A 33-year-old man was found to have early renal failure in 1973 when he presented with hypertension and albuminuria. In April 1976 he developed congestive cardiac failure and required peritoneal dialysis: maintenance haemodialysis commenced in June 1976 but because of accelerated hypertension, which was not controlled by 8-adrenoceptor blocking drugs in high doses, he underwent bilateral nephroureterectomy 2 months later. At this operation an aneurysm arising from the front of the abdominal aorta was noted. In December 1976 the patient required a laparotomy for intestinal obstruction and the aneurysm was found to have increased in size. Repair of this aneurysm was scheduled as an elective procedure.On examination the patient was a lean man of 66 kg with a Brescia-Cimino shunt in the left arm: the only abnormal signs were of left ventricular hypertrophy. Haemodialysis was arranged for 4 of the last 5 pre-operative days: the patient presented for anaesthesia with a serum potassium of 3.9 mmols/litre and a packed cell volume of 35%. Eight units of fresh blood drawn from donors on the morning of surgery were crossmatched.Premedication with papavereturn 15 mg and hyoscine 0.3 mg by subcutaneous injection produced little sedation. In the anaesthetic room the patient's left arm was padded. The right brachial artery and right internal jugular vein were cannulated and connected to pressure transducers. An intravenous drip was set up into a large vein on the dorsum of the right hand.Anaesthesia was induced with thiopentone 325 mg and pancuronium 6 mg. The onset of muscle relaxation was much slower than anticipated and was probably a reflection of the cardiovascular effects of the volume depletion achieved by dialysis. The patient was ventilated using a Bain circuit with the fresh gas flow adjusted so as to achieve normocapnia.' The analgesic effect of the premedication required supplementation by a single dose of fentanyl (100 pg) and one increment of pancuronium (1 mg) was required during the 3-h procedure.The aneurysm was resected and the aorta closed without the need for either a Dacron patch or a trouser graft. The total blood loss was 1140 ml and fluid replacement comprised 1 litre of fresh blood and 350 ml of 5 % dextrose. There were no major changes in blood pressure throughout the procedure and the central venous presrire (CVP) remained steady at 7 cmH20.At the end of the operation reversal of neuromuscular blockade was achieved without difficulty using atropine 1.2 mg and neostigmine 3.75 mg and the patient was comfortable and alert in the recovery room. One hour later, however, he became sweaty, his blood pressure fell to 70/40 mmHg and the CVP was -1 cmH20. Physiological saline 500 ml was rapidly infused and the patient's condition improved over the next 15 min with restoration