Randomized clinical trial analyzing maintenance of peripheral venous catheters in an internal medicine unit: Heparin vs. saline

BACKGROUND: Peripheral venous catheters (PVCs) require adequate maintenance based on heparin or saline locks in order to prevent complications. Heparin has proven effective in central venous catheters, although its use in PVCs remains controversial. Our hypothesis was that saline locks are as effective as heparin locks in preventing problems with PVCs. The objective of the present study was to compare phlebitis and catheter tip colonization rates between PVCs locked with saline and those locked with heparin in patients admitted to an internal medicine department (IMD). METHODS: We performed a 19-month prospective, controlled, open-label, randomized clinical study of patients with at least 1 PVC admitted to the IMD of our hospital. The patients were randomized to receive saline solution (PosiFlush(®), group A) or heparin (Fibrilin(®), group B) for daily maintenance of the PVC. Clinical and microbiological data were monitored to investigate the frequency of phlebitis, catheter tip colonization, and catheter-related bloodstream infection (C-RBSI), as well as crude mortality, days of hospital stay, and days of antimicrobial treatment. RESULTS: We assessed 339 PVCs (241 patients), of which 192 (56.6%) were locked with saline (group A) and 147 (43.4%) with heparin (group B). The main demographic characteristics of the patients were distributed equally between the 2 study groups. The median (IQR) catheter days was 5 (3–8) for both groups (p = 0.64). The frequency of phlebitis was 17.7% for group A and 13.3% for group B (p = 0.30). The frequency of colonization of PVC tips was 14.6% and 12.2% in groups A and B, respectively (p = 0.63). Only 2 episodes of C-RBSI were detected (1 patient in group A). Saline lock was not an independent factor for phlebitis or catheter colonization. CONCLUSIONS: Our study revealed no statistically significant differences in the frequency of phlebitis and catheter tip colonization between PVCs locked with saline and PVCs locked with heparin. We suggest that PVC can be maintained with saline solution, as it is safer and cheaper than heparin.