title: Haemoglobin responses to transfusion in severe iron deficiency anaemia: potential impact of gastrointestinal disorders.
abstract: OBJECTIVE
  Red blood cell (RBC) transfusion may be justified in iron deficiency anaemia (IDA) when an increase in oxygen delivery is needed, as sometimes occurs in subjects with haemoglobin <8·0 mg/dL, serious comorbidities or at risk of cardiovascular instability. Earlier investigations showed that some patients with severe IDA requiring transfusion had lower than expected post-transfusion haemoglobin levels with poorer clinical outcomes than other patients. After hypothesizing that haemoglobin responses to transfusion were different and that the underlying gastrointestinal (GI) disorders causing IDA could be a confounder explaining this association, these responses were analysed in a prospective cohort of IDA adults referred for outpatient GI investigation.
  
  
  METHODS
  Transfused patients with proven IDA, baseline haemoglobin at referral <9·0 g/dL and no extraintestinal bleeding were eligible. To assess a homogeneous population, only GI disorders known to cause occult bleeding were considered. Haemoglobin increments per 100 mL of RBCs were investigated.
  
  
  RESULTS
  In total, 2818 patients were enrolled over 10·5 years. On multivariable regression, diffuse angiodysplasias and GI cancer independently predicted for reduced increments in post-transfusion haemoglobin [adjusted regression coefficients: -0·082 (95% confidence interval, -0·093 to -0·072) and -0·073 (95% confidence interval, -0·081 to -0·066), respectively, P < 0·001 in both]. Haemoglobin responses in the remaining bleeding disorders were adequate and agreed with the principle that one RBC unit increases the haemoglobin an average of 1 g/dL.
  
  
  CONCLUSIONS
  The potential differential impact of GI disorders on changes in haemoglobin levels after RBC transfusion could be useful for transfusing physicians, especially for diagnostic purposes.
authors.affiliation: Quick Diagnosis Unit, Adult Day Care Center, Hospital Clínic, University of Barcelona, Barcelona, Spain.|Department of Internal Medicine, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Bosch
authors.affiliation: Quick Diagnosis Unit, Department of Internal Medicine, Hospital Plató, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Montori
authors.affiliation: Quick Diagnosis Unit, Adult Day Care Center, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Guerra-García
authors.affiliation: Primary Healthcare Center-CAPSE, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Costa-Rodríguez
authors.affiliation: Department of Internal Medicine, Hospital San Roque, Gonnet, La Plata, Argentina.
authors.forename: M H
authors.initials: MH
authors.lastname: Quintanilla
authors.affiliation: Department of Internal Medicine, Hospital San Martín, La Plata, Argentina.
authors.forename: P E
authors.initials: PE
authors.lastname: Tolosa-Chapasian
authors.affiliation: Department of Internal Medicine, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Moreno
authors.affiliation: Quick Diagnosis Unit, Adult Day Care Center, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Guasch
authors.affiliation: Department of Internal Medicine, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: López-Soto
mesh_terms: D000328:Adult; D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000209:etiology / Q000628:therapy*; D016888:Angiodysplasia / Q000150:complications / Q000473:pathology; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications* / Q000473:pathology; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies
chemical_list: D006454:Hemoglobins
keywords: diffuse angiodysplasias; gastrointestinal cancer; haemoglobin responses; iron deficiency anaemia; occult gastrointestinal bleeding; red blood cell transfusion