Intracranial pressure response to severe head injury induced apnea and catecholamine surge

Background Apnea and catecholamine surge have been known sequelae in the first few minutes of postexperimentally induced severe head injury for over a century. However, the intracranial pressure (ICP) response to these two pathophysiologic processes is poorly understood. Methods We used the rat fluid percussion head injury model to study apnea and catecholamine surge separately and in combination on measured ICP response. Results The three experimental groups of apnea, hypertensive surge, and both combined revealed significantly different ICP responses with markedly elevated pressures correlating closely with mean arterial blood pressure. Conclusion ICP and mean arterial blood pressure correlate closely in the first few minutes after head injury in the absence of space-occupying hematomas, and may initiate pathophysiologic sequelae that can only be treated by earlier medical intervention at the scene.