Quantitative assessment of the diagnostic value of drowning signs based on a retrospective analysis of drowning cases

BACKGROUND: Determination of the cause of death during forensic autopsy of bodies recovered from water remains a challenging expert task. The diagnostic algorithm relies on a comprehensive assessment of specific morphological features of drowning, general asphyxial manifestations, and laboratory findings. However, the diagnostic reliability of these features often raises doubts.

AIM: This work aimed to evaluate the diagnostic significance of morphological signs of drowning based on their frequency and statistical probability derived from archival data of the Moscow Region Bureau of Forensic Medical Examination for 2017–2019.

METHODS: It was a retrospective, single-center, observational study. Archival data from autopsy, histological, algological, and forensic chemical examinations of drowning cases in the Moscow Region from 2017 to 2019 were analyzed. Data were compiled into a database (Microsoft Excel). Qualitative variables were presented as absolute and relative frequencies with 95% confidence intervals. The Pearson χ² test and the Bonferroni correction were used for group comparisons and for pairwise comparisons, respectively. Quantitative data distribution was assessed using the Shapiro–Wilk test. Statistical significance was set at p < 0.05.

RESULTS: Of the total number of drowned individuals (n = 179), 81% were male. The median age of all deceased individuals was 42 years [29; 57]. In 69.8% of cases, the results of forensic chemical analysis of blood and urine for ethanol were positive. According to archival expert reports from the Moscow Region Bureau of Forensic Medical Examination, the most frequent (≥50%) diagnostic signs of drowning included: Paltaulf spots (89.9%), Sveshnikov sign (84.4%), foam in the tracheal and bronchial lumen (75.4%), emphysema and wet swelling of the lungs (87.2%), pulmonary edema (57.5%), rib impressions on the lung surface (53.6%), and quartz-containing mineral particles in the sphenoid sinus (76.0%) and in the left ventricular cavity (68.2%), in combination with general asphyxial signs. No statistically significant correlations were found between the frequency of drowning signs, lung weight, or degree of alcohol intoxication. None of the identified drowning signs alone provided absolute diagnostic accuracy. Based on the observed frequency distribution, a pilot computer model was developed to estimate the probability of drowning.

CONCLUSION: Only a comprehensive approach and combined assessment of diagnostic features, when properly interpreted, can ensure the formation of an evidence-based expert conclusion on the cause of death in individuals recovered from water.