Incidence, prognostic factors, and outcomes of venous thromboembolism in critically ill patients: data from two prospective cohort studies

Incidence of venous thromboembolic disease and risk of bleeding in critically ill patients with hematologic malignancies: A retrospective study

OBJECTIVE

Our objectives were to describe the use of thromboprophylaxis and the incidence of VTE/bleeding in critically ill patients with hematologic malignancies (HM).

DESIGN

Retrospective cohort study (2014-2022).

SETTING

Medic-Surgical Intensive Care Unit (ICU) in a tertiary care academic center.

PATIENTS

Adult patients admitted to ICU with a concomitant diagnosis of a hematological malignancy.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

We analyzed demographic data, use of thromboprophylaxis and secondary outcomes that included incidence of VTE (venous thromboembolism), bleeding, mortality, severity scores and organ support. We applied a multivariable logistic regression model to examine the risk of thrombosis in the ICU.

RESULTS

We included 862 ICU admissions (813 unique patients). Thromboprophylaxis was given during 65% of admissions (LMWH 14%, UFH 8%, and SCDs 43%); in 21% it was contraindicated due to thrombocytopenia; 14% of cases lacked documentation on prophylaxis. There were 38 unique incident cases of VTE (27 DVT, 11 PE), constituting 4.4% of ICU episodes. Most of VTE cases happened in patients with various degrees of thrombocytopenia. In the multivariable analysis, SOFA score on the first ICU day was independently associated (OR 0.85, 95% CI 0.76-0.96) with the risk of VTE. Bleeding occurred in 7.2% (minor) and 14.4% (major) of episodes; most frequent sites being CNS, abdomen/GI and pulmonary.

CONCLUSIONS

In this cohort of critically ill patients with HM, there was considerable variability in the utilization of DVT prophylaxis, with predominant use of SCDs. The incidence of VTE was 4.4% and major bleeding 14%.

CLINICAL TRIAL REGISTRATION

NCT05396157. Venous Thromboembolism in Hematologic Malignancy and Hematopoietic Cell Transplant Patients: a Retrospective Study (https://clinicaltrials.gov/).

Acute pulmonary embolism in cancer patients admitted to intensive care unit: Impact of anticoagulant treatment on 90-day mortality and risk factors, results of a multicentre retrospective study

BACKGROUND

Acute pulmonary embolism (PE) is a life-threatening situation in cancer patients. In this situation, anticoagulant therapy is complex to administer due to the risk of bleeding. Only few studies have been conducted when these patients are admitted to the intensive care unit (ICU). The aim of this study was to assess the association between anticoagulation strategies as well as other factors with 90-day mortality in patients with cancer and PE admitted to ICU. Major bleeding was also evaluated according to the type of anticoagulation.

METHODS

Retrospective study carried out in 4 ICUs in France over a 12-year period (2009-2021). All patients with cancer and PE were included. An overlap propensity score weighting analysis was performed in the subgroup of patients treated with either unfractionated heparins (UFH) alone or low-molecular-weight heparins (LMWH) alone on 90-day mortality and major bleeding.

RESULTS

A total of 218 consecutive cancer patients admitted to ICU and presenting PE were included. The 90-day mortality rate was 42 % for the global cohort. After propensity score analysis in the subgroup of patients treated with either "UFH alone" (n = 80) or "LMWH alone" (n = 71), the 90-day mortality was similar in patients treated with UFH alone (42.6 %) vs LMWH alone (39.9 %): OR = 1.124, CI 95 % [0.571-2.214], p = 0.750. There was a significant increased toward major bleeding rates in the "UFH alone" group (25.5 %) as compared to "LMWH alone" group (11.5 %), p = 0.04.

CONCLUSION

In 218 patients admitted to ICU and presenting PE, the 90-day mortality rate was 42 %. Treatment with UFH alone was associated with a mortality comparable to treatment with LMWH alone but it appeared to be more prone to major bleeding.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

PURPOSE

The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

METHODS

We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

RESULTS

Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77-3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09-3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62-3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42-8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56-0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48-0.84) were associated with a lower incidence of VTE.

CONCLUSION

Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.

Antithrombin III levels in critically ill surgical patients: do they correlate with VTE?

Objective

Antithrombin III (ATIII) deficiency may result from hereditary or acquired reduction in ATIII levels and is associated with an increase in venous thromboembolism (VTE) in the general population. VTE is a potentially preventable complication in the critically ill surgical patients. The objective of this study was to evaluate the relation between ATIII levels and VTE in surgical intensive care unit (SICU) patients.

