Japan-based study involving Osaka University finds valuable correlation between use of advanced airway management and ECG rhythms indicating need/non-need for defibrillation during out-of-hospital cardiac arrest. During out-of-hospital //cardiac arrest (OHCA), effective treatment starts with cardiopulmonary resuscitation (CPR) and, if necessary, electric shock by a defibrillator. In performing the process, emergency medical service (EMS) personnel also provide oxygen and ventilation either by the bag-valve-mask method or via more invasive advanced airway management (AAM) techniques, such as tube insertion, to keep the airway open. The ventilation methods have pros and cons in the immediate and longer term.
While AAM has been proven effective at protecting the airway during cardiac arrest treatment, many studies found it led to worse outcomes after survival. Its use compared with bag-valve-mask is controversial. The researchers sought to shed light on the debate.
"We noted that outcomes differed based on patients' first-documented ECG rhythm," says study co-author Sho Komukai. "We found shockable patients did not have improved 1-month outcomes after AAM. However, non-shockable patients treated with AAM showed better outcomes."
A shockable rhythm indicates receptivity to defibrillation, while a non-shockable rhythm is treated with only CPR, often accompanied by intravenous adrenaline. Favorable outcomes include recovering the neurological functioning and early hospital discharge, whereas unfavorable outcomes include function loss and death.
The findings were made possible by the researchers' use of an advanced statistical technique called time-dependent propensity-score sequential-matching analysis. This method accounts for the timing of AAM administration, and offsets bias from patients undergoing longer resuscitation and receiving more interventions. The result was a more accurate portrait of AAM's outcomes, and the positive connection with AAM in non-shockable patients.