Abstract:
Methaemoglobinaemia occurs when iron in haemoglobin is oxidised into a form that cannot transport oxygen. At low levels, it is asymptomatic, though at rising levels symptoms arise from impaired oxygenation, and it can ultimately be fatal. While uncommon, it is important to consider in hypoxaemic COVID-19 patients, especially if they are not clinically improving on standard treatments and workup for other causes does not explain the ongoing hypoxaemia. It is often diagnosed through a mismatch in peripheral and arterial oxygen, with the former typically less than the latter. We present the case of a COVID-19 patient who was found to have methaemoglobinaemia due to dapsone use for Pneumocystic jirovecii pneumonia (PJP) prophylaxis while on chemotherapy. Dapsone was stopped and supplemental high-flow nasal cannula was provided, and methaemoglobin levels improved over a 5-day period. She was discharged to follow-up with her haematologist in the clinic.
摘要:
当血红蛋白中的铁被氧化成不能运输氧气的形式时,就会发生高铁血红蛋白血症。在低水平,它是无症状的,尽管在升高的水平下,氧合受损会引起症状,最终可能是致命的。虽然不常见,在低氧血症COVID-19患者中,重要的是要考虑,特别是如果他们在标准治疗和其他原因的检查中没有临床改善,则不能解释持续的低氧血症。它通常是通过外周和动脉血氧不匹配来诊断的,前者通常小于后者。我们介绍了一名COVID-19患者的病例,该患者在化疗期间因使用氨苯砜预防肺囊性吉罗韦西肺炎(PJP)而被发现患有高铁血红蛋白血症。停止氨苯砜,并提供补充的高流量鼻插管,和高铁血红蛋白水平在5天内改善。她已出院,在诊所接受血液学家的随访。