Clinically important deep vein thrombosis in the intensive care unit: a survey of intensivists

Venous Thromboembolism Prophylaxis in Critically Ill Adults: A Systematic Review and Network Meta-analysis

BACKGROUND

Critically ill adults are at increased risk of VTE, including DVT, and pulmonary embolism. Various agents exist for venous thromboprophylaxis in this population.

RESEARCH QUESTION

What is the comparative efficacy and safety of prophylaxis agents for prevention of VTE in critically ill adults?

STUDY DESIGN AND METHODS

Systematic review and network meta-analysis of randomized clinical trials (RCTs) evaluating efficacy of thromboprophylaxis agents among critically ill patients. We searched six databases (including PubMed, EMBASE, and Medline) from inception through January 2021 for RCTs of patients in the ICU receiving pharmacologic, mechanical, or combination therapy (pharmacologic agents and mechanical devices) for thromboprophylaxis. Two reviewers performed screening, full-text review, and extraction. We used the Grading of Recommendations Assessment, Development, and Evaluation to rate certainty of effect estimates.

RESULTS

We included 13 RCTs (9,619 patients). Compared with control treatment (a composite of no prophylaxis, placebo, or compression stockings only), low-molecular-weight heparin (LMWH) reduced the incidence of DVT (OR, 0.59 [95% credible interval [CrI], 0.33-0.90]; high certainty) and unfractionated heparin (UFH) may reduce the incidence of DVT (OR, 0.82 [95% CrI, 0.47-1.37]; low certainty). LMWH probably reduces DVT compared with UFH (OR, 0.72 [95% CrI, 0.46-0.98]; moderate certainty). Compressive devices may reduce risk of DVT compared with control treatments; however, this is based on low-certainty evidence (OR, 0.85 [95% CrI, 0.50-1.50]). Combination therapy showed unclear effect on DVT compared with either therapy alone (very low certainty).

INTERPRETATION

Among critically ill adults, compared with control treatment, LMWH reduces incidence of DVT, whereas UFH and mechanical compressive devices may reduce the risk of DVT. LMWH is probably more effective than UFH in reducing incidence of DVT and should be considered the primary pharmacologic agent for thromboprophylaxis. The efficacy and safety of combination pharmacologic therapy and mechanical compressive devices were unclear.

TRIAL REGISTRY

Open Science Framework; URL: https://osf.io/694aj.

Surveillance or no surveillance ultrasonography for deep vein thrombosis and outcomes of critically ill patients: a pre-planned sub-study of the PREVENT trial

PURPOSE

We examined the association between surveillance for deep vein thrombosis (DVT) among medical-surgical critically ill patients by twice-weekly ultrasonography and 90-day all-cause mortality.

METHODS

This was a pre-planned sub-study of the Pneumatic Compression for Preventing Venous Thromboembolism (PREVENT) trial (Clinicaltrials.gov: NCT02040103) that compared addition of intermittent pneumatic compression (IPC) to pharmacologic prophylaxis versus pharmacologic prophylaxis alone. The surveillance group included enrolled patients in the trial, while the non-surveillance group included eligible non-enrolled patients. Using logistic regression and Cox proportional hazards models, we examined the association of surveillance with the primary outcome of 90-day mortality. Secondary outcomes were DVT and pulmonary embolism (PE).

RESULTS

The surveillance group consisted of 1682 patients and the non-surveillance group included 383 patients. Using Cox proportional hazards model with bootstrapping, surveillance was associated with a decrease in 90-day mortality (adjusted HR 0.75; 95% CI 0.57, 0.98). Surveillance was associated with earlier diagnosis of DVT [(median 4 days (IQR 2, 10) vs. 20 days (IQR 16, 22)] and PE [median 4 days (IQR 2.5, 5) vs. 7.5 days (IQR 6.1, 28.9)]. There was an increase in diagnosis of DVT (adjusted HR 5.49; 95% CI 2.92, 13.02) with no change in frequency in diagnosis of PE (adjusted HR 0.56; 95% CI 0.19, 1.91).

CONCLUSIONS

Twice-weekly surveillance ultrasonography was associated with an increase in DVT detection, reduction in diagnostic testing for non-lower limb DVT and PE, earlier diagnosis of DVT and PE, and lower 90-day mortality.

