Rectal Diazepam Compared to Intramuscular Pethidine/Promethazine/Chlorpromazine with Regard to Gastric Contents in Paediatric Anaesthesia

Sixty children, aged 1—12 years, were investigated with regard to gastric pH and volume before general anaesthesia. Thirty children (group D) received diazepam 0.75 mg/kg b.w. rectally 1 h before anaesthesia. Thirty children (group L) received a "lytic cocktail" (pethidine 28 mg, promethazine 7 mg, chlorpromazine 7 mg per ml) 0.05 ml/kg b.w. intramuscularly 1 h before anaesthesia. The pH values were significantly higher and the amount of gastric juice was significantly lower in group L compared to group D. The number of children in group L with gastric juice volume exceeding 0.4 ml/kg and the number of children with pH less than 2.5 was significantly smaller compared to group D. The number of children with both gastric pH less than 2.5 and gastric juice volume greater than 0.4 ml/kg was significantly smaller in the group receiving "lytic cocktail" intramuscularly compared to the group receiving diazepam rectally. Bile-stained gastric contents was not related to the gastric pH.     

Large volumes of apple juice preoperatively do not affect gastric pH and volume in children

The effect on gastric pH and volume of 0, 6 and 10 ml.kg-1, of apple juice given 2.5 hours before surgery to children aged five to ten years was investigated in this prospective, randomized, single-blind study. Gastric contents were aspirated after induction of anaesthesia, and the volume measured. The pH of the gastric aspirate was then assessed using pH paper. Neither gastric volume nor pH immediately following the induction of general anaesthesia were significantly different among the three groups. Gastric volumes after 0, 6 and 10 ml.kg-1, of juice averaged (mean +/- SD) 0.45 +/- 0.31, 0.66 +/- 0.79 and 0.71 +/- 0.76 ml.kg-1, respectively; gastric pH averaged 1.7 +/- 0.6, 1.7 +/- 0.6 and 1.8 +/- 0.8, respectively. On the basis of questions asked immediately before induction of anaesthesia, patients who drank 6 ml.kg-1 of apple juice had decreased thirst and were less irritable and upset before anaesthesia than those who had not (P less than 0.05). It is concluded that drinking large volumes of clear apple juice 2.5 hours before scheduled surgery does not have a measurable effect on gastric volume and pH and may offer benefits such as improved patient comfort.     

The effect of oral administration of roxatidine acetate hydrochloride 3 hours prior to the operation on pH and volume of gastric juice]

The effect of roxatidine acetate hydrochloride, administered 3 hours prior to induction of anesthesia, on pH and volume of gastric juice was investigated in preoperative patients. In fifty patients, who were scheduled to undergo elective surgery, 150 mg of roxatidine acetate hydrochloride was administered orally 3 hours before the induction of anesthesia. The volume and pH of gastric juice were measured immediately after the induction of anesthesia. In 46 patients out of fifty, pH of gastric juice was more than 2.5, and its volume was below 25 ml. In another 4 patients, pH of gastric juice was more than 2.5, or its volume below 25 ml. We conclude that, oral administration of 150 mg roxatidine 3 hours preoperatively could be effective for the prevention of an aspiration pneumonitis.     

The effect of preoperative oral administration of ranitidine on pH and volume of gastric juice]

The effect of ranitidine, administrated 2 or 4 hours prior to induction of anesthesia, on volume and pH of gastric juice was investigated in patients undergoing elective surgery. Three-hundred mg of ranitidine was administrated orally in 54 patients 2 hours prior to anesthesia and in 50 patients 4 hours prior to anesthesia. The volume and pH of gastric juice were measured immediately after induction of anesthesia. In more than 90% of patients of both groups, volume of gastric juice was smaller than 25 ml and its pH was more than 2.5. Ranitidine 450 mg was administrated orally in 7 patients, and its plasma concentration was measured 2, 4 and 6 hours after administration. In one patient, volume of gastric juice was larger than 25 ml and its pH was less than 2.5. Ranitidine concentration in this patient was below the effective level 2 hours after administration and it was above the level after 4 hours. We concluded that oral administration of ranitidine 300 mg, 4 hours preoperatively, could be more effective to prevent aspiration pneumonitis than when it is given 2 hours preoperatively.     

