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 neurological outcome, survival to discharge, ROSC - no studies identified

0

N/A

Outcome: Time to completion of first CPR cycle

2

EXP

0

- -

0

0

0

0

0

Two experimental, simulator-based studies found that the CAB approach had a shorter time to completion of the first resuscitation cycle compared with the ABC approach

Very low

Introduction

High quality chest compressions are considered essential for positive CPR outcomes. There has been an emphasis on shortening the time to commencement of chest compressions in CPR guidelines.1 The current adult human CPR guidelines acknowledge a lack of evidence on which to make a recommendation whether to start CPR with airway and breathing or with chest compressions first, and they suggest starting compressions first (CAB) in adult OHCA.2 This suggestion is based on the fact that most OHCA in adults is cardiac in cause in addition to data on manikin-based studies that show decreased time to initiation of chest compressions with the CAB approach. In contrast, current human pediatric CPR guidelines consider the evidence so limited that no recommendation can be made but acknowledge that most pediatric arrests are asphyxial in nature, which suggests that early ventilation is paramount.3 It is believed that the majority of arrests in dogs and cats are asphyxial in nature.

Consensus on science

For the most critical outcomes of FNO, Survival to discharge, and ROSC, we identified no studies addressing the PICO question.

Outcome 4: Time to completion of the first CPR cycle

For the important outcome of time to completion of the first CPR cycle, we found 2 experimental, simulator-based studies (very low level of evidence, downgraded for very serious indirectness) that address the PICO question.4,5 Both studies found that CPR using the CAB approach had a shorter time to completion of the first chest compression cycle compared to CPR using the ABC approach. This evidence suggests that compression first (CAB) CPR shortens the time for the completion of the first CPR cycle when compared to ventilation first (ABC) CPR.

Treatment recommendation

For multi-rescuer CPR in dogs and cats, we recommend that chest compressions be initiated without delay to assess airway and gain airway access.(strong recommendation, very low quality of evidence)

For multi-rescuer CPR in dogs and cats, we recommend that the airway be evaluated and the animal endotracheally intubated as soon as possible after initiation of chest compressions .(strong recommendation, expert opinion)

For single-rescuer CPR in dogs and cats, prior to initiation of chest compressions, we recommend that an airway evaluation be performed during the initial patient assessment (shake & shout) prior to initiation of chest compressions.(strong recommendation, expert opinion)

Justification of treatment recommendation

Considering the critical importance of circulation in delivering oxygen to tissues, the committee believes that high-quality chest compressions should not be delayed in non-responsive, non-intubated, apneic dogs and cats, even in cases of asphyxial arrest. Practically, the period of time required to assess and secure an airway, even in the hospital setting, is too long a period to wait to initiate chest compressions in our opinion. However, we recognize the importance of oxygenation and ventilation in asphyxial arrest scenarios and believe that the airway should be assessed and ventilation provided as quickly as possible, as long as this does not preclude the immediate provision of high-quality compressions.

These recommendations vary based on the number of rescuers. For single-rescuer CPR, airway evaluation should occur during the initial patient assessment steps, and then chest compressions started immediately; we believe this is a reasonable approach in that it delays ventilation by only 15 seconds. We considered this 15 second delay acceptable even in the face of asphyxial arrest to promote consistency in guidelines and at presumed low risk for individual patients. For multi-rescuer CPR, we recommend against delay in chest compressions since airway evaluation, intubation, and compressions can occur simultaneously.

Knowledge gaps

Studies in dogs and cats comparing these two approaches (CAB vs ABC) are needed, ideally with evaluation of critical outcomes of FNO, Survival to discharge, and ROSC.