The relationship between positional asphyxia and increasing body mass index

Review of the files of the Pathology section of Forensic Science SA over 17 yrs (January 2003-December 2019) revealed 32 adult cases of positional asphyxia (age range 18-87 years; average 49 years - m:f ratio 3:1). Predisposing/causative conditions were accidents, N = 8, alcohol intoxication N = 7, neurological disease N = 7, drug intoxication N = 5, morbid obesity N = 2, combinations of factors N = 2, and a single homicide N = 1. There was one case with below normal weight (BMI 17.9), with 6 cases having normal weights (BMI range 18.9-24.6, average 22.3), 9 being overweight (BMI range 25.3-29.5, average 27.9), and 16 being obese (BMI range 30-66.2, average 40.9). Only 7 cases (22%) had either under/normal weight compared to 25 (78%) who were overweight/obese (p < 0.05). Increasing body mass appears to be a risk factor to be considered in all forms of positional asphyxia; BMI should, therefore, be routinely taken into account in the forensic evaluation of such cases.