In case of cardiac arrest, be sure to correctly place pads, in particular during shockable rhythms and above all if ventricular fibrillation is REFRACTORY. Incorrect position of defibrillator pads may reduce the chance of unsuccessful termination of ventricular fibrillation.
Correct self-adhesive pads placement for defibrillation
- Place pads in the conventional antero-lateral (sternal-apical) position.
- The right (sternal) pad is placed to the right of the sternum, below the clavicle.
- The apical pad is placed in the left mid-axillary line, approximately level with the V6 ECG electrode. This position should be clear of any breast tissue. It is important that this pad is placed sufficiently laterally and in practical terms, the pad should be placed just below the armpit.
Either pad can be placed in either position (apex or sternal). An observational study in patients undergoing elective cardioversion showed that transthoracic impedance was lower when the paddle was orientated in a cranio-caudal direction. Consider shaving the chest if it is very hairy and the electrodes will not stick firmly. Do not delay shock delivery, and consider alternative pad positions if necessary.
Why it matters
Pads should be positioned in an optimal position to maximise transmyocardial current density and minimise transthoracic impedance. Transmyocardial current during defibrillation is likely to be maximal when pads are placed so that the area of the heart that is fibrillating lies directly between them.
Other acceptable pad positions
- Placement of each pad on the lateral chest walls, one on the right and the other on the left side (bi-axillary).
- One pad in the standard apical position and the other on the right upper back.
- One pad anteriorly, over the left precordium, and the other pad posteriorly to the heart just inferior to the left scapula.