{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T22:10:25Z","timestamp":1782771025456,"version":"3.54.5"},"reference-count":15,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,17]],"date-time":"2023-01-17T00:00:00Z","timestamp":1673913600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Methemoglobinemia (MetHb) is a rare and potentially severe dyshemoglobinemia that can be induced by exposure to oxidizing agents, decreasing the functional capacity of the hemoglobin molecule to transport and release oxygen into the tissues. MetHb can originate from gases with oxidizing capacity generated by internal combustion engines, although since the universalization of catalyst converters in automobiles, a tiny proportion of MetHb poisoning is due to exposure to engine gases and fumes. Within this group, only two cases due to suicidal motivations have been reported in the last 30 years. Case presentation: Here, we expose the case of a patient with MetHb levels of 25.2% (normal 0\u20131.5%) who with suicidal motivations had attached and locked a hose to the exhaust pipe of her vehicle with electrical tape, becoming exposed to a sustained concentration of the vehicle\u2019s exhaust. Upon her arrival at the emergency department, the presence of generalized greyish cyanosis with alterations of the sensorium, dissociation between saturation measured by arterial blood gas analysis and pulse oximetry (98% vs. 85%), no response to high-flow oxygen therapy, and an excellent response to intravenous methylene blue treatment were highlighted. Conclusions: This report illustrates an original case of acute toxic acquired MetHb due to inhalation of oxidizing substances originating from the bad ignition of an internal combustion engine. When evaluating a patient with suspected gas intoxication, we usually consider poisoning by the most common toxins, such as carbon monoxide or cyanide. In this context, we propose an algorithm to assist in the suspicion of this entity in patients with cyanosis in the emergency department. MetHb poisoning should be suspected, and urgent co-oximetry should be requested when there is no congruence between cyanosis intensity and oxygen saturation measured by pulse oximetry, if there is discordance between the results of oxygen saturation measured by arterial blood gas and pulse oximeter, and if there is no response to oxygen treatment. This algorithm could be useful to not delay diagnosis, improve prognosis, and limit potential sequelae.<\/jats:p>","DOI":"10.3390\/jcm12030734","type":"journal-article","created":{"date-parts":[[2023,1,17]],"date-time":"2023-01-17T03:41:52Z","timestamp":1673926912000},"page":"734","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Methemoglobinemia Secondary to Inhalation of Automobile Emissions with Suicide Motivations"],"prefix":"10.3390","volume":"12","author":[{"given":"Manuel Antonio","family":"Taz\u00f3n-Varela","sequence":"first","affiliation":[{"name":"Emergency Department, Laredo Hospital, 39770 Laredo, Spain"},{"name":"Community Health Group, Valdecilla Research Institute (IDIVAL), 39011 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c1ngel","family":"Padilla-Mielgo","sequence":"additional","affiliation":[{"name":"Emergency Department, Laredo Hospital, 39770 Laredo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raquel","family":"Villaverde-Plazas","sequence":"additional","affiliation":[{"name":"Emergency Department, Laredo Hospital, 39770 Laredo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabiola","family":"Espinoza-Cuba","sequence":"additional","affiliation":[{"name":"Emergency Department, Laredo Hospital, 39770 Laredo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nekane","family":"Gallo-Salazar","sequence":"additional","affiliation":[{"name":"Emergency Department, Laredo Hospital, 39770 Laredo, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1387-2655","authenticated-orcid":false,"given":"Pedro","family":"Mu\u00f1oz-Cacho","sequence":"additional","affiliation":[{"name":"Community Health Group, Valdecilla Research Institute (IDIVAL), 39011 Santander, Spain"},{"name":"Primary Care Unit, Cantabria Health Service, 39011 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1666","DOI":"10.1002\/ajh.26340","article-title":"SWG of red cell and iron of EHA and EuroBloodNet. 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J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"bcr2016215102","DOI":"10.1136\/bcr-2016-215102","article-title":"Naphthalene ball poisoning: A rare cause of acquired methaemoglobinaemia","volume":"2016","author":"Deo","year":"2016","journal-title":"BMJ Case Rep."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/3\/734\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:07:57Z","timestamp":1760119677000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/3\/734"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,17]]},"references-count":15,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["jcm12030734"],"URL":"https:\/\/doi.org\/10.3390\/jcm12030734","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,17]]}}}