Prevention of succinylcholine induced hyperkalemia by neurolept anesthesia and hexafluorenium in anephric patients.

Forty patients, half of them with normal kidney function, the other half anephric were included in the study. All received diphenhydramine, meperidine and atropine for premedication and droperidol, fentanyl, N2O and O2 for anesthesia. For endotracheal intubation and further relaxation 0.3 mg/kg hexafluorenium, followed in 5 minutes by 0.2 mg/kg succinylcholine were given intravenously. Anesthesia was maintained by 0.5 micrograms/kg increments of fentanyl, muscle relaxation by increments of 0.15 mg/kg or less hexafluorenium and 0.2 mg/kg or less succinylcholine, depending on the surgical time requirements. The drop in serum potassium concentration was sustained and similar in both groups. In the anephric group the drop after induction of neurolept anesthesia was statistically significant. The concentration remained low in both groups over the entire observation period. Unchanged serum sodium excluded hemodilution and the fact that there was no significant change in PvCO2 and pH mitigates against alkalosis as the cause for the observed drop. The anesthesia and muscle relation, as described, appears to be a suitable and hazard free alternative to other techniques.

Prevention of suxamethonium-induced changes in serum potassium concentration by hexafluorenium. Is their combined use justified?

Sixty patients, none of whom was suffering from renal failure, received neurolept anaesthesia. They were divided into six groups of 10 patients each. Groups I and IV, II and V, and III and VI were given suxamethonium 0.2, 0.6 and 1.0 mg kg-1 respectively. Groups IV-VI were pretreated with hexafluorenium 0.3 mg kg-1. The serum potassium concentration decreased significantly after the induction of anaesthesia and also following the administration of hexafluorenium. Neither suxamethonium 0.2 mg nor 0.6 mg kg-1 with or without hexafluorenium restored the potassium concentration to the control value. Suxamethonium 1.0 mg kg-1 alone caused the serum potassium to increase to values greater than control; hexafluorenium attenuated this effect. The combination of hexafluorenium and suxamethonium may be of benefit in patients who are anephric or are in chronic renal failure.

Role of the chemoreceptor trigger zone in cyclopropane induced emesis in dogs.

Inhalation of cyclopropane in dogs, by the closed circuit method, for a fixed period, produced an emetic response during recovery from anaesthesia. Bilateral surgical ablation of the emetic chemoreceptor trigger zone of the area postrema rendered the dogs refractory to several times (3-6) the threshold emetic dose of cyclopropane.