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 (17 October 2012), the Cochrane Central Register of Controlled Trials (The Cochrane Library) (Issue 10, 2012), MEDLINE (Ovid) 1946 to October 2012, EMBASE (Ovid) 1980 to October 2012, ISI Web of Science: Science Citation Index Expanded (1970 to October 2012), ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to October 2012), PubMed (October 2012), www.clinical trials.gov and www.controlled-trials.com. We also searched the bibliographies of relevant studies and review articles.
  
  
  METHODS
  Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials involving pregnant women and neonates.
  
  
  METHODS
  Two review 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 78 eligible trials; 70 of these presented mortality data.COLLOIDS COMPARED TO CRYSTALLOIDS: Albumin or plasma protein fraction - 24 trials reported data on mortality, including a total of 9920 patients. The pooled risk ratio (RR) from these trials was 1.01 (95% confidence interval (CI) 0.93 to 1.10). When we excluded the trial with poor-quality allocation concealment, pooled RR was 1.00 (95% CI 0.92 to 1.09). Hydroxyethyl starch - 25 trials compared hydroxyethyl starch with crystalloids and included 9147 patients. The pooled RR was 1.10 (95% CI 1.02 to 1.19). Modified gelatin - 11 trials compared modified gelatin with crystalloid and included 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 and included 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65). COLLOIDS IN HYPERTONIC CRYSTALLOID COMPARED TO ISOTONIC CRYSTALLOID: Nine trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1985 randomised participants. Pooled RR for mortality was 0.91 (95% CI 0.71 to 1.06).
  
  
  CONCLUSIONS
  There is no evidence from randomised controlled trials that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. Furthermore, the use of hydroxyethyl starch might increase mortality. As colloids are not associated with an improvement in survival and are considerably more expensive than crystalloids, it is hard to see how their continued use in clinical practice can be justified.
authors: Cochrane Injuries Group, London School of Hygiene & Tropical Medicine, London, UK. pablo.perel@Lshtm.ac.uk.
authors: Pablo
authors: P
authors: Perel
authors: Ian
authors: I
authors: Roberts
authors: Katharine
authors: K
authors: Ker
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*; D000077324:Crystalloid Solutions; D003911:Dextrans / Q000627:therapeutic use; D005440:Fluid Therapy / Q000379:methods; D005780:Gelatin / Q000627:therapeutic use; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000009:adverse effects / Q000627:therapeutic use; D007552:Isotonic Solutions / Q000627:therapeutic use*; D010952:Plasma Substitutes / Q000009:adverse effects / 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; D000077324:Crystalloid Solutions; D003911:Dextrans; D006895:Hydroxyethyl Starch Derivatives; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D015532:Rehydration Solutions; D005780:Gelatin