Circulatory Response to Intra-abdominal Manipulation During Ether Anesthesia in Man
Of 38 patients studied during a steady state of ether anesthesia before performance of the definitive phase of operation, hypotensive episodes were produced in 8 by deliberate intra-abdominal stimulation of various types. The production of hypotension was therefore not only unpredictable in the group as a whole, but it was also possible that a positive response in each case could have been mediated by a different circulatory mechanism. The protocol of these experiments was not designed either by method employed or time interval chosen to detect rapid or early changes responsible for the final steady-state measurements that were made. Arterial systolic, diastolic, mean, and pulse pressures decreased with a decline in pulse rate in several cases. As a result of a decreased stroke volume or slowing of the pulse, the cardiac output declined and was responsible for the pressure alterations observed. There was no directional change in the calculated overall peripheral resistance. The remainder of the circulatory measurements, including central venous pressure and central blood volumes, suggest that the circulatory changes are by no means simply explained and that vasodilation in peripheral vascular beds cannot be ruled out.
- © 1962 American Heart Association, Inc.