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Effects of Cocaine in an Experimental Model of Traumatic Brain Injury
Author(s) -
McBeth Brian D.,
Stern Susan A.,
Wang Xu,
Mertz Michelle,
Zink Brian J.
Publication year - 2005
Publication title -
academic emergency medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.221
H-Index - 124
eISSN - 1553-2712
pISSN - 1069-6563
DOI - 10.1197/j.aem.2004.11.028
Subject(s) - medicine , traumatic brain injury , anesthesia , cerebral blood flow , cerebral perfusion pressure , cardiorespiratory fitness , saline , psychiatry
Abstract Background: Cocaine intoxication is found in a significant subset of emergency department (ED) patients presenting with traumatic brain injury (TBI). Objectives: To investigate the effects of acute cocaine intoxication on physiologic and metabolic parameters in a model of experimental TBI. Methods: Under inhalational anesthesia, swine were instrumented and subjected to fluid percussion TBI of 3 atm. Two groups were studied: TBI and cocaine ( n = 7) and TBI only ( n = 7). Two sequential doses of cocaine hydrochloride were administered intravenously to the animals receiving cocaine: 4 mg/kg 10 minutes prior to injury and 2 mg/kg 1 minute prior to injury. Control animals received normal saline. Cardiorespiratory and cerebral physiologic data were monitored for 180 minutes following injury. Cerebral blood flow (CBF) was measured using dye‐labeled microspheres. Serum cocaine levels were measured by gas chromatography/mass spectrometry. Results: Mean (±SD) cocaine levels at the time of injury were 1,771 (±403) ng/mL. All animals survived the 180‐minute observation period. There was a trend toward higher intracranial pressure (ICP) in the control (15.4 ± 8.2) vs. cocaine‐treated (11.1 ± 5.8) animals, although this did not reach statistical significance (p = 0.18). Cerebral venous lactate (CVL) levels also trended higher in the control (1.14 ± 0.22) vs. cocaine‐treated (0.91 ± 0.19) groups (p = 0.06). Cerebral perfusion pressures (CPPs), however, did not differ between groups. The CBF values decreased significantly from baseline in both groups but were not different between groups. Conclusions: Cocaine‐intoxicated animals subjected to TBI showed no significant difference in primary outcome measures of CPP or CBF, although a nonsignificant trend toward lower ICP was noted. Overall, acute cocaine intoxication did not adversely affect the physiologic parameters examined in this TBI model.