Interesting case of a woman who injected herself with pentobarbital
A 79-year-old woman was found by her general practitioner at home in a coma. A 100 mL brown bottle without label, containing about 2-3 mL of an unknown viscous liquid and precipitated crystals were found near the patient, together with a syringe (figure 1). A small injection mark and purple spot were observed on her left elbow.
Toxicology screening of the liquid and crystals in the bottle indicated the presence of ethanol, propylene glycol and a barbiturate-like compound. e STIP analysis revealed the presence of pentobarbital in the bottle. The pH of the mixture in the bottle was 11. This can be attributed to the presence of the pentobarbital in the form of the sodium salt. The pentobarbital concentration of the liquid in the bottle was 16g/100 mL.
In this case, it was possible to estimate the amount of pentobarbital present in the body and the minimal volume of the pentobarbital mixture that the patient had injected into herself.
Therapeutic ranges of pentobarbital in serum are between 1-10 mg/L. Serum levels above 10 mg/L can cause coma and levels above 30 mg/L as observed in the present case are usually lethal.
The volume of distribution (Vd) of pentobarbital is 1 L/kg. The woman's weight was approximately 70 kg, resulting in a Vd of pentobarbital of approximately 70 L.The estimated amount of pentobarbital in the body at the time of sampling was approximately 2.1 grams. In the present case of a presumed auto-injection with a concentrated pentobarbital solution of 16 g/100 mL, it is possible to calculate that at least 13 mL of a possibly veterinary pentobarbital solution has been injected.
Interestingly, other cases have shown the death of individuals after auto-injection with similar doses of pentobarbital. For instance, Romain et al. describe a 51-year old man who was found dead who also had a purple spot at the site of injection. The concentration of the injected pentobarbital mixture was 21.7 mg/L and the estimated amount of injected pentobarbital was approximately 1.6 g.
Netherlands Journal of Critical Care
https://de-intensivist.nl/wp-conten...on-by-intravenous-pentobarbital-injection.pdf
