Venous thromboembolism in the critically ill: A prospective observational study of occurrence, risk factors and outcome

Thromboembolic Diseases Among Intensive Care Unit Patients in Al-Qassim Region, Saudi Arabia

Background Venous and arterial thrombotic conditions are the two types of thromboembolic events. Main venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and pulmonary embolism (PE), while arterial thromboses include ischemic stroke and ischemic heart disease (IHD). Aim This study aimed to assess the prevalence of thromboembolic events among intensive care unit (ICU) patients in Al-Qassim region, Saudi Arabia. Patients and methods This is a retrospective chart review of ICU patients diagnosed with thromboembolic disease who were seen at the intensive care unit of King Fahad Specialist Hospital between July 2020 and June 2022. Data were obtained from hospital medical files and gathered into an Excel sheet (Microsoft Corp., Redmond, WA, USA). All data analyses were carried out using Statistical Package for the Social Sciences (SPSS) version 26 (IBM SPSS Statistics, Armonk, NY, USA). Results Of the 38 patients included, 52.6% were males (mean age: 60.7; standard deviation (SD): 23.9). The most common risk factors for thromboembolic events were immobilization (23.7%) and major surgeries (18.4%). The incidence of DVT was 42.1%, while PE was 39.5%. Seven patients were detected with combined incidence (DVT and PE). Mortality rates accounted for 39.5%. It is interesting to note that the prevalence of patients who use heparin treatment was statistically significantly higher among DVT patients (p=0.043). Conclusion The incidence of deep vein thrombosis was 42.1%, while pulmonary embolism occurred in 39.5%. However, 18.4% of the ICU patients had an occurrence of both DVT and PE. Furthermore, immobilization was identified as the most common risk factor for thromboembolic events, followed by major surgeries. More research is necessary to determine the incidence and prevalence of thromboembolic disease and its manifestations.

Prevalence of Venous Thromboembolism in Intensive Care Units: A Meta-Analysis

OBJECTIVE

Venous thromboembolism (VTE) is a life threating complication in intensive care units (ICUs). This study aimed to pool the prevalence of VTE and examined the risk factors of VTE in intensive care patients worldwide.

METHODS

A systematic search in PubMed, EMBASE and Web of Science databases was performed. Studies reported that the data on the prevalence of VTE or relevant information were synthesized using a random-effects model.

RESULTS

A total of 42 studies reporting on 27,344 patients were included. The pooled prevalence of VTE was 10.0% (95% CI: 7.0-14.0%). Subgroup and metaregression analyses found that thromboprophylaxis strategy, simplified acute physiology score (SAPS II), age, study quality, sample size, malignancy, sex, spinal cord injury and injury severity score (ISS) moderated the prevalence of VTE in intensive care patients.

CONCLUSIONS

The present meta-analysis revealed a high prevalence of VTE in critically ill patients. The risk factors of VTE included thromboprophylaxis strategy, SAPS II, age, malignancy, sex, spinal cord injury and ISS. Therefore, we need to pay more attention to high-risk populations of VTE in intensive care patients.

Incidence and risk factors of deep vein thrombosis after extracorporeal life support

Background

Deep vein thrombosis (DVT) after decannulation of extracorporeal life support (ECLS) is not uncommon. Moreover, the impact of anticoagulation and potential risk factors is unclear. Furthermore, it is unclear if cannula‐associated DVT is more common in ECLS patients compared to critically ill patients without ECLS.

Methods

All adult patients who were successfully weaned from ECLS and were screened for DVT following decannulation were included in this observational cohort study. The incidence of post‐ECLS‐DVT was assessed and the cannula‐associated DVT rate was compared with that of patients without ECLS after central venous catheter (CVC) removal. The correlation between the level of anticoagulation, risk factors, and post‐ECLS‐DVT was determined.

Results

We included 30 ECLS patients and 53 non‐ECLS patients. DVT was found in 15 patients (50%) of which 10 patients had a DVT in a cannulated vein. No correlation between the level of anticoagulation and DVT was found. V‐V ECLS mode was the only independent risk factor for post‐ECLS‐DVT (OR 5.5; 95%CI 1.16–26.41). We found no difference between the ECLS and non‐ECLS cohorts regarding cannula‐associated DVT rate (33% vs. 32%).

