It’s 4:30 in the morning and the emergency department (ED) calls the poison center about multiple patients. A car was found disabled on the highway. When police arrived on scene, they found an unresponsive female in the front seat. Obstructing their view was a sign on the window stating – “Toxic Gas. Do Not Enter. ” The police officer broke the front window to extract the patient. EMS is en route to the ED with the extracted patient, and three police officers who complain of feeling dizzy. . .
Suicide clusters and suicide contagion have long been recognized, and are well described in the literature.1,2 Teenagers and adolescents appear to be the most vulnerable to increases in suicide rates and attempted suicides secondary to media reports.1 Exposure to suicide methods through media reports
Chemical suicides first became popular in Japan. Known as detergent suicides, these cases involved using a mixture of a bath additive plus toilet cleaner to create hydrogen sulfide. From March through June 2008, there were 220 suicides by this method reported in Japan, with the mortality rate an astonishing 95%.4 After the first cases were reported, due to suicide contagion, this method of suicide began to spread
The most common cause of detergent suicide
Similar to cyanide, hydrogen sulfide is a potent inhibitor of cytochrome oxidase resulting in rapid inhibition of oxidative phosphorylation. And luckily, I don’t have to recreate the wheel and try to explain oxidative phosphorylation because Dr. Curry already did. Symptom onset after large exposure is typically abrupt, leading to it being referred to as a “rapid knockdown agent”. The effects on the electron transport chain do not fully explain this effect and there is increasing evidence that hydrogen sulfide causes considerably more oxidative stress than cyanide. The exact mechanisms for this are currently under investigation.10 H2S causes a reduction in oxygen consumption due to its inhibition of complex IV of the electron transport chain. Additionally, it increases cellular acid production likely due to a switch to anaerobic metabolism and subsequently an increased lactate production. There is also emerging research that hydrogen sulfide is a brain stem toxin.10,11
Hydrogen sulfide has the irritating odor of rotten eggs. The rotten egg smell occurs at very low concentrations of 0.1 to 0.3 parts per million (ppm) with the notable strong intense odor occurring at 20 – 30 ppm. It is irritating to mucous membranes, and causes eye irritation at concentrations between 20 – 100 ppm. At concentrations higher than 100 to 150 ppm, it causes olfactory nerve paralysis. This leads the unknowing victim to have a false sense of security . . . if they don’t smell it, they must be safe. At concentrations of greater than 500 ppm, it leads to rapid cardiac arrest.
Treatment is largely supportive, with removal from the source, and aggressive supportive care. Unlike cyanide, the administration of antidotal therapy is not as clearly indicated after hydrogen sulfide poisoning. There are animal models showing that methemoglobin is protective against toxicity, and because of this, it is not unreasonable to give sodium nitrite to severely poisoned patients.12 Additionally, hydroxocobalamin and cobinamide are being studied for their potential benefits.10 Cobinamide (IV or IM) has been shown to be effective against lethal IV hydrogen sulfide exposures in both rabbits and pigs.11 Methylene blue is also being investigated as an antidote.13,14 There are several postulated mechanisms suggesting the beneficial effects of methylene blue
We have all heard the stories of carbon monoxide poisoning. Running a car in the garage; a hose from the exhaust pipe into the window; a charcoal grill in an enclosed space. But, did you know that people can create carbon monoxide in a chemical reaction by mixing two relatively common ingredients? Carbon monoxide is formed when sulfuric acid and formic acid are combined. How much CO is formed? Enough that carboxyhemoglobin levels have been reported to be greater than 30% in the victims.15,16
This isn’t a post on carbon monoxide toxicity, and certainly not a post about the role of hyperbaric oxygen treatment. But remember, having high concentrations of carboxyhemoglobin results in a shift of the oxygen dissociation curve to the left, and less oxygen delivered to tissues. Certainly, the toxic effects can’t be explained purely by this mechanism and there are other pathophysiologic mechanisms. Some of which are known and some of which remain unknown. Inactivation of cytochrome oxidase results in inflammatory processes that result in ischemic reperfusion after CO exposure and during recovery, white blood cells adhere to the microvasculature. This results in delayed lipid peroxidation which then activates excitatory amino acids which are ultimately responsible for neuronal cell loss.17
Treatment includes administration of 100% oxygen immediately, either by non-rebreather or endotracheal tube. IV normal saline and/or vasopressors should be administered for hypotension. Hyperbaric oxygen should be considered in patients with syncope, persistent altered mental status, or CO levels greater than 25%. ECMO may play a role in severely poisoned patients with cardiogenic shock.18
Secondary Contamination and Decontamination
Are we all doomed to be exposed and become ill when taking care of the victims of chemical suicide? Do all of these cases turn into a mass casualty incident? How can our colleagues that work in prehospital medicine protect themselves?
