Clear fluids three hours before surgery do not affect the gastric fluid contents of children. [Possibility of rice porridge for preoperative feeding in children]. Shortened preanesthetic fasting interval in pediatric cardiac surgical patients. Preoperative drinking does not affect gastric contents. Ingestion of liquids compared with preoperative fasting in pediatric outpatients. The effect of pre-operative oral fluids on morbidity following anaesthesia for minor surgery. Effects of 2-, 4- and 12-hour fasting intervals on preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis in children. Effect of preoperative oral fluids on gastric volume and pH in postpartum patients. Ingestion of clear fluids is safe for adolescents up to 3 h before anaesthesia.
This prospective, randomized, single-blind study of 121 healthy children aged 2 to 12 yr investigated the effect of clear fluids on gastric contents. Gastric fluid volume and pH were measured immediately following the induction of general anaesthesia and were not significantly affected by the ingestion of unlimited clear fluids up to three hours preoperatively. After a prolonged fast (mean fast 14 hr), gastric fluid volume was 0.39 +/- 0.37 ml.kg-1 and gastric pH was 1.7 +/- 0.4; after unlimited clear fluids (203 +/- 109 ml) up to three hours before surgery gastric fluid volume was 0.34 +/- 0.28 ml.kg-1 and gastric pH was 1.8 +/- 0.7 (mean +/- SD). Gastric fluid volume (ml.kg-1) increased in both the control and study groups as age increased, P less than 0.005. It is concluded that drinking clear fluid up to three hours before scheduled surgery does not have a measurable effect on gastric volume and pH of healthy children of ages 2 to 12 yr. To determine the effect of rice porridge feeding before elective surgery on preoperative gastric fluid pH, volume and starvation, a prospective study was undertaken in pediatric patients. Twenty healthy children ranged in age from 5 to 12 years were allocated randomly to either a fasted or rice porridge group. The children of fasted group (control group) were allowed to take solid food until midnight before the operation. The rice porridge group (study group) patients received a small amount of rice porridge 5 hours 30 minutes before the induction of anesthesia. The patients of both groups were permitted to take clear fluid until 5 hours before the induction of anesthesia. After the induction of anesthesia, gastric fluid was aspirated through an orogastric tube. The mean gastric fluid volume was 0.43 +/- 0.32 ml.kg-1 in the control group and 0.5 +/- 0.6 ml.kg-1 in the study group. The mean gastric fluid pH was 1.43 +/- 0.27 ml.kg-1 in the control group and 1.89 +/- 0.75 ml.kg-1 in the study group. There were no significant differences between the two groups concerning the gastric fluid volume and pH. The patient of the study group complained of less hunger. Preoperative rice porridge feeding is a possible preoperative feeding for pediatric patients. The recent liberalization of preoperative feeding orders in healthy pediatric outpatients prompts the question of whether this applies to children about to have cardiac surgery. The authors compared gastric fluid volume and pH in two groups of children undergoing elective cardiac surgery, one of which was not only permitted ad libitum clear liquids but was mandated to drink clear liquids 2-3 h before induction of anesthesia (study group). The other group followed routine inpatient preoperative fasting orders (control group). The study group (n = 44) averaged 3.1 +/- 4.1 yr and weighed 15.3 +/- 16.3 kg; the control group averaged 3.3 +/- 3.9 yr and weighed 14.3 +/- 12.1 kg (P = 0.82, 0.73, respectively). Aspiration of residual gastric fluid volume was attempted in all patients after induction of anesthesia. Gastric fluid volume averaged 0.6 +/- 0.9 mL/kg in the study group and 0.4 +/- 0.6 mL/kg in the control group (P = 0.13). Of the study patients, 41% had a measured gastric volume greater than or equal to 0.4 mL/kg compared with 32% of the control patients (P = 0.50). Of the 42 patients who had residual gastric fluid aspirated, pH determinations were completed on 37 aspirates; of these 19 of 20 (95%) in the study group and 14 of 17 (82%) in the control group had a gastric pH less than or equal to 2.5. Using a linear analogue scale, parents rated children in the study group to be more comfortable, less hungry, and less thirsty compared with the control patients (P = 0.004, 0.002, 0.0001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS) We have compared the effect of allowing free clear fluids until the time of oral premedication with conventional preoperative fasting. In a prospective, randomized trial, the residual volume and pH of gastric contents after induction of anaesthesia were measured in 100 elective surgical patients allocated randomly to a group in whom the intake of free clear fluids up to the time of premedication was measured (mean 388 ml in 6 h before surgery) or a control group who were fasted for 6 h. Preoperative drinking did not affect either mean (SD) residual gastric volume (22 (21) ml in the study group vs 19 (16) ml in the control group) or pH (study group 2.64 (1.57) vs control group 2.26 (1.45)). The study group experienced less preoperative thirst. Problems with aspiration or regurgitation were not encountered. We believe that allowing elective surgical patients to drink clear fluids until 2 h before anaesthesia may enhance patient comfort without compromising safety. The preoperative fast is often an unpleasant preoperative experience that might be alleviated by allowing children to drink clear liquids. The authors compared gastric fluid volume and pH in two groups of children, one of whom was permitted clear liquids until 2 h before surgery (study group) and the other followed routine preoperative fasting orders (control group). The study group was not limited in the quantity of clear liquid allowed with the exception that the last intake prior to surgery was limited to 8 ounces. The study group (n = 53) averaged 5.9 +/- 5 yr and weighed 23.6 +/- 17 kg, while the control group averaged 7.3 +/- 4.6 yr and weighed 29 +/- 17.7 kg (P = NS). Gastric contents were aspirated following induction of anesthesia. Gastric fluid volume averaged 0.44 +/- 0.51 ml/kg for study group and 0.57 +/- 0.51 ml/kg in the control group (P = 0.12). Of the study patients, 48% had a measured gastric fluid volume greater than or equal to 0.4 ml/kg compared with 58% of the control patients (P = 0.77). Eighty three patients had sufficient gastric fluid for pH determination; of these 34/35 (97%) in the study group and 44/48 (92%) in the control group had a gastric fluid pH less than or equal to 2.5. Using a linear analog scale parents rated the children in the study group to be less irritable (P less than 0.001) and to have had a better overall preoperative experience (P less than 0.01) compared with the control patients.