TRIAL REGISTRATION

The PREVENT trial is registered at ClinicalTrials.gov, ID: NCT02040103. Registered on 3 November 2013; Current controlled trials, ID: ISRCTN44653506. Registered on 30 October 2013.

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

BACKGROUND

The aim of the study was to explore occurrence, risk factors and outcome of venous thromboembolism (VTE) in intensive care unit (ICU) patients.

METHODS

Prospective observational study of ICU patients receiving thromboprophylaxis at Oslo University Hospital in Norway. Adult medical and surgical patients with ICU length of stay (LOS) longer than 48 hours were included. For detection of VTE, Doppler ultrasound screening of neck, upper and lower extremity veins was used, and computed tomography angiography when clinically indicated for any medical reason.

RESULTS

Among 70 included patients, 79% were males and mean age was 62 (±12.1) years. All received thromboprophylaxis with dalteparin, and 44 (63%) used graduated compression stockings. VTE was found in 19 (27%) patients; deep vein thrombosis in 15 (21%) and pulmonary embolism in 4 (6%). Among the VTEs, 11 (58%) presented within the first 48 hours after admission, two (11%) were located in the lower limbs and five (26%) were symptomatic. Risk factors for VTE in multivariable analyses were malignancy, abdominal surgery and SAPS II score <41 with an AuROC (95% CI) of 0.72 (0.58-0.85, P = 0.01). Patients with and without VTE had comparable ICU LOS (13 vs 11 days, P = 0.27) and mortality (16% vs 20%, P = 0.72).

CONCLUSION

Venous thromboembolism was observed in 27% of ICU patients receiving thromboprophylaxis. Factors associated with increased risk of VTE were malignancy, abdominal surgery and SAPS II score <41. Presence of VTE did not impact on patient outcome.

Venous Thromboembolism Prophylaxis: A Narrative Review With a Focus on the High-Risk Critically Ill Patient

Venous thromboembolism (VTE) is a major health concern associated with significant morbidity and mortality. Critically ill patients are at an increased risk of VTE compared to general medical patients due to unique risk factors: prolonged immobilization, invasive lines and devices, certain medications, and acquired thrombophilia. Furthermore, VTE in the critically ill is associated with increased duration of mechanical ventilation, increased length of intensive care unit and hospital stay, and a trend toward increased mortality. Clinical practice guidelines therefore recommend VTE prophylaxis with either subcutaneous heparin or low-molecular-weight heparin for all critically ill patients without contraindication. Yet, many patients will develop VTE despite appropriate pharmacologic prophylaxis, which has led to interest in risk-stratifying critically ill patients for more aggressive prophylaxis strategies. Recent research identified patients at highest risk of failure of thromboprophylaxis and provided insight into the pathophysiologic mechanisms. Obesity and the receipt of vasopressors are 2 risk factors consistently identified in observational studies; further clinical data support decreased absorption of anticoagulant administered via the subcutaneous route as the likely mechanism behind thromboprophylaxis failure in these patient populations. Several studies have investigated novel thromboprophylaxis strategies to circumvent pharmacokinetic limitations in patients who are obese or on vasopressors: increased fixed-dose, weight-based subcutaneous, or continuous intravenous infusion of a prophylactic dose of anticoagulant has shown promise in limited studies; however, the results have yet to demonstrate superiority compared to current standard-of-care. This review discusses observational studies identifying patients at risk of thromboprophylaxis failure and critiques clinical studies evaluating novel thromboprophylaxis strategies in high-risk, critically ill patients with a focus on their limitations. Future studies are currently being conducted that will provide further guidance into the appropriate use of individualized thromboprophylaxis.

VTE Incidence and Risk Factors in Patients With Severe Sepsis and Septic Shock

BACKGROUND

Prospective studies on the incidence of VTE during severe sepsis and septic shock remain absent, hindering efficacy assessments regarding VTE prevention strategies in sepsis.

METHODS

We prospectively studied 113 consecutively enrolled patients in the ICU with severe sepsis and septic shock at three hospitals. All patients provided informed consent. VTE thromboprophylaxis was recorded for all patients. Patients underwent ultrasonography and were followed for VTE prior to ICU discharge. All-cause 28-day mortality was recorded. Variables from univariate analyses that were associated with VTE (including central venous catheter [CVC] insertion, age, length of stay, and mechanical ventilation) were included in a multivariable logistic regression analysis using backward stepwise elimination to determine VTE predictors.

