title: Methaemoglobin and COHb in patients with malaria.
abstract: BACKGROUND
  Haemolytic conditions may contribute to disease pathogenesis and severe clinical manifestations through the liberation of free haemoglobin (Hb) and production of toxic free haem. Thus, free Hb and haem should be associated with altered MetHb and COHb levels in malaria as in other conditions.
  
  
  METHODS
  This study comprises data collected at three different sites: (i) a retrospective analysis of the first arterial blood gas result (ABGS) of any patient during 2010 at the University Hospital in Lisbon; (ii) a retrospective analysis of ABGS from patients with severe malaria admitted to the intensive care unit in Berlin, Germany; and (iii) a prospective study of non-invasive MetHb measurements in children with and without malaria in Lambaréné, Gabon.
  
  
  RESULTS
  In Lisbon, the mean MetHb level was 1.4% (SD: 0.5) in a total of 17,834 ABGS. Only 11 of 98 samples with a MetHb level of >3.0 referred to infections. COHb levels showed no particular association with clinical conditions, including sepsis. In 13 patients with severe malaria in Berlin, the mean MetHb levels on admission was 1.29%, with 1.36% for cerebral malaria and 1.14% for non-cerebral malaria (P > 0.05). All COHb measurements were below 2.3%. In Lambaréné, Gabon, 132 healthy children had a mean MetHb level of 1.57%, as compared to 150 children with malaria, with a value of 1.77% and 2.05% in uncomplicated and complicated cases, respectively (P < 0.01).
  
  
  CONCLUSIONS
  The data appears consistent with the methaemoglobin/haem hypothesis in malaria and sepsis pathogenesis. However, although MetHb was significantly different between healthy controls and children with malaria in Africa, the difference was rather small, also when compared to previous studies. Still, non-invasive bedside MetHb testing may warrant further evaluation as it could be a simple adjuvant tool for prognosis in resource poor settings.
authors: Thomas
authors: T
authors: Hänscheid
authors: Tom
authors: T
authors: Gresnigt
authors: Sascha
authors: S
authors: Löhr
authors: Arnaud
authors: A
authors: Flamen
authors: Thomas
authors: T
authors: Zoller
authors: José
authors: J
authors: Melo-Cristino
authors: Centre de Recherches Médicales en Lambaréné (CERMEL), Hôpital Albert Schweitzer, Lambaréné, Gabon. M.P.Grobusch@amc.uva.nl.
authors: Martin P
authors: MP
authors: Grobusch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002263:Carboxyhemoglobin / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005681:Gabon / Q000453:epidemiology; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008288:Malaria / Q000097:blood* / Q000453:epidemiology*; D016779:Malaria, Cerebral / Q000097:blood / Q000453:epidemiology; D008297:Male; D008706:Methemoglobin / Q000032:analysis*; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D008706:Methemoglobin; D002263:Carboxyhemoglobin