(ABSTRACT TRUNCATED AT 250 WORDS) Postoperative morbidity and serum osmolality were studied in 46 patients who were encouraged to drink water until 3 h pre-operatively and 49 receiving the normal fasting regimen prior to minor surgery. There was significantly less thirst in the postoperative period in those patients allowed to drink and subjectively better recovery than after previous anaesthesia. There was no morbidity from ingestion of up to 11 of water 2.5 h pre-operatively. Although there was only a moderate improvement in postoperative recovery we feel that allowing patients to drink water pre-operatively improves patient comfort, especially since patients may have to fast for much longer than guidelines recommend, simply because of the traditional organisation of operating lists. We evaluated 105 randomly-selected unpremedicated children aged 1-14 years to determine the effects of a 2-, 4- and 12-h preoperative fasting interval on the preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis. Each child undergoing elective surgery ingested a large volume (approximately 10 ml/kg b.w.) of apple juice and then fasted for 2, 4 or 12 h before the estimated induction of anaesthesia. After induction of anaesthesia, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube. Plasma concentrations of glucose, total ketone bodies, non-esterified fatty acid (NEFA), triglycerides, and cortisol were measured at the time of induction to evaluate the fasting interval effects on preoperative plasma glucose and lipid homeostasis. There were no significant differences between the three groups in either gastric fluid volume or pH. In addition, there were no significant differences between the groups with respect to the proportion with a pH < 2.5 and volume > 0.4 ml/kg b.w. Neither plasma concentrations of glucose, triglycerides, nor cortisol at the time of anaesthetic induction differed between the three groups. Both 4 and 12 h nil per os (NPO) caused an increase in lipolysis, which was presumably a compensatory mechanism to maintain normoglycaemia. The plasma NEFA and total ketone bodies concentrations were therefore significantly higher in these two fasting intervals than in 2 h NPO. These data suggest that a 2-h NPO, after a large volume of ingested apple juice, may offer additional benefits by preventing an increase in lipolysis during the fasting interval without either increasing the volume of gastric fluid or decreasing the gastric pH.(ABSTRACT TRUNCATED AT 250 WORDS) The effect of preoperative oral fluids to postpartum patients on the gastric volume and pH was compared with normally fasting postpartum and non-pregnant patients undergoing sterilisation. Forty consecutive postpartum patients and twenty non-pregnant patients scheduled for sterilisation procedure were selected for the study. All patients were fasted overnight. Twenty postpartum patients were randomly allocated to receive 150 ml of plain water two and half hours before surgery (Group 1), while the remaining postpartum patients (Group 2) and non-pregnant patients (Group 3) continued their overnight fast as usual. After induction of anesthesia, gastric volume and pH was measured in all the patients. The mean gastric volume was found to be 21.9 +/- 8.49 ml in Group 1, 22.55 +/- 8.30 ml in Group 2 and 22.65 +/- 8.17 ml in Group 3. The mean pH was found to be 2.21 +/- 0.98 in Group 1, 2.18 +/- 0.88 in Group 2 and 2.12 +/- 1.02 in Group 3. The difference in the volume and pH in all the three groups was statistically insignificant. The difference in the incidence of patients with combined high risk factors of acid aspiration syndrome (gastric fluid volume > 25 ml and pH < 2.5) among the three groups was also insignificant. The authors conclude that ingestion of 150 ml of plain water approximately two and half hours before scheduled time of surgery in overnight fasted postpartum patients does not increase the risk of aspiration syndrome. We have studied the effect of ingestion of unlimited clear fluids by adolescents up to 3 h before anaesthesia to determine the effect this fluid ingestion would have on thirst, hunger and gastric contents at induction of anaesthesia. We studied prospectively 152 adolescents (ages 13-19 yr) undergoing elective surgery. Fifty percent of the patients had nothing by mouth after midnight. The other 50% were instructed to ingest unlimited clear fluids up to 3 h before surgery. On arrival in the operating room, subjects were asked to assess thirst and hunger with a linear analogue scale of 0-10 (0 corresponding to no thirst or no hunger). After induction of anaesthesia, gastric contents were aspirated via a 16-French gauge orogastric tube. Gastric fluid volume (GV) was measured with a syringe and gastric pH (GpH) was assessed with Merck pH strips. GV, GpH and subject hunger were unaffected by ingestion of clear fluids. Subject thirst was reduced by clear fluids. It is concluded that unlimited clear fluid ingestion by healthy adolescents up to 3 h before operation decreases thirst and does not affect gastric contents.
There is no evidence that children who are denied oral fluids for more than six hours preoperatively benefit in terms of intraoperative gastric volume and pH compared with children permitted unlimited fluids up to two hours preoperatively. Children permitted fluids have a more comfortable preoperative experience in terms of thirst and hunger. This evidence applies only to children who are considered to be at normal risk of aspiration/regurgitation during anaesthesia.