Cardiac and respiratory effects of assisted respiration during inhalation narcosis in cattle
Becker, M.; Walti, R.
Schweizer Archiv für Tierheilkunde 122(5): 287-299
1980
ISSN/ISBN: 0036-7281 PMID: 7403838 Document Number: 161881
Ten cows were anaesthetized (halothane, N2O and O2) for 150 minutes, respiration being spontaneous, and the effects on the ECG, blood pressure and acid base balance measured. One week later the process was repeated using a pressure-controlled respirator. Differences in heart rate and in blood pressure were unimportant. Under spontaneous breathing, the ECG showed lengthening of systole at the expense of diastole, which could result in myocardial fatigue. There was also considerable respiratory acidosis which had to be compensated. No such effects were observed when the respirator was used. A respirator is therefore regarded as obligatory during long inhalation anaesthesia.