Very bad deep … When the scuba tank smells like smoke

Abstract

Presentation and discussion of positive tests results for cannabis in a person who died following a diving accident. Scuba diving is a sport that is becoming more and more popular. However, if this sport isn’t practiced properly it can quickly become dangerous. Scuba diving is practiced with a scuba suit composed of the following elements: a stabilizing jacket, a pressure regulator, a mask, palms and a scuba tank. Strict rules must be respected. Given that there is an increase of cannabis users in the general population, it is therefore not uncommon to find some cannabis users practicing scuba diving. This drug has important psychoactive effects that can cause fatal consequences when practicing this activity. The authors report a case of death while scuba diving under the influence of cannabis. A 64-year-old man collapsed after scuba diving, when he was return to the surface. People on the spot took charge of him directly to perform first aid resuscitation, but he rapidly died. Toxicological analyses were requested to document the cause of the death. The matrices collected at the autopsy included femoral blood, cardiac blood, urine, bile, gastric contents, and hair (10 cm, blond, no orientation). After comprehensive toxicological investigations, cannabis exposure was identified. GC-MS/MS (Agilent 7010B) was used for the determination of Δ9-tetrahydrocannabinol (THC), and its metabolites (11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor Δ9-tetrahydrocannabinol-carboxylic acid (THC-COOH)) in blood. The analysis of THC-COOH in urine and THC and cannabinol (CBN) and cannabidiol (CBD) in hair was performed on a GC/MS (Perkin Elmer). Blood was analyzed after extraction with n-hexane/ethyl acetate (90:10, v/v) and then derivatizated with BSTFA in the presence of THC-D3. In hair, THC, CBN and CBD were extracted in a mixture of n-hexane and ethyl acetate (90:10, v/v) after hydrolysis in alkaline conditions. Δ9-THC was detected with a concentration of 70.5 ng/mL in the femoral blood, 11-OH-THC and THC-COOH were found at 1.6 ng/mL and 27.8 ng/mL respectively. THC-COOH tested positive at 858 ng/mL in the urine. In hair, 2432 pg/mg of THC, 85 pg/mg of CBN and 398 pg/mg of CBD were measured. The concentration of Δ9-THC in blood indicated that the man was under the influence of cannabis when the accident occurred. In addition, the concentrations found in the hair indicate regular cannabis use. In addition to cannabis exposure, amlodipine was found at therapeutic concentration (69 ng/mL) in blood. A very small concentration of ethanol was found in the blood (0.09 g/L) and urine (0.20 g/L). The concentration of strontium was 23 ng/mL, which is inconclusive with respect to vital drowning. The concentrations of cannabis found in blood revealed recent cannabis use before diving, demonstrating that the subject was under the influence during the dive. In addition, regular use of this recreative drug was revealed by the hair test. The recent use of cannabis, ethanol and his hypertension (demonstrated by the amlodipine treatment) could be the cause of this man's discomfort and death.