Background A substantial proportion of critically ill COVID-19 patients develop thromboembolic complications, but it is unclear whether higher doses of thromboprophylaxis are associated with lower mortality rates. The purpose of the study was to evaluate the association between initial dosing strategy of thromboprophylaxis in critically ill COVID-19 patients and the risk of death, thromboembolism, and bleeding. Method In this retrospective study, all critically ill COVID-19 patients admitted to two intensive care units in March and April 2020 were eligible. Patients were categorized into three groups according to initial daily dose of thromboprophylaxis: low (2500–4500 IU tinzaparin or 2500–5000 IU dalteparin), medium (> 4500 IU but < 175 IU/kilogram, kg, of body weight tinzaparin or > 5000 IU but < 200 IU/kg of body weight dalteparin), and high dose (≥ 175 IU/kg of body weight tinzaparin or ≥ 200 IU/kg of body weight dalteparin). Thromboprophylaxis dosage was based on local standardized recommendations, not on degree of critical illness or risk of thrombosis. Cox proportional hazards regression was used to estimate hazard ratios with corresponding 95% confidence intervals of death within 28 days from ICU admission. Multivariable models were adjusted for sex, age, body mass index, Simplified Acute Physiology Score III, invasive respiratory support, and initial dosing strategy of thromboprophylaxis. Results A total of 152 patients were included: 67 received low-, 48 medium-, and 37 high-dose thromboprophylaxis. Baseline characteristics did not differ between groups. For patients who received high-dose prophylaxis, mortality was lower (13.5%) compared to those who received medium dose (25.0%) or low dose (38.8%), p = 0.02. The hazard ratio of death was 0.33 (95% confidence intervals 0.13–0.87) among those who received high dose, and 0.88 (95% confidence intervals 0.43–1.83) among those who received medium dose, as compared to those who received low-dose thromboprophylaxis. There were fewer thromboembolic events in the high (2.7%) vs medium (18.8%) and low-dose thromboprophylaxis (17.9%) groups, p = 0.04. Conclusions Among critically ill COVID-19 patients with respiratory failure, high-dose thromboprophylaxis was associated with a lower risk of death and a lower cumulative incidence of thromboembolic events compared with lower doses. Trial registration Clinicaltrials.gov NCT04412304 June 2, 2020, retrospectively registered.

Background: A substantial proportion of critically ill COVID-19 patients develop thromboembolic complications, but it is unclear whether higher doses of thromboprophylaxis are associated with lower mortality rates. The purpose of the study was to evaluate the association of initial dosing strategy of thromboprophylaxis in critically ill COVID-19 patients and the risk of death, thromboembolism, and bleeding. Method: All critically ill COVID-19 patients admitted to two intensive care units in March and April 2020 were eligible. Patients were categorized into three groups according to initial daily dose of thromboprophylaxis: low (2500−4500 IU tinzaparin or 2500−5000 IU dalteparin), medium (>4500 IU but <175 IU/kilogram, kg, of body weight tinzaparin or >5000 IU but <200 IU/kg of body weight dalteparin), and high dose (≥ 175 IU/kg of body weight tinzaparin or ≥200 IU/kg of body weight dalteparin). Thromboprophylaxis dosage was based on local standardized recommendations, not on degree of critical illness or risk of thrombosis. Cox proportional hazards regression was used to estimate hazard ratios with corresponding 95% confidence intervals of death within 28 days from ICU admission. Multivariable models were adjusted for sex, age, body-mass index, Simplified Acute Physiology Score III, invasive respiratory support, and initial dosing strategy of thromboprophylaxis. Results: A total of 152 patients were included; 67 received low, 48 medium, and 37 high dose thromboprophylaxis. Baseline characteristics did not differ between groups. Mortality was lower in high (13.5%) vs medium (25.0%) and low dose thromboprophylaxis (38.8%) groups, p≡0.02. The hazard ratio of death was 0.33 (95% confidence intervals 0.13 − 0.87) among those who received high dose, respectively 0.88 (95% confidence intervals 0.43 − 1.83) among those who received medium dose, as compared with those who received low dose thromboprophylaxis. There were fewer thromboembolic events in the high (2.7%) vs medium (18.8%) and low dose thromboprophylaxis (17.9%) groups, p≡0.04, but no difference in the proportion of bleeding events, p≡0.16. Conclusions: Among critically ill COVID-19 patients with respiratory failure, high dose thromboprophylaxis was associated with a lower risk of death and a lower cumulative incidence of thromboembolic events compared with lower doses.

Background COVID‐19 can cause severe disease with need of treatment in the intensive care unit (ICU) for several weeks. Increased knowledge is needed about the long‐term consequences. Methods This is a single‐center prospective follow‐up study of COVID‐19 patients admitted to the ICU for respiratory organ support between March and July 2020. Patients with invasive ventilation were compared with those with high‐flow nasal oxygen (HFNO) or non‐invasive ventilation (NIV) regarding functional outcome and health‐related qualify of life. The mean follow‐up time was 5 months after ICU discharge and included clinical history, three well‐validated questionnaires about health‐related quality of life and psychological health, pulmonary function test, 6‐minute walk test (6MWT) and work ability. Data were analyzed with multivariable general linear and logistic regression models with 95% confidence intervals. Results Among 248 ICU patients, 200 patients survived. Of these, 113 patients came for follow‐up. Seventy patients (62%) had received invasive ventilation. Most patients reported impaired health‐related quality of life. Approximately one third suffered from posttraumatic stress, anxiety and depression. Twenty‐six percent had reduced total lung capacity, 34% had reduced 6MWT and 50% worked fulltime. The outcomes were similar regardless of ventilatory support, but invasive ventilation was associated with more bodily pain (MSD ‐19, 95% CI: ‐32 to ‐5) and <80% total lung capacity (OR 4.1, 95% CI: 1.3‐16.5). Conclusion Among survivors of Covid‐19 who required respiratory organ support, outcomes 5 months after discharge from ICU were largely similar among those requiring invasive compared to non‐invasive ventilation.