The relationship between the tip position of an indwelling venous catheter and the subcutaneous edema

The present observational study aimed to clarify the relationship between the tip position of an indwelling venous catheter and the subcutaneous edema using ultrasonography images. Data were obtained before catheter removal in a medical ward of a university hospital in Tokyo, Japan. Two hundred peripheral intravenous catheters (PIVCs) from 154 patients were observed just before removal. We analyzed data for 194 PIVCs from 150 patients. Subcutaneous edema was observed in 43.8% of ultrasonography images. According to the univariate analysis, insertion site, PIVC tip contact with the vessel wall, and irritant drug's presence were selected as independent variables for logistic regression analysis. Both irritant drug and PIVC tip contact were associated with the presence of subcutaneous edema [adjusted odds ratio (OR) = 2.68, 95% confidence interval (CI) = 1.14-6.33; and OR = 2.01, 95% CI = 1.04-3.88, respectively]. To the best of our knowledge, this is the first study to use ultrasonography to simultaneously observe PIVC tip position and subcutaneous edema. Using ultrasonography to observe PIVC may be a useful method to understand these mechanisms. Medical staff should select an appropriate vein and indwelling catheter to avoid contact of PIVC tip with the vessel wall. Further studies exploring the causality of the relationship between subcutaneous edema, catheter placement, and thrombus formation is required. In addition, further development of nursing skills and medical devices to reduce mechanical stress is required.