) and 95 credible intervals (CrIs) with the change from baseline in a Bayesian network meta-analysis with random effect. Results Fifty-eight articles ( N = 4936 patients) fulfilled the eligibility criteria and were included in the meta-analysis. Both preoperative oral low-dose carbohydrate loading (MD: –3.25, 95% CrI: –5.27 to –1.24) and oral high-dose carbohydrate loading (MD: –2.57, 95% CrI: –4.33 to –0.78) were associated with postoperative insulin resistance compared to placebo/water. When trials at high risk of bias were excluded, association with insulin resistance was found for oral low-dose carbohydrate loading compared with placebo/water (MD: –1.29, 95%CrI: –2.26 to –0.27) and overnight fasting (MD: –1.17, 95%CrI: –1.88 to –0.43). So, there was large uncertainty for all estimates vs. control groups. In terms of safety, oral low-dose carbohydrate administration was associated with the occurrences of postoperative infection compared with fasting by 0.42 (95%Crl: 0.20–0.81). In the other outcomes, there was no significant difference between the carbohydrate and control groups. Conclusion Although preoperative carbohydrate loading was associated with postoperative insulin resistance and the occurrences of postoperative infection, there is no evidence that preoperative carbohydrate administration alleviates patients’ discomfort. Systematic review registration [ ], identifier [CRD42022312944].
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The ACERTO project is a multimodal perioperative care protocol. Implemented in 2005, the project in the last 15 years has disseminated the idea of a modern perioperative care protocol, based on evidence and with interdisciplinary team work. Dozens of published studies, using the protocol, have shown benefits such as reduced hospital stay, postoperative complications and hospital costs. Disseminated in Brazil, the project is supported by the Brazilian College of Surgeons and the Brazilian Society of Parenteral and Enteral Nutrition, among others. This article compiles publications by the authors who belong to the CNPq research group “Acerto em Nutrição e Cirurgia”, refers to the experience of other national authors in various surgical specialties, and finally outlines the evolution of the ACERTO project in the timeline.
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Objective: to present recommendations based on the ACERTO Project (Acceleration of Total Post-Operative Recovery) and supported by evidence related to perioperative nutritional care in General Surgery elective procedures. Methods: review of relevant literature from 2006 to 2016, based on a search conducted in the main databases, with the purpose of answering guiding questions previously formulated by specialists, within each theme of this guideline. We preferably used randomized controlled trials, systematic reviews and meta-analyzes but also selected some cohort studies. We contextualized each recommendation-guiding question to determine the quality of the evidence and the strength of this recommendation (GRADE). This material was sent to authors using an open online questionnaire. After receiving the answers, we formalized the consensus for each recommendation of this guideline. Results: the level of evidence and the degree of recommendation for each item is presented in text form, followed by a summary of the evidence found. Conclusion: this guideline reflects the recommendations of the group of specialists of the Brazilian College of Surgeons, the Brazilian Society of Parenteral and Enteral Nutrition and the ACERTO Project for nutritional interventions in the perioperative period of Elective General Surgery. The prescription of these recommendations can accelerate the postoperative recovery of patients submitted to elective general surgery, with decrease in morbidity, length of stay and rehospitalization, and consequently, of costs.
