Adverse effects of subcutaneous vs intravenous hydration in older adults: An assessor-blinded randomised controlled trial (RCT).

Background Hydration therapy is essential in the care of the older patient. Subcutaneous (SC) hydration is a relevant method for parenteral hydration, but clinical trials on the subject have methodological shortcomings compared to updated standards. Design Assessor-blinded, non-inferiority RCT to explore if SC is a safe alternative to intravenous (IV) hydration. Participants Eligible patients were: Admitted patients 65 years or older with a need for parenteral hydration. The targeted sample size was 67 patients in each group. Intervention Patients were randomised to parenteral hydration via an IV or SC catheter during a 24 hours observation period. The non-randomised catheter (inactive) was placed as a sham on the patient, thereby blinding the caregivers and outcome assessors. Measurement Our primary outcome was the proportion of patients reporting at least one adverse effect with a non-inferiority calculation using a 20% margin. Results We included 51 patients, with 24 randomised to SC and 27 to IV. We were unable to reach our target sample size due to challenges in recruitment, time limitation, and COVID-19. For the outcome of adverse effects, SC was non-inferior to IV (p = 0.012). Time spent on inserting the catheters was shorter with SC (p = 0.001). The groups did not differ by pain of insertion, discomfort during infusion, or the risk of developing delirium. Conclusion SC is a safe alternative to IV hydration, is faster to place and should be an available method for parenteral hydration wherever older adults are cared for. Trial registration ClinicalTrials.gov Identifier: NCT03710408.