Subcutaneous safer than intravenous hydration in seniors

Subcutaneous (SC) is safer but is less effective than intravenous (IV) hydration in elderly adults, reports a recent meta-analysis.

From the databases of Medline, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials, researchers identified 31 publications, corresponding to 29 studies. Of these, seven were randomized controlled trials (RCTs), 11 were prospective cross-sectional studies, six were retrospective cross-sectional studies, four were case reports, and one was a case-control investigation.

Pooled analysis of the four RCTs with the least risk of bias showed that SC hydration was safer than IV hydration, carrying a 31-percent lower risk of adverse effects (risk ratio [RR], 0.69, 95 percent confidence interval [CI], 0.53–0.88; p=0.003).

Combining two more RCTs and the 13 observational studies, researchers saw that in absolute numbers, the incidence rate of adverse events in SC rehydration was 53 events per 1,000 infusions. In IV rehydration, this number was 130 adverse events per 1,000 infusions.

Serious adverse events were also nominally less likely to occur with SC vs IV hydration (RR, 0.5, 95 percent CI, 0.2–1.2; p=0.13).

However, SC was also found to be less effective than IV hydration. Serum osmolality, for instance, was more greatly improved after IV hydration (mean difference, 5.75 mmol/kg; 95 percent CI, 0.13–11.37; p=0.045). Other markers, such as creatinine, urea, and patient discomfort, were comparable between the two hydration methods. Death rate was likewise similar between groups.