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Studies showing the improvement of insulin sensitivity by reducing the term of preoperative fasting are mostly done in patients undergoing major operations. More information about the role of shortened preoperative fasting in perioperative metabolism is needed for such elective minor/moderate abdominal procedures as laparoscopic cholecystectomy. We investigated the influence of a carbohydrate-rich drink given 2 h before laparoscopic cholecystectomy on insulin resistance and the metabolic response to trauma. A group of 21 female candidates (18-65 years old) for elective laparoscopic cholecystectomy were randomized to either an 8 h fasting group (control group: n = 10) or to a group receiving 200 ml of a carbohydrate beverage containing 12.5% (25 g, 50 kcal per 100 ml and approximately 285 mOsm) of maltodextrin 2 h before operation (CHO group: n = 11). Blood samples for various biochemical assays were collected both at induction of anesthesia and after the 10th postoperative hour. Insulin resistance was assessed by the HOMA-IR equation (Insulin (microU/ml) x blood glucose (mg/dl)/405). There were no postoperative complications. Seventy percent (7/10) of the controls and 27.3% (3/11) of the CHO group experienced at least one episode of vomiting (RR = 2.42, 95% Confidence Interval [CI] = 0.88-6.68; P = 0.08). Biochemical analysis showed that serum glucose (P < 0.01), insulin (P < 0.01), lactate/pyruvate ratio (P = 0.03), and triglycerides (P < 0.01) for the control group were higher than for the CHO group. The value of HOMA-IR was significantly greater (P = 0.03) in the conventionally fasted patients than in the CHO group. Abbreviation of the period of preoperative fasting and administration of a carbohydrate beverage diminishes insulin resistance and the organic response to trauma.
Objective: To examine the relationship between glutamine supplementation and hospital length of stay, complication rates, and mortality in patients undergoing surgery and experiencing critical illness. Data sources: Computerized search of electronic databases and search of personal files, abstract proceedings, relevant journals, and review of reference lists. Study selection: We reviewed 550 titles, abstracts, and articles. Primary studies were included if they were randomized trials of critically ill or surgical patients that evaluated the effect of glutamine vs. standard care on clinical outcomes. DATA EXTRACTION We abstracted relevant data on the methodology and outcomes of primary studies in duplicate, independently. DATA SYNTHESIS There were 14 randomized trials comparing the use of glutamine supplementation in surgical and critically ill patients. When the results of these trials were aggregated, with respect to mortality, glutamine supplementation was associated with a risk ratio (RR) of 0.78 (95% confidence interval [CI], 0.58-1.04). Glutamine supplementation was also associated with a lower rate of infectious complications (RR, 0.81; 95% CI, 0.64-1.00) and a shorter hospital stay (-2.6 days; 95% CI, -4.5 to -0.7). We examined several -specified subgroups. Although there were no statistically significant subgroup differences detected, there were some important trends. With respect to mortality, the treatment benefit was observed in studies of parenteral glutamine (RR, 0.71; 95% CI, 0.51-0.99) and high-dose glutamine (RR, 0.73; 95% CI, 0.53-1.00) compared with studies of enteral glutamine (RR, 1.08; 95% CI, 0.57-2.01) and low-dose glutamine (RR, 1.02; 95% CI, 0.52-2.00). With respect to hospital length of stay, all of the treatment benefit was observed in surgical patients (-3.5 days; 95% CI, -5.3 to -1.7) compared with critically ill patients (0.9 days; 95% CI, -4.9 to 6.8). Conclusion: In surgical patients, glutamine supplementation may be associated with a reduction in infectious complication rates and shorter hospital stay without any adverse effect on mortality. In critically ill patients, glutamine supplementation may be associated with a reduction in complication and mortality rates. The greatest benefit was observed in patients receiving high-dose, parenteral glutamine.
Samenvatting Als de anesthesie in werking is, worden slik-, hoest- en ademhalingsreflexen onderdrukt, en de mate waarin deze reflexen zijn onderdrukt is afhankelijk van het niveau van anesthesie en kan zich uitbreiden tot afwezigheid van onder andere faryngale en laryngale reflexen. Deze reflexen hebben een beschermende functie voor de luchtweg. Deze door de narcose beperkte functie vormt een extra risico in het geval door oprisping of overgeven van de maaginhoud de maaginhoud in de longen komt.
