Methaemoglobinaemia  is  a  rare  but  potentially  life-threatening  condition  in  which  there  is  diminution  of  the  oxygen-carrying  capacity  of  the  circulating  haemoglobin.  It  can  result  from  either  congenital  or  acquired  processes.  Acquired  methaemoglobinaemia is more prevalent than congenital methaemoglobinaemia, and notably it has a higher prevalence in infants and neonates than in adults; it results from exposure to oxidising agents. Methaemoglobin forms when haemoglobin is oxidised to contain iron in the ferric (Fe3+) state rather than the normal ferrous (Fe2+) state. Methaemoglobinaemia is a clinical diagnosis and is suspected in the presence of hypoxaemia refractory to supplemental oxygen and in the presence of chocolate-coloured blood. Symptoms are usually dependent on the methaemoglobin levels; at levels higher than 35%, systemic symptoms from tissue hypoxia may be fatal. We present a case of severe life-threatening methaemoglobinaemia following intra-abdominal use of cetrimide during hydatid cyst removal in a 60-year-old female.

Radwan Zeidan is a Senior Pulmonary and Critical Care Fellow at the University of Balamand, Lebanon. He has 2 publications to his name.