Assessment of Intravenous Fluid Prescribing and Cannulation Appropriateness in an Acute Medical Unit: A Prospective Service Evaluation

Background Intravenous (IV) fluid therapy and peripheral venous cannulation (PVC) are central to acute medical care, yet inappropriate IV fluid prescribing and unnecessary cannulation can expose patients to avoidable risks. Acute Medical Units (AMUs) are high‑turnover environments where IV fluids and cannulas are often initiated early, but may not be routinely reviewed once patients stabilise and can drink orally. Objective This study aimed to evaluate the appropriateness of IV fluid prescribing and peripheral cannulation in an AMU, particularly in patients able to maintain oral hydration, and to assess the quality of fluid balance documentation. Methods A prospective service evaluation was conducted in the AMU of a district general hospital between March and April 2025. Adult patients (≥16 years) admitted during the study period who were clinically able to swallow were eligible. Data were collected for 200 consecutive admissions following a 20‑patient pilot. Information was obtained from bedside review, fluid balance charts, and electronic records. Variables included IV fluid use, oral intake status, presence and indication for peripheral cannulation, prescriber seniority, and completeness of input-output documentation. Data were analysed descriptively using simple counts, percentages, and summary statistics. Results Of 200 patients, the median age was 76 years (range 18-96), and 89% had a peripheral cannula in situ. Overall, 18% received IV fluids during their AMU stay. Among those receiving IV fluids only, all were able to take oral fluids, and none had fully completed input-output charts. The majority of IV fluids were prescribed by senior clinicians. Fluid balance documentation was limited: only a minority of patients had fluid charts in place, and of these, just over a quarter were completed accurately. Among cannulated patients, almost one‑third had no clear documented clinical indication for IV access. Conclusions In this AMU, IV fluids were frequently administered to patients who were able to maintain oral intake; fluid balance documentation was often incomplete, and a substantial proportion of peripheral cannulas lacked a clear indication. These findings highlight opportunities to improve IV fluid stewardship, strengthen documentation, and review cannulation practice to reduce avoidable risk and support safer, more efficient acute medical care.