Objective: To report on the effects of cardiopulmonary resuscitation (CPR) instituted immediately after a cardiac arrest on cerebral perfusion pressure (CPP) and cerebral tissue oxygen tension (PbrO(2)).
Design: Case report.
Setting: ICU of a university hospital.
Patient: A head-injured 17-year-old man submitted to multimodal neurological monitoring underwent sudden cardiac arrest and successful CPR.
Interventions: External chest compression, 100% oxygen ventilation, volume expansion and standard ACLS protocols.
Measurements and results: Heart rate, ECG, mean arterial blood pressure (MABP), ETCO(2), PaO(2), intracranial pressure (ICP), CPP and PbrO(2) were continuously monitored during CPR and data recorded at 15-s intervals by a dedicated personal computer. At the onset of the cardiac arrest, PbrO(2) decreased to zero. The institution of CPR resulted in a progressive increase of MABP, CPP and PbrO(2). Assuming, on the basis of previous experimental and clinical reports, 8 mmHg PbrO(2) as a possible ischaemic/hypoxic threshold value, during the first 6.5 min of CPR, PbrO(2) values were below this threshold (range 0-7 mmHg) and CPP values were <25 mmHg for 81.5% of the time. In the following 5.5 min, more efficient CPR generated CPP values >25 mmHg for 77.3% of the time. These values were associated with a PbrO(2) >8 mmHg (range 8-28 mmHg) at all times.
Conclusions: In the clinical setting of a witnessed cardiac arrest, immediate institution of CPR can be effective in generating PbrO(2) values above a supposed ischaemic/hypoxic threshold when CPP is >25 mmHg. PbrO(2) monitoring by the Licox system is sensitive and reliable, even at low values, and can be suitable for evaluating cerebral oxygenation during experimental CPR.