{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T16:28:23Z","timestamp":1787502503676,"version":"build-2736575974"},"reference-count":13,"publisher":"Springer Science and Business Media LLC","issue":"4","license":[{"start":{"date-parts":[[2025,8,4]],"date-time":"2025-08-04T00:00:00Z","timestamp":1754265600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,8,4]],"date-time":"2025-08-04T00:00:00Z","timestamp":1754265600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J. Med. Toxicol."],"published-print":{"date-parts":[[2025,10]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Significant cases of methemoglobinemia will cause a signal interference in traditional dual-wavelength pulse oximetry leading to the classic finding of \u201crefractory hypoxemia\u201d. As smartwatches begin to incorporate pulse oximetry capabilities, it is unclear whether these devices will demonstrate the same type of interference in the presence of methemoglobinemia. This article reports a case where a patient\u2019s Apple Watch\u00a9 reported a hypoxemia alert in the setting of phenazopyridine induce methemoglobinemia.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case Report<\/jats:title>\n                    <jats:p>\n                      This is a case report of a 71-year-old female whose Apple Watch\u00a9 reported a hypoxemia alarm in the setting of methemoglobinemia caused by phenazopyridine use. The patient\u2019s smartwatch began signaling hypoxemia alerts the day before she noticed clinical cyanosis. 24\u00a0hours after the hypoxemia alerts began, she presented to the Emergency Department (ED) with shortness of breath and blue discoloration of skin. The Apple Watch\u00a9 recorded oxygen saturation readings between 73% and 86%. Upon arrival to the ED, the patient\u2019s SpO\n                      <jats:sub>2<\/jats:sub>\n                      was 84% on traditional hospital-grade dual-wavelength pulse oximetry and her methemoglobin level was 19.8%. Her symptoms and methemoglobinemia resolved after administration of 1\u00a0mg\/kg of IV methylene blue.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Pulse oximetry used in smartwatch technology can trigger a hypoxemia alarm in the presence of drug-induced methemoglobinemia. If demonstrated to be a reproducible finding, smartwatch technology has the potential to be used as part of an early detection system for clinically significant methemoglobinemia.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s13181-025-01090-9","type":"journal-article","created":{"date-parts":[[2025,8,4]],"date-time":"2025-08-04T20:34:54Z","timestamp":1754339694000},"page":"430-433","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Smartwatch Detection of Refractory Hypoxemia in Phenazopyridine-Induced Methemoglobinemia: A Case Report"],"prefix":"10.1007","volume":"21","author":[{"given":"Leann N.","family":"Tulisiak","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mackenzie E.","family":"Loesing","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander","family":"Ljungberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric E.","family":"Kaczor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,8,4]]},"reference":[{"issue":"6","key":"1090_CR1","doi-asserted-by":"publisher","first-page":"789","DOI":"10.1016\/j.rmed.2013.02.004","volume":"107","author":"ED Chan","year":"2013","unstructured":"Chan ED, Chan MM, Chan MM. Pulse oximetry: Understanding its basic principles facilitates appreciation of its limitations. Respiratory Med [Internet]. 2013;107(6):789\u201399. https:\/\/doi.org\/10.1016\/j.rmed.2013.02.004.","journal-title":"Respiratory Med [Internet]"},{"key":"1090_CR2","unstructured":"Price D. Methemoglobin Inducers. In: Goldfrank\u2019s Toxicologic Emergencies, 11e [Internet]. 2019. Available from: https:\/\/accesspharmacy.mhmedical.com\/content.aspx?bookid=2569&sectionid=210264643"},{"issue":"6","key":"1090_CR3","doi-asserted-by":"publisher","first-page":"845","DOI":"10.3390\/clinpract12060089","volume":"12","author":"O KC","year":"2022","unstructured":"KC O, Subedi A, Sharma R, Dahal PH, Koirala M. A case of severe hypoxia caused by Phenazopyridine-Induced methemoglobinemia: A near fatal event from Over-the-Counter medication use. Clin Pract. 2022;12(6):845\u201351. https:\/\/doi.org\/10.3390\/clinpract12060089.","journal-title":"Clin Pract"},{"issue":"10S","key":"1090_CR4","doi-asserted-by":"publisher","first-page":"S2539","DOI":"10.14309\/01.ajg.0001044940.05142.36","volume":"119","author":"TJ Mathews","year":"2024","unstructured":"Mathews TJ, Mok A, Jackson M. S3893 using a smartwatch as a diagnostic tool in a patient with ulcerative colitis who developed unexplained Anemia and hypoxia. Am J Gastroenterol. 