Methods

All patients admitted to the SICU from January 2017 to April 2018 who had ATIII levels drawn were included in the study. An ATIII level below 80% of normal was considered low. The rate of VTE during the same admission was compared among patients with normal and low levels of ATIII. Prolonged length of stay (LOS >10 days) and mortality were also measured.

Results

Of the 227 patients included, 59.9% were male. The median age was 60 years. Overall, 66.9% of patients had low ATIII levels. Trauma patients had a higher rate of normal ATIII levels, whereas those weighing more than 100 kg had a higher rate of low ATIII levels. Patients with low ATIII levels had higher VTE rates compared with those with normal ATIII levels (28.9% vs. 16%, p=0.04). Patients with low ATIII levels also had prolonged LOS (76.3% vs. 60%, p=0.01) and increased mortality (21.7% vs. 6.7%, p<0.01). Trauma patients with VTE were more likely to have normal ATIII levels (38.5% in low ATIII cohort vs. 61.5% VTE in normal ATIII cohort, p<0.01).

Conclusion

Critically ill surgical patients with low ATIII levels have higher incidence of VTE, longer LOS, and higher mortality. In contrast, critically ill trauma patients may have high incidence of VTE even with normal ATIII levels.

Level of evidence

III.

Thrombotic Events Develop in 1 Out of 5 Patients Receiving ECMO Support: An 11-Year Referral Centre Experience

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) for critically ill patients is growing rapidly given recent developments in technology. However, adverse events are frequently reported that have potentially devastating impacts on patient outcomes. The information on predictors and risk factors for thrombotic events, especially that focusing on the comparison of veno-arterial and veno-venous ECMO configurations, are still inconsistent and sparse; therefore, we aimed to close this gap.

METHODS

We performed a retrospective analysis of all patients on extracorporeal life support admitted to the intensive care units of a tertiary university center in Europe.

RESULTS

From 645 patients, 417 who received extracorporeal life support due to cardiogenic shock (290, 70%), respiratory failure (116, 28%) or hypothermia (11, 3%) were included. In total, 22% (92) of the patients experienced thrombotic events with a similar incidence in both ECMO configurations. Anticoagulation consisted of unfractionated heparin (296, 71%) and argatroban (70, 17%). Univariate Cox analyses identified hemoconcentration and increased maximal clot firmness (thromboelastometry) as risk factors for thrombosis. Moreover, the patients experiencing thrombosis had longer ECMO duration and intensive care stays.

CONCLUSIONS

ECMO is a specialized life-support modality with a high risk of complications. A longer ECMO duration is associated with thrombosis occurrence in patients receiving ECMO support. Following hemorrhage, thromboembolic complications are common adverse events. However, in contrast to major bleeding, no impact on mortality was observed. The question arises if a protocol with less anticoagulation may have a role to play in the future.

Modern thromboprophylaxis protocol based on guidelines applied in a respiratory intensive care unit: a single-center prospective cohort study

BACKGROUND

Critically ill patients in intensive care units (ICUs) are at high risk of venous thromboembolism (VTE). This study aimed to explore the prophylaxis effect under a guideline-based thromboprophylaxis protocol among critically ill patients in a respiratory ICU.

METHODS

For this single-center prospective cohort study, we followed the thromboprophylaxis protocol, which was drawn up based on relevant guidelines and Chinese experts' advice. Clinical data were entered into an electronic case report form and analyzed. Multivariate logistic regression was conducted to explore independent risk factors of VTE event under this protocol.

RESULTS

From August 1, 2014, to December 31, 2020, 884 patients underwent thromboprophylaxis according to this protocol; 10.5% of them received mechanical prophylaxis, 43.8% received pharmacological prophylaxis, and 45.7% received pharmacological combined with mechanical prophylaxis. The proportion of VTE events was 14.3% for patients who received the thromboprophylaxis protocol, of which 0.1% had pulmonary thromboembolism (PTE), 2.0% had proximal deep vein thrombosis (DVT), and 12.1% had isolated distal DVT. There was no significant difference between different thromboprophylaxis measures. Cirrhosis (OR 5.789, 95% CI [1.402, 23.894], P = 0.015), acute asthma exacerbation (OR 39.999, 95% CI [4.704, 340.083], P = 0.001), and extracorporeal membrane oxygenation treatment (OR 22.237, 95%CI [4.824, 102.502], P < 0.001) were independent risk factors for proximal DVT under thromboprophylaxis.