RESULTS

Mean APACHE (Acute Physiology and Chronic Health Evaluation) II score was 18.2 ± 7.0, and age was 50 ± 18 years. Despite all patients receiving guideline-recommended thromboprophylaxis, the incidence of VTE was 37.2% (95% CI, 28.3-46.8). Most VTE events were clinically significant (defined as pulmonary embolism, proximal DVT, and/or symptomatic distal DVT) and associated with an increased length of stay (18.2 ± 9.9 days vs 13.4 ± 11.5 days, P < .05). Mortality was higher in patients with acute VTE but did not reach statistical significance. Insertion of a CVC and longer mechanical ventilation duration were significant VTE risk factors. VTE incidence did not differ by thromboprophylaxis type.

CONCLUSIONS

To our knowledge this is the first multicenter prospective study to identify a high incidence of VTE in patients with severe sepsis and septic shock, despite the use of universal, guideline-recommended thromboprophylaxis. Our findings suggest that the systemic inflammatory milieu of sepsis may uniquely predispose patients with sepsis to VTE. More effective VTE prevention strategies are necessary in patients with sepsis.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT02353910; URL: www.clinicaltrials.gov.

Physicians declining patient enrollment in a critical care trial: a case study in thromboprophylaxis

PURPOSE

To analyze the frequency, rationale and determinants of attending physicians requesting that their eligible patients not be approached for participation in a thromboprophylaxis trial.

METHODS

Research personnel in 67 centers prospectively documented eligible non-randomized patients due to physicians declining to allow their patients to be approached.

RESULTS

In 67 centers, 3,764 patients were enrolled, but 1,460 eligible patients had no consent encounter. For 218 (14.9 %) of these, attending physicians requested that their patients not be approached. The most common reasons included a high risk of bleeding (31.2 %) related to fear of heparin bioaccumulation in renal failure, the presence of an epidural catheter, peri-operative status or other factors; specific preferences for thromboprophylaxis (12.4 %); morbid obesity (9.6 %); uncertain prognosis (6.4 %); general discomfort with research (3.7 %) and unclear reasons (17.0 %). Physicians were more likely to decline when approached by less experienced research personnel; considering those with[10 years of experience as the reference category, the odds ratios (OR) for physician refusals to personnel without trial experience was 10.47 [95 % confidence interval (CI) 2.19-50.02] and those with less than 10 years experience was 1.72 (95 % CI 0.61-4.84). Physicians in open rather than closed units were more likely to decline (OR 4.26; 95 % CI 1.27-14.34). Refusals decreased each year of enrollment compared to the pilot phase.

CONCLUSIONS

Tracking, analyzing, interpreting and reporting the rates and reasons for physicians declining to allow their patients to be approached for enrollment provides insights into clinicians' concerns and attitudes to trials. This information can encourage physician communication and education, and potentially enhance efficient recruitment.

Pulmonary Embolism in the Mechanically-Ventilated Critically Ill Patient: Is it Different?

Pulmonary embolism (PE) confers significant in-hospital morbidity and mortality, and critically ill patients remain at risk for venous thromboembolism despite thromboprophylaxis. Recognition of the clinical manifestations and immediate management of PE are of paramount importance. Despite diagnostic advances, PE is often undiagnosed and untreated in patients receiving mechanical ventilation, as these patients do not exhibit the common clinical features of the condition, making the diagnosis very challenging. Computed tomographic pulmonary angiography is probably the reference standard for the diagnosis of acute PE in the haemodynamically stable, ventilated patient. In the setting of circulatory collapse, bedside echocardiography may be used to risk stratify these patients, based on the presence or absence of right ventricular dysfunction, and guide further management. Treatment options include anticoagulation alone, anticoagulation plus thrombolysis, surgical or catheter embolectomy. Inotropes, vasopressors and pulmonary artery vasodilators may be considered after initial resuscitation of the right ventricle. Few studies have focused on estimating the prevalence of PE among mechanically-ventilated intensive care unit (ICU) patients and there is notable lack of data assessing predictive factors, prevention, diagnostic strategy and management of PE in the ICU setting.

Survey of pharmacologic thromboprophylaxis in critically ill children

OBJECTIVE

There is lack of evidence to guide thromboprophylaxis in the pediatric intensive care unit. We aimed to assess current prescribing practice for pharmacologic thromboprophylaxis in critically ill children.

SETTING

Pediatric intensive care units in the United States and Canada with at least ten beds.

