Comparison of Anesthetic Depth and Its Relationship with Hemodynamic Changes in Patients Candidate for Total Abdominal Hysterectomy Under General Anesthesia with Propofol or Isofluran Using Bispectral Index

Hemodynamic changes during surgery are initially controlled by changes in dosage of anesthetics. Decreasing the dose of anesthetics in order to cope with hypotension during surgery may reduce the anesthetic depth and increases the chance of awareness. This study was designed to investigate the depth of anesthesia in patients whose anesthtics is prescribed by controlling blood pressure and is aimed to investigate the possibility of reducing the depth of anesthesia during surgery.
In this study, females candidate for hysterectomy underwent general anesthesia according to specific inclusion criteria enrolled in two types of intravenous (propofol) or inhaled (isoflurane) anesthesia. The dose of maintenance anesthetic drugs were increased or decreased during the operation by the anesthetist technician (blinded to the depth of anesthesia) according to specified protocol. At defined intervals, depth of anesthesia was recorded by the anesthetist . Mean of obtained data were analyzed.
In addition to the weight and height similarity, there was no statistically significant difference in systolic, diastolic blood pressure and heart rate in two groups at intervals, between two groups. The median of recorded BIS, which showed depth of anesthesia, was not different in either of the two groups, and no patients during the operation reached the level of awakening and the number above 60.
The traditional method to control hemodynamic changes during surgery by changing the doses of maintenance drugs, does not result in severe changes in the depth of anesthesia and does not significantly increase the BIS to the awareness level.