Afin ďévaluer ľeffetde ľingestion de liquide par voie orale en période préopératoire avec ou sans ranitidine sur te volume liquidien gastrique ainsi que son pH, 300 patients chirurgkaux électifs, ASA classe I ou 11 ont été randomisés et divisés en six groupes. Les trots groupes avant reçu du placebo sont discutés dans cette étude (la premiére partie) et les trois ayant reçu la ranitidine dans la deuxiéme partie. Entre deux et trois heures avant le temps cédulé de la chirurgie les patients ont reçu soil 150mlde café (groupe 1), ou 150 ml de jus ďorange (groupe2), alors que le groupe contrôle a continué son jeùne (groupe 3). Aucune prémédication aux opiacés ou belladone n’a été administrée. Immédiatement aprés ľinduction de ľanesthésie le liquide gastrique résiduelfut obtenu par succion sur te tube nasogastrique et son volume etpH ont été mesurés. Les volumes du liquide gastrique résiduel n’ont pas démontré de différence statistiquement significative entre les groupes (groupe 1: 24.5 ± 21.6 ml; groupe2; 23.7 ± 18.4 ml; groupe 3:23.2 ± 17.3 ml;p> 0.1). Les valeurs de pH entre les groupes etaient aussi similaires (groupe 1: 2.18 ± 1.58; groupe 2: 1.95 ± 1.24; groupe 3: 1.95 ± 1.62; p> 0.1).
Preoperative starvation has many undesirable effects but the minimum length of fasting is limited by gastric emptying, which may be dependent on nutrient content, viscosity and osmolarity of the feed. We compared the gastric emptying of two types of preoperative metabolic preconditioning drinks [Oral Nutritional Supplement (ONS) (Fresenius Kabi, Germany) and preOp (Nutricia Clinical Care, UK)] in healthy volunteers. Twenty (10 male, 10 female) healthy adult volunteers were studied on 3 separate occasions in a randomised crossover manner. Volunteers ingested 400 ml preOp, which is a clear carbohydrate drink (CCD) (50 g carbohydrate, 0 g protein), 70 g ONS (50 g carbohydrate and 15 g glutamine) dissolved in water to a total volume of 400 ml (ONS400) and 300 ml (ONS300). Gastric emptying time was measured using magnetic resonance imaging. Mean (95% CI) T(50) and T(100) gastric emptying times for CCD were significantly lower (p<0.001) compared with ONS400 and ONS300. T(50) was 47 (39-55), 78 (69-87) and 81 (70-92)min for CCD, ONS400 and ONS300 respectively. Correspondingly T(100) was 94 (79-110), 156 (138-173) and 162 (140-184)min. Residual gastric volumes returned to baseline 120 min after CCD and 180 min after ONS400 and ONS300. The faster gastric emptying for CCD compared to ONS400 and ONS300 signifies that gastric emptying may be more dependent on nutrient load than volume or viscosity in healthy volunteers. While it is safe to give CCD 2h preoperatively, ONS400 and ONS300 should be given at least 3h preoperatively.
Glutamine is the most abundant free amino acid of the human body. Besides its role as a constituent of proteins and its importance in amino acid transamination, glutamine has regulatory capacity in immune and cell modulation. Glutamine deprivation reduces proliferation of lymphocytes, influences expression of surface activation markers on lymphocytes and monocytes, affects the production of cytokines, and stimulates apoptosis. Moreover, glutamine administration seems to have a positive effect on glucose metabolism in the state of insulin resistance. Glutamine influences a variety of different molecular pathways. Glutamine stimulates the formation of heat shock protein 70 in monocytes by enhancing the stability of mRNA, influences the redox potential of the cell by enhancing the formation of glutathione, induces cellular anabolic effects by increasing the cell volume, activates mitogen-activated protein kinases, and interacts with particular aminoacyl-transfer RNA synthetases in specific glutamine-sensing metabolism. Glutamine is applied under clinical conditions as an oral, parenteral, or enteral supplement either as the single amino acid or in the form of glutamine-containing dipeptides for preventing mucositis/stomatitis and for preventing glutamine-deficiency in critically ill patients. Because of the high turnover rate of glutamine, even high amounts of glutamine up to a daily administration of 30 g can be given without any important side effects.