Does 360 ml of apple juice ingested before elective surgery worsen gastric volume and acidity in patients given acid aspiration prophylaxis?

STUDY OBJECTIVE: To evaluate whether 360 ml of oral clear liquids consumed within 4 hours of elective surgery worsens gastric volume and acidity in patients given acid aspiration prophylaxis. DESIGN: Randomized, unblinded study. SETTING: Main operating room at a U.S. military hospital. PATIENTS: Eighty-three adult inpatients scheduled to receive general anesthesia for elective surgery. INTERVENTIONS: Nineteen patients (Group 1) were given 150 mg of oral ranitidine (two doses), 10 mg of metoclopramide, and 360 ml of apple juice 3 hours before the scheduled start of surgery. Thirty-four patients (Group 2) fasted before surgery but received acid aspiration prophylaxis identical to that given to Group 1. Twenty-three additional patients (Group 3) received no oral fluids or acid aspiration prophylaxis before surgery. MEASUREMENTS AND MAIN RESULTS: The residual gastric volume (RGV) and the pH of Group 1 patients were compared with measurements obtained in the two groups of patients who fasted. RGV measurements in Group 1 (14 +/- 3 ml) were similar to those in Group 2 (11 +/- 2 ml) and were significantly less than (p less than 0.05) those in Group 3 (26 +/- 4 ml). Gastric pH was significantly higher (p less than 0.001) in Group 1 (5.16 +/- 0.69) and Group 2 (5.78 +/- 0.43) than in Group 3 (1.97 +/- 0.27). CONCLUSIONS: Three hundred and sixty ml of apple juice consumed within 4 hours of elective surgery by patients given ranitidine and metoclopramide did not worsen gastric volume and acidity.     

Lansoprazole reduces preoperative gastric fluid acidity and volume in children

The purpose of this study was to explore the efficacy of lansoprazole, a proton pump inhibitor, in reducing the acidity and volume of gastric aspirate in children immediately following the induction of anaesthesia. One hundred healthy in-patients aged 3–11 yr undergoing elective surgery were randomly allocated to four groups (n = 25 each): lansoprazole-lansoprazole, placebo-placebo, placebo-lansoprazole, and lansoprazole-placebo. For each treatment regimen, the first medication was administered at 9:00 pm on the night before surgery and the second at 5:30 am on the morning of the day of surgery (three hours preoperatively). The dose of lansoprazole was 30 mg (approximately 1.4 mg · kg^?1 mean). Children were offered 10 ml · kg^?1 apple juice three hours before induction of anaesthesia. After induction of anaesthesia and tracheal intubation, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube and analyzed for pH and total fluid volume. Lansoprazole increased gastric fluid pH and decreased gastric fluid volume regardless of whether it was administered before or after placebo. Two consecutive doses of lansoprazole was the most effective means of increasing the pH and reducing the volume of gastric aspirate; in this group, there were no subjects with gastric aspirate volume >0.4 ml · kg^?1 and pH <2.5. Oral lansoprazole, at least 30 mg, given on the night before surgery or on the morning of surgery will improve the gastric environment at the time of induction of paediatric anaesthesia. The most effective regimen was two doses (at bedtime and on the morning) of lansoprazole.     

Comparison of the effect of two dose schedules of oral omeprazole with oral ranitidine on gastric aspirate pH and volume in patients undergoing elective surgery

We have compared gastric aspirate pH and volume at induction of anaesthesia in 222 patients who had received either omeprazole or ranitidine before elective operations. Omeprazole was given orally either as 40 mg on the evening before and 40 mg on the morning of surgery or as 80 mg on the morning of surgery. Ranitidine 150 mg was given orally on the evening before surgery and 2 h before anaesthesia. Treatment success was defined as aspirate pH > or = 2.5 and volume < 25 ml at induction of anaesthesia. Treatment was successful in 84% (95% confidence interval (CI) 73-91%) of patients in the omeprazole 40 + 40 mg group, 84% (95% CI 73-91%) in the ranitidine group and 73% (95% CI 61-83%) in the omeprazole 80 mg group. There were no statistically significant differences between the groups. Twelve patients in the omeprazole 80 mg group had gastric pH < 2.5 and four had volume > 25 ml. Only three patients had a gastric pH < 2.5 in the omeprazole 40 + 40 mg group and none had volume > 25 ml, which compared well with the ranitidine group. Omeprazole, given as 40 mg in the evening and 40 mg on the morning of operation, has a potential role for use in patients at risk for aspiration during general anaesthesia.      

