Pneumomediastinum and Cervical Soft Tissue Emphysema as an Important Vital Sign in Hanging: An Autopsy Based Prospective Study

Objective: To determine the frequency and reliability of cervical soft tissue emphysema and pneumomediastinum in autopsy cases of hanging. Material and Method: We prospectively studied 30 autopsy cases of hanging including 18 males and 12 females with age ranging from 19 to 65 years. The control group consisted of age and sex matched 30 cases that died due to various natural pathologies. Along with this, a small group of five cases consisting of homicidal asphyxial deaths from ligature and manual strangulation was also studied for this purpose. Various other known vital phenomenon in hanging were also recorded in the form of hemorrhages in the subcutaneous tissues, laryngeal hyoid skeleton fractures, conjunctival and facial petechial hemorrhages, hemorrhages over clavicular origin of sternocleidomastoid muscle, carotid intimal tears (Amussat’s sign), Simon’s bleeding and hemorrhages in the respiratory auxiliary muscles of respiration. The dissection and preparation of the neck was done in layers. None of the cases underwent cardiopulmonary resuscitation. Signs of putrefaction were absent. Results: The soft tissue emphysema was seen in 22 cases (73.3%) of hanging as fine soapy air bubbles in the mediastinum that could be traced further in the superficial and deep tissues of the neck up to the level of ligature mark beyond which it was missing. Among two other groups, 3 controls depicted this finding while no traces of emphysema were seen in any of the strangulation cases. Conclusion: Cervical soft tissue emphysema along with pneumomediastinum is a frequent and important vital finding in cases of death due to hanging. Whenever possible, the vitality of the sign should be considered in conjunction with other known vital signs of hanging. However a proper care should be taken during dissection of cervical and thoracic structures to avoid artefactual introduction of air in the soft tissues. The interpretation must be based on sound medical grounds and observations.