Coughing after fentanyl.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to T Gin.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We describe the anaesthetic management of a patient who underwent transthoracic endoscopic vagotomy. One-lung ventilation was necessary to provide adequate surgical access. Potential intraoperative problems involved arterial oxygen saturation during one-lung ventilation, unequal intrathoracic pressures causing mediastinal displacement and inadvertent myocardial injury by surgical instruments and diathermy. The management of these problems and the benefits of endoscopic surgery to the patient are discussed.
One hundred and sixty-two Chinese women undergoing emergency Caesarean section were allocated at random on admission to the labour ward to receive one of three regimens for orally administered chemoprophylaxis against acid aspiration: ranitidine 150 mg 6 hourly with sodium citrate at induction of anaesthesia, omeprazole 40 mg 12 hourly with sodium citrate, or omeprazole 40 mg 12 hourly alone. Intragastric pH and volume were measured immediately after induction of anaesthesia. Ten patients (17%) in the omeprazole-only group, three (6%) in the omeprazole and citrate group and one (2%) in the ranitidine group had an intragastric pH less than 2.5 and volume greater than 25 ml (p less than 0.05). The use of sodium citrate resulted in higher intragastric pH but larger intragastric volumes (p less than 0.05). The sodium citrate and ranitidine regimen was the most cost-effective among the three.
Explore the source record for details and available documents.
1. It has been suggested that hypertension may be an important determinant of the rate of progression of diabetic microangiopathy. 2. Renal microvascular disease as assessed by urinary albumin excretion and glomerular ultrastructure was evaluated in a model in which streptozotocin diabetes was induced in spontaneously hypertensive rats (SHR). 3. Diabetes was associated with increases in urinary albumin excretion, and hypertension resulted in a further increase in albuminuria. 4. Various antihypertensive regimens were administered to diabetic SHR, with the angiotensin-converting enzyme inhibitor perindopril and triple therapy (hydralazine, reserpine and hydrochlorothiazide) being more effective than the calcium antagonist (lacidipine) in retarding the increase in albuminuria in diabetic SHR. 5. Antihypertensive therapy appears to ameliorate the development of diabetic renal disease.
This double-blind randomised study compared postoperative analgesia after a loading regimen of methadone or morphine in thirty women undergoing abdominal hysterectomy. Methadone or morphine, 0.25 mg.kg-1, was given intravenously at induction of anaesthesia with further increments in the recovery room for analgesia if required. The mean (SD) total doses of methadone and morphine required were 0.43 (0.13) mg.kg-1 and 0.45 (0.15) mg.kg-1 respectively. Patients in the methadone group had lower pain scores in the subsequent 48 hours (P less than 0.001) and required less supplementary intramuscular opioids (P less than 0.001). Ten patients in the methadone group did not request any further opioid analgesics while all patients in the morphine group made at least two requests for opioids. The overall postoperative course was remembered as less painful by patients in the methadone group (P less than 0.001). There was no significant respiratory depression or excessive sedation in either group.
A preliminary study of 24 hours' postoperative analgesia using a patient-controlled analgesia technique was undertaken in eight European and fourteen Asian adult patients. All patients had upper abdominal surgery and received weight-related doses of pethidine postoperatively via a Cardiff Palliator. Both groups had a similar degree of analgesia as assessed by visual analogue score but the Asian patients were more sedated in the postoperative period. The Asian patients made 24% fewer demands for analgesia and had a smaller mean (SD) pethidine consumption, 7.62 (2.04) mg.kg-1, compared with the European patients, 9.97 (2.14) mg.kg-1, (P less than 0.05) during the first 24 hours. Further research is necessary to determine whether the smaller requirement for analgesia in Asian patients is a result of pharmacokinetic or pharmacodynamic differences.
Explore the source record for details and available documents.
