Canadian Anaesthetists' Society journal最新文献

The management of a patient with severe airway obstruction secondary to a thyroid mass is reported. When breathing room air the patient appeared in severe respiratory distress but when inspiring 22 per cent oxygen in helium she reported almost instantaneous relief and there was a marked decrease in respiratory rate, and increase in tidal volume and arterial oxygen tension. This improvement was to be expected because in situations where turbulent flow predominates a decrease in the density of inspired gases will result in an increase in flow rates. Contrary to established dogma a marked improvement was sustained when the patient was breathing 50 per cent oxygen in helium. The concentration of oxygen in helium was adjusted to obtain subjective relief for the patient in conjunction with adequate oxygenation.

A case of venous air embolism occurring during liver resection is reported. Diagnosis was made early from the continuous recording of pulmonary artery pressure. The aetiology was neither surgical nor an obvious disconnection of a venous line. It was caused by a blockage of the blood filter, resulting in subambient pressure between the filter and a peristaltic pump, leading to aspiration of numerous small air bubbles. The clinical course after replacement of the defective material was uneventful, except for transient postoperative pulmonary oedema.

Three cases of trismus caused by oropharyngeal sepsis are described where fibreoptic-assisted awake intubation using an oral airway intubator and nebulised lidocaine was safely and successfully achieved.

The effect of nalbuphine on common bile duct (CBD) pressure was studied by measurements through T-tubes on the first and second postoperative days after cholecystectomy and choledochotomy. Nalbuphine in a dose of 0.25 mg X kg-1 was injected intramuscularly in 11 patients, and changes in biliary pressure, heart and respiratory rate, blood pressure, and arterial blood gases were recorded during the subsequent four hours. The patients were free of pain, had stable common bile duct pressures and did not have any statistically significant changes in their vital signs. These results are similar to our previous observations during perioperative intravenous injection of nalbuphine. It is suggested that nalbuphine does not significantly change, or even may relax, the sphincter of Oddi, and can therefore be recommended as a safe analgesic in the postoperative period after extrahepatic biliary surgery.

A critical analysis of the arterial/alveolar oxygen tension ratio (a/APO2) is presented by rearranging the terms of the pulmonary shunt equation. The influence of the shunt and inspired oxygen concentration on a/APO2 are illustrated. It is shown that, despite reports to the contrary, a/APO2 varies with F1O2, particularly at high shunt levels.

To investigate the effect of dose and concentration of rectal methohexitone for induction of anaesthesia, 60 children (ASA physical status 1 or 2) undergoing outpatient surgery were studied. Each child was randomly assigned to receive one of three rectal solutions (each containing atropine 0.02 mg X kg-1): Group A - ten per cent methohexitone, 25 mg X kg-1 (n = 20); Group B - ten per cent methohexitone, 15 mg X kg-1 (n = 20); or Group C - one per cent methohexitone, 15 mg X kg-1 (n = 20). After induction of anaesthesia, or a maximum period of 20 minutes following rectal administration of methohexitone, halothane, nitrous oxide, and oxygen were administered by mask. The time to induction of anaesthesia, complications, postanaesthetic recovery scores, and recovery time did not differ significantly among the three groups. The incidence of failed inductions did not differ significantly between Group A (zero per cent) and Group C (ten per cent) but both were significantly less than Group B (45 per cent) (p less than 0.05). Heart rate increased significantly between 10 and 30 minutes after rectal administration of methohexitone and atropine. The authors conclude that ten per cent rectal methohexitone 25 mg X kg-1 and one per cent rectal methohexitone 15 mg X kg-1 are equally effective for induction of anaesthesia in children and both are significantly more effective than ten per cent methohexitone 15 mg X kg-1.