Clinical experience in diagnosis and management of acquired methaemoglobinaemia: a case report and retrospective review

TT Chan, William CY Leung, CK Chan, Heinz KT Lo, Winnie WY Tso, SH Tsui, Thomas SY Chan, Richard SK Chang
2021 Hong Kong Medical Journal  
In June 2008, a 9-month-old boy with unremarkable medical and developmental history presented to the emergency department with acute cyanosis. The child had been fed about 200 g of congee containing rice, vegetables, fish, and egg. He was then noted to have pallor of face and perioral cyanosis. He was conscious and irritable and reported to have vomiting. His respiratory rate was 40 breaths per minute and heart rate was 190 beats per minute. Pulse oximetry showed 90% oxygen saturation on 100%
more » ... ygen via a face mask. Physical examination was otherwise unremarkable. He was admitted to the paediatric intensive care unit. During blood sampling, his blood was noted to be chocolate brown. While on 100% oxygen, his arterial blood gas showed a pH value of 7.33, PaO 2 51.8 kPa, PaCO 2 4.2 kPa, and bicarbonate 17 mmol/L. Blood methaemoglobin (MetHb) level was 51%. He was treated with intravenous methylene blue 15 mg (about 1.5 mg/kg) and urine was observed to be light blue (Fig) . His cyanosis resolved within 1 hour after treatment and
doi:10.12809/hkmj209028 pmid:34706989 fatcat:rfao2ftdbzemxbbpuft5njzfzy