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Published on: February 28, 2012
Initial Defibrillator Pad Position and Outcomes for Shockable Out-of-Hospital Cardiac Arrest
Joshua R Lupton1, Craig D Newgard1, David Dennis2
1Department of Emergency Medicine, Oregon Health and Science University, Portland.
Insights
Anterior-posterior defibrillator pad placement in out-of-hospital cardiac arrest (OHCA) with ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) was associated with higher return of spontaneous circulation (ROSC) compared to anterior-lateral placement.
Area of Science:
- Emergency Medicine
- Cardiology
- Resuscitation Science
Background:
- Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) are primary causes of out-of-hospital cardiac arrest (OHCA).
- Defibrillator pad placement (anterior-posterior vs. anterior-lateral) is a critical factor in OHCA management, but its impact on patient outcomes remains unclear.
Purpose of the Study:
- To investigate the association between initial defibrillator pad placement position (anterior-posterior vs. anterior-lateral) and patient outcomes in OHCA cases presenting with VF or pVT.
Main Methods:
- A prospective cohort study was conducted involving 255 adult patients with OHCA and VF/pVT treated by a single North American EMS agency.
- Data were collected from July 2019 to June 2023, excluding pediatric patients, interfacility transfers, traumatic arrests, and those with DNR status.
- Outcomes included return of spontaneous circulation (ROSC), pulses at ED arrival, survival to admission and discharge, and functional survival, analyzed using multivariable logistic regression and competing risks regression.
Main Results:
- Patients with anterior-posterior (AP) pad placement (n=158) showed a significantly higher adjusted odds ratio for ROSC at any time compared to anterior-lateral (AL) placement (n=97) (aOR, 2.64).
- Competing risk analysis revealed a significantly greater cumulative incidence of ROSC with initial AP placement versus AL placement (SHR, 1.81; P=.003).
- No significant differences were observed in pulses at ED arrival, survival to hospital admission, survival to discharge, or functional survival between the two pad placement groups.
Conclusions:
- Anterior-posterior defibrillator pad placement in OHCA patients with VF or pVT is associated with a higher likelihood of achieving return of spontaneous circulation compared to anterior-lateral placement.
- While AP placement shows a benefit in ROSC, further research is needed to determine its impact on other critical patient outcomes such as survival to discharge and functional recovery.
Importance:
Ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) are the most treatable causes of out-of-hospital cardiac arrest (OHCA). Yet, it remains unknown if defibrillator pad position, placement in the anterior-posterior (AP) or anterior-lateral (AL) locations, impacts patient outcomes in VF or pVT OHCA.
Objective:
To determine the association between initial defibrillator pad placement position and OHCA outcomes for patients presenting with VF or pVT.
Design, Setting, And Participants:
This prospective cohort study included patients with OHCA and VF or pVT treated by a single North American emergency medical services (EMS) agency from July 1, 2019, through June 30, 2023. The study included patients with OHCA treated by a large suburban fire-based EMS agency that covers a population of 550 000. Consecutive patients with an initial EMS-assessed rhythm of VF or pVT receiving EMS defibrillation were included. Pediatric patients (younger than 18 years), interfacility transfers, arrests of obvious traumatic etiology, and patients with preexisting do-not-resuscitate status were excluded.
Exposure:
AP or AL pad placement.
Main Outcomes And Measures:
Return of spontaneous circulation (ROSC) at any time with secondary outcomes of pulses present at emergency department (ED) arrival, survival to hospital admission, survival to hospital discharge, and functional survival at hospital discharge (cerebral performance category score of 2 or less). Measures included adjusted odds ratios (aOR), multivariable logistic regressions, and Fine-Gray competing risks regression.
Results:
A total of 255 patients with OHCA were included (median [IQR] age, 66 [55-74] years; 63 females [24.7%]), with initial pad positioning documented as either AP (158 patients [62.0%]; median [IQR] age, 65 [54-74] years; 37 females [23.4%]) or AL (97 patients [38.0%]; median [IQR] age, 66 [57-74] years; 26 females [26.8%]). Patients with AP placement had higher adjusted odds ratio (aOR) of ROSC at any time (aOR, 2.64 [95% CI, 1.50-4.65]), but not significantly different odds of pulses present at ED arrival (1.34 [95% CI, 0.78-2.30]), survival to hospital admission (1.41 [0.82-2.43]), survival to hospital discharge (1.55 [95% CI, 0.83-2.90]), or functional survival at hospital discharge (1.86 [95% CI, 0.98-3.51]). Competing risk analysis found significantly greater cumulative incidence of ROSC among those at risk with initial AP placement compared with AL (subdistribution hazard ratio, 1.81 [95% CI, 1.23-2.67]; P = .003).
Conclusions And Relevance:
In this cohort study of patients with OHCA and VF or pVT, AP defibrillator pad placement was associated with higher ROSC compared with AL placement.