DESIGN

Cross-sectional self-administered survey of pediatric intensivists using adolescent, child, and infant scenarios.

PARTICIPANTS

Pediatric intensive care unit clinical directors or section heads.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Physician leaders from 97 of 151 (64.2%) pediatric intensive care units or their designees responded to the survey. In mechanically ventilated children, 42.3% of the respondents would usually or always prescribe thromboprophylaxis for the adolescent but only 1.0% would prescribe it for the child and 1.1% for the infant. Considering all pediatric intensive care unit patients, 3.1%, 32.0%, and 44.2% of respondents would never prescribe thromboprophylaxis for the adolescent, child, and infant scenarios, respectively. These findings were significant (p < .001 for the adolescent vs. child and infant; p = .002 for child vs. infant). Other patient factors that increased the likelihood of prescribing prophylaxis to a critically ill child for all three scenarios were the presence of hypercoagulability, prior deep venous thrombosis, or a cavopulmonary anastomosis. Prophylaxis was less likely to be prescribed to patients with major bleeding or an anticipated invasive intervention. Low-molecular-weight heparin was the most commonly prescribed drug.

CONCLUSIONS

In these scenarios, physician leaders in pediatric intensive care units were more likely to prescribe thromboprophylaxis to adolescents compared with children or infants, but they prescribed it less often in adolescents than is recommended by evidence-based guidelines for adults. The heterogeneity in practice we documented underscores the need for rigorous randomized trials to determine the need for thromboprophylaxis in critically ill adolescents and children.

Screening and prevention of venous thromboembolism in critically ill patients: a decision analysis and economic evaluation

RATIONALE

Venous thromboembolism is difficult to diagnose in critically ill patients and may increase morbidity and mortality.

OBJECTIVES

To evaluate the cost-effectiveness of strategies to reduce morbidity from venous thromboembolism in critically ill patients.

METHODS

A Markov decision analytic model to compare weekly compression ultrasound screening (screening) plus investigation for clinically suspected deep vein thrombosis (DVT) (case finding) versus case finding alone; and a hypothetical program to increase adherence to DVT prevention. Probabilities were derived from a systematic review of venous thromboembolism in medical-surgical intensive care unit patients. Costs (in 2010 $US) were obtained from hospitals in Canada, Australia, and the United States, and the medical literature. Analyses were conducted from a societal perspective over a lifetime horizon. Outcomes included costs, quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios.

MEASUREMENTS AND MAIN RESULTS

In the base case, the rate of proximal DVT was 85 per 1,000 patients. Screening resulted in three fewer pulmonary emboli than case-finding alone but also two additional bleeding episodes, and cost $223,801 per QALY gained. In sensitivity analyses, screening cost less than $50,000 per QALY only if the probability of proximal DVT increased from a baseline of 8.5-16%. By comparison, increasing adherence to appropriate pharmacologic thromboprophylaxis by 10% resulted in 16 fewer DVTs, one fewer pulmonary emboli, and one additional heparin-induced thrombocytopenia and bleeding event, and cost $27,953 per QALY gained. Programs achieving increased adherence to best-practice venous thromboembolism prevention were cost-effective over a wide range of program costs and were robust in probabilistic sensitivity analyses.

CONCLUSIONS

Appropriate prophylaxis provides better value in terms of costs and health gains than routine screening for DVT. Resources should be targeted at optimizing thromboprophylaxis.

Venous thromboembolism following microsurgical breast reconstruction: an objective analysis in 225 consecutive patients using low-molecular-weight heparin prophylaxis

BACKGROUND

Free flap breast reconstruction involves major risk factors for postsurgical venous thromboembolism. The main study objectives were (1) to estimate objectively the incidence of symptomatic and asymptomatic lower extremity deep vein thrombosis in patients who received postoperative thromboprophylaxis after free flap breast reconstruction, (2) to evaluate the safety of low-molecular-weight heparin postoperatively, and (3) to assess the incidence of symptomatic pulmonary embolism or sudden death.

METHODS

A cohort study of 225 consecutive patients who underwent abdominally based free flap breast reconstruction at a single cancer center was conducted. The postoperative thromboprophylaxis regimen was based on the American College of Chest Physicians guidelines. A study group of 118 patients systematically underwent bilateral lower extremity duplex ultrasound before hospital discharge to assess objectively the status of the lower extremity deep venous system. A retrospective cohort of 107 women who were not systematically screened for deep vein thrombosis was used for comparison.

