Abstract 204: Intracranial Pressure During Compression-Only and Compression-Ventilation CPR in a Porcine Model of Ventricular Fibrillation
Introduction: Recent guidelines recommend compression-only CPR for bystander response to adults who experience sudden cardiac arrest. However, gasping/apnea is known to cause hypercapnia which increases intracranial pressure (ICP) affecting cerebral perfusion. We hypothesized, that compression-only CPR would significantly increase ICP compared to compression-ventilation CPR. The aim of the study was to compare ICP values during different means of CPR (no-CPR vs. compression-only CPR vs. compression-ventilation CPR) in a porcine model of ventricular fibrillation (VF).
Methods: We prospectively studied 14 anesthetized domestic pigs (32 ± 2 kg). ICP was measured via brain intraparenchymal probe Codman MicroSensor Transducer (Codman, Raynham, MA, USA). Cerebral perfusion pressure was calculated according to the formula CPP = MAP — (ICP + CVP). VF was induced with an alternating current 5–10 V using intra-cardiac pacing lead. After 5 min of untreated VF, chest compressions were provided using an AutoPulse resuscitation system (Zoll Medical, Chelmsford, MA, USA) simulating compression-only CPR for 5 min, followed with compression-ventilation CPR (compression-ventilation ratio of 30:2, FiO2=1.0, VT 8 mL·kg-1) for the next 5 min. Differences were analyzed using two-way ANOVA for repeated measurements. Fisher's LSD test was used for post hoc testing to identify the differences. P-value lower than 0.05 was considered statistically significant.
Results: Intracranial pressure (mean ± SD) during pre-arrest period, untreated VF, compression-only CPR, and compression-ventilation CPR was 7.0 ± 3.9, 14.5 ± 3.6, 11.0 ± 4.1, and 10.1 ± 3.4 mmHg respectively. Cerebral perfusion pressure measured in the same periods was 55.1 ± 9.2, −13.4 ± 4.2, 16.8 ± 4.0, and 18.7 ± 4.3 mmHg respectively. There were no statistical differences between periods of compression-only CPR compared to compression-ventilation CPR (P = 0.30 for ICP, and P = 0.35 for cerebral perfusion pressure).
Conclusion: Compression-only CPR did not lead to increase of intracerebral pressure compared to compression-ventilation CPR in this porcine model of ventricular fibrillation.
- © 2010 by American Heart Association, Inc.