Abstract 12120: Intracranial Pressure Increases Both During Mild Therapeutic Hypothermia and During Rewarming Period in Post Cardiac Arrest Patients

Abstract

Introduction: Elevation of intracranial pressure (ICP) may induce secondary brain injury and worsen the neurological outcome. Some studies on traumatic brain injury show that rapid rewarming can result in poorer outcomes contributory due to elevation of ICP. However, little is known about ICP during therapeutic hypothermia (TH) and rewarming period in post cardiac arrest patients. Hypothesis: We tested if there is occurrence of increased ICP during mild TH and rewarming period and whether it is related to outcome in patients resuscitated after cardiac arrest. Methods: Comatose patients resuscitated from cardiac arrest, treated with TH and ICP monitored were enrolled in the study. Surface cooling device was used for TH. Patients were maintained in target core temperature of 34 °C for 24 hrs. Thereafter, the temperature was regulated to increase to normothermia (37.0 °C) at the rate of 0.25 °C/hr. ICP and cerebral perfusion pressure (CPP) were monitored during the period. Cerebral Performance Category (CPC) scale was obtained 28 days later. Results: Data of 9 patients were analyzed (8 [89 %] men, age: 62 ± 17 years, cardiac origin 3 [33 %]/non-cardiac origin: 6 [67 %], CPC 1: 2 patients; CPC 2: 1 patient; CPC 3: 1 patient; CPC 4: 2 patients; CPC 5: 3 patients). ICP was 7.7 ± 4.4 mmHg at the beginning of TH and significantly elevated to 17.4 ± 13.3 mmHg at the end of TH (p = 0.03). ICP was 23.6 ± 19.1 mmHg at the end of rewarming which was higher than the end of TH (p = 0.04). At the end of rewarming, ICP value ranged in variety from 10 mmHg (CPC 1) to 68 mmHg (CPC 5). CPP was 81.3 ± 15.6 mmHg at the beginning of TH and was 72.1 ± 22.7 mmHg (p = 0.22) at the end of rewarming. All the cases with CPP less than 40 mmHg within 48 hrs died. Conclusions: ICP is increasing both during TH of target temperature 34°C and during rewarming at speed of 0.25 °C/hr in patients after cardiac arrest. Increment of ICP seems to be greater in cases with poorer outcome. CPP decrease was not usually observed and was limited to fatal cases.