RESULTS

The incidence of postoperative deep vein thrombosis confirmed by duplex ultrasound was 3.4 percent in the study group, all events being clinically silent. Bleeding complications in the entire patient sample were estimated at 5.3 percent. Partial flap loss and total flap loss rates were 2.7 and 1.9 percent, respectively. No venous thromboembolism event was diagnosed in the control group.

CONCLUSIONS

This report shows that the objective incidence of deep vein thrombosis was 3.4 percent within 5 postoperative days in this patient population. The authors' findings support the use of triple thromboprophylaxis and demonstrate that low-molecular-weight heparin is a safe and effective method for prevention of venous thromboembolism in this population.

An evaluation of practice pattern for venous thromboembolism prevention in Lebanese hospitals

BACKGROUND

Venous thromboembolism (VTE) is a major cause of death among hospitalized patients. Many VTE prophylaxis guidelines have been developed, including the American College of Chest Physicians (ACCP). VTE prophylaxis is required in specific patients; however, its practice is not always optimal, and often depends on the hospitals' protocols. In Lebanon, information about the appropriateness of VTE prophylaxis in health care centers is lacking.

OBJECTIVE

The primary objective of this study was to evaluate the pattern of VTE prophylaxis application, including agents, doses, duration of treatment, and route of administration, in Lebanese health care centers.

METHODS

A Lebanese multi-center, prospective, chart review study was conducted over 4 months. Data on demographics, VTE prophylaxis medication, dose, route, duration, and associated risk factors were collected by pharmacy students. The appropriateness of VTE prophylaxis was determined as per ACCP guidelines. Patients receiving VTE treatment were excluded from the study. Institutional review board (IRB) approval was obtained from each hospital center.

RESULTS

A total of 840 patients were included. Both gender groups were equally represented in the sample and the mean age was 59 +/- 19.53 years. The majority (639/840, 76.1%) of the sample were at high risk for deep venous thrombosis (DVT), and inappropriate VTE prophylaxis was reported in 35% of the low-risk group, in 70% of the moderate-risk group, and in 39% of the high-risk group (P < 0.0001). Comparing proper VTE prophylaxis practice between intensive care unit (ICU) and non-ICU patients, there was no statistical difference observed in teaching hospitals (67.2% vs. 65.5%, P = 0.312). However, in non-teaching hospitals, appropriate VTE prophylaxis practice was more prevalent in ICU than non-ICU patients (65.9% vs. 51.2%, P = 0.004). The average duration of VTE prophylaxis was less than 10 days. Missing data was a major limitation for this study, where, for instance, the duration of prophylaxis could not be accurately abstracted in half of the sample. Another limitation was the absence of laboratory results needed for clinical assessment of the regimen used.

CONCLUSION

This study reflected the importance of assessing VTE prophylaxis in Lebanese hospitals, thus, the need for implementing established guidelines to improve the overall patient safety.

Minimizing errors of omission: Behavioural rEenforcement of Heparin to Avert Venous Emboli: The BEHAVE Study*

OBJECTIVE

To improve patient safety by increasing heparin thromboprophylaxis for medical-surgical intensive care unit patients using a multiple-method approach to evidence-based guideline development and implementation.

DESIGN

Prospective longitudinal observational study.

SETTING

Medical-surgical intensive care unit.

PARTICIPANTS

Multidisciplinary clinicians caring for critically ill patients in a 15-bed medical-surgical closed intensive care unit.

INTERVENTIONS

Phase 1 was a 3-month baseline period during which we documented anticoagulation and mechanical thromboprophylaxis. Phase 2 was a 1-yr period in which we implemented a thromboprophylaxis guideline using a) interactive multidisciplinary educational in-services; b) verbal reminders to the intensive care unit team; c) computerized daily nurse recording of thromboprophylaxis; d) weekly graphic feedback to individual intensivists on guideline adherence; and e) publicly displayed graphic feedback on group performance. Phase 3 was a 3-month follow-up period 10 months later, during which we documented thromboprophylaxis. Computerized daily nurse recording of thromboprophylaxis continued in this period.

