Abstract
A man in his 20s presented with severe left-sided chest pain, shortness of breath and acute confusion. Initial examination revealed central cyanosis, normal heart sounds, vesicular breath sounds in both lung fields and a bruised right calf. The patient reported that he had recently injured his right leg and that he had not taken medication prescribed for blood clots for several days. Peripheral oxygen saturations were 85% despite high flow oxygen via a non-rebreather mask. ECG revealed sinus tachycardia. Arterial blood gas sampling confirmed hypoxaemia. Given the history and the severe hypoxia, he was managed for pulmonary embolism initially.Closer inspection of his arterial blood results showed a methaemoglobin percentage of 20.4%. He was given intravenous methylene blue which resulted in resolution of his symptoms within 30 min. He subsequently confirmed that he was undergoing genetic testing for likely congenital methaemoglobinaemia.
Reference10 articles.
1. Drugs may be induced methemoglobinemia;Alanazi;J Hematol Thrombo Dis,2017
2. Poppers-Induced methemoglobinemia: a curious case of the blues;Tello;Cureus,2021
3. Prilocaine induced methaemoglobinaemia in a medically compromised patient. was this an inevitable consequence of the dose administered?;Adams;Br Dent J,2007
4. Ludlow JT , Wilkerson RG , Nappe TM . Methemoglobinemia. In: StatPearls. Treasure Island (FL): StatPearls Publishing, 2021. https://www.ncbi.nlm.nih.gov/books/NBK537317/
5. Code blue: life-threatening methemoglobinemia;Ponce Ríos;Clin Pract Cases Emerg Med,2019