An anaesthetic technique for laryngeal microsurgery is described and evaluated using intravenous propofol infusion and topical lignocaine with the patient breathing spontaneously without an endotracheal tube. Eighty adult patients divided into two groups according to their ASA status (Group A; 58 ASA I and Il; Group B; 22 ASA III and IV) were analysed. Operating conditions were good in all but one case. Good anaesthesia was achieved in about 70% of patients. The requirement for propofol was less in Group B. Blood pressures decreased signifcantly following induction (P < 0.001) but returned towards the preoperative values after ten minutes in Group A patients whereas the recovery was slower in Group B. Apnoea occurred on induction in about 40% of patients overall. P aeo2 showed a similar small increase in both groups. Oxygenation was adequate. The results show that propofol as an infusion in this simple tubeless technique is satisfactory. As the technique was considered potentially hazardous in those patients with upper airway obstruction, such patients were not included in this study.

Two disposable condenser humidifiers were evaluated in nine ventilated intensive care patients. The Portex "Humid Vent" delivered end-inspired absolute humidifies oj 22-26.3 g/m3 at endinspired temperatures oj 27-28.3 cc. Corresponding humidities and temperatures with the Servo "Humidifier 150" were higher and were constant, at 27.7-29 g/m3 and 29.3-29. rc respectively. These disposable devices can be used jor humidification in intensive care, but only jor patients breathing room air, or on a short term basis.

Increases in endotracheal tube cuff volume and pressure during anaesthesia have been reported to be due to the diffusion of nitrous oxide into the cuff. This study compared cuff volume and pressure changes in anaesthetized intubated patients who were ventilated with those aI/owed to breath spontaneously. The cuffs of Magill red rubber endotracheal tubes were inflated with either air or Cl nitrous oxide-oxygen mixture.Serial pressure and Folume recordings confirmed that both parameters increased when the cuff was inflated with air. The increase in cuff pressure was however, greater during intermittent positive pressure I'entilation than for spontaneous respiration. There were no significant changes II'hen the cuff was inflated with the nitrous oxide-oxygen mixture.

Lithium toxicity following frusemide administration is reported. The clinical features, possible causative mechanisms, and mallagemellt of the intoxication are discussed.