This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Yokoo, N. Articles by Warner, D. S. Search for Related Content PubMed PubMed Citation Articles by Yokoo, N. Articles by Warner, D. S. Related Collections Critical Care Neuroanesthesia Complications

---

NEUROSURGICAL ANESTHESIA

Intraischemic Nitrous Oxide Alters Neither Neurologic Nor Histologic Outcome: A Comparison with Dizocilpine

Noriko Yokoo, MD^*, Huaxin Sheng, MD^*, Javier Mixco, BA, H. Mayumi Homi, MD^*, Robert D. Pearlstein, PhD, and David S. Warner, MD^*,,

Departments of *Anesthesiology, Surgery, and Neurobiology, Duke University Medical Center; and Duke University School of Medicine, Durham, North Carolina

Address correspondence and reprint requests to David S. Warner, MD, Box 3094, Duke University Medical Center, Durham, NC 27710. Address e-mail to warne002{at}mc.duke.edu

N-Methyl-D-aspartate receptor antagonism contributes to the anesthetic action of nitrous oxide (N₂O). We examined the effects of the N-methyl-D-aspartate antagonists N₂O and dizocilpine on outcome from filament occlusion of the middle cerebral artery (MCAO). Rats breathed 70% nitrogen/30% oxygen or 70% N₂O/30% oxygen during MCAO. A third group breathed 70% nitrogen/30% oxygen and was given dizocilpine (0.25 mg/kg IV). After 75 min of MCAO, the rats recovered for 3 or 14 days. Pericranial temperature was maintained at 37.5°C ± 0.2°C during ischemia and for 20 h postischemia. N₂O did not alter neurologic scores at 3 days (N₂O, 21 ± 6; nitrogen, 22 ± 8; P = 0.95; 0 = normal; 48 = maximal deficit; mean ± SD; n = 15) or 14 days (N₂O, 13 ± 6; nitrogen, 12 ± 6; P = 0.93; n = 15–16) postischemia. N₂O had no effect on infarct size at 3 days (N₂O, 162 ± 45 mm³; nitrogen, 162 ± 61 mm³; P > 0.99) or 14 days (N₂O, 147 ± 56 mm³; nitrogen, 151 ± 62 mm³; P = 0.99) postischemia. Dizocilpine treatment caused smaller infarcts (3 days: 66 ± 49 mm³, P < 0.0001 versus nitrogen; 14 days: 84 ± 50 mm³, P < 0.006 versus nitrogen) and reduced the neurologic deficit (3 days: 10 ± 10, P = 0.002 versus nitrogen; 14 days: 6 ± 7, P = 0.006 versus nitrogen). N₂O (70%) had no effect on either behavioral or histologic outcome from transient focal cerebral ischemia when compared with results in rats breathing 70% nitrogen. These results indicate that normobaric N₂O does not alter the response of rat brain to a focal ischemic insult.

IMPLICATIONS: Rats were subjected to temporary focal cerebral ischemia and allowed to recover for 3 days or 2 wk. There was no effect of intraischemic N₂O on histologic or behavioral outcome at either recovery interval, whereas the N-methyl-D-aspartate antagonist dizocilpine caused persistent improvement in both outcome measures.

This article has been cited by other articles:

				J. H. Abraini, H. N. David, E. T. MacKenzie, and M. Lemaire Postischemic Nitrous Oxide Alone Versus Intraischemic Nitrous Oxide in the Presence of Isoflurane: What It May Change for Neuroprotection Against Cerebral Stroke in the Rat Anesth. Analg., August 1, 2005; 101(2): 614 - 614. [Full Text] [PDF]

				D. S. Warner and N. Yokoo Postischemic Nitrous Oxide Alone Versus Intraischemic Nitrous Oxide in the Presence of Isoflurane: What It May Change for Neuroprotection Against Cerebral Stroke in the Rat Anesth. Analg., August 1, 2005; 101(2): 614 - 614. [Full Text] [PDF]