Safety of the inter-nipple line hand position landmark for chest compression

No previous study has investigated the safety of hand position during chest compression determined by the inter-nipple line, in which the heel of one hand is positioned on the centre of the chest between the nipples, from the standpoint of prevention of organ injury.

We measured the distance from the xiphisternal junction to the inter-nipple line (dN) in 1000 surgical patients and the heel length (H) of hands in 100 healthy volunteers, then used the formula H/2-dN to determine the amount of deviation when the heel of the rescuer's hand extended to the xiphoid process (D). Next, 100 surgical patients were randomly assigned to 18 anaesthesiologists, who placed the heels of their hands on the sternum for validation.

The D value was positive in 551 patients, indicating that the heel may extend to the xiphoid process during chest compression in those individuals. Multivariate logistic-regression analyses showed that deviations beyond the xiphoid process to the epigastric region were more likely to occur in female (OR 3.52), elderly (OR 2.00), and short-statured (OR 2.09) patients, and with male rescuers (OR 2.81). During actual positioning, deviation occurred in 51 patients and extended to the epigastric region in 5 females.

Simulation of hand position determined by the inter-nipple line resulted in placement of the rescuer's hands over the xiphoid process in nearly half of the patients. Hand deviation to the epigastric region may occur when the patient is a short-statured or elderly female, and when the rescuer is male.