TY - JOUR T1 - Sulfhaemoglobinaemia caused by ferrous sulfate JF - BMJ Case Reports DO - 10.1136/bcr-2017-220521 VL - 2017 SP - bcr-2017-220521 AU - Laith Derbas AU - Mohamed Warsame AU - Mohannad Abu Omar AU - Yousaf Zafar AU - Gregory Howell Y1 - 2017/06/13 UR - http://casereports.bmj.com/content/2017/bcr-2017-220521.abstract N2 - A 78-year-old man was referred from his primary care clinic to the emergency department due to bluish discolouration of his lips and decreased oxygen saturation on pulse oximetry. The patient was asymptomatic. Physical exam was normal except for lip cyanosis. A CT pulmonary angiogram was negative for pulmonary embolism. Arterial blood gas (ABG) analysis with co-oximetry showed low oxyhaemoglobin, normal partial pressure of oxygen and methaemoglobinaemia, but an unexplained ‘gap’ in total haemoglobin saturation. This gap was felt to be due to sulfhaemoglobinaemia. After a thorough review of his medications, ferrous sulfate was stopped which resulted in resolution in patient’s cyanosis and normalisation of his ABG after 7 weeks. ER -