Quality of BLS decreases with increasing resuscitation complexity

Multiple procedures performed in parallel may cause each procedure to be performed less effectively than if performed in isolation. BLS performed by prehospital providers potentially includes artificial ventilations, chest compressions, and application of an automated external defibrillator (AED). This study examines the effectiveness of artificial ventilation and chest compressions both with and without an AED.

Thirty-six prehospital providers participated in a prospective observational study. Tested in pairs (n=18), subjects randomly completed three, 6-min scenarios [apneic patient with a pulse (VENT), a pulseless patient (CPR), and a pulseless patient with an AED available (CPR+AED)]. A full-torso manikin capable of generating a carotid pulse was connected to a computer to record number of ventilations, tidal volume, flow rate, number of compressions, and compression depth. Data were analyzed by t-test, ANOVA, and Mann-Whitney U-test.

Artificial ventilation performed in isolation provided more correct ventilations than during CPR or CPR+AED (25.7%, 14.2%, 13.7%, p=0.02). Fewer ventilations were delivered during CPR and CPR+AED (p=0.03). More compressions were delivered with CPR alone vs. CPR+AED (51.9, 35.7 min(-1), p=0.00). More correct compressions were delivered during CPR alone vs. CPR+AED (p=0.05).

Both the quality and quantity of BLS decreases as the number of procedures performed simultaneously increases. Further decrements might occur when ALS skills enter into resuscitation. These results suggest a need to automate and/or prompt the performance of BLS to optimize resuscitation.