This clinical study was designed to assess the results of new preoperative fasting guidelines in which patients are instructed that they must not eat any solid food after midnight, but that they may drink unrestricted amounts of clear fluid until three hours before their scheduled time of surgery. We studied 199 healthy, elective surgical inpatients aged 18-70 yr to determine whether there was any correlation between the ingestion interval or the volume of fluid ingested, with the volume and pH of residual gastric fluid at induction of anaesthesia. Pregnant patients, and those with gastric disorders or who were taking medications that affect gastric motility or secretion, were excluded. Either no premedication was given, or oral diazepam 5-15 mg was given 90 min preoperatively. Of the 199 patients, 105 ingested 50-1200 ml on the morning of surgery. The ingestion-induction interval was less than three hours in 12 patients whose actual surgery time was ahead of schedule. The remaining 94 patients did not drink because they were scheduled for surgery before 11:00 (n = 51), they did not want to drink (n = 24), or they were advised not to drink by their nurse or surgeon (n = 16). Following induction of anaesthesia, gastric fluid was aspirated through a #18 Salem sump orogastric tube, the volume was recorded and pH was measured with a calibrated pH meter. Patients were divided retrospectively into four groups (in three of which patients ingested fluid) according to the ingestion-induction interval (1.3-3.0 hr, 3.1-5.0 hr, 5.1-8.0 hr, and nothing by mouth after midnight).(ABSTRACT TRUNCATED AT 250 WORDS)
One hundred and twenty healthy, elective surgical inpatients were randomly assigned to one of four groups. Between two and three hours before the scheduled time of surgery all patients ingested a marker dye, phenol red, 50 mg in 10 ml water, with placebo tablet alone (Groups 1 and 2), placebo tablet with 150 ml oral fluid (Group 3), or oral ranitidine 150 mg with oral fluid 150 ml (Group 4). Patients in Group 1 received oral diazepam or no premedication, while those in Groups 2, 3, and 4 received IM narcotic and atropine one hour preoperatively. Following induction of anaesthesia the residual gastric fluid was aspirated through a Salem sump tube and its volume, pH, and phenol red content measured. Mean volumes were Group 1: 24 ml; Group 2: 13 ml; Group 3: 17 ml; Group 4: 14 ml. Mean pH values were Group 1: 2.99; Group 2: 3.03; Group 3: 3.44; Group 4: 5.28. The amount of phenol red in the samples indicated at least 90 per cent gastric emptying had occurred in 90 per cent of patients. We conclude that, in healthy patients, 150 ml oral fluid is almost completely emptied from the stomach within two hours of ingestion, even when followed one hour later by narcotic-atropine premedication.
The gastric emptying characteristics of physiological saline (0.9% NaCl) and glucose solutions of three different concentrations (0.05, 0.125, 0.25 g/ml) were examined in order to identify distinctions in the control of the stomach's activity. Saline emptied rapidly and exponentially. Glucose assumed, soon after filling the stomach, a slow and calorie-constant emptying pattern such that 2.13 kcal of glucose were delivered per minute to the duodenum for all three concentrations of glucose. When, by means of a catheter passed beyond the pylorus, glucose was infused into the duodenum in amounts varying from 26.5 to 120 kcal, an inhibition on the gastric emptying of physiological saline of 0.46 min/kcal of intraduodenal glucose was demonstrated. Since 2.13 kcal/min and 0.46 min/kcal are reciprocals, it appeared that in emptying saline, the gastroduodenal system acts as an "open-loop" system passing liquids from the stomach at a rate primarily determined by the volume of gastric contents. With glucose, however, a "closed-loop" system is established that assumes a steady-state balance between the delivery of glucose to the duodenum and the inhibition of this delivery evoked from the duodenum by the glucose that enters it.