CONCLUSIONS

The thromboprophylaxis protocol based on guidelines applied in the ICU was practicable and could help decrease the proportion of PTE and proximal DVT events. The risk factors of VTE events happening under the thromboprophylaxis protocol require more attention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02213978.

Mechanical Ventilation and Hospital-Acquired Venous Thromboembolism Among Critically Ill Children

OBJECTIVES

To estimate the occurrence of, and evaluate associations between, hospital-acquired venous thromboembolism (HA-VTE) and invasive mechanical ventilation (MV) among children hospitalized in the PICU.

METHODS

We performed a multicenter, retrospective cohort study comparing HA-VTE frequencies among subjects <18 years of age hospitalized in the PICU from January 2018 through December 2019 among 47 participating centers, via the Pediatric Health Information Systems registry. We excluded perinatal encounters, those with VTE present at admission, and those with observational status. The primary outcome was the proportion of HA-VTE events before hospital discharge, including extremity deep venous thrombosis, pulmonary embolism, and organ-specific deep venous thrombosis. The HA-VTE frequencies were compared using χ2 tests. The association between HA-VTE and MV was investigated via multivariable logistic regression, adjusting for previously described VTE risk factors.

RESULTS

Of the 205 231 PICU encounters identified for study, 70 829 (34.5%) underwent MV. The occurrence of HA-VTE was 2.2% and was greater among children who received, versus did not receive, MV (4.4% versus 1.1%, P < .001). Multivariable logistic regression revealed significant association between MV and HA-VTE (odds ratio 2.51, 95% confidence interval 2.33-2.69; P < .001).

CONCLUSIONS

In this multicenter, retrospective, registry-based cohort study, HA-VTE were diagnosed in 2.2% of critically-ill children, and after adjustment for central venous catheterization, MV independently increased the risk of HA-VTE 2.5-fold. These findings warrant prospective validation to inform the design of future risk-stratified clinical trials of thromboprophylaxis in critically-ill children.

Influence of Early Multidisciplinary Collaboration on Prevention of ICU-Acquired Weakness in Critically Ill Patients

Objective. This study focused on elucidating the influence of early multidisciplinary collaboration on preventing intensive care unit- (ICU-) acquired weakness (AW) in critically ill patients (CIPs). Methods. Ninety-five CIPs admitted between December 2018 and December 2021 were selected and assigned to the following two groups according to the intervention pattern: the control group (the Con; $n=40$ ) treated with routine early rehabilitation intervention, and the research group (the Res; $n=55$ ) intervened by early multidisciplinary collaborative intervention. The incidence of complications (ICU-AW, deep vein thrombosis (DVT), and pressure ulcers (PSs)) and recovery indices (days of ventilator use, ICU treatment time, and length of hospital stay (LOS)) were recorded. Besides, patients’ activity function and quality of life (QoL) were evaluated and compared, among which the former was evaluated by the Barthel Index (BI), ICU Mobility Scale (IMS), and Medical Research Council (MRC) Scale, and the latter was assessed by the World Health Organization Quality of Life Assessment (100-item version) (WHOQOL-100). Results. The data identified statistically a lower incidence of complications (ICU-AW, DVT, and PSs) and shorter time of ventilator use, ICU residence, and LOS in the Res compared with the Con. In addition, BI, IMS, MRC, and WHOQOL-100 scores in the Res elevated statistically after treatment and were higher than those of the Con. Conclusions. Early multidisciplinary collaboration can validly prevent ICU-AW in CIPs, reduce the incidence of DVT and PSs, and promote patients’ rehabilitation, mobility, and QoL.

Anti-factor Xa Activity Is Not Associated With Venous Thromboembolism in Critically Ill Patients Receiving Enoxaparin for Thromboprophylaxis: A Retrospective Observational Study

Background

Anti-factor Xa activity has been suggested as a surrogate parameter for judging the effectiveness of pharmacological thromboprophylaxis with low molecular weight heparins in critically ill patients. However, this practice is not supported by evidence associating low anti-factor Xa activity with venous thromboembolism.

Methods

We performed a retrospective observational study including 1,352 critically ill patients admitted to 6 intensive care units of the Medical University of Vienna, Austria between 01/2015 and 12/2018. Included patients received prophylactically dosed enoxaparin (≤100 IU/kg body weight per day). We analyzed median peak, 12-h trough and 24-h trough anti-factor Xa activity per patient and compared anti-factor Xa activity between patients without vs. with venous thromboembolic events.