Effect of preoperative oral erythromycin, erythromycin-ranitidine, and ranitidine-metoclopramide on gastric fluid pH and volume

STUDY OBJECTIVE: To determine whether combining erythromycin with ranitidine is more efficacious than erythromycin or established ranitidine-metoclopramide combination in reducing the volume and acidity of gastric aspirate. DESIGN: Randomized, double-blind study. SETTING: Operating room complex. PATIENTS: Eighty ASA physical status I and II patients. INTERVENTION: Patients were divided into 4 groups of 20 patients each. All patients received the study medication (in tablet form) packed in identical gelatin capsules 60 to 90 minutes before surgery in the premedication room. Patients in group PP were given two placebo tablets; group EP received erythromycin 250 mg, and placebo; group ER received erythromycin 250 mg, and ranitidine 150 mg; and group RM was given ranitidine 150 mg, and metoclopramide 10 mg. MEASUREMENTS: After tracheal intubation, gastric fluid was aspirated via orogastric tube, and volume and pH of the aspirate were studied. RESULTS: Significantly higher gastric volume occurred in group PP than groups EP, ER, or RM (P < 0.001). There were no differences in volumes among groups EP, ER, and RM. Gastric pH was significantly lower (P < 0.001) in groups PP and EP than in groups ER and RM. CONCLUSION: Erythromycin and ranitidine combination is more efficacious than erythromycin alone in reducing the acidity and volume of gastric fluid. No difference was found between erythromycin-ranitidine and ranitidine-metoclopramide combination.     

Bicitra (sodium citrate) and metoclopramide in outpatient anesthesia for prophylaxis against aspiration pneumonitis

To evaluate the effect of Bicitra (Willen Drug Company, Baltimore, Maryland), a commercial preparation of sodium citrate and metoclopramide, on gastric contents 150 elective outpatients allocated into six groups with 25 patients in each group were studied. Patients in Group 1 served as controls. Patients in Groups 2, 3, 5, and 6 received Bicitra, po, either 15 ml (Groups 2 and 5) or 30 ml (Groups 3 and 6). In addition, patients in Groups 5 and 6 also received metoclopramide 10 mg, iv; Group 4 patients received metoclopramide 10 mg, iv. Eighty-eight per cent of patients in the control group had a gastric pH less than or equal to 2.5, while 36% had a gastric content volume greater than or equal to 25 ml with pH less than or equal to 2.5. Bicitra, 15 ml and 30 ml, po, increased mean gastric pH and decreased the proportion of patients with a gastric pH less than or equal to 2.5 to 32 and 16%, respectively, in Groups 2 and 3. However, Bicitra 15 ml and 30 ml, increased the mean gastric volume in Group 3 and also increased the proportion of patients with a gastric volume greater than or equal to 25 ml to 56% in Group 2 and 84% in Group 3. The addition of metoclopramide 10 mg, iv, to Bicitra reduced the proportion of patients with a gastric volume greater than or equal to 25 ml in Groups 5 and 6 to 28 and 36%, respectively. Metoclopramide (Group 6) independently reduced mean gastric volume (15.6 ml vs. 32.7 ml) and the proportion of patients with a gastric volume greater than or equal to 25 ml (20% vs. 36%). Bicitra and metoclopramide combination significantly reduced the proportion of patients with gastric contents greater than or equal to 25 ml with pH less than or equal to 2.5.     

The effect of preoperative apple juice on gastric contents,thirst, and hunger in children

The effect of 3 ml.kg-1 of apple juice given 2.6 +/- 0.4 hours preoperatively was investigated in 80 healthy children of ages five to ten years in this prospective, randomized, single blind study. The children who drank apple juice preoperatively had decreased gastric volume, thirst, and hunger (p less than 0.05). The gastric volume in the control group was 0.43 +/- 0.46 ml.kg-1 and in the patients who received apple juice the gastric volume was 0.24 +/- 0.31 ml.kg-1. The gastric pH was not significantly different, with the control group's gastric pH being 1.7 +/- 0.6 and the treated group's pH was 2.2 +/- 1.2. Further studies of the effects of different volumes and timing of preoperative clear fluids are indicated in paediatric patients.     

