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: Surrogate markers of perfusion

4

EXP

0

- -

--

0

0

0

+

0

Various surrogate markers of perfusion are improved when shorter duty cycles and less fraction of time spent “leaning” on the chest occur.

Moderate

Introduction

Incomplete chest wall recoil during CPR may increase intrathoracic pressure between chest compressions and thereby decrease venous return. Leaning on the chest between compressions will impair chest wall recoil and has been found to occur commonly in human clinical studies. The current human and previous veterinary guidelines recommend allowing for complete chest wall recoil between compressions based primarily on experimental data. This question investigates whether impaired chest wall recoil affects outcome in dogs and cats undergoing CPR.

Consensus on science

For the most critical outcomes of favorable neurologic outcome, survival to discharge and ROSC, we identified no studies that address the PICO question.

Outcome 4: Surrogate markers of perfusion:

Four experimental studies (moderate level of evidence, downgraded for serious indirectness) in a porcine ventricular fibrillation model of cardiopulmonary arrest were identified, 2 of which document that leaning decreases cardiac index and left ventricular myocardial index.1,2 Two studies evaluated different duty cycles and documented decreased duty cycle or maximizing the recoil phase increased cerebral or myocardial perfusion pressure; we considered adequate time in non-compression to be important for left ventricular filling during the recoil phase.3,4 Cerebral perfusion pressure and aortic pressure were optimized by a 50:50 duty cycle of compression : non-compression in 8-week-old piglets.4

Treatment recommendations

We recommend allowing full chest wall recoil between chest compressions in dogs and cats undergoing CPR (strong recommendation, moderate quality of evidence).

We recommend targeting a duty cycle of 50:50 for compression : non-compression during CPR in dogs and cats (strong recommendation, moderate quality of evidence).

Justification of treatment recommendation

All pertinent evidence to date shows improved surrogate markers of perfusion when there is adequate opportunity for full chest wall recoil.

Knowledge gaps

Whether allowing full chest wall recoil during CPR in dogs and cats improves neurologic outcome, survival to discharge, or ROSC is unknown.

There is no supporting evidence to address the PICO question in human clinical trials, nor in dogs and cats in any setting.

Whether veterinary health care providers can maintain adequate chest compression technique without leaning between compressions for a full 2-minute BLS cycle during CPR in dogs and cats of variable size and conformations is unknown.

It is unclear whether health care providers are able to assess themselves and others for leaning during the recoil phase of CPR in dogs and cats.