Conclusion

Post‐ECLS‐DVT is a common finding that occurs in half of all patients supported with ECLS. The incidence of cannula‐associated DVT was equal to CVC‐associated DVT in critically ill patients without ECLS. V‐V ECLS was an independent risk factor for post‐ECLS‐DVT.

Development and validation of a prediction model of deep venous thrombosis for patients with acute poisoning following hemoperfusion: a retrospective analysis

Objective

To develop and confirm an individualized predictive model to ascertain the probability of deep venous thrombosis in patients with acute poisoning after undergoing hemoperfusion.

Methods

Three hundred eleven patients with acute poisoning who were admitted to a hospital in China between October 2017 and February 2019 were included in the development group. Eighty patients with acute poisoning who were admitted between February and May 2019 were included in the validation group. The independent risk factors for deep venous thrombosis were examined. An individualized predictive model was developed using regression coefficients.

Results

The number of catheter indwelling days, having a catheter while being transported, elevated serum homocysteine concentrations, and dyslipidemia were independent risk factors for deep venous thrombosis following hemoperfusion in patients with acute poisoning. The areas under the receiver operating characteristic curve of the development and validation groups were 0.713 and 0.702, respectively, which suggested that the prediction model had good discrimination capacity. The calibration belts of the two groups were ideal.

Conclusions

Our prediction model has a moderate predictive effect for the occurrence of deep venous thrombosis in patients with acute poisoning. In clinical practice, this model could be combined with a common thrombosis risk assessment model.

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.

Basic ultrasound head-to-toe skills for intensivists in the general and neuro intensive care unit population: consensus and expert recommendations of the European Society of Intensive Care Medicine

Purpose

To provide consensus, and a list of experts’ recommendations regarding the basic skills for head-to-toe ultrasonography in the intensive care setting.

Methods

The Executive Committee of the European Society of Intensive Care (ESICM) commissioned the project and supervised the methodology and structure of the consensus. We selected an international panel of 19 expert clinicians–researchers in intensive care unit (ICU) with expertise in critical care ultrasonography (US), plus a non-voting methodologist. The panel was divided into five subgroups (brain, lung, heart, abdomen and vascular ultrasound) which identified the domains and generated a list of questions to be addressed by the panel. A Delphi process based on an iterative approach was used to obtain the final consensus statements. Statements were classified as a strong recommendation (84% of agreement), weak recommendation (74% of agreement), and no recommendation (less than 74%), in favor or against.

Results

This consensus produced a total of 74 statements (7 for brain, 20 for lung, 20 for heart, 20 for abdomen, 7 for vascular Ultrasound). We obtained strong agreement in favor for 49 statements (66.2%), 8 weak in favor (10.8%), 3 weak against (4.1%), and no consensus in 14 cases (19.9%). In most cases when consensus was not obtained, it was felt that the skills were considered as too advanced. A research agenda and discussion on training programs were implemented from the results of the consensus.

Conclusions

This consensus provides guidance for the basic use of critical care US and paves the way for the development of training and research projects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06486-z.

What Do We Know about Thromboprophylaxis and Its Monitoring in Critically Ill Patients?

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is an important complication in patients hospitalized in intensive care units (ICU). Thromboprophylaxis is mainly performed with Low Molecular Weight Heparin (LMWH) and, in some specific patients, with Unfractionated Heparin (UFH). These intensive units are an environment where individual patient variability is extreme and where traditional antithrombotic protocols are frequently ineffective. This was known for a long time, but the hospitalization of many patients with COVID-19 inflammatory storms suddenly highlighted this knowledge. It is therefore reasonable to propose variable antithrombotic prevention protocols based initially on a series of individual criteria (weight, BMI, and thrombotic risks). Secondly, they should be adjusted by the monitoring of anticoagulant activity, preferably by measuring the anti-Xa activity. However, we still face unresolved questions, such as once- or twice-daily LMWH injections, monitoring at the peak and/or trough, and poorly defined therapeutic targets. Equally surprisingly, we observed a lack of standardization of the anti-Xa activity kits.

