PURPOSE: Adequate chest compression (CC) depth is critical for effective cardiopulmonary resuscitation. Pediatric resuscitation guidelines recommend that CC be at least one-third of the anterior-posterior (AP) chest diameter or approximately 4 cm in infants and 5 cm in children. We aimed to find a better indicator of CC depth that maximizes CC depth while also minimizing injury. BASIC PROCEDURES: Chest computed tomographic images of patients aged 8 years and younger were measured for external diameter (ED) (AP distance from skin to skin) and internal diameter (AP distance between internal surface of anterior chest wall and anterior surface of vertebral body) at the midway of the lower half of the sternum. Compressible depth was defined as 1 cm short of internal diameter. We determined that up to a 10% estimated risk of overcompression is acceptable and approximated a quantile regression line for the 10th percentile of compressible depth on ED. After rounding coefficients, we used its equation as a new indicator. MAIN FINDINGS: A total of 426 images were analyzed. The new indicator had a slope of 0.5 and an intercept of -1.9 cm (1 fingerbreadth). Compared to one-third ED, the new indicator would provide deeper CC with average difference of 1.9 mm (95% confidence interval, 1.6-2.2 mm) without increasing the risk of overcompression (both 4.9%). Chest compression of 4/5 cm would provide deeper CC compared to the new indicator (difference, 3.5 mm; 95% confidence interval, 2.7-4.1 mm); however, its overcompression risk was too high (31.5%). PRINCIPAL CONCLUSION: Chest compression of one-half ED minus 1 fingerbreadth maximizes CC depth without increasing overcompression in pediatric population.
PURPOSE: Adequate chest compression (CC) depth is critical for effective cardiopulmonary resuscitation. Pediatric resuscitation guidelines recommend that CC be at least one-third of the anterior-posterior (AP) chest diameter or approximately 4 cm in infants and 5 cm in children. We aimed to find a better indicator of CC depth that maximizes CC depth while also minimizing injury. BASIC PROCEDURES: Chest computed tomographic images of patients aged 8 years and younger were measured for external diameter (ED) (AP distance from skin to skin) and internal diameter (AP distance between internal surface of anterior chest wall and anterior surface of vertebral body) at the midway of the lower half of the sternum. Compressible depth was defined as 1 cm short of internal diameter. We determined that up to a 10% estimated risk of overcompression is acceptable and approximated a quantile regression line for the 10th percentile of compressible depth on ED. After rounding coefficients, we used its equation as a new indicator. MAIN FINDINGS: A total of 426 images were analyzed. The new indicator had a slope of 0.5 and an intercept of -1.9 cm (1 fingerbreadth). Compared to one-third ED, the new indicator would provide deeper CC with average difference of 1.9 mm (95% confidence interval, 1.6-2.2 mm) without increasing the risk of overcompression (both 4.9%). Chest compression of 4/5 cm would provide deeper CC compared to the new indicator (difference, 3.5 mm; 95% confidence interval, 2.7-4.1 mm); however, its overcompression risk was too high (31.5%). PRINCIPAL CONCLUSION: Chest compression of one-half ED minus 1 fingerbreadth maximizes CC depth without increasing overcompression in pediatric population.