Minimal interruption of cardiopulmonary resuscitation for a single shock as mandated by automated external defibrillations does not compromise outcomes in a porcine model of cardiac arrest and resuscitation

Comparison Between 30:1 and 30:2 Compression-to-ventilation Ratios for Cardiopulmonary Resuscitation: Are Two Ventilations Necessary?

OBJECTIVES

Controversy is continuing over the need for ventilation and the optimal compression-ventilation (CV) ratio during cardiopulmonary resuscitation (CPR). The aim of this study was to comparatively elucidate the effect on hemodynamics and arterial oxygen saturation of a single ventilation relative to two consecutive ventilations during CPR in a dog model of cardiac arrest.

METHODS

Twenty mongrel dogs were divided into two groups. After 3 minutes of ventricular fibrillation (VF), the single-ventilation group received CPR with a 30:1 CV ratio, and the two-ventilation group received CPR with a 30:2 CV ratio, all with room air for 7 minutes. Thereafter, continuous chest compressions and intermittent ventilation at rate of 10 per minute were followed for both groups for 10 minutes. Hemodynamic parameters, arterial blood gas profiles, and variables from CPR were compared at baseline and at 5, 10, 15, and 20 minutes after induction of VF.

RESULTS

Hemodynamic parameters including aortic systolic and diastolic pressures, right atrial systolic and diastolic pressures, coronary perfusion pressure, end-tidal carbon dioxide tension, and arterial blood gas profiles including arterial oxygen tension, arterial oxygen saturation, and arterial carbon dioxide tension were not different between two groups during CPR. In the 30:1 group, the period of compression interruption was shorter and chest compression fraction was higher than that in the 30:2 group (6 sec/min vs. 10.9 sec/min, p < 0.001; 90.0% vs. 81.8%, p < 0.001).

CONCLUSIONS

CPR with a 30:1 CV ratio, compared to CPR with a 30:2 CV ratio, results in comparable arterial oxygenation saturation and hemodynamics.

RECOVER evidence and knowledge gap analysis on veterinary CPR. Part 7: Clinical guidelines

OBJECTIVE

To present a series of evidence-based, consensus guidelines for veterinary CPR in dogs and cats.

DESIGN

Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence and quality, and development of consensus on conclusions for application of the concepts to clinical practice. Questions in five domains were examined: Preparedness and Prevention, Basic Life Support, Advanced Life Support, Monitoring, and Post-Cardiac Arrest Care. Standardized worksheet templates were used for each question, and the results reviewed by the domain members, by the RECOVER committee, and opened for comments by veterinary professionals for 4 weeks. Clinical guidelines were devised from these findings and again reviewed and commented on by the different entities within RECOVER as well as by veterinary professionals.

SETTING

Academia, referral practice and general practice.

RESULTS

A total of 74 worksheets were prepared to evaluate questions across the five domains. A series of 101 individual clinical guidelines were generated. In addition, a CPR algorithm, resuscitation drug-dosing scheme, and postcardiac arrest care algorithm were developed.

CONCLUSIONS

Although many knowledge gaps were identified, specific clinical guidelines for small animal veterinary CPR were generated from this evidence-based process. Future work is needed to objectively evaluate the effects of these new clinical guidelines on CPR outcome, and to address the knowledge gaps identified through this process.