Histomorphometric study for the differential diagnosis between pulmonary barotrauma in scuba diving and pulmonary taphonomic changes

Abstract

Background: Diving is a popular recreational sport on the Spanish coast. Despite the safety measures, deaths related to this activity are frequently reported. PBt/AGE has been described as the cause of death in SCUBA divers in 13-24% of the cases. The main impediment in the diagnosis of PBt/AGE is the existence of entities that can mask it and divert the cause of death, especially putrefaction. Studies have delved into this field to reinforce macroscopic autopsy, imaging, and gas analysis techniques. Microscopic studies have fallen short in refining the diagnoses. Therefore, we propose the histomorphometric analysis of lung tissue to provide objective quantitative data and more reliable information for the diagnoses of PBt/AGE and its differentiation from putrefaction. Objectives: To describe and quantify the histomorphological changes observed in lung tissue samples for the differential diagnosis between pulmonary barotrauma in deaths due to SCUBA diving and taphonomic lung damage secondary to putrefaction. Design: Cross sectional and descriptive study to be performed in Girona from 2020-2021. Population: The study population will be divided in three groups: 1) Divers deaths from PBt/AGE, 2) Non-diving-related deaths and in an emphysematous evolutionary period, and 3) Non-diving-related deaths with low probability of putrefaction. All samples will be obtained from the Forensic Pathology Service of the Legal Medicine and Forensic Sciences Institute of Catalonia. Methods: Pulmonary histological preparations will be sampled and analysed. The histomorphometric analysis will be done through a FIJI ImageJ2 (National Institutes of Health) image analysis programme