A Low Dose Heparinized Saline Protocol Is Associated with Improved Duration of Arterial Line Patency in Critically Ill COVID-19 Patients

Introduction: Critically ill patients with Coronavirus Disease 2019 (COVID-19) have high rates of line thrombosis. Our objective was to examine the safety and efficacy of a low dose heparinized saline (LDHS) arterial line patency protocol in this population.

Materials and Methods: In this observational cohort study, patients≥18 years with COVID-19 admitted to an ICU at one institution from March 20, 2020-May 25, 2020 were divided into two cohorts. Pre-LDHS patients had an episode of arterial line thrombosis between March 20-April 19 while receiving 0.9% NaCl through their arterial line pressure bag. Post-LDHS patients had an episode of arterial line thrombosis between April 20-May 25 and received an LDHS solution (10 units/hour) through their arterial line pressure bag. Duration of arterial line patency and bleeding complication rates were compared using Wilcoxon test and Fisher’s exact test, respectively. Kaplan Meier and Cox proportional hazard regression analysis (adjusting for age, sex, obesity, history of thrombosis, presence of thrombotic risk factors, recent surgery, SOFA score, arterial line location, total arterial lines prior to index arterial line, and systemic anticoagulation use) were performed with arterial line thrombosis as the endpoint.

Results: Forty-one pre-LDHS patients and 30 post-LDHS patients were identified. Baseline characteristics were similar between groups, including age (61 versus 54 years; p=0.24), median Sequential Organ Failure Assessment score (6 versus 7; p=0.67) and systemic anticoagulation (47% versus 33%; p= 0.32). The overall median duration of arterial line patency was significantly longer in post-LDHS versus pre-LDHS patients (8.5 versus 2.9 days; p<0.001). On planned sub-analysis of patients on systemic anticoagulation, median duration of arterial line patency remained significantly longer in post-LDHS patients compared to pre-LDHS patients (13.9 versus 4.1 days; p<0.001). Similarly, among patients not on systemic anticoagulation, post-LDHS patients had longer median duration of arterial line patency (4.9 versus 2.2 days; p=0.026). Cox regression showed post-LDHS patients to have an 87% thrombosis risk reduction compared to pre-LDHS patients (hazard ratio 0.13, 95% CI 0.05-0.34; p<0.001). Kaplan Meier curves were significantly different by log rank test (Figure 1) (p<0.0001). Incidence of bleeding complications was similar between cohorts (13% versus 10%, p=0.71).

Conclusions: A LDHS protocol was associated with a clinically significant improvement in arterial line patency duration in COVID-19 patients, without increased bleeding risk. The results of this study suggest that a LDHS protocol is a safe and effective therapeutic option to implement more broadly in patients with COVID-19 who develop arterial line thrombosis.