Cardio-respiratory effects of nitrous oxide:oxygen:halothane anaesthesia administered to dental outpatients in the upright position

The cardio-respiratory responses of fifty-three healthy dental patients receiving 30% oxygen with nitrous oxide and halothane whilst seated upright are reported. A high degree of sympathetic autonomic activity was noted with considerable lability of the blood pressure and pulse rate. Hypoxaemia caused by respiratory obstruction, unrecognised by the anaesthetist, occurred in approximately 20% of patients at the time of insertion of the prop or pack and during removal of teeth.

Identification and quantitation of hypersensitivity reactions to intravenous anaesthetic agents

It is not possible to distinguish between direct pharmacological effects and immune-mediated hypersensitivity reactions by clinical observation alone and errors may occur in the absence of laboratory tests. A convenient and simple test is the measurement of plasma complement C3 consumption and conversion in sequential blood samples taken at intervals over the 24 h following an adverse response.

Subanaesthetic dosage of Althesin as a sedative for conservative dentistry. A controlled trial

A randomized partial cross-over clinical trial of two intravenous techniques for outpatient conservative dentistry was performed in 61 patients. Subanaesthetic incremental doses of Althesin were used at 52 sessions and a single sedative dose of diazepam at 45 sessions. Each technique produced similar cardiovascular and respiratory changes. With Althesin, recovery after operation was more rapid and there was some evidence of a stronger anxiolytic effect and of less frequent and less severe thrombophlebitis. In contrast, Althesin was sometimes associated with jaw tremor or shivering and was less frequently mentioned by those patients who expressed a strong preference for one of the two techniques.

Althesin infusion for cardiac catheterisation

A trial of a continuous intravenous infusion of Althesin is described for sedation during cardiac catheterisation, both for children and adults. The conditions produced for the procedure were very satisfactory. The advantages and problems of its use are discussed. The technique justifies further trials.