The Effect of Isoflurane, Enflurane and Propofol on Extradural Pressure

Kil, Ho Yeong; Hwang, Sung Mi; You, Hong Seong; Lee, Seung Joon; Lee, Sung Woo

Abstract

BACKGROUND: Intracranial pressure monitoring gives useful information in many neurosurgical conditions. And, measurement of the extradural pressure has always seemed an attractive alternative for intracranial pressure (ICP) monitoring. Also, choice of anesthetic agent may affect the management of intracranial pressure. The aim of this study was to evaluate the effect of propofol, isoflurane and enflurane on ICP by measuring lumbar epidural pressure.
METHODS
Forty seven adult patients scheduled for elective orthopedic surgery were randomly allocated to three groups according to anesthetic agent for maintenance: group I (isoflurane, n = 15), group P (propofol, n = 17), and group E (enflurane, n = 15). Premedication was performed by intramuscular injection of 0.2 mg of glycopyrrolate. ECG, noninvasive blood pressure monitoring device, and pulse oximeter was used for patient monitoring. A twenty gauge epidural catheter was placed 3-4 cm above the insertion site (L3-4). The pressure monitoring kit was connected to a catheter and was zeroed at the middle ear level. Epidural pressure was cheked every 10 min and compared to the control and among groups during maintenance of anesthesia.
RESULTS
Demographic data showed no difference among groups. Preinduction epidural pressures were 7.4 +/- 1.4, 7.1 +/- 1.1, 7.2 +/- 1.0 mmHg in group P, I and E, respectively. During maintenance, group I did not show any statistically significant changes in epidural pressure, but pressure was reduced in group P and elevated in group E significantly 100 min after administering the maintenance anesthetics.
CONCLUSIONS
Among the three anesthetic agents, propofol may be a more suitable maintenanace anesthetic agent for patients with increased ICP.