Ultrasound to Assess Site of Optimal Chest Compressions for CPR in Children

Introduction: The American Heart Association (AHA) provides guidelines for the optimal location of chest compressions during cardiopulmonary resuscitation at the lower half of the sternum to a depth of one-third the anterior-posterior diameter of the chest. Imaging studies show variations in the area of maximal compression (AMC) based on body habitus or disease states in adults. The goal of this study is to assess the AMC using ultrasound and compare position changes with anthropometric variables in children.


Methods: A single-center, prospective, observational study using point-of-care ultrasound (POCUS) to locate the AMC at a pediatric quaternary care hospital. The optimal AMC was represented by the mid-left ventricle (mid-LV), and images were captured with parasternal long axis and parasternal short axis views. The following measurements were obtained: horizontal displacement of the AMC from the mid-sternum, vertical displacement of the AMC from the xiphoid process, and depth of the mid-LV at the end of systole. Anthropometric variables (age, weight, height, BMI) were recorded.


Results: 43 children aged 1 to 18 years were enrolled in this study. The mean age was 7.5 yrs (SD  5.0). The mean horizontal displacement of the AMC was 2.8 cm (SD ± 1.5), the mean vertical distance of the AMC was 5.5 cm (SD ± 2.3), and the depth of the mid-LV was 4.9 cm (SD ± 1.0). No significant correlation was found between horizontal or vertical displacements of AMC and age, weight, or height. There was a strong positive correlation between depth of the mid-LV and age (r = 0.68, p < 0.001), height (r = 0.61, p < 0.001), and weight (r = 0.78, p < 0.001). There was a statistically significant difference in depth among all age groups (F(2,40) = 16.2, p < 0.001). Age stratification showed a strongly positive correlation between depth and weight in 13-18 year-olds and 6-12 year-olds versus 1-5 year-olds (r = 0.93, p < 0.001 and r = 0.77, p < 0.001 vs r = 0.30, p = 0.20).


Conclusions: This study located the AMC using ultrasound and demonstrated that the depth of the AMC strongly correlated with age, height, and weight. These distances by age group differed from the distances recommended by the AHA. Further study on the optimal depth of chest compressions in pediatric patients is warranted.