BackgroundAlthough Cocaine use is common in trauma victims, little is known about how cocaine affects the cardiovascular response to trauma and associated blood loss. This study determined the effect of chronic cocaine use on the cardiovascular response to hemorrhage in awake and anesthetized sheep.MethodsThe hemodynamic and acid-base responses to graded hemorrhage were determined in awake and anesthetized sheep at baseline and after 15 and 18 days of chronic cocaine exposure.ResultsChronic cocaine exposure resulted in a moderate paradoxical bradycardic response to hemorrhage in awake sheep, but did not otherwise alter the hemodynamic response to hemorrhage. In anesthetized animals, cocaine exposure impaired the ability to maintain mean arterial pressure and cardiac output during hemorrhage, and resulted in a marked paradoxical bradycardic response to hemorrhage.ConclusionsChronic cocaine exposure did not have an important effect on the cardiovascular response to hemorrhage in awake sheep. However, in anesthetized sheep, chronic cocaine exposure diminished the compensatory cardiovascular response to graded hemorrhage.