Colloid solutions for fluid resuscitation.
BACKGROUND
Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy.


OBJECTIVE
To compare the effects of different colloid solutions in patients thought to need volume replacement.


METHODS
We searched the Cochrane Injuries Group specialised register, CENTRAL (2007, Issue 1), MEDLINE (1994 to March 2007), EMBASE (1974 to March 2007), and the National Research Register (2007, issue 1). Bibliographies of trials retrieved were searched, and drug companies manufacturing colloids were contacted for information. The search was last updated in March 2007.


METHODS
Randomised and quasi-randomised trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement. The outcomes measured were death, amount of whole blood transfused, and incidence of adverse reactions.


METHODS
Two authors independently extracted the data and assessed the quality of the trials.


RESULTS
Seventy trials, with a total of 4375 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 24 trials and poor or uncertain in the rest. Deaths were obtained in 46 trials. For albumin or PPF versus hydroxyethyl starch (HES) 25 trials (n = 1234) reported mortality. The pooled relative risk (RR) was 1.14 (95% CI 0.91 to 1.43). For albumin or PPF versus gelatin, seven trials (n = 636) reported mortality. The RR was 0.97 (95% CI 0.68 to 1.39). For albumin or PPF versus Dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 18 trials (n = 1337) reported mortality and RR was 1.00 (95% CI 0.80 to 1.25). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Thirty-seven trials recorded the amount of blood transfused, however quantitative analysis was not possible due to skewness and variable reporting. Nineteen trials recorded adverse reactions, but none occurred.


CONCLUSIONS
From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the confidence intervals are wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.
Bunn
F
F
University of Hertfordshire, Centre for Research in Primary and Community Care (CRIPACC), College Lane, Hatfield, Hertfordshire, UK AL10 9PN. f.bunn@herts.ac.uk
Trivedi
D
D
Ashraf
S
S
D001798:Blood Proteins / Q000627:therapeutic use*; D003102:Colloids / Q000627:therapeutic use; D003911:Dextrans / Q000627:therapeutic use*; D005440:Fluid Therapy; D006801:Humans; D010952:Plasma Substitutes / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D015532:Rehydration Solutions / Q000627:therapeutic use*
D001798:Blood Proteins; D003102:Colloids; D003911:Dextrans; D010952:Plasma Substitutes; D015532:Rehydration Solutions