Prevalence of Venous Thromboembolism in Critically Ill Patients With Coronavirus Disease 2019: A Meta-Analysis

Background: Accumulating evidence suggests that coronavirus disease 2019 (COVID-19) is associated with hypercoagulative status, particularly for critically ill patients in the intensive care unit. However, the prevalence of venous thromboembolism (VTE) in these patients under routine prophylactic anticoagulation remains unknown. A meta-analysis was performed to evaluate the prevalence of VTE in these patients by pooling the results of these observational studies. Methods: Observational studies that reported the prevalence of VTE in critically ill patients with COVID-19 were identified by searching the PubMed and Embase databases. A random-effect model was used to pool the results by incorporating the potential heterogeneity. Results: A total of 19 studies with 1,599 patients were included. The pooled results revealed that the prevalence of VTE, deep venous thrombosis (DVT), and pulmonary embolism (PE) in critically ill patients with COVID-19 was 28.4% [95% confidence interval (CI): 20.0-36.8%], 25.6% (95% CI: 17.8-33.4%), and 16.4% (95% CI: 10.1-22.7%), respectively. Limited to studies, in which all patients received routine prophylactic anticoagulation, and the prevalence for VTE, DVT, and PE was 30.1% (95% CI: 19.4-40.8%), 27.2% (95% CI: 16.5-37.9%), and 18.3% (95% CI: 9.8%-26.7%), respectively. The prevalence of DVT was higher in studies with routine screening for all patients, when compared to studies with screening only in clinically suspected patients (47.5% vs. 15.1%, P < 0.001). Conclusion: Critically ill patients with COVID-19 have a high prevalence of VTE, despite the use of present routine prophylactic anticoagulation.

Utility of coagulation analyses to assess thromboprophylaxis with dalteparin in intensive care unit patients

BACKGROUND

The aim of this study was to evaluate the utility of coagulation analyses to assess thromboprophylaxis with dalteparin in intensive care unit (ICU) patients.

METHODS

Prospective observational study of ICU patients receiving dalteparin prophylaxis at Oslo University Hospital in Norway. Trough and peak antithrombin, protein C, anti-factor Xa activity (aFXa), d-dimer, thromboelastography, calibrated automated thrombogram and microparticles were analysed. Levels were compared in patients with and without venous thromboembolism (VTE), major bleeding, acute kidney injury (AKI) with use of renal replacement therapy (RRT) and variable dalteparin dose.

RESULTS

Among 50 included patients (76% male, mean age 62 years) five (10%) developed VTE and eight (16%) major bleeding. Median through aFXa level was 0.03 (0.02-0.05) IU/mL, and 48 (96%) of patients were within and two (4%) above target range. Peak aFXa level was 0.21 (0.13-0.29) IU/mL, the number of patients below, within and above prophylactic range were 21 (42%), 25 (50%) and four (8%). Peak aFXa levels were similar in patients with and without VTE (0.18 vs 0.21 IU/L, P = .72), major bleeding (0.22 vs 0.21 IU/mL, P = .38) and AKI with RRT (0.18 vs 0.24, P = .13), but lower in patients receiving dalteparin 5000 IU od compared to 7500 IU od (0.19 vs 0.30 IU/mL, P < .01).

CONCLUSIONS

Intensive care unit patients receiving dalteparin prophylaxis had half of patients within prophylactic peak aFXa target range. Peak aFXa levels was affected by administered dalteparin dose, but not presence of VTE, major bleeding or AKI with RRT.

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

Background

The objective of this study was to describe the prevalence, incidence, prognostic factors, and outcomes of venous thromboembolism in critically ill patients receiving contemporary thrombosis prophylaxis.

Methods

We conducted a pooled analysis of two prospective cohort studies. The outcomes of interest were in-hospital pulmonary embolism or lower extremity deep vein thrombosis (PE-LDVT), in-hospital nonleg deep vein thrombosis (NLDVT), and 90-day mortality. Multivariable logistic regression analysis was used to evaluate the association between predefined baseline prognostic factors and PE-LDVT or NLDVT. Cox regression analysis was used to evaluate the association between PE-LDVT or NLDVT and 90-day mortality.

Results

A total of 2208 patients were included. The prevalence of any venous thromboembolism during 3 months before ICU admission was 3.6% (95% CI 2.8–4.4%). Out of 2166 patients, 47 (2.2%; 95% CI 1.6–2.9%) developed PE-LDVT and 38 patients (1.8%; 95% CI 1.2–2.4%) developed NLDVT. Renal replacement therapy (OR 3.5 95% CI 1.4–8.6), respiratory failure (OR 2.0; 95% CI 1.1–3.8), and previous VTE (OR 3.6; 95% CI 1.7–7.7) were associated with PE-LDVT. Central venous catheters (OR 5.4; 95% CI 1.7–17.8) and infection (OR 2.2; 95% CI 1.1–4.3) were associated with NLDVT. Occurrence of PE-LDVT but not NLDVT was associated with increased 90-day mortality (HR 2.7; 95% CI 1.6–4.6, respectively, 0.92; 95% CI 0.41–2.1).

