The performance of a hollow fibre artificial lung (,Capiox E,) was analysed by measurement of the 'parallel dead space , of the device under varying conditions in 21 patients. The efficiency with which carbon dioxide was exchanged was determined by the time available for equilibration between the blood and gas phases. When this equilibration coefficient was less than 12 seconds per litre of blood flow per litre of gas flow, there was a marked reduction in the efficiency of gas exchange. Under certain conditions, the 'counter-current' design of the device apparently permitted the clearance of carbon dioxide at a partial pressure greater than that which was found in the mixed venous blood. This anomalous behaviour may represent in vivo confirmation of the Haldane effect.

Epidural analgesia with morphine sulphate was administered to 130 patients. Of 96 patients with postoperative pain, 74 experienced good analgesia, 14 obtained a fair degree of pain relief, and in eight the method was unsatisfactory. Of the 34 non-operated patients 30 had good pain relief and the method failed in one. The most common cause of failure of analgesia was an incorrectly placed epidural catheter. Urinary difficulties and pruritus were encountered as the principal side-effects. One patient suffered depression of the level of consciousness following epidural drug administration and in one, epidural opiate appears to have contributed to hypotension.

No abstract

Alfentanil and fentanyl were compared as supplements to thiopentone, nitrous oxide, relaxant anaesthesia in a randomised, double blind trial carried out on 55 adult patients undergoing elective surgery. The fentanyl-treated patients resumed spontaneous ventilation more rapidly at the end of anaesthesia (3 minutes) than the alfentanil-treated group (5.1 minutes, p < 0.02). In other respects the drugs appeared indistinguishable. A computer model is used to explain why, despite the shorter elimination half-life, the alfentanil-treated patients did not awaken more rapidly than those in the fentanyl group.

An analysis of 200 consecutive patients treated by saphenous‐vein bypass grafting has been carried out. One patient died in hospital, and one died nine months after surgery. Some of the factors which predispose to postoperative complications can be defined preoperatively. These are unstable angina, multiple vessel disease, and impaired left ventricular function. The complications of postoperative infarction, low cardiac output, and arrhythmia were higher in the presence of these factors. The use of cardioplegia myocardial protection lessened the incidence of complications in patients with impaired left ventricular function. Early follow‐up revealed 96% of patients truly or virtually angina‐free. Three patients suffered infarction within nine months of operation.