Critically ill patients - Crystalloids are safer than colloids
Purchasing Bottom Line
Use of colloids was associated with an increase of absolute risk of mortality of 4%.
Citation
Schierhout G, Roberts I, Alderson P. Colloids compared to crystalloids in fluid resuscitation of critically ill patients (Cochrane Review). In: The Cochrane Library, 4, 1998. Oxford: Update Software.
Purchasing Question
In routine resuscitation of critically ill patients, are colloids or crystalloids more effective?
Search Terms
"colloids" AND "crystalloids" and "resuscitation" in The Cochrane Library, MEDLINE
The Study
Systematic review of 37 RCTs with a total of 1622 patients. Mortality data derived from 19 of the 37 RCTs with 1315 patients.
The Evidence
| AR(colloids) | AR(crystalloids) | RR AR1/AR2 |
ARR | NNH with colloids (or treat with crystalloids to avoid death) | |
|---|---|---|---|---|---|
| Total deaths (all patients) | 168/685 = 0.25 |
118/630 = 0.19 |
1.31 | 0.058 | 17 |
| Deaths from trauma | 82/335 = 0.24 |
44/301 = 0.15 |
1.60 | 0.09 | 11 |
| Deaths from surgery* | 3/105 = 0.029 |
6/86 = 0.07 |
0.41 | -0.04 | 25 (NNH with crystalloids) |
| Deaths from burns | 60/207 = 0.29 |
50/209 = 0.24 |
1.20 | 0.05 | 20 |
The evidence (from weighted data in relative risk table and results section)
| RR | ARR | NNT | |
|---|---|---|---|
| Total deaths (all patients) | 1.19 (0.98-1.45) | 0.04 (0.0-0.08) | 25 (13 to infinity) |
Comments
- *On first glance, it appears that surgical patients do better with colloids, but it should be noted that this result is not significant, and based on a small number of patients (117) and deaths (9).
- It might be noted that the overall relative risk of mortality from colloids vs. crystalloids is not statistically significant (the confidence intervals cross the 1.0 line). However, this probably does not invalidate the main message from the study that crystalloids are at least as safe if not safer than colloids, and an awful lot cheaper for general use in Accident and Emergency!
Appraised By
Anna Donald and Sam Vincent March 1999.
Expiry Date
March 2001