Conclusion

Thrombotic events are common in critically ill patients, both before and after ICU admittance. Development of PE-LDVT but not NLDVT was associated with increased mortality. Prognostic factors for developing PE-LDVT or NLDVT despite prophylaxis can be identified at ICU admission and may be used to select patients at higher risk in future randomized clinical trials.

Trial registration

NCT03773939.

Continuous intravenous infusion of enoxaparin controls thrombin formation more than standard subcutaneous administration in critically ill patients. A sub-study of the ENOKSI thromboprophylaxis RCT

INTRODUCTION

Standard subcutaneous low-molecular-weight heparin (LMWH) thromboprophylaxis yields low anti-factor Xa activity in patients in the intensive care unit (ICU). The aim of the study was to assess coagulation status in ICU patients randomized to receive enoxaparin thromboprophylaxis either as a standard subcutaneous bolus (SCB) or continuous intravenous infusion (CII) for 3 consecutive days after the initiation of LMWH thromboprophylaxis.

MATERIALS AND METHODS

Thirty-eight patients were studied by conventional coagulation variables: prothrombin fragment F 1+2 (F 1+2) representing FXa inhibition and antithrombin (AT). Additionally, 18 patients were analyzed by the thrombin generation assay-calibrated automated thrombogram (TGA-CAT). Blood samples were collected before the initiation of the LMWH thromboprophylaxis (ie, baseline), at 51 h, and at 72 h.

RESULTS

At beginning, no differences in coagulation biomarkers were observed. The levels of F 1+2 were significantly lower at 51 and 72 h in the CII group than in the SCB group. AT levels increased during the follow-up in the CII group, unlike in the SCB group. TGA-CAT was poor in some patients overall. In a subset of patients at 51 h lag time (4.3 vs 7.5 min, respectively, P < 0.05) and time to peak (7.7 vs 14.3 min, respectively, P < 0.05) were prolonged in the SCB group. At 72 h, however, peak thrombin was lower in the CII than in the SCB group: 271 vs 356 nM, respectively (P < 0.05).

CONCLUSIONS

Enoxaparin thromboprophylaxis administered by CII inhibited more prominently FXa and preserved better the AT level, compared with standard subcutaneous care.

Hypercoagulopathy in Severe COVID-19: Implications for Acute Care

COVID-19 was first described in late 2019 and has since developed into a pandemic affecting more than 21 million people worldwide. Of particular relevance for acute care is the occurrence of COVID-19-associated coagulopathy (CAC), which is characterised by hypercoagulability, immunothrombosis and venous thromboembolism, and contributes to hypoxia in a significant proportion of patients. This review describes diagnosis and treatment of CAC in the emergency department and in intensive care. We summarise the pathological mechanisms and common complications of CAC such as pulmonary thrombosis and venous thromboembolic events and discuss current strategies for thromboprophylaxis and therapeutic anti-coagulation in the acute care setting.

Thromboembolism risk of COVID-19 is high and associated with a higher risk of mortality: A systematic review and meta-analysis

BACKGROUND

Studies have suggested that there is increased risk of thromboembolism (TE) associated with coronavirus disease 2019 (COVID-19). However, overall arterial and venous TE rates of COVID-19 and effect of TE on COVID-19 mortality is unknown.

METHODS

We did a systematic review and meta-analysis of studies evaluating TE in COVID-19. We searched PubMed, Cochrane, and Embase for studies published up to June 12, 2020. Random effects models were used to produce summary TE rates and odds ratios (OR) of mortality in COVID-19 patients with TE compared to those without TE. Heterogeneity was quantified with I 2 .