The substances used are usually liquid products. The most important component of these scenarios is rapid recognition. Many times, the victim places signs on their vehicle, or on the outside of an enclosed space with sayings such as “Toxic Gas: Do not Enter”. If there is a victim in a vehicle, the windows should be broken from the farthest point away from the patient to allow for the gas to dissipate. If there is a victim in an enclosed space other than a vehicle, standard self contained breathing apparatus is sufficient, or Level B PPE. One of the most important take home points is to NOT GO INTO AN ENCLOSED SPACE WITHOUT RESPIRATORY PROTECTION UNDER ANY CIRCUMSTANCES. Standard precautions, including gloves and gowns, will protect you from topical exposure to the chemicals.
Ocular and dermal decontamination of the victims is often necessary due to exposure to liquid products during mixing. However, gas exposures carry no risk of secondary contamination to healthcare workers and therefore, larger decontamination efforts are not needed.19 Decontamination should largely be done prehospital, but in the event that a patient is brought in to the ED without being decontaminated, removal of their clothes is imperative. Removal of clothing removes an estimated 75 to 90% of the exposure.19 Once their clothes have been removed, they should be placed in a plastic bag and sealed. If there are any solid materials on the skin, unlikely in this scenario, they should be brushed off, followed by decontamination with water and soap, if available.
Don’t forget the eyes! Acids burn. Acids in the eye cause chemical burns via coagulative necrosis. Decontamination should be started immediately and the eyes should be flushed for a minimum of 15 minutes with water or normal saline until neutral pH. Thereafter, care is supportive.
Despite the concerns surrounding “13 Reasons Why”, the show was released. Netflix did add a warning to viewers about the theme of the show. Additionally, in July 2019, the suicide scene in the first season’s final episode was edited out. But, sadly, the warnings and removal of the suicide scene did not impact the suicide contagion. The concerns of suicide contagion were valid. A recent retrospective review utilizing data from the Centers for Disease Control (CDC) Wide-ranging Online Data for Epidemiologic research database (WONDER) confirms that suicide rates among both males and females between the ages of 10 and 19 years of age increased during the times when the show was trending on social media sites. This data also showed that there was an increase in suicides by hanging, which was the method used in the series.1
We have seen this trend of suicide contagion in chemical suicides and this will likely continue with increased media reports of the ease of these methods. Nearly 90% of suicide victims have a significant psychiatric illness at the time of their death, which may be undiagnosed, untreated or both.20 It is imperative that we attempt to identify at risk populations. The National Suicide Prevention Lifeline at 1-800-273-TALK (8255) is an invaluable resource.
Approach to these Patients
- Removal from the source is imperative
- Aggressive supportive care and ACLS as needed
- Removal of clothes and decontamination of skin and eyes of the victims
- Consider sodium nitrite and/or hydroxocobalamin in patients with suspected hydrogen sulfide that remain symptomatic after initial supportive care
- Hyperbaric oxygen therapy in severely poisoned CO patients
- 1.Niederkrotenthaler T, Stack S, Till B, et al. Association of Increased Youth Suicides in the United States With the Release of 13 Reasons Why. JAMA Psychiatry. May 2019. https://www.ncbi.nlm.nih.gov/pubmed/31141094.
- 2.Ortiz P, Khin K. Traditional and new media’s influence on suicidal behavior and contagion. Behav Sci Law. 2018;36(2):245-256. https://www.ncbi.nlm.nih.gov/pubmed/29659071.
- 3.Fekete S, Schmidtke A, Takahashi Y, Etzersdorfer E, Upanne M, Osvath P. Mass media, cultural attitudes, and suicide. Results of an international comparative study. Crisis. 2001;22(4):170-172. https://www.ncbi.nlm.nih.gov/pubmed/11848661.
- 4.Morii D, Miyagatani Y, Nakamae N, Murao M, Taniyama K. Japanese experience of hydrogen sulfide: the suicide craze in 2008. J Occup Med Toxicol. 2010;5:28. https://www.ncbi.nlm.nih.gov/pubmed/20920221.