The disposition of propofol was studied in women undergoing elective Caesarean section. Indices of maternal recovery and neonatal assessment were correlated with venous concentrations of propofol. After induction of anaesthesia with propofol 2.0 mg.kg-1, ten patients received propofol 6 mg.kg-1.hr-1 with nitrous oxide 50 per cent in oxygen (low group) and nine were given propofol 9 mg.kg-1.hr-1 with oxygen 100 per cent (high group). Pharmacokinetic variables were similar between the groups. The mean +/- SD Vss = 2.38 +/- 1.16 L.kg-1, Cl = 39.2 +/- 9.75 ml.min-1.kg-1 and t1/2 beta = 126 +/- 68.7 min. At the time of delivery (8-16 min), the concentration of propofol ranged from 1.91-3.82 micrograms.ml-1 in the maternal vein (MV), 1.00-2.00 micrograms.ml-1 in the umbilical vein (UV) and 0.53-1.66 micrograms.ml-1 in the umbilical artery (UA). Neonates with high UV concentrations of propofol at delivery had lower neurologic and adaptive capacity scores 15 minutes later. The concentrations of propofol were similar between groups during the infusion but they declined at a faster rate in the low group postoperatively. Maternal recovery times did not depend on the total dose of propofol but the concentration of propofol at the time of eye opening was greater in the high group than the low group (1.74 +/- 0.51 vs 1.24 +/- 0.32 micrograms.ml-1, P less than 0.01). The rapid placental transfer of propofol during Caesarean section requires propofol infusions to be given cautiously, especially when induction to delivery times are long.
We have compared the pharmacokinetics of a bolus dose of propofol 2 mg kg-1 in eight patients undergoing Caesarean section with those in eight postpartum patients undergoing sterilization by mini-laparotomy. The Caesarean section group had a total body clearance of (median) 31.5 (range 24.4-53.3) ml min-1 kg-1, apparent volume of distribution at steady state 5.10 (2.46-6.61) litre kg-1 and mean residence time 161 (52.3-251) min; values for the post-partum group were 33.8 (21.5-47.2) ml min-1 kg-1, 5.17 (3.47-8.09) litre kg-1 and 163 (92.3-238) min, respectively. The 95% confidence interval for the umbilical venous to maternal venous ratio of propofol at delivery was 0.62-0.86. Plasma protein binding studies showed there was less unbound propofol in maternal plasma (1.28-2.29%) compared with umbilical plasma (2.08-3.88%) (P less than 0.01). Neonatal concentrations of propofol were greater than maternal concentrations at 2 h and were in the range 0.05-0.11 micrograms ml-1 at 4 h.
A propofol infusion regimen and a standard general anaesthetic were compared in 40 Chinese women undergoing elective Caesarean section. Twenty patients received propofol 2 mg/kg for induction of anaesthesia followed by propofol 6 mg/kg/hour, while 20 patients received thiopentone 4 mg/kg with enflurane 1% for maintenance of anaesthesia. All patients were given atracurium and their lungs ventilated with nitrous oxide 50% in oxygen until delivery of the neonate. The hypertensive response after intubation was of shorter duration in the propofol group compared with the thiopentone group. Induction to delivery times ranged from 5 to 14 minutes and neonates from both groups had similar and satisfactory Apgar scores. Neurologic and Adaptive Capacity Scores and umbilical cord blood gas analysis. However, a prolonged propofol infusion time before delivery may cause lower Neurologic and Adaptive Capacity Scores. There were no differences in maternal recovery times or psychomotor performance.
We measured gastric emptying, using the technique of paracetamol absorption, in eight women on their first and third postpartum day. Gastric emptying was rapid and there was no difference between the first and third day in the time to peak plasma concentration of paracetamol. Six women returned after six weeks for a further study. Gastric emptying was still rapid but the metabolism of paracetamol appeared to be slower than that found during the immediate postpartum period. These findings suggest that fluid fasting guidelines in patients more than one day postpartum need not be different from those in non-pregnant patients.
