British journal of anaesthesia
-
Randomized Controlled Trial Comparative Study Clinical Trial
Hormonal responses to high-dose fentanyl anaesthesia. A study in patients undergoing cardiac surgery.
The hormonal responses to anaesthesia and cardiac surgery were studied in 20 patients. Ten patients were anaesthetized with fentanyl 60 microgram kg-1 and nitrous oxide in oxygen and 10 with etomidate 0.3 mgkg-1 and nitrous oxide in oxygen plus halothane. ⋯ Patients anaesthetized with etomidate and halothane showed a significant increase in adrenaline and glucose concentrations not seen in the fentanyl group. Cardiopulmonary bypass was associated with marked increases in catecholamines in both groups.
-
Interstitial fluid pressure (IFP) and plasma colloid osmotic pressure (plasma COP) were measured in dogs following acute haemorrhage and following the infusion of saline, 10% dextra 40 in saline and 3% dextran 40 in lactated Ringer's solution. Exsanguination decreased IFP, plasma COP and total plasma protein and albumin concentrations, and increased plasma glucose concentration and osmotic pressure. A massive infusion of physiological saline increased IFP, and decreased plasma COP and total plasma protein and albumin concentrations. ⋯ When a 10% dextran 40 saline solution was used, there was a marked increase in plasma COP but a decrease in IFP. When 3% dextran 40 in lactated Ringer's solution was infused, IFP was little affected in the early stage, but gradually increased thereafter. Plasma COP increased slightly immediately after infusion, but remained near the pre-exsanguination value for at least 3 h.
-
Cyanide antidotes were given to dogs before an infusion of sodium nitroprusside 1.5 mg kg-1 for 1 h. Dogs given thiosulphate 75 mg kg-1 had significantly lower plasma and red cell cyanide concentrations while plasma thiocyanate concentrations were significantly increased in comparison with control. These changes were associated with only minimal disturbance of tissue oxygenation. ⋯ There was no evidence of a synergistic action between thiosulphate and hydroxocobalamin. The vascular response to nitroprusside was unchanged in the thiosulphate-treated dogs, but was significantly greater in those given hydroxocobalamin. The implications for prophylaxis and treatment of cyanide poisoning following nitroprusside overdose are discussed.