Examining Compression-to-Ventilation Ratios for Optimal Neurologic, Survival Outcomes

medical team performing CPR on a patient
medical team performing CPR on a patient
Adults with cardiac arrest have better outcomes with continuous compressions with asynchronous ventilations or compression-to-ventilation ratios of 30:2.

Adults experiencing cardiac arrest who receive continuous compression with asynchronous ventilation or 30:2 compression-to-ventilation ratios and infants who receive 30:2 or 15:2 compression-to-ventilation ratios may experience improved neurologic and survival outcomes, according to a study published in the Annals of Emergency Medicine.

A systematic review of 28 studies and 13 companion reports was conducted to determine which compression-to-ventilation ratio resulted in the best cardiac arrest outcomes in both adult and pediatric populations. Studies included a cluster-crossover randomized controlled trial, 3 randomized controlled trials, and 24 cohort trials.  Of the selected studies, 20 were conducted in adults only, with 27 studies investigating cardiac arrest outcomes that occurred outside the hospital setting. 

Study results found more favorable neurologic (risk difference [RD], 1.72; 95% CI, 0.52-2.91) and survival (RD, 2.48; 95% CI, 1.57-3.38) outcomes in adults given cardiopulmonary resuscitation (CPR) at a compression-to-ventilation ratio of 30:2 compared with 15:2. Of note, compression-only CPR had worse neurologic (RD, –0.74; 95% CI, –0.85 to –0.63) and survival (RD, –1.42; 95% CI, –1.58 to –1.25) outcomes when compared with 30:2 CPR. No differences in neurologic outcomes or survival were found with adult 30:2 CPR and continuous compression CPR with asynchronous ventilations.

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Both 30:2 and 15:2 compression-to-ventilation ratios in pediatric patients resulted in favorable neurologic (RD, –3.02; 95% CI, –4.57 to –1.47) and survival (RD, –2.98; 95% CI, –5.51 to –0.45) outcomes when compared with compression-only CPR.

Investigators concluded that both 30:2 compression-to-ventilation ratio CPR and compression-only CPR with asynchronous ventilations in adults and 30:2 and 15:2 CPR in pediatric patients resulted in improved neurologic and survival outcomes. Therefore, clinicians should continue to educate and perform CPR utilizing these ratios.


Nikolla DA, Carlson JN. Which compression-to-ventilation ratio yields better cardiac arrest outcomes? [published online on November 14, 2017]Ann Emerg Med. doi:10.1016/j.annemergmed.2017.10.009