Helium poisoning: new procedure for sampling and analysis
An increasing number of suicidal asphyxiation with a plastic bag with inert gases, and in particular helium (He), have been reported from numerous countries over the last decade. These cases are differently managed and lead to different and variable interpretations. Based on the 12 last cases analysed in the laboratory and on the review of the most recent literature about this topic, updated autopsy guidelines for sampling have been proposed regarding to the samples choice and analytical challenges required by the gaseous state of this substance. Biological samples from airways (lungs lobe) followed by brain and cardiac blood are the best matrices to take during the autopsy to diagnose He exposure. Gaseous samples from trachea, pulmonary bronchi, gastric and cardiac areas are also recommended as alternative samples. The anatomical site of sampling must be carefully detailed, and to this end, forensic imaging constitutes a beneficial tool. Even if He detection is sufficient to conclude to He exposure, He concentrations in samples may be related to He exposure conditions (duration, breathing rate, etc.). A quantification in biological samples could be helpful to document more precisely the case. He concentrations in gaseous samples are reported up to 6.0 μmol/mL (tracheal gas), 2.4 μmol/mL (pulmonary gas), 0.64 μmol/mL (cardiac gas) and 12 μmol/mL (gastric gas). He concentrations in solid/liquid samples are reported up to 28 μmol/g (lungs) and 0.03 μmol/g (cardiac blood). The other matrices usually sampled during autopsy such as urine, peripheral blood, liver, fat matter and kidney appear as not relevant.
KeywordsHelium Suicide Suffocation Asphyxia GC-MS
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- 13.Ogden RD, Wooten RH (2002) Asphyxial suicide with helium and a plastic bag. Am J Forensic Med Pathol 23:234–237. https://doi.org/10.1097/01.paf.0000022963.33157.9B CrossRefPubMedGoogle Scholar
- 15.Gilson T, Parks BO, Porterfield CM (2003) Suicide with inert gases. Addendum to final exit. Am J Forensic Med Pathol 24:306–308. https://doi.org/10.1097/01.paf.0000083363.24591.5d CrossRefPubMedGoogle Scholar
- 16.Gallagher KE, Smith DM, Mellen PF (2003) Suicidal asphyxiation by using pure helium gas. Case report, review, and discussion of the influence of the internet. Am J Forensic Med Pathol 24:361–363. https://doi.org/10.1097/01.paf.0000097856.31249.ac CrossRefPubMedGoogle Scholar
- 18.Humphry D (1992) Final exit: the practicalities of self-deliverance and assisted suicide for the dying. Hemlock Society, EugeneGoogle Scholar
- 28.Murty OP (2008) Plastic bag asphyxia with LPG (butane-propane) inhalation—fatal asphyxiphilia or suicide? J Indian Acad Forensic Med 30:216–220Google Scholar
- 30.Billoch Lima JG, Sannabria-Bellasai D, Rivera-Diez I (2011) New suicide modalities: the use of helium as an oxygen displacement agent. P R Health Sci J 30:157Google Scholar
- 33.Tsujita A, Okazaki H, Nagasaka A, Gohda A, Matsumoto M, Matsui T (2018) A new and sensititve method for quantitative determination of helium in human blood by gas chromatography-mass spectrometry using naturally existing neon-21 as internal standard. Forensic toxicol 37:75–81. https://doi.org/10.1007/s11419-018-0437-6 CrossRefPubMedGoogle Scholar
- 38.Varlet V, Smith F, Giuliani N, Egger C, Rinaldi A, Dominguez A, Chevallier C, Bruguier C, Augsburger M, Mangin P, Grabherr S (2015) When gas analysis assists with postmortem imaging to diagnose causes of death. Forensic Sci Int 251:1–10. https://doi.org/10.1016/j.forsciint.2015.03.010 CrossRefPubMedGoogle Scholar
- 44.Živković V, Cvetković D, Nikolić S (2018) Correspondence on: “gas embolism as a potential cause of death by helium poisoning—postmortem computed tomography changes in two cases of suicidal helium inhalation”. Legal Med 35:86–87. https://doi.org/10.1016/j.legalmed.2018.09.018 CrossRefPubMedGoogle Scholar