title: Higher vs. lower haemoglobin threshold for transfusion in septic shock: subgroup analyses of the TRISS trial.
abstract: BACKGROUND
  Using a restrictive transfusion strategy appears to be safe in sepsis, but there may be subgroups of patients who benefit from transfusion at a higher haemoglobin level. We explored if subgroups of patients with septic shock and anaemia had better outcome when transfused at a higher vs. a lower haemoglobin threshold.
  
  
  METHODS
  In post-hoc analyses of the full trial population of 998 patients from the Transfusion Requirements in Septic Shock (TRISS) trial, we investigated the intervention effect on 90-day mortality in patients with severe comorbidity (chronic lung disease, haematological malignancy or metastatic cancer), in patients who had undergone surgery (elective or acute) and in patients with septic shock as defined by the new consensus definition: lactate above 2 mmol/l and the need for vasopressors to maintain a mean arterial pressure above 65 mmHg.
  
  
  RESULTS
  The baseline characteristics were mostly similar between the two intervention groups in the different subgroups. There were no differences in the intervention effect on 90-day mortality in patients with chronic lung disease (test of interaction P = 0.31), haematological malignancy (P = 0.47), metastatic cancer (P = 0.51), in those who had undergone surgery (P = 0.99) or in patients with septic shock by the new definition (P = 0.20).
  
  
  CONCLUSIONS
  In exploratory analyses of a randomized trial in patients with septic shock and anaemia, we observed no survival benefit in any subgroups of transfusion at a haemoglobin threshold of 90 g/l vs. 70 g/l.
authors.affiliation: Department of Intensive Care, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: S L
authors.identifier: http://orcid.org/0000-0001-5920-2588
authors.initials: SL
authors.lastname: Rygård
authors.affiliation: Department of Intensive Care, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: L B
authors.initials: LB
authors.lastname: Holst
authors.affiliation: Copenhagen Trial Unit, Centre for Clinical Intervention Research, Copenhagen, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Wetterslev
authors.affiliation: Section for Transfusion Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: P I
authors.initials: PI
authors.lastname: Johansson
authors.affiliation: Department of Intensive Care, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.|Centre for Research in Intensive Care, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Perner
mesh_terms: D000368:Aged; D001803:Blood Transfusion; D015897:Comorbidity; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008875:Middle Aged; D012772:Shock, Septic / Q000097:blood / Q000628:therapy*
chemical_list: D006454:Hemoglobins