Cardiopulmonary resuscitation in pediatric pectus excavatum patients—Where is the heart?

Abstract

In children with pectus excavatum, the posteriorly depressed sternum compresses and displaces the heart. However, the currently recommended compression site and depth for cardiopulmonary resuscitation have not been studied in this population. This retrospective study investigated the location of the center of ventricles with the largest cross-sectional area to determine the optimal site and depth for chest compressions in pediatric pectus excavatum patients. Chest computed tomography images of 94 pediatric pectus excavatum patients before and after correction surgery were compared with normal patients. The caudal displacement of the ventricles was calculated by dividing the length of sternum by the length from the suprasternal notch to the transverse level of the largest cross-sectional area of the ventricles. The proportional leftward deviation of the center of the ventricles from the midline versus transverse diameter of the thorax was calculated. The remaining internal thickness was calculated at the midline assuming the recommended compression depth of one-third of the anterior to posterior diameter. Compared with the normal population (mean=81% [SD=10.3%]), pediatric pectus excavatum patients showed caudal displacement of ventricles before (98.2% [15.1%], 95% CI of mean difference; 13.7%-20.5%, P<.001) and after correction (100.4% [13.5%], 95% CI of mean difference; 16.2%-22.5%, P<.001). Compared with the normal population (6.9% [2.7%]), pediatric pectus excavatum patients showed leftward deviation of ventricles before (16.2% [5.5%], 95% CI of mean difference; 8.2%-10.4%, P<.001) and after correction (13.3% [4.8%], 95% CI of mean difference; 5.3%-7.3%, P<.001). The remaining internal thickness assuming the recommended chest compression was <10mm in 54/94(57.4%) and 18/94 (19.1%) of pediatric pectus excavatum patients before and after correction, respectively. Pediatric pectus excavatum patients showed significant caudal displacement and leftward deviation of the ventricles compared with the normal population despite correction surgery and the currently recommended compression site and depth might injure intrathoracic structures without effective cardiac compression during cardiopulmonary resuscitation.