Comparison of the anaesthetic and haemodynamic effects of chlormethiazole and thiopentone
Christensen, J.H.; Andreasen, F.; Kristoffersen, M.B.
British Journal of Anaesthesia 55(5): 391-397
1983
ISSN/ISBN: 0007-0912 PMID: 6849724 Document Number: 197181
Two groups of 8 women (60-85 yr) undergoing gynecological operations of 50-130 min duration were compared. Anesthesia was induced with either thiopentone (mean 4.5 mg/kg) or chlormethiazole (mean 6.0 mg/kg) and maintained with N2O 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 per h and 27 .mu.mol/l) compared with 1.3 mg/kg per h (P < 0.01) and 16 .mu.mol/l respectively for thiopentone (P < 0.02). Impedance cardiography showed that cardiac output was decreased by 30-40% in the thiopentone group (P < 0.01), whereas no significant change was observed in the chlormethiazole group. Chlormethiazole anesthesia was followed by a significant increase (P < 0.02) in stroke volume. No correlations were found between the plasma concentrations and changes in the hemodynamic indices for either of the drugs.