Influence of fine-bore catheter length on infusion thrombophlebitis in peripheral intravenous nutrition: a randomised controlled trial.

Previous studies indicated that the risk of thrombophlebitis associated with continuous infusion of intravenous nutrition (IVN) via peripheral veins was reduced when fine-bore catheters, inserted to 15 cm, were used in place of standard intravenous cannulas. An explanation has not been identified, but may be owing to the greater length of the catheters. A randomised controlled study was performed in which a standard nutritional solution was infused via 22G polyurethane catheters inserted to a length of either 5 cm or 15 cm. Catheters were reviewed twice each day and removed when complications occurred, or when IVN was no longer required. There was no significant difference in median time to thrombophlebitis or extravasation, or in daily risk of thrombophlebitis, between insertion lengths. Survival proportions were similar for each length at all times. Catheters inserted into cephalic veins were more prone to thrombophlebitis or extravasation (nine episodes, 14 catheters) than catheters inserted into basilic veins (five episodes, 24 catheters, P = 0.009). The survival proportion was at all times greater when catheter tips lay in basilic veins. Thus, the risk of thrombophlebitis or extravasation was not influenced by the length of catheter within the vein. However, the vein in which the catheter tip lay appeared to influence the development of morbidity.