Effects of clear liquids on gastric volume and pH in healthy volunteers

The effects of clear liquids on gastric volume and pH were examined in 30 healthy ASA physical status I volunteers. After overnight fasting, a Salem-sump nasogastric tube was inserted and gastric contents were removed for measurement of volume and pH. Gastric contents were then reinserted through the nasogastric tube into the stomach. The volunteers were randomly divided into three groups: group 1 (n = 10) received 240 mL water, group 2 (n = 10) received 240 mL coffee, and group 3 (n = 10) received 240 mL pulp-free orange juice. All liquids were administered orally. Gastric contents were then again aspirated, measured for volume and pH, and reinserted through the nasogastric tube every half hour until gastric volume was less than 25 mL. All volunteers had gastric volumes less than 25 mL with a slight decrease in pH within 2 h of orally taking one of the three 240-mL liquids. These data suggest that if patients have ingested a moderate amount of clear liquids it is safe to conduct general anesthesia after a 2-h fast in healthy surgical patients.     

An oral sodium citrate-citric acid non-particulate buffer in humans

We have investigated the effect on the pH of the gastric fluid of a single dose of sodium citrate 0.3 mol litre-1 (antacid) and a solution containing sodium citrate dehydrate (100 mg ml-1) with citric acid monohydrate (66 mg ml-1) (buffer). The dose for both solutions was 0.4 ml kg-1 via a nasogastric tube. Each group comprised 10 patients undergoing neurosurgical operations of 5-7 h duration. A control group of 10 patients received no gastric solution. The pH of the gastric aspirate was measured hourly using a Metrohm 632 digital pH meter (Synectics Medical, Sweden). Mean baseline gastric pH was 2.64 (SD 1.71). In the control group, pH increased to 4.4 (1.51) at 5 h, returning to baseline at 7 h. In the antacid group, pH increased to 6.11 (0.47) at 15 min and decreased to 3.70 (1.94) at 7 h (P < 0.01). In the buffer group, pH was stable at 3.80-3.95 (0.22) over 7 h (P > 0.01). Total mean gastric aspirate was 0.5 ml kg-1.      

Effect of intravenous pirenzepine on hemodynamics and gastric juice volume as well as pH in surgical patients]

The effects of pirenzepine on blood pressure, heart rate and gastric juice volume as well as pH were evaluated and compared with those after atropine and cimetidine in 54 adult patients divided into five groups. Patients in Groups A, P, AP, AC and ACP received atropine, pirenzepine, atropine plus pirenzepine, atropine plus cimetidine, or atropine, cimetidine plus pirenzepine, respectively. Atropine 0.5 mg and cimetidine 200 mg were given intramuscularly 60 min before induction of anesthesia, and pirenzepine 10 mg was given intravenously 5 min before induction. Gastric juice was aspirated just after, 60 and 120 min after induction of anesthesia. Mean blood pressure and heart rate remained unchanged following intravenous pirenzepine in Group P, whereas heart rate increased significantly in Groups AP and ACP. There were no significant differences in mean volume and pH of gastric juice among the groups just after and 120 min after induction of anesthesia, although gastric volume in Group AC was significantly less than in Groups P, AP and ACP 60 min after induction. Gastric pH increased gradually and gastric volume decreased slightly following intravenous pirenzepine. The incidence of samples with a pH higher than 2.5 was greater in Group AC than in Group P just after and 60 min after induction, whereas there was no difference between the two groups after 120 min. We conclude that intravenous pirenzepine 10 mg is effective to reduce gastric juice volume and acidity, and it should be given at least 60 min before induction of anesthesia.     

The effects of cimetidine and ranitidine with and without metoclopramide on gastric volume and pH in morbidly obese patients

The efficacy of preanaesthetic intravenous cimetidine versus ranitidine with and without metoclopramide for acid aspiration prophylaxis was assessed in 60 morbidly obese patients in a double-blind manner. Group 1 patients received cimetidine 300 mg + saline. Group 2 patients received cimetidine 300 mg + metoclopramide 10 mg. Group 3 patients received ranitidine 100 mg + saline. Group 4 patients received ranitidine 100 mg + metoclopramide 10 mg. Gastric fluid was aspirated for analysis of volume and pH following induction of anaesthesia. All four premedication regimens were equally effective in reducing the gastric volume and acidity and the inclusion of metoclopramide had no additive effect. Although statistically not significant, two patients in the cimetidine groups remained at risk (volume greater than 25 ml and pH less than 2.5) while no patients in the ranitidine groups remained so.     