FINDINGS

Of 425 studies identified, 42 studies enrolling 8271 patients were included in the meta-analysis. Overall venous TE rate was 21% (95% CI:17-26%): ICU, 31% (95% CI: 23-39%). Overall deep vein thrombosis rate was 20% (95% CI: 13-28%): ICU, 28% (95% CI: 16-41%); postmortem, 35% (95% CI:15-57%). Overall pulmonary embolism rate was 13% (95% CI: 11-16%): ICU, 19% (95% CI:14-25%); postmortem, 22% (95% CI:16-28%). Overall arterial TE rate was 2% (95% CI: 1-4%): ICU, 5% (95%CI: 3-7%). Pooled mortality rate among patients with TE was 23% (95%CI:14-32%) and 13% (95% CI:6-22%) among patients without TE. The pooled odds of mortality were 74% higher among patients who developed TE compared to those who did not (OR, 1.74; 95%CI, 1.01-2.98; P = 0.04).

INTERPRETATION

TE rates of COVID-19 are high and associated with higher risk of death. Robust evidence from ongoing clinical trials is needed to determine the impact of thromboprophylaxis on TE and mortality risk of COVID-19.

FUNDING

None.

Meta-Analysis of the Role of Intermittent Pneumatic Compression of the Lower Limbs to Prevent Venous Thromboembolism in Critically Ill Patients

Critically ill patients (patients treated in a medical or surgical intensive care unit) are at high risk of venous thromboembolism (VTE) development (deep vein thrombosis [DVT] and/or pulmonary embolism). Multiple thromboprophylaxis strategies have been used for the prevention of VTE in this population with various outcomes. Therefore, we aimed to evaluate the efficacy of intermittent pneumatic compression (IPC) prophylaxis in the lower limb compared with no treatment, anticoagulant use, or their combinations in reducing risk. A comprehensive electronic database search was conducted for all randomized clinical trials (RCTs) comparing the clinical outcomes of IPC versus anticoagulants or no treatment or their combinations for the prevention of VTE for critically ill patients. The primary outcome was VTE. The secondary outcome was DVT. We performed a Bayesian network meta-analysis to calculate odds ratios (ORs) and 95% credible intervals (CrIs). We included 5 RCTs with 3133 total patients, represented by a mean age of 49.61 ± 18 years, while 60.28% were male. There was a significant reduction of the primary outcome (incidence of VTE events) when no treatment was compared with IPC (OR = 0.36; 95% CrI = 0.18-0.71), anticoagulation alone (OR = 0.30; 95% CrI = 0.12-0.68), or anticoagulation with IPC (OR = 0.34; 95% CrI = 0.13-0.81). In addition, there was a significant reduction in DVT when no treatment was compared with IPC (OR = 0.45; 95% CrI = 0.21-0.9), anticoagulation alone (OR = 0.16; 95% CrI = 0.03-0.66), or anticoagulation with IPC (OR = 0.18; 95% CrI = 0.03-0.84). However, there were no significant differences between other comparisons (IPC vs anticoagulation alone, anticoagulation alone vs anticoagulation with IPC, or anticoagulation with IPC vs IPC alone) regarding VTE or DVT incidence. Among critically ill patients, IPC alone, anticoagulation alone, and IPC with anticoagulation were associated with a significant reduction of VTE and DVT incidence compared with no treatment. However, there was no significant difference between these modalities when compared together. Therefore, further larger studies comparing those different thromboprophylaxis modalities and their combinations are needed to provide more robust results for future clinical recommendations.

Barriers and challenges in the process of including critically ill patients in clinical studies

Background

Clinical research in severely ill or injured patients is required to improve healthcare but may be challenging to perform in practice. The aim of this study was to analyse barriers and challenges in the process of including critically ill patients in clinical studies.

Methods

Data from critically ill patients considered for inclusion in an observational study of venous thromboembolism in Norway were analysed. This included quantitative and qualitative information from the screening log, consent forms and research notes.

Results

Among 279 eligible critically ill patients, 204 (73%) were omitted from the study due to challenges and barriers in the inclusion process. Reasons for omission were categorised as practical in 133 (65%), medical in 31 (15%), and legal or ethical in 40 (20%) of the patients. Among 70 included patients, 29 (41%) consents were from patients and 41 (59%) from their next of kin. Several challenges were described herein; these included whether patients were competent to give consent, and which next of kin that should represent the patient. Furthermore, some included patients were unable to recall what they have consented, and some appeared unable to separate research from treatment.

Conclusions

Barriers and challenges in the inclusion process led to the omission of near three out of four eligible patients. This analysis provided information about where the problem resides and may be solved. The majority of challenges among included patients were related to issues of autonomy and validity of consent.

Trial registration

ClinicalTrials.gov (NCT03405766).