Results

19 patients (1.4%) developed a total of 22 venous thromboembolic events. We did not observe a difference of median (IQR) anti-factor Xa activity between patients without venous thromboembolism [peak 0.22 IU/mL (0.14–0.32); 12-h trough 0.1 IU/mL (<0.1–0.17), 24-h trough < 0.1 IU/mL (<0.1– <0.1)] vs. patients with venous thromboembolism [peak 0.33 IU/mL (0.14–0.34); 12-h trough 0.12 IU/mL (<0.1–0.26); 24-h trough < 0.1 IU/mL (<0.1–<0.1)].

Conclusion

Patients who developed venous thromboembolism had anti-factor Xa activities comparable to those who did not suffer from venous thromboembolism.

Prognostic Nomogram for Predicting Lower Extremity Deep Venous Thrombosis in Neurointensive Care Unit Patients: A Prospective Observational Study

Background

Deep venous thrombosis (DVT) of the lower extremities is one of the common complications for neurointensive care unit patients, which leads to increased morbidity and mortality. The purpose of our study was to explore risk factors and develop a prognostic nomogram for lower extremity DVT in neurointensive care unit patients.

Methods

We prospectively collected and analyzed the clinical data of 420 neurointensive care unit patients who received treatment in our institution between January 2018 and September 2019. Stepwise logistic regression was used to select predictors. R software was used to develop the prognostic nomogram. The performance of the nomogram was validated using a validation cohort of patients with data collected between October 2019 and March 2020.

Results

Among 420 patients, 153 (36.4%) had lower extremity DVT and five (1.2%) had both DVT and pulmonary embolism (PE) in our study. Logistic regression analysis indicated that age [odds ratio (OR): 1.050; 95% confidence interval (CI): 1.029–1.071; P < 0.001], Glasgow Coma Scale (GCS) score (OR: 0.889; 95% CI: 0.825–0.959; P = 0.002), D-dimer level (OR: 1.040; 95% CI: 1.008–1.074; P = 0.014), muscle strength (OR: 2.424; 95% CI: 1.346–4.366; P = 0.003), and infection (OR: 1.778; 95% CI: 1.034–3.055; P = 0.037) were independent predictors for lower extremity DVT. These predictors were selected to be included in the nomogram model. The area under the curve values in the primary cohort and validation cohort were 0.817 (95% CI: 0.776–0.858) and 0.778 (95% CI: 0.688–0.868), respectively, and respective Brier scores were 0.167 and 0.183.

Conclusion

Age, GCS score, D-dimer level, muscle strength, and infection are independent predictors for lower extremity DVT. The nomogram is a reliable and convenient model to predict the development of lower extremity DVT in neurointensive care unit patients.

Risk Factors for Pulmonary Embolism in ICU Patients: A Retrospective Cohort Study from the MIMIC-III Database

Pulmonary embolism (PE) is a common and potentially lethal form of venous thromboembolic disease in ICU patients. A limited number of risk factors have been associated with PE in ICU patients. In this study, we aimed to screen the independent risk factors of PE in ICU patients that can be used to evaluate the patient's condition and provide targeted treatment. We performed a retrospective cohort study using a freely accessible critical care database Medical Information Mart for Intensive Care (MIMIC)-III. The ICU patients were divided into two groups based on the incidence of PE. Finally, 9871 ICU patients were included, among which 204 patients (2.1%) had pulmonary embolism. During the multivariate logistic regression analysis, sepsis, hospital_LOS (the length of stay in hospital), type of admission, tumor, APTT (activated partial thromboplastin time) and platelet were independent risk factors for patients for PE in ICU, with OR values of 1.471 (95%CI 1.001-2.162), 1.001 (95%CI 1.001-1.001), 3.745 (95%CI 2.187-6.414), 1.709 (95%CI 1.247-2.341), 1.014 (95%CI 1.010-1.017) and 1.002 (95%CI 1.001-1.003) (P_s < 0.05). ROC curve analysis showed that the composite indicator had a higher predictive value for ICU patients with PE, with a ROC area under the curve (AUC) of 0.743 (95%CI 0.710 -0.776, p < 0.001). Finally, sepsis, tumor, platelet count, length of stay in the hospital, emergency admission and APTT were independent predictors of PE in ICU patients.

