Effect of anaesthetic technique on blood loss in termination of pregnancy.

Seventy-five patients were anaesthetized for termination of pregnancy by suction curettage using four methods of anaesthesia. Blood loss was measured with a haemoglobin dilution technique. The patients' opinion of the anaesthetic was recorded. Blood loss was unacceptably high with thiopentone, nitrous oxide and oxygen with trichloroethylene compared with the other three techniques which were: diazepam/pentazocine, paracervical block with incremental doses of methohexitone, thiopentone, suxamethonium and hyperventilation with nitrous oxide and oxygen, and ketamine with paracervical block. Postoperative side effects occurred least frequently in association with the diazepam/pentazocine technique.