Postmortem CT Gas Distribution in Pediatric Cases With a History of Perimortem Cardiopulmonary Resuscitation

To evaluate the frequency, anatomic distribution, and potential mechanisms of postmortem gas formation identified on postmortem computed tomography (PMCT) in infants and young children, with emphasis on the association between postmortem gas and perimortem cardiopulmonary resuscitation (CPR).

This retrospective study included 63 pediatric decedents (age range: birth to 25 mo) who underwent PMCT as part of medicolegal investigations, followed by autopsy. Two radiologists independently reviewed PMCT images, reports, and autopsy findings to determine the presence, location, and likely cause of postmortem gas. The presence of CPR was established based on documented history, autopsy findings, and imaging indicators. Descriptive statistics were used to characterize the cohort, and Fisher exact and t tests were applied for group comparisons with statistical significance set at P<0.05.

Postmortem gas was detected in 56 of 63 cases (89%). Among 61 cases with known CPR status, 57 had received CPR, and 4 had not. Gas was significantly more frequent in those with CPR (89%, 51/57) than in those without (25%, 1/4; P=0.008). The most commonly affected regions were the heart (64%) and liver (61%). Gas in the heart, liver, or brain was associated with a longer mean interval between death and imaging (7.4 vs. 3.9 h), although this difference did not reach statistical significance (P=0.06). Gas formation was observed as early as 0.5 hours postmortem.

PMCT frequently demonstrates postmortem gas in pediatric deaths, most notably in cases with prior CPR. The distribution pattern-favoring the heart and liver-and early appearance within hours of death suggest a major contribution from resuscitation-related mechanisms rather than decomposition only. Recognition of these CPR-related imaging patterns is essential for distinguishing physiological postintervention findings from decomposition or pathologic processes and may improve the forensic interpretive value of PMCT in pediatric death investigations.