Anterior-posterior defibrillator pad placement may significantly increase the odds of return of spontaneous circulation in patients with shockable out-of-hospital cardiac arrest compared with anterior-lateral placement, according to a recent study.

In the cohort study, published in JAMA Network Open, investigators examined the impact of initial defibrillator pad positioning—anterior-posterior (AP) vs anterior-lateral (AL)—on outcomes in patients presenting with shockable out-of-hospital cardiac arrest (OHCA). They specifically focused on patients experiencing ventricular fibrillation or pulseless ventricular tachycardia, the most treatable causes of OHCA.

The prospective analysis included 255 patients with a median age of 66 years (interquartile range = 55–74), of whom 24.7% (n = 63) were female. All of the patients were treated by a single emergency medical services agency, with AP pad placement used in 62% of cases and AL in 38%. 

The primary outcome measured was the return of spontaneous circulation (ROSC). After adjusting for confounders, AP pad placement was associated with a higher odds of achieving ROSC compared with AL (adjusted odds ratio [OR] = 2.64, 95% confidence interval [CI] = 1.50–4.65). However, no statistically significant differences were found between AP and AL placements for secondary outcomes, including pulses at emergency department (ED) arrival (adjusted OR = 1.34, 95% CI = 0.78–2.30), survival to hospital admission (adjusted OR = 1.41, 95% CI = 0.82–2.43), survival to discharge (adjusted OR = 1.55, 95% CI = 0.83–2.90), or favorable neurologic outcomes at discharge (adjusted OR = 1.86, 95% CI = 0.98–3.51).

A competing risk analysis assessing the cumulative incidence of ROSC demonstrated a subdistribution hazard ratio of 1.81 (95% CI = 1.23–2.67), with a statistically significant P value of .003. This indicated a higher incidence of ROSC with AP placement compared with AL placement during resuscitation efforts. 

Overall, the findings suggested that AP pad placement was linked to improved odds of ROSC, though it did not significantly affect long-term survival or neurologic outcomes. The investigators called for further prospective studies to determine optimal initial pad placement strategies in OHCA management to improve defibrillation and neurologically intact survival.

Full disclosures can be found in the published study.