2024;119(10S):S2539\u201340. https:\/\/doi.org\/10.14309\/01.ajg.0001044940.05142.36.","journal-title":"Am J Gastroenterol"},{"key":"1090_CR5","doi-asserted-by":"publisher","unstructured":"Koch AA, Stolzenberg L, Pathak PR, Penot AR. Phenazopyridine-Induced methemoglobinemia: A case report. Cureus. 2023;15(1). https:\/\/doi.org\/10.7759\/cureus.33715.","DOI":"10.7759\/cureus.33715"},{"key":"1090_CR6","doi-asserted-by":"publisher","unstructured":"Murphy T, Fernandez M. Acquired methemoglobinemia from phenazopyridine use. Int J Emerg Med. 2018;11(1). https:\/\/doi.org\/10.1186\/s12245-018-0208-5.","DOI":"10.1186\/s12245-018-0208-5"},{"issue":"1","key":"1090_CR7","doi-asserted-by":"publisher","first-page":"143","DOI":"10.1213\/ANE.0b013e3181c91bb6","volume":"111","author":"JR Feiner","year":"2010","unstructured":"Feiner JR, Bickler PE, Mannheimer PD. Accuracy of methemoglobin detection by pulse CO-Oximetry during hypoxia. Anesth Analgesia. 2010;111(1):143\u20138. https:\/\/doi.org\/10.1213\/ANE.0b013e3181c91bb6.","journal-title":"Anesth Analgesia"},{"key":"1090_CR8","unstructured":"Wagh A, Masimo Announces CE, Marking and Release of Oxygen Reserve Index\u2122 rainbow Lite Sensors. Business Wire India. Updated on: September 3, 2018. https:\/\/digitalconqurer.com\/bw-tech\/masimo-announces-ce-marking-and-release-of-oxygen-reserve-index-rainbow-lite-sensors-3\/. Accessed May 20, 2025."},{"key":"1090_CR9","unstructured":"Radical-7\u00a9. Accessed May, 20 Pulse CO-Oximeter\u00a9. Operatory\u2019s Manual. https:\/\/techdocs.masimo.com\/globalassets\/techdocs\/pdf\/lab-5475j_master.pdf. 2025."},{"key":"1090_CR10","unstructured":"Blood Oxygen App on the Apple Watch. 2022 p. 1\u20139. https:\/\/www.apple.com\/healthcare\/docs\/site\/Blood_Oxygen_app_on_Apple_Watch_October_2022.pdf. Accessed 7 April 2025."},{"key":"1090_CR11","doi-asserted-by":"publisher","unstructured":"Rafl J, Bachman TE, Rafl-Huttova V, Walzel S, Rozanek M. Commercial smartwatch with pulse oximeter detects short-time hypoxemia as well as standard medical-grade device: validation study. Digit HEALTH. 2022 Jan. https:\/\/doi.org\/10.1177\/20552076221132127.","DOI":"10.1177\/20552076221132127"},{"key":"1090_CR12","unstructured":"Alex Alderson. Garmin patent revealed with aim of improving SpO2 monitoring in smartwatches. NotebookChekc. May 2022. https:\/\/www.notebookcheck.net\/Garmin-patent-revealed-with-aim-of-improving-SpO2-monitoring-in-smartwatches.621254.0.html. Accessed 7 April 2025."},{"issue":"5","key":"1090_CR13","doi-asserted-by":"publisher","first-page":"e142","DOI":"10.1213\/ANE.0000000000004325","volume":"129","author":"LQ Rong","year":"2019","unstructured":"Rong LQ, Mauer E, Mustapich TL, White RS, Di Franco A, Girardi LN, Gaudino M, Pryor KO. Characterization of the rapid drop in pulse oximetry after intraoperative administration of methylene blue in open thoracoabdominal aortic repairs. Anesth Analgesia. 2019;129(5):e142\u20135. https:\/\/doi.org\/10.1213\/ANE.0000000000004325.","journal-title":"Anesth Analgesia"}],"container-title":["Journal of Medical Toxicology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s13181-025-01090-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s13181-025-01090-9","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s13181-025-01090-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T10:12:31Z","timestamp":1781604751000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s13181-025-01090-9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,4]]},"references-count":13,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2025,10]]}},"alternative-id":["1090"],"URL":"https:\/\/doi.org\/10.1007\/s13181-025-01090-9","relation":{},"ISSN":["1556-9039","1937-6995"],"issn-type":[{"value":"1556-9039","type":"print"},{"value":"1937-6995","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,4]]},"assertion":[{"value":"8 April 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 July 2025","order":2,"name":"revised","label":"Revised","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"16 July 2025","order":3,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"4 August 2025","order":4,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Consent for publication of this case was obtained and provided to the journal in accordance with\n                      JMT\n                      policy.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Compliance and Ethical"}},{"value":"Data in this manuscript were previously presented at ACMT\u2019s Annual Scientific Meeting, Washington, DC, 2024.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Previous Presentations"}},{"value":"The authors have no conflicts of interest to disclose.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of Interest (Includes Financial Disclosures)"}}]}}