Abstract
Intracranial hypertension represents a significant risk factor of poor neurological outcome in critically ill, specifically those with craniotrauma. Methods: In a porcine model of cardiac arrest (CA) the dynamics of intracranial pressure (ICP) was studied.
Threeminutes of untreated CA were followed by 5-minutes of cardiopulmonary resuscitation (CPR) with chest compressions and mechanical ventilation. No other interventions were allowed since out-of-hospital resuscitation was simulated.
Throughout the protocol the ICP, arterial and venous pressures and carotid blood flow were continuously recorded. Results: During cardiac arrest ICP increased to 27 +/- 4.8 mmHg, i.e. hypertensive values.
Mechanical chest compressions resulted in a transient ICP increase followed by a steady decline at approximately 2.25 mmHg/min. By five minutes of CPR intracranial pressure reached prearrest values despite significant elevation of central venous pressure (39 mmHg) and gradual decrease of arterial pressure and flow.
We hypothesize that cerebral autoregulation is capable of maintaining ICP even during failing circulation.