Premium
Cardiovascular Effects of Enflurane and Asphyxia during Long‐Term Beta 1 ‐Adrenoceptor Blockade
Author(s) -
HENRIKSSON B.Å.,
BIBER B.,
HÄGGENDAL J.,
LUNDBERG D.,
PONTÉN J.,
ROSÉN K. G.
Publication year - 1985
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1985.tb02216.x
Subject(s) - enflurane , metoprolol , medicine , anesthesia , chloralose , halothane , blood pressure
The haemodynamic effects of enflurane (1.7% and 3.4% expiratory concentrations) were investigated in sheep (n = 6) pretreated with an infusion of metoprolol (0.2 mg ˙ kg ‐1 ˙ h ‐1 for 5 days) and in control animals (n = 6). Chloralose was used as basal anaesthetic. A 90 s apnoea period was included in the experiment to evaluate further the possible side‐effects of long‐term metoprolol treatment in combination with enflurane anaesthesia. MAC 1.0 for enflurane in the sheep was found at 1.45% end‐tidal concentration by separate measurements. Before enflurane administration, the only significant differences between the two groups of animals were a lower systemic vascular resistance and a higher stroke volume during metoprolol treatment. Enflurane abolished these discrepancies in a dose‐dependent fashion and similar cardiovascular depression was observed in both groups of animals at 3.4% expiratory concentration of enflurane. Metoprolol did not significantly affect the hypertensive response to apnoea during chloralose anaesthesia alone. At enflurane 1.7% expiratory concentration the apnoea response was small and only the metoprolol‐treated animals showed a significant increase in left ventricular end‐diastolic pressure. We conclude that 5 days of pretreatment with metoprolol in the sheep model does not significantly impair cardiovascular performance during enflurane anaesthesia.