Dose-response effects of intravenous ranitidine on gastric pH and volume in outpatients

The dose-response effects of intravenous ranitidine given 45 min to 5 h earlier on gastric pH and volume were evaluated in six groups of 25 outpatients, each undergoing elective surgery under general anesthesia. Patients in Group 1 received no ranitidine and served as controls. Patients in Groups 2-6 received ranitidine intravenously in incremental doses of 0.5 mg X kg-1 body weight from 0.5 mg to 2.5 mg (Group 2, 0.5 mg; Group 3, 1.0 mg; Group 4, 1.5 mg; Group 5, 2.0 mg; and Group 6, 2.5 mg). Ninety-six per cent of patients in the control group (Group 1) had gastric pH less than or equal to 2.5 while 36% of the patients had gastric content volumes greater than or equal to 25 ml with pH less than or equal to 2.5. Ranitidine, in incremental doses of 05.-2.5 mg X kg-1 body weight, caused a significant reduction of gastric acidity and volume. The ED50 of ranitidine producing a gastric pH greater than 2.5 was 0.36 mg X kg-1, and the ED95 was 0.98 mg X kg-1 body weight. The ED95 of ranitidine producing a gastric volume less than 25 ml was 1.96 mg X kg-1. At the dose of 1.5 mg X kg-1 of ranitidine, 100% of the patients had gastric contents with pH greater than 2.5. The proportion of patients with volume less than 25 ml was 68% with ranitidine, 0.5 mg X kg-1, and gradually increased to 100% with 2.5 mg X kg-1 body weight.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preanesthetic cimetidine and metoclopramide for acid aspiration prophylaxis in elective surgery

The effect of preanesthetic cimetidine and metoclopramide on gastric contents in inpatients undergoing elective surgery was studied. One hundred and fifty patients were allocated randomly into six groups with 25 patients in each group. Patients in Group 1 served as control. Group 2 patients received metoclopramide in the morning. Group 3 patients received cimetidine at bedtime and in the morning. Patients in Group 4 received cimetidine at bedtime and metoclopramide in the morning. Group 5 patients received cimetidine and metoclopramide in the morning, while patients in Group 6 received cimetidine at bedtime and metoclopramide and cimetidine in the morning. Cimetidine 300 mg and metoclopramide 10 mg were administered by mouth with a sip of water at bedtime or in the morning 1-4 h prior to the induction of anesthesia. Patients with gastric pH less than or equal to 25 or gastric content volume greater than or equal to 25 ml were defined to be at risk of pulmonary damage if aspiration should occur. In the control group the mean pH and volume of gastric contents were 2.89 and 22.3 ml, respectively, with 64% of patients with pH less than or equal to 2.5 and 32% of patients with volumes of greater than or equal to 25 ml. Cimetidine and metoclopramide favorably modified the risk factors in all the experimental groups. This study demonstrated that the three groups receiving cimetidine in the morning (Groups 3, 5, and 6) had significantly greater mean gastric pH than the other groups. Gastric volumes were significantly less in all experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

The efficacy of ranitidine in children

The effect of preoperative oral ranitidine on intragastric pH and volume of aspirate was evaluated in anaesthetized children. Five groups of eight randomly assigned children were evaluated. The first group acted as control and the other groups received 2, 2.5, 3, 3.5 mg kg-1 ranitidine, respectively. The drug was administered 1-4 h preoperatively. The intragastric pH was measured by a pH electrode through an orogastric tube, and the volume of aspirate was recorded every hour. At the time of first measurement oral ranitidine was significantly effective (P less than 0.001) in increasing the pH of intragastric contents to above the safe level of 2.5 in 94% of the children. At the second measurement an hour later, it was effective in all the children. Ranitidine has no significant effect on the volume of gastric aspirate and also there was no significant difference in the effect on the pH of the various doses of ranitidine studied. Oral ranitidine at doses of 2-3.5 mg kg-1 is effective in decreasing gastric acidity in children.     

