Abstract: We included 12 studies (2351 participants: range 27 to 841). Characteristics: The 12 included studies compared hypertonic (colloids) with isotonic fluids (crystalloids); of these, five studies (1420 participants) also compared 0.9% saline with another fluid. No data were available to make other comparisons. Delay from stroke to recruitment varied from less than 24 hours to 72 hours. Duration of fluid delivery was between two hours and 10 days. Bias assessment: Investigators and participants in eight of the 12 included studies were blind to treatment allocation, seven of the 12 included studies gave details of randomisation, and eight of the 12 included studies reported all outcomes measured. Results: There were no relevant completed trials that addressed the effect of volume, duration, or mode of fluid delivery on death or dependence in people with stroke. The odds of death or dependence were similar in participants allocated to colloids or crystalloid fluid regimens (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.79 to 1.21, five studies, I² = 58%, low-quality evidence), and between 0.9% saline or other fluid regimens (OR 1.04, 95% CI 0.82 to 1.32, three studies, I² = 71%, low-quality evidence). There was substantial heterogeneity in these estimates. The odds of death were similar between colloids and crystalloids (OR 1.02, 95% CI 0.82 to 1.27, 12 studies, I² = 24%, moderate-quality evidence), and 0.9% saline and other fluids (OR 0.87, 95% CI 0.67 to 1.12, five studies, I² = 53%, low-quality evidence). The odds of pulmonary oedema were higher in participants allocated to colloids (OR 2.34, 95% CI 1.28 to 4.29, I² = 0%). Although the studies observed a higher risk of cerebral oedema (OR 0.20, 95% CI 0.02 to 1.74) and pneumonia (OR 0.58, 95% CI 0.17 to 2.01) with crystalloids, we could not exclude clinically important benefits or harms. We found no evidence that colloids were associated with lower odds of death or dependence in the medium term after stroke compared with crystalloids, though colloids were associated with greater odds of pulmonary oedema. We found no evidence to guide the best volume, duration, or mode of parenteral fluid delivery for people with acute stroke.

Plain-language summary: The evidence is current to May 2015. We found 12 relevant studies (with 2351 participants) comparing colloids with crystalloids. Eleven of these studies included people with ischaemic stroke (stroke sustained due to a clot), whilst one study included people with haemorrhagic stroke (stroke due to a bleed). Five of these studies (1420 participants) also made a comparison between 0.9% saline, the most commonly prescribed iv fluid, and another fluid type. The largest study had 841 participants, whilst the smallest had 27 participants. The length of time that fluids were given varied between trials, from two hours to 10 days. Ten studies revealed a source of funding. Of these, two studies were funded by fluid manufacturers. We did not find any studies that examined the best fluid volume, mode of fluid delivery, or duration of fluid treatment. We found that people with acute stroke given crystalloids (including 0.9% saline) had about the same risk of death or dependence as people given other fluid types. People given crystalloids also had a lower risk of pulmonary oedema, a complication that can lead to breathlessness due to excess collection of watery fluid in the lungs. From the evidence we obtained, it was difficult to make any concrete conclusions about which fluids were better for reducing brain swelling (cerebral oedema) or a serious lung infection (pneumonia). We found no evidence to guide the best volume, duration, or mode of parenteral fluid delivery for people with acute stroke. The majority of studies had a low to moderate risk of bias based on study limitations and inconsistency. Most studies reported the outcomes they stated they would.