Methaemoglobinaemia-induced oxygen desaturation complicating chest trauma
A 72-year-old man presented to the Emergency Department by ambulance following a rollover motor vehicle crash preceded by black-out symptoms. He had been suffering from dermatitis herpetiformis for the last six years and was being treated with dapsone 100 mg and a partially gluten-free diet. On admission he had a respiratory rate of 22, pulse oximetry saturations of 89% improving to 93% with 3 l/min via nasal prongs, a heart rate of 75 bpm, and a non-invasive blood pressure of 111/52. No life-threatening injuries were identified on primary or secondary survey. A trauma CT-series noted left sided rib fractures.