Risk Factors for Coated Midline Catheter-Related Thrombosis: A Secondary Analysis of Existing Trial Data

Midline catheter-related thrombosis (MCRT) is a high-stakes complication. The authors aimed to explore risk factors for the development of symptomatic MCRT, including patient, procedure, catheter, and vein characteristics. This study performed an analysis of existing trial data that compared MCRT in 2 MCs with differing antithrombotic properties. Cox regression was used for univariable and multivariable analyses to evaluate the primary outcome of MCRT. Among 191 patients in this analysis, the average age was 60.2 years (standard deviation = 16.7 years), and 59.7% were female (114/191). Clinical indications for MC placement included antibiotics (60.7%), difficult venous access (32.5%), or both (6.8%). Body temperature ≥38°C (adjusted hazard ratio [aHR] = 6.26; 95% CI, 1.24-20.29; P = .03), catheter-to-vein ratio >0.40 (aHR = 2.65; 95% CI, 0.99-6.74; P = .05), and MC distance from antecubital fossa >7.0 cm (aHR = 2.82; 95% CI, 1.10-7.90; P = .03), were each significantly associated with the higher risk of the occurrence of symptomatic MCRT. This study found that catheter-to-vein ratio >0.40, distance from the antecubital fossa >7 cm, and body temperature ≥38°C were each associated with higher risk of MCRT. Current practices should be modified to include a minimum vein size to avoid MC insertions that occupy >40% of a given vein. Further research is needed to explain the impact of the catheter tip position and fever in relation to MCRT.