Study Design

Reduced Quality Factors

0 = no serious, - = serious,

- - = very serious

Positive Quality Factors

0 = none, + = one, ++ = multiple

Dichotomous Outcome Summary

Non-Dichotomous Outcome Summary

Brief description

Overall Quality

High, moderate, low,
very low, none

No of studies

Study Type

RoB

Indirectness

Imprecision

Inconsistency

Large Effect

Dose-Response

Confounder

# Intervention with Outcome

# Control with Outcome

RR (95% CI)

Outcome: Favorable neurologic outcome, Survival to discharge, ROSC, Surrogate markers of perfusion

0

Introduction

There is evidence that performing high-quality chest compressions for 2 minutes before pausing to analyze the ECG rhythm during ALS improves outcome compared to stopping compressions more frequently.[ref[1]] Current human and previous veterinary guidelines have recommended changing chest compressors every 2 minutes based on the likelihood of rescuer fatigue with longer periods of continuous compressions.[ref] The ideal length of continuous chest compression cycle for dogs and cats is unknown.

Consensus on science

For the most critical outcomes of FNO, Survival to discharge, ROSC, and Surrogate markers of perfusion, we identified no studies that address the PICO question.

There are currently no studies that directly address the question of specific timing for interruptions to chest compressions to diagnose the heart rhythm for any outcome of interest. There is evidence that the frequency and duration of interruptions to chest compressions can impact the outcome following CPR. In experimental pig studies, it has been shown that it takes approximately 60 seconds of continuous chest compressions to generate and maintain maximal CPP and pauses in chest compressions are associated with immediate decrease in CPP.1,2 There is some evidence from human clinical trials that a period of BLS CPR is beneficial prior to performing a rhythm check. In a prospective, observational analysis of witnessed human arrests, providing 2-minute (200 chest compressions at 100 compressions/min) blocks of uninterrupted chest compressions, pausing only to perform a rhythm check ± defibrillation, was associated with significant improvement in survival and neurological state when compared to a cohort of patients treated using the 2000 American Heart Association guidelines in which chest compressions were frequently interrupted.3 Mosier et al. reported similar results in a retrospective analysis of the use of the same protocol.4

Treatment recommendation

In intubated dogs and cats undergoing CPR, we recommend delivering CPR in 2-minute cycles of continuous high-quality chest compressions. (strong recommendation, expert opinion)

Justification of treatment recommendation

Recommendations for the 2-minute interval follow from the evidence that more frequent interruptions of chest compressions have been associated with worse outcome, while personnel may become fatigued when performing manual chest compressions for longer than 2 minutes. As a pause is needed for changing of compressors, it is a logical time to check the ECG.

Knowledge gaps

The optimal cycle duration of continuous high-quality chest compressions during CPR in dogs and cats is unknown.

It is unknown whether the 2-minute chest compression cycle should be paused for patient and ECG evaluation when there is a marked increase in ETCO2 or another compelling sign of ROSC.