- 5.Bott E, Dodd M. Suicide by hydrogen sulfide inhalation. Am J Forensic Med Pathol. 2013;34(1):23-25. https://www.ncbi.nlm.nih.gov/pubmed/23361075.
- 6.Azrael D, Mukamal A, Cohen A, Gunnell D, Barber C, Miller M. Identifying and Tracking Gas Suicides in the U.S. Using the National Violent Death Reporting System, 2005-2012. Am J Prev Med. 2016;51(5 Suppl 3):S219-S225. https://www.ncbi.nlm.nih.gov/pubmed/27745610.
- 7.Anderson A. Characterization of Chemical Suicides in the United States and Its Adverse Impact on Responders and Bystanders. West J Emerg Med. 2016;17(6):680-683. https://www.ncbi.nlm.nih.gov/pubmed/27833671.
- 8.Dorevitch S, Forst L, Conroy L, Levy P. Toxic inhalation fatalities of US construction workers, 1990 to 1999. J Occup Environ Med. 2002;44(7):657-662. https://www.ncbi.nlm.nih.gov/pubmed/12134529.
- 9.Reedy S, Schwartz M, Morgan B. Suicide fads: frequency and characteristics of hydrogen sulfide suicides in the United States. West J Emerg Med. 2011;12(3):300-304. https://www.ncbi.nlm.nih.gov/pubmed/21731786.
- 10.Jiang J, Chan A, Ali S, et al. Hydrogen Sulfide–Mechanisms of Toxicity and Development of an Antidote. Sci Rep. 2016;6:20831. https://www.ncbi.nlm.nih.gov/pubmed/26877209.
- 11.Ng P, Hendry-Hofer T, Witeof A, et al. Hydrogen Sulfide Toxicity: Mechanism of Action, Clinical Presentation, and Countermeasure Development. J Med Toxicol. May 2019. https://www.ncbi.nlm.nih.gov/pubmed/31062177.
- 12.Hall A, Rumack B. Hydrogen sulfide poisoning: an antidotal role for sodium nitrite? Vet Hum Toxicol. 1997;39(3):152-154. https://www.ncbi.nlm.nih.gov/pubmed/9167244.
- 13.Haouzi P, Sonobe T, Judenherc-Haouzi A. Hydrogen sulfide intoxication induced brain injury and methylene blue. Neurobiol Dis. May 2019:104474. https://www.ncbi.nlm.nih.gov/pubmed/31103557.
- 14.Haouzi P, Tubbs N, Cheung J, Judenherc-Haouzi A. Methylene Blue Administration During and After Life-Threatening Intoxication by Hydrogen Sulfide: Efficacy Studies in Adult Sheep and Mechanisms of Action. Toxicol Sci. 2019;168(2):443-459. https://www.ncbi.nlm.nih.gov/pubmed/30590764.
- 15.Yang C, Ger J, Li C. Formic acid: a rare but deadly source of carbon monoxide poisoning. Clin Toxicol (Phila). 2008;46(4):287-289. https://www.ncbi.nlm.nih.gov/pubmed/18363119.
- 16.Lin P, Dunn W. Suicidal carbon monoxide poisoning by combining formic acid and sulfuric acid within a confined space. J Forensic Sci. 2014;59(1):271-273. https://www.ncbi.nlm.nih.gov/pubmed/24328850.
- 17.Tomaszewski C. Carbon Monoxide. In: Nelson L, Howland M, Lewin N, Smith S, Goldfrank L, Hoffman R, eds. Goldfrank’s Toxicologic Emergencies. 11th ed. New York: McGraw Hill; 2019:1663-1675.
- 18.Simonsen C, Magnusdottir S, Andreasen J, Rohde M, Kjærgaard B. ECMO improves survival following cardiogenic shock due to carbon monoxide poisoning – an experimental porcine model. Scand J Trauma Resusc Emerg Med. 2018;26(1):103. https://www.ncbi.nlm.nih.gov/pubmed/30466470.
- 19.Houston M, Hendrickson R. Decontamination. Crit Care Clin. 2005;21(4):653-672, v. https://www.ncbi.nlm.nih.gov/pubmed/16168307.
- 20.Arsenault-Lapierre G, Kim C, Turecki G. Psychiatric diagnoses in 3275 suicides: a meta-analysis. BMC Psychiatry. 2004;4:37. https://www.ncbi.nlm.nih.gov/pubmed/15527502.