Two propofol infusion regimens and a standard general anaesthetic were compared in thirty Chinese women undergoing elective Caesarean section. After induction of anaesthesia with propofol 2 mg.kg-1, ten patients received propofol 6 mg.kg-1.hr-1 and nitrous oxide 50 per cent in oxygen while ten were given propofol 9 mg.kg-1.hr-1 with 100 per cent oxygen. The other ten patients received thiopentone 4 mg.kg-1 and nitrous oxide 50 per cent in oxygen with enflurane one per cent. Maternal recovery times and psychomotor performance were recorded. Neonates were assessed by Apgar scores, neurologic and adapative capacity scores (NACS) and umbilical cord blood gas analysis. Haemodynamic changes were similar immediately following induction but the low propofol infusion group had the best haemodynamic stability subsequently. Recovery times were fastest in the low-infusion group but there were no differences in later postbox testing. Neonatal Apgar scores and umbilical blood gas analysis were similar but NACS at two hours were poorer in the high infusion group. A propofol infusion coupled with nitrous oxide appears to be a satisfactory technique for Caesarean section.
We have compared the pharmacokinetics of a bolus induction dose of propofol 2 mg kg-1 in 10 Chinese women undergoing elective Caesarean section with those in six non-pregnant Chinese women having laparoscopic sterilization. Blood propofol concentrations were measured using high pressure liquid chromatography with fluorimetric detection. Pharmacokinetic data were analysed by a model independent method based on statistical moment theory. Data from the laparoscopy group also underwent compartmental analysis, which produced similar kinetic results. Non-compartmental analysis estimated that the women undergoing Caesarean section had a similar elimination half-life (mean 81.27 (SD 18.87) min) and apparent volume of distribution at steady state (2.66 (0.63) litre kg-1) as non-obstetric patients (99.45 (29.40) min and 3.36 (1.87) litre kg-1). Clearance was more rapid in the Caesarean section group (39.32 (8.07) ml min-1 kg-1 vs 29.40 (8.72) ml min-1 kg-1) (P less than 0.05). The increased total body clearance may result from blood loss and delivery of the fetus and placenta at operation, although an increase in extrahepatic clearance is also possible.
Bupivacaine 2.5 mg kg-1 (0.5 ml kg-1 of 0.5% solution), with or without adrenaline 5 micrograms ml-1, was administered by interpleural injection to 12 patients after elective cholecystectomy. Noncompartmental analysis indicated that the addition of adrenaline had no effect on total body clearance, apparent volume of distribution at steady state or elimination half-life of bupivacaine. However, peak plasma concentrations were lower in the adrenaline group (mean (SD) [range]: 2.57 (0.61) [1.52-3.11] vs 3.22 (0.27) [2.84-3.53] micrograms ml-1, P less than 0.05) and the time to maximum concentration was delayed (median [range]: 25 [15-30] vs 15 [10-20] min, P less than 0.05). Analgesia was variable and no differences were detected between the two groups. The addition of adrenaline appears prudent to minimize possible bupivacaine toxicity.
We have studied in obstetric patients the efficacy of omeprazole in increasing intragastric pH to more than 2.5 and reducing volume to less than 25 ml. Omeprazole 40 mg was given orally the night before and again on the morning of surgery to 30 Asian women scheduled to undergo elective Caesarean section. After induction of anaesthesia, a gastric tube was inserted and intragastric contents aspirated. Volume and pH were recorded and measurements were repeated on completion of surgery. The median (range) volume was 2 (1-13) ml before surgery and 4 (0-14) ml at the end of surgery. There was insufficient volume to measure pH in all patients. The median (range) pH was 6.7 (4.6-7.4) before surgery in 20 patients and 6.6 (4.6-7.8) at the end of surgery in 28 patients. No adverse drug reactions were noted in mothers or neonates. Omeprazole 40 mg orally twice before elective Caesarean section appeared to be effective in reducing intragastric volume and acidity to acceptable values.
Explore the source record for details and available documents.