Risk Factors for Venous Thromboembolism in Severe COVID-19: A Study-Level Meta-Analysis of 21 Studies

Venous thromboembolism (VTE) in patients with COVID-19 in intensive care units (ICU) is frequent, but risk factors (RF) remain unidentified. In this meta-analysis (CRD42020188764) we searched for observational studies from ICUs reporting the association between VTE and RF in Medline/Embase up to 15 April 2021. Reviewers independently extracted data in duplicate and assessed the certainty of the evidence using the GRADE approach. Analyses were conducted using the random-effects model and produced a non-adjusted odds ratio (OR). We analysed 83 RF from 21 studies (5296 patients). We found moderate-certainty evidence for an association between VTE and the D-dimer peak (OR 5.83, 95%CI 3.18–10.70), and length of hospitalization (OR 7.09, 95%CI 3.41–14.73) and intubation (OR 2.61, 95%CI 1.94–3.51). We identified low-certainty evidence for an association between VTE and CRP (OR 1.83, 95% CI 1.32–2.53), D-dimer (OR 4.58, 95% CI 2.52–8.50), troponin T (OR 8.64, 95% CI 3.25–22.97), and the requirement for inotropic drugs (OR 1.67, 95% CI 1.15–2.43). Traditional VTE RF (i.e., history of cancer, previous VTE events, obesity) were not found to be associated to VTE in COVID-19. Anticoagulation was not associated with a decreased VTE risk. VTE RF in severe COVID-19 correspond to individual illness severity, and inflammatory and coagulation parameters.

Coagulopathies in Intensive Care Medicine: Balancing Act between Thrombosis and Bleeding

Patient Blood Management advocates an individualized treatment approach, tailored to each patient's needs, in order to reduce unnecessary exposure to allogeneic blood products. The optimization of hemostasis and minimization of blood loss is of high importance when it comes to critical care patients, as coagulopathies are a common phenomenon among them and may significantly impact morbidity and mortality. Treating coagulopathies is complex as thrombotic and hemorrhagic conditions may coexist and the medications at hand to modulate hemostasis can be powerful. The cornerstones of coagulation management are an appropriate patient evaluation, including the individual risk of bleeding weighed against the risk of thrombosis, a proper diagnostic work-up of the coagulopathy's etiology, treatment with targeted therapies, and transfusion of blood product components when clinically indicated in a goal-directed manner. In this article, we will outline various reasons for coagulopathy in critical care patients to highlight the aspects that need special consideration. The treatment options outlined in this article include anticoagulation, anticoagulant reversal, clotting factor concentrates, antifibrinolytic agents, desmopressin, fresh frozen plasma, and platelets. This article outlines concepts with the aim of the minimization of complications associated with coagulopathies in critically ill patients. Hereditary coagulopathies will be omitted in this review.

Compliance with American College of Chest Physicians (ACCP) recommendations for thromboembolic prophylaxis in the intensive care unit: a level I trauma center experience

Background

Recommendations are for nearly universal venous thromboembolism (VTE) prophylaxis in critically ill hospitalized patients because of their well-recognized risks. In those intensive care units (ICUs) where patient care is more uniformly directed, it may be expected that VTE prophylaxis would more closely follow this standard over units that are less uniform, such as open-model ICUs.

Methods

This was a retrospective cohort study on all patients aged 18+ admitted to an open ICU between 6/1/2017 and 5/31/2018. Patients were excluded if they had instructions to receive comfort measures only or required therapeutic anticoagulant administration. Prophylaxis administration practices, including administration of mechanical and/or pharmacologic prophylaxis and delayed (≥48 h post-ICU admission) initiation of pharmacologic prophylaxis, were compared between patients admitted to the ICU by the trauma service versus other departments. Root causes for opting out of pharmacological prophylaxis were documented and compared between the two study groups.

Results

One-hundred two study participants were admitted by the trauma service, and 98 were from a non-trauma service. Mechanical (98% trauma vs. 99% non-trauma, P = 0.99) and pharmacologic (54% vs. 44%, P = 0.16) prophylaxis rates were similar between the two admission groups. The median time from ICU admission to pharmacologic prophylaxis initiation was 53 h for the trauma service and 10 h for the non–trauma services (P ≤ 0.01). In regression analyses, trauma-service admission (odds ratio (OR) = 2.88, 95% confidence interval (CI) 1.21–6.83) and increasing ICU length of stay (OR = 1.13, 95% CI 1.05–1.21) were independently associated with pharmacologic prophylaxis use. Trauma-service admission (OR = 8.30, 95% CI 2.18–31.56) and increasing hospital length of stay (OR = 1.15, 95% CI 1.03–1.28) were independently associated with delayed prophylaxis initiation.

Conclusions

Overall, the receipt of VTE prophylaxis of any type was close to 100%, due to the nearly universal use of mechanical compression devices among ICU patients in this study. However, when examining pharmacologic prophylaxis specifically, the rate was considerably lower than is currently recommended: 54% among the trauma services and 44% among non-trauma services.