Anesthesiology 2003; 98:1085–90 © 2003 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc. The Effects of Isoflurane and Desflurane on Intracranial Pressure, Cerebral Perfusion Pressure, and Cerebral Arteriovenous Oxygen Content Difference in Normocapnic Patients with Supratentorial Brain Tumors Marcial Fraga, M.D.,* Pablo Rama-Maceiras, M.D.,* Sara Rodiño, M.D.,* Humberto Aymerich, M.D.,* Pilar Pose, M.D.,† Javier Belda, Ph.D.‡ Background: Desflurane is a volatile anesthetic agent with low solubility whose use in neurosurgery has been debated because of its effect on intracranial pressure and cerebral blood flow. The purpose of this study was to determine the variations on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) as well as on cerebral arteriovenous oxygen content dif- ference (AVDO 2 ) in normocapnic patients scheduled to undergo removal of supratentorial brain tumors with no evidence of mass effect during anesthesia with isoflurane or desflurane. Methods: In 60 patients scheduled to undergo craniotomy and removal of supratentorial brain tumors with no evidence of midline shift, anesthesia was induced with intravenous fenta- nyl, thiopental, and vecuronium and was maintained with 60% nitrous oxide in oxygen. Patients were assigned to two groups randomized to receive 1 minimum alveolar concentration isoflurane or desflurane for 30 min. Heart rate, mean arterial pressure, intraparenchymal ICP, and CPP were monitored con- tinuously. Before and after 30 min of continuous administration of the inhaled agents, AVDO 2 was calculated. Results: There were no significant differences between groups in heart rate, mean arterial pressure, ICP, and CPP. ICP measure- ments throughout the study did not change within each group compared to baseline values. Mean arterial pressure decreased significantly in all patients compared to baseline values, changing from 105  14 mmHg (mean  SD) to 85  10 mmHg in the isoflurane group and from 107  11 mmHg to 86  10 mmHg in the desflurane group (P < 0.05 in both groups). CPP also decreased within each group compared with baseline values, changing from 95  15 mmHg to 74  11 mmHg in the isoflurane group and from 95  16 mmHg to 74  10 mmHg in the desflu- rane group (P < 0.05 in both groups). Cerebral AVDO 2 decreased significantly in both groups throughout the study, changing from 2.35  0.77 mM to 1.82  0.61 mM (mmol/l) in the isoflu- rane group (P < 0.05) and from 2.23  0.72 mM to 1.94  0.76 mM in the desflurane group (P < 0.05), without differences between groups. Conclusions: The results of this study indicate that there are no variations on ICP in normocapnic patients undergoing re- moval of supratentorial brain tumors without midline shift, as they were anesthetized with isoflurane or desflurane. CPP and cerebral AVDO 2 decreased with both agents. ONE of the objectives in neurosurgical procedures is to achieve an early recovery after the anesthesia to facilitate the neurologic evaluation of the patients. Desflurane is a volatile anesthetic agent with lower solubility than isoflurane 1 and with faster recovery after prolonged an- esthesia. 2,3 Therefore, it may be an attractive choice for this type of procedures, especially when its duration is prolonged. However, the use of desflurane in neurosur- gery has been debated because of its theoretical capacity to promote cerebral vasodilatation, which can jeopar- dize cerebral hemodynamics as it increases intracranial pressure (ICP) or lumbar cerebrospinal fluid pressure (CSFP). This increment of the CSFP has been demon- strated both in animals 4–6 and in hypocapnic patients. 7 Some studies in normocapnic patients also seem to con- firm this theory, but the observed effects on CSFP were common to isoflurane and desflurane. 8 The monitoring of cerebral arteriovenous oxygen con- tent difference (AVDO 2 ) has been used as a parameter of assessment in the relation between cerebral metabolic oxygen requirement (CMRO 2 ) and cerebral blood flow (CBF): AVDO 2 = CMRO 2 /CBF. 9,10 The aim of this study was to determine the variations in ICP, mean arterial pressure, and cerebral perfusion pressure (CPP) as well as to determine the AVDO 2 in normocapnic and normothermic patients without mid- line shift in the cranial computerized tomography (CT) scan who were scheduled to undergo removal of supra- tentorial mass lesions during anesthesia with isoflurane or desflurane. Materials and Methods After obtaining approval from the investigation com- mittee of our institution (Complejo Hospitalario Juan Canalejo, A Coruña, Spain) and written informed con- sent, 60 patients with American Society of Anesthesiol- ogists physical status II or III were studied. Patients who were aged between 18 and 70 yr, had supratentorial mass lesions, were scheduled for elective surgery (non- urgent), had 15 points on the Glasgow Coma Scale, and did not have a midline shift of greater than 5 mm on CT scan were included. Premenopausal women with posi- tive pregnancy tests, patients with serious cardiovascular or respiratory diseases, obese patients (weight of over 25% of their recommended weight), those who con- * Staff Anesthesiologist, † Chairman, Department of Anesthesiology, Complejo Hospitalario Juan Canalejo. ‡ Chairman, Department of Anesthesiology, Hospi- tal Clínico Universitario de Valencia, Valencia, Spain. Received from the Department of Anesthesiology and Perioperative Medicine, Complejo Hospitalario Juan Canalejo, A Coruña, Spain. Submitted for publication August 2, 2002. Accepted for publication December 9, 2002. Support was provided solely from institutional and/or departmental sources. Presented in part at the 8th annual meeting of the European Society of Anaesthesiologists, Vienna, Austria, April 1– 4, 2000. Address reprint requests to Dr. Rama-Maceiras: Department of Anesthesiology and Perioperative Medicine, Complejo Hospitalario Juan Canalejo, Xubias de Arriba 84, 15006, A Coruña, Spain. Address electronic mail to: prmaceiras@wanadoo.es. Individual article reprints may be purchased through the Journal Web site, www.anesthesiology.org. Anesthesiology, V 98, No 5, May 2003 1085 Downloaded from http://pubs.asahq.org/anesthesiology/article-pdf/98/5/1085/406842/0000542-200305000-00010.pdf by guest on 20 November 2021