Suicide by oxygen deprivation with helium: a preliminary study of British Columbia coroner investigations

Helium Suicide, a Rapid and Painless Asphyxia: Toxicological Findings

Suicide by helium inhalation has become increasingly common in the last few decades in Europe and the US because it produces a quick and painless death. Inhaled-gas suicides can easily be assessed through death scene investigation and autopsy. However, helium is a colorless and odorless inert gas that unfortunately cannot be detected using standard toxicological analysis. A successful gas analysis was performed following the suicide of a 17-year-old female. For the detection of helium, central/peripheral blood samples and gaseous samples from the esophagus, stomach, and upper and lower respiratory airways (from the trachea and the primary left and right bronchia) were collected with a gastight syringe, ensuring minimal dilution. Qualitative analyses were positive in all gaseous samples. Quantitative analyses were performed using a special gas-inlet system with a vacuum by which the sample can be transferred to a mass spectrometer, reducing the risk of contamination. Helium concentrations were 20.16% from the trachea, 12.33% from the right lung, and 1.5% from the stomach. Based on the high levels of helium, the cause and manner of death were assessed as asphyxia suicide by inhalation of helium. Therefore, toxicological analyses should always be applied in order to gain evidence of inhaled gas in gaseous samples.

Suicide by helium inhalation in the Netherlands between 2012 and 2019

INTRODUCTION

In 2012 and 2013 a movie and a book about a 'dignified end of life' were published in the Netherlands. These items described suicide using an 'exit bag' to establish asphyxiation using helium (the helium method). 'Right-to-die-organisations' inform the elderly about this method. The purpose of this study is to investigate whether the use of suicidal asphyxiation by means of the helium method substituted other, related, methods following its publication in the Netherlands.

MATERIAL AND METHODS

We analysed suicides in the Netherlands over the period from 1 July 2012 to 30 June 2019. We compared the number of deaths caused by the helium method with other, related, cases. Secondly, we related these deaths to the total number of inhabitants and suicides recorded by Statistics Netherlands.

RESULTS

The study showed a stable trend in the use of the helium method in the period 2012-2019 and this was the same for the other, related methods. Individuals using the helium method were significantly younger than those using other, related, methods. At the scene of death, information about suicide and suicide notes were found more often at 'helium method' cases than with the 'other, related, methods' cases. Family was significantly more often present during a helium method suicide than during suicide by other, related, methods.

DISCUSSION

The number of suicides by the helium method and other, related, cases is stable in the Netherlands over the past years. Therefore, we conclude that there is no substitution effect within this category of suicides. Whilst 'right-to-die-organisations' strive to inform the old and sick of the helium method, it is noteworthy that the individuals using the helium method are significantly younger than the individuals who choose other, related, methods.

Suicide deaths by gas inhalation in Toronto: An observational study of emerging methods of suicide

BACKGROUND

Suicide death by gas inhalation has been the subject of global scientific interest due to a rapid increase in the use of helium and charcoal gas for suicide. These may be particularly amenable to means restriction strategies. There has been little scientific attention of this phenomenon in Canada.

METHODS

A review of coroner records was conducted for all suicide deaths in Toronto (1998-2015). Deaths were categorized as due to inhalational asphyxia by compressed gas (i.e. helium or nitrogen), charcoal burning or motor vehicle exhaust, with suicide deaths by other methods as a comparator. Demographic, clinical and suicide specific differences between decedents in these four categories were compared using chi-squared or ANOVA global test of significance with additional pairwise comparisons where appropriate. Secular trends were also examined.

RESULTS

Gas inhalational deaths accounted for 190 (4.7%) of all suicides in Toronto (n = 4062) over the study period and a higher proportion of males used compressed gas or motor vehicle exhaust gases than those who died by other methods (83.3% and 84.0% vs.69.7%, both p = 0.01). Comparing 1998-2003 to 2010-2015 there was a 1075% increase in deaths by helium (4 vs. 43 deaths) and a 533% increase in deaths by charcoal burning (3 vs. 16 deaths) although helium and charcoal burning deaths still accounted for only 4.2% of total suicides 2010-2015. Deaths by helium were more likely to be accompanied by the book "Final Exit" than those by non-inhalational methods (15% vs. 0.7%, p < 0.0001) while 13 of 14 people who died by charcoal burning whose ethnicity could be determined were Asian.

LIMITATIONS

Ethnicity and specific details of procurement of suicide methods were not systematically available in coroner records.

DISCUSSION

Suicide by inhalational asphyxia, particularly by compressed gases, has increased substantially over time in Toronto consistent with observations in other countries. Increased surveillance of these deaths, efforts to restrict access to these methods, and timely interventions including minimizing media reporting are all warranted.

Identifying and Tracking Gas Suicides in the U.S. Using the National Violent Death Reporting System, 2005-2012

INTRODUCTION

Identifying the source and specific type of gas used in suicides is difficult using most data systems owing to limitations in ICD-10 coding. The National Violent Death Reporting System (NVDRS), with its rich collection of both coded and free-text variables, has the potential to overcome these limitations. This study used a multipronged approach to identify gas-specific suicides in NVDRS and to track the incidence of these suicides over time.

METHODS

Using suicide cases from the 16 NVDRS states that participated throughout 2005-2012, free-text and code searches were conducted for four types of variables-incident narratives, coroner/medical examiner cause-of-death statements, cause-of-death codes, and substance names-to identify suicides by carbon monoxide, helium, hydrogen sulfide, and four other gases. All analyses were conducted in 2015.

RESULTS

Approximately 4% (3,242 of 80,715) of suicides recorded in NVDRS over the study period were the result of gas inhalation. Of these, the majority (73%) were carbon monoxide suicides (almost exclusively from motor vehicle exhaust and charcoal burning). Other types of gas (most notably helium), once rare, are now more common: At the start of the study period non-carbon monoxide gas suicides represented 15% of all gas suicides; at the end of the study period, they represented 40%.

CONCLUSIONS

Public health policies to reduce a suicidal person's access to more lethal suicide methods require a reliable source of surveillance data on specific methods used in suicide. Small changes to NVDRS could make it an efficient and nimble surveillance system for tracking these deaths.