MEASUREMENTS AND MAIN RESULTS

Intensive care unit and hospital mortality rates were similar across phases, although patients in phase 2 had higher Acute Physiology and Chronic Health Evaluation II scores than patients in phases 1 and 3. The proportion (median % [interquartile range]) of intensive care unit patient-days of heparin thromboprophylaxis in phases 1, 2, and 3 was 60.0 (0, 100), 90.9 (50, 100), and 100.0 (60, 100), respectively (p=.01). The proportion (median % [interquartile range]) of days during which heparin thromboprophylaxis was omitted in error in phases 1, 2, and 3 was 20 (0, 53.8), 0 (0, 6.3), and 0 (0, 0), respectively (p<.001).

CONCLUSIONS

After development and implementation of an evidence-based thromboprophylaxis guideline, we found significantly more patients receiving heparin thromboprophylaxis. Guideline adherence was maintained 1 yr later. Further research is needed on which are the most effective strategies to implement patient safety initiatives in the intensive care unit.

Clinically important venous thromboembolism in pediatric critical care: a Canadian survey

PURPOSE

Pediatric venous thromboembolism (VTE) is becoming an increasingly recognized morbidity associated with critical illness. The objective of this survey is to identify the patient factors and radiological features that pediatric intensivists consider more or less likely to make a venous thrombosis (VTE) clinically important in their patients.

MATERIALS AND METHODS

Our definition of clinically important VTE was a VTE likely to result in short- or long-term morbidity or mortality if left untreated. We asked respondents to rate the likelihood that patient factors and radiological features make a venous thrombosis clinically important using a 5-point scale (1 = much less likely to 5 = much more likely).

RESULTS

The 38 (58.5%) of 65 pediatric intensivists responding rated 4 patient factors as most likely to make a VTE clinically important: clinical suspicion of pulmonary embolism (mean score, 4.8), symptoms (mean, 4.5), detection by physical exam (mean, 4.4), and the presence of an acute or chronic cardiopulmonary comorbidity that might limit a patient's ability to tolerate pulmonary embolism (mean, 4.3). Of the radiological features, the 2 considered most important were VTE involving the vena cava extending into the right atrium (mean, 5) and central veins (mean, 4.5).

CONCLUSIONS

When labeling a VTE as clinically important, pediatric intensivists rely on several specific patient factors and thrombus characteristics.

Deep venous thrombosis in medical-surgical critically ill patients: prevalence, incidence, and risk factors

OBJECTIVE

Critically ill patients may be at high risk of venous thromboembolism. The objective was to determine the prevalence, incidence, and risk factors for proximal lower extremity deep venous thrombosis among critically ill medical-surgical patients.

DESIGN

Prospective cohort.

SETTING

Closed university-affiliated intensive care unit.

PATIENTS

We enrolled consecutive patients > or =18 yrs of age expected to be in intensive care unit for > or =72 hrs. Exclusion criteria were an admitting diagnosis of trauma, orthopedic surgery, pregnancy, and life support withdrawal.

INTERVENTIONS

Interventions included bilateral lower extremity compression ultrasound within 48 hrs of intensive care unit admission, twice weekly, and if venous thromboembolism was clinically suspected. Thromboprophylaxis was protocol directed and universal. We recorded deep venous thrombosis risk factors at baseline and daily, using multivariate regression analysis to determine independent predictors. Patients were followed to hospital discharge.

RESULTS

Among 261 patients with a mean Acute Physiology and Chronic Health Evaluation II score of 25.5 (+/-8.4), the prevalence of deep venous thrombosis was 2.7% (95% confidence interval 1.1-5.5) on intensive care unit admission, and the incidence was 9.6% (95% confidence interval 6.3-13.8) over the intensive care unit stay. We identified four independent risk factors for intensive care unit-acquired deep venous thrombosis: personal or family history of venous thromboembolism (hazard ratio 4.0, 95% confidence interval 1.5-10.3), end-stage renal failure (hazard ratio 3.7, 95% confidence interval 1.2-11.1), platelet transfusion (hazard ratio 3.2, 95% confidence interval 1.2-8.4), and vasopressor use (hazard ratio 2.8, 95% confidence interval 1.1-7.2). Patients with deep venous thrombosis had a longer duration of mechanical ventilation (p = .03), intensive care unit stay (p = .005), and hospitalization (p < .001) than patients without deep venous thrombosis.

CONCLUSIONS

Despite universal thromboprophylaxis, medical-surgical critically ill patients remain at risk for lower extremity deep venous thrombosis. Further research is needed to evaluate the risks and benefits of more intense venous thromboembolism prophylaxis.