Gastric fluid pH and volume in gynaecologic out-patients. Influences of cimetidine and cimetidine-sodium citrate combination

Eighty consecutive ASA physical status 1 women scheduled for day-case gynaecological laparoscopy under general anaesthesia were randomly allocated during the pre-operative visit to receive one of four premedication regimes. Patients in group 1 received hydroxyzine 100 mg; patients in group 2 received hydroxyzine 100 mg and cimetidine 400 mg; patients in group 3 received hydroxyzine 100 mg and effervescent cimetidine (cimetidine 200 mg + sodium citrate 1.8 g). All were given orally in 30 ml of water, 90 min before anaesthetic induction. Patients in group 4 received effervescent cimetidine orally in 30 ml of water 5 min before anaesthetic induction. Following induction of anaesthesia, gastric pH and residual volume (phenol red dilution technique) were measured. Gastric pH was higher (P < 0.05) in groups 2, 3 and 4 (medians: 5.71, 4.84, 6.07, respectively) than in group 1 (2.18). No patient had a gastric pH < or = 2.5 in group 4 compared with 13/14 n group 1, 1/15 in group 2 and 2/14 in group 3 (P < 0.0001). Mean gastric volumes were higher (P < 0.05) in group 4 (30.4 +/- 23.2 ml) than in groups 1, 2 and 3 (11.8 +/- 6.4, 15.8 +/- 11.2, 17.2. +/- 24.4 ml, respectively). Nine of the 19 patients in group 4 had a volume higher than 25 ml. Only one patient in group 1 had both gastric pH < or = 2.5 and volume > or = 25 ml. The administration of effervescent cimetidine 5 min prior to anaesthetic induction seems to be an easy and effective method of decreasing the acidity of gastric contents in day surgery.     

Oral ranitidine for prophylaxis against Mendelson's syndrome

The effect of the new H2 receptor antagonist ranitidine on gastric pH was studied using a double-blind technique in 36 patients undergoing elective surgery, 18 of whom were given 150 mg of ranitidine orally the night before and on the morning of surgery. The incidence of gastric residue pH higher than 2.5 (p less than 0.01) was significantly greater in patients given ranitidine than in 18 untreated control patients. The mean volume of gastric aspirate in the treated group as 6.7 ml (range 2 to 20 ml) compared with the control group 15.6 ml (range 2 to 44 ml). The higher potency, longer duration of action, and fewer side effects of ranitidine compared with cimetidine suggest that this drug may have clinical advantages over other H2 receptor antagonists.     

Ranitidine suspension or famotidine resoriblette and gastric fluid volume and pH

We studied the effect of two new formulations of H₂-receptor antagonists on gastric fluid pH and volume. Forty-five healthy, elective adult in-patients in three study groups, 15 in each, were premedicated using oral diazepam 10 mg with 100 ml of a dose of water soluble suspension of ranitidine 300 mg with sodium citrate/bicarbonate, or a resoriblette of famotidine 40 mg, or placebo. Gastric fluid samples were obtained by blind aspiration after anaesthesia induction, 50–70 min from premedication, and again 90 min from premedication. After a mean period of 60 min from ingestion the patients medicated with H₂-antagonists had higher gastric juice pH than those in the control group (1.5 (1.1–6.3), median (range)) (P < 0.0001) for ranitidine (6.8 (4.1–7.8)), P< 0.01 for famotidine (3.9 (1.5–7.6)); P < 0.05 ranitidine vs famotidine). Recovered volumes were similar for the groups (median 3–4 ml, range 0–50 ml). None of the H₂ patients had pH < 3.5 and volume ≥0.3 ml · kg^?1 (P<0.05 vs placebo). In second aspirations, taken 90 min from premedication, the group differences from control in pH persisted. Famotidine patients had the lowest volumes (P < 0.05 vs controls); yet one famotidine patient had a pH < 2.5 and volume ≥ 0.3 ml · kg^?1. It is concluded that, at the moment of oral anxiolytic premedication, ranitidine-buffer suspension effectively reduced gastric juice acidity, whereas famotidine resoriblette failed to increase reliably gastric pH in 50–90 min.