title: Colloids versus crystalloids for fluid resuscitation in critically ill patients.
abstract: BACKGROUND
  Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.
  
  
  OBJECTIVE
  To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.
  
  
  METHODS
  We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S), and The Controlled Trials metaRegister (www.controlled-trials.com). Reference lists of relevant studies and review articles were searched for further trials. The searches were last updated in September 2008.
  
  
  METHODS
  Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials in pregnant women and neonates.
  
  
  METHODS
  Two authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.
  
  
  RESULTS
  We identified 65 eligible trials; 56 of these presented mortality data.Colloids compared to crystalloidsAlbumin or plasma protein fraction - 23 trials reported data on mortality, including a total of 7754 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval (95% CI) 0.92 to 1.10). When we excluded the trial with poor quality allocation concealment, pooled RR was 1.00 (95% CI 0.91 to 1.09). Hydroxyethyl starch - 17 trials compared hydroxyethyl starch with crystalloids, n = 1172 patients. The pooled RR was 1.18 (95% CI 0.96 to 1.44). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65).Colloids in hypertonic crystalloid compared to isotonic crystalloidEight trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1283 randomised participants. Pooled RR was 0.88 (95% CI 0.74 to 1.05).
  
  
  CONCLUSIONS
  There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.
authors.affiliation: Cochrane Injuries Group, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK, WC1E 7HT.
authors.forename: Pablo
authors.initials: P
authors.lastname: Perel
authors.forename: Ian
authors.initials: I
authors.lastname: Roberts
mesh_terms: D000418:Albumins / Q000627:therapeutic use; D001798:Blood Proteins / Q000627:therapeutic use; D003102:Colloids / Q000627:therapeutic use*; D016638:Critical Illness / Q000401:mortality / Q000628:therapy*; D003911:Dextrans / Q000627:therapeutic use; D005440:Fluid Therapy / Q000379:methods*; D005780:Gelatin / Q000627:therapeutic use; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use; D010952:Plasma Substitutes / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D015532:Rehydration Solutions / Q000627:therapeutic use*; D012151:Resuscitation / Q000379:methods
chemical_list: D000418:Albumins; D001798:Blood Proteins; D003102:Colloids; D003911:Dextrans; D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes; D015532:Rehydration Solutions; D005780:Gelatin