Depth of sternal compression and intra-arterial blood pressure during CPR in infants following cardiac surgery.

The optimal depth of sternal compressions during cardiopulmonary resuscitation (CPR) in infants is unknown; current guidelines recommend compressing to a depth of 1/3rd to 1/2 the anterior-posterior (AP) diameter of the chest. Our experience to compress the chest at 1/3rd the AP diameter often fails to provide an adequate blood pressure response. We reviewed our experience with CPR, depth of compressions, and arterial blood pressure response in a cohort of 6 infants having cardiac surgery and subsequent cardiac arrest. Pediatric advanced life support measures were initiated, with attempted compressions to 1/3rd the AP chest diameter. Depth of attempted compressions was increased to approximately 1/2 the AP chest diameter if systolic BP response was inadequate (i.e., <60mm Hg systolic). BP tracings were reviewed and contiguous recordings were evaluated as compressions were attempted at 1/3rd and 1/2 the AP chest diameter. The age range was from 2 weeks to 7.3 months, and median age was of 1.0 month. The mean systolic BP was 83.4mm Hg for the 1/2 AP chest diameter technique vs. 51.6mm Hg for the 1/3rd AP diameter approach, p<0.001. The mean diastolic pressure was similar with both strategies (30.5 vs. 30.6mm Hg, p=0.99). In this cohort of 6 infants having cardiac surgery and subsequent cardiac arrest, attempting to compress the chest at 1/2 the AP diameter increased systolic blood pressure by 62% compared to attempting to compress 1/3rd the AP diameter. Perhaps resuscitators should attempt to compress infants' chests 1/2 rather than 1/3rd the AP diameter of the chest.