Cyclopropane and Caesarean section.

In a prospective study 589 patients were anaesthetized by the inhalation of cyclopropane 40% for 2--3 min. Relaxation was provided with suxamethonium and anaesthesia was maintained with cyclopropane 7.5%. The series was divided into four groups: patients in optimal condition (96 elective (group 1), 164 emergency (group 3)) and those not in optimal condition (75 elective (group 2), 254 emergency (group 4)). All infants from groups 1 and 3 had high Apgar scores, and all survived. Infants in groups 2 and 4 had lower Apgar scores, eight and 96 respectively were depressed, and 10 and 20 died because of obstetric and neonatal factors unrelated to the anaesthesia. Respiratory distress syndrome (RDS) developed in 44 infants. Among 29 infants in whom the birth weight was less than 2.5 kg the mortality was 31%, whereas no death occurred in mature infants. RDS was significantly more frequent after elective than after emergency surgery. Neonatal depression was independent of the length of the induction-delivery interval, which averaged 13.3 min. The frequency of awareness was 1.5%.

Hepatitis following thiopentone. A case report.

A patient developed pyrexia and jaundice following repeated anaesthesia. The evidence suggests that thiopentone was the causative agent. This incident emphasizes the need for caution in associating jaundice and hepatitis with halothane in patients who have received thiopentone and halothane.

Comparison of the anaesthetic and haemodynamic effects of chlormethiazole and thiopentone.

Two groups of eight women (60-85 yr) undergoing gynaecological operations of 50 to 130 min duration were compared. Anaesthesia was induced with either thiopentone (mean 4.5 mg kg-1) or chlormethiazole (mean 6.0 mg kg-1) and maintained with nitrous oxide and pethidine in combination with the drug used for the induction. The hourly maintenance dose and the plasma concentration determined at equilibrium were greater for chlormethiazole (means 4.7 mg kg-1 h-1 and 27 mumol litre-1) compared with 1.3 mg kg-1 h-1 (P less than 0.01) and 16 mumol litre-1 respectively for thiopentone (P less than 0.02). Impedance cardiography showed that cardiac output was decreased by 30-40% in the thiopentone group (P less than 0.01), whereas no significant change was observed in the chlormethiazole group. Chlormethiazole anaesthesia was followed by a significant increase (P less than 0.02) in stroke volume. No correlations were found between the plasma concentrations and changes in the haemodynamic indices for either of the drugs.

Chlormethiazole (Heminevrin), pethidine and nitrous oxide as compared to halothane for general anesthesia.

The anaesthetic and postanaesthetic course in a group of gynaecological patients anaesthetized with chlormethiazole (Heminevrin) was investigated and the results compared to a similar group of patients anaesthetized with halothane. Both drugs were used as the main anaesthetic agent in the respective regimes, supplemented by nitrous oxide/oxygen and muscle relaxants. Because chlormethiazole is devoid of analgetic effects, the importance of using pethidine in combination with chlormethiazole is emphasized. An advantage of using chlormethiazole is that it can serve as both an induction and maintenance agent. The plasma concentrations of chlormethiazole were studied in seven patients. For induction, the mean concentration was 4.5 micrograms/ml. The mean concentration on waking at the termination of operation was 1.3 micrograms/ml. No serious side effects were encountered in either treatment. The results suggested that chlormethiazole in combination with an analgetic drug and nitrous oxide could be suitable in elderly patients, although occasionally less effective in the young.