The frequency of clinically diagnosed venous thromboembolism (VTE) including deep venous thrombosis (DVT) and pulmonary embolism (PE) in medical-surgical critically ill patients is unclear. The objectives of this study were to estimate the prevalence and incidence of radiologically confirmed DVT and PE in medical-surgical intensive care unit (ICU) patients and to determine the impact of prophylaxis on the frequency of these events.
In a retrospective observational cohort study in 12 adult ICUs, we identified prevalent cases (diagnosed in the 24 hours preceding ICU admission up to 48 hours post-ICU admission) and incident cases (diagnosed 48 hours or more after ICU admission and up to 8 weeks after ICU discharge) of upper or lower limb DVT or PE. Deep venous thrombosis was diagnosed by compression ultrasound or venogram. Each DVT was classified as clinically suspected or not clinically suspected in that the latter was diagnosed by scheduled screening ultrasonography. Pulmonary embolism was diagnosed by ventilation-perfusion lung scan, computed tomography pulmonary angiography, echocardiography, electrocardiography, or autopsy.
Among 12,338 patients, 252 (2.0%) patients had radiologically confirmed DVT or PE and another 47 (0.4%) had possible DVT or PE. Prevalent DVTs were diagnosed in 0.4% (95% confidence interval [CI], 0.3%-0.5%) of patients and prevalent PEs were diagnosed in 0.4% (95% CI, 0.3%-0.6%). Incident DVTs were diagnosed in 1.0% (95% CI, 0.8%-1.2%) of patients, and incident PEs were diagnosed in 0.5% (95% CI, 0.4%-0.6%). Of patients with incident VTE, 65.8% of cases occurred despite receipt of thromboprophylaxis for at least 80% of their days in ICU. The median (interquartile range) ICU length of stay was similar for patients with DVT (7 [3-17]) and PE (5 [2-8]). For all patients with VTE, ICU mortality was 16.7% (95% CI, 12.0%-21.3%) and hospital mortality was 28.5% (95% CI, 22.8%-34.1%).
Venous thromboembolism appears to be an apparently infrequent, but likely underdiagnosed problem, occurring among patients receiving prophylaxis. Findings suggest the need for increased suspicion among clinicians, renewed efforts at thromboprophylaxis, and evaluation of superior prevention strategies.
Challenging the assumptions about chemical thromboprophylaxis in knee replacement: commentary on an article by Alma B. Pedersen, MD, PhD, et al.: "Venous thromboembolism in patients having knee replacement and receiving thromboprophylaxis: a danish population-based follow-up study".
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.
Prospective longitudinal observational study.
Medical-surgical intensive care unit.
Multidisciplinary clinicians caring for critically ill patients in a 15-bed medical-surgical closed intensive care unit.
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.
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
Comment In: Crit Care Med. 2006 Mar;34(3):908-1016505680
This review deals with the problem of delayed thrombosis and thereby the potential need of prolonged prophylaxis. The risk of late thrombosis and pulmonary embolism is discussed from pathogenetic factors and data on frequencies of thromboembolic complications in the literature. The problems concerning long term or prolonged prophylaxis are indicated and studies on prolonged prophylaxis-our own included-are analyzed. There is an urgent need to define which risk factors motivate prolonging thromboprophylaxis for more than the standard 7-14 days.
To investigate the risk of ipsilateral versus contralateral recurrent deep vein thrombosis in the leg.
An open prospective long term follow-up multicentre trial. Patients were followed by frequent outpatient visits at each centre during the first 12 months after inclusion and thereafter annually.
Sixteen hospitals in central Sweden.
A total of 790 consecutive patients with objectively verified first episode of acute deep vein thrombosis and without diagnosed malignant disease were recruited from a randomized study comparing 6 weeks with 6 months of oral antivitamin K therapy as secondary thromboprophylaxis.
Deep vein thrombosis in the contralateral leg was confirmed by venography or ultrasound. With regard to the ipsilateral leg, venography was required.
A recurrent episode of venous thromboembolism was documented in 192 patients after a mean (+/-SD) period of 31(+/-29) months. In 26 additional patients with ipsilateral symptoms the diagnostic critera were not fulfilled. One hundred and eleven patients have deceased and 69 patients withdrew from the study. The 392 patients without recurrent episodes were followed for a median of 96 months with 90% for at least 48 months. An objectively verified recurrent contralateral and ipsilateral deep vein thrombosis occurred in 95 and 54 cases, respectively, and in 41 patients pulmonary embolism was documented. In two patients thromboses with unusual locations were registered. The risk of contralateral versus ipsilateral recurrence was significantly increased with a risk ratio of 1.6 (95% confidence interval 1.4-1.9) in a time to event model. In a multivariate analysis none of the investigated variables were significantly associated with the side of recurrent thrombosis.
The risk of a recurrent deep vein thrombosis is increased in the contralateral leg. This brings into question the importance of an impaired venous flow for recurrent episodes of thrombosis.
We examined the rate of venous thromboembolism, as well as changes over time, in a population-based cohort of patients who underwent knee arthroplasty.
Using medical databases, we identified all patients who underwent primary knee arthroplasties with pharmacological thromboprophylaxis performed in Denmark from 1997 to 2007. The outcome was hospitalization with symptomatic venous thromboembolism within ninety days of surgery. We examined several potential patient and surgery-related predictors for venous thromboembolism using Cox regression analyses.
The overall rate of hospitalization for venous thromboembolism among 37,223 patients within ninety days after primary knee arthroplasty was 1.2% (441 patients) at a median of fifteen days. The rate of hospitalization was 0.9% (323 patients) for deep venous thrombosis and 0.3% (127 patients) for pulmonary embolism, with nine patients who had both. The rate of venous thromboembolism increased during the ten-year study period. Patients with a high score on the Charlson comorbidity index had an increased relative risk for venous thromboembolism compared with patients with a low score (adjusted relative risk = 1.73; 95% confidence interval, 1.24 to 2.41). Patients with a history of cardiovascular disease or a previous venous thromboembolism had an increased risk for postoperative venous thromboembolism compared with patients without these conditions. Surgery-related factors were not predictors for venous thromboembolism.
Despite pharmacological thromboprophylaxis, patients undergoing knee arthroplasty remain susceptible for venous thromboembolism events after surgery. Future efforts should focus on the improvement of prophylaxis following hospital discharge, particularly among elderly patients and those with a history of cardiovascular diseases or previous venous thromboembolism.
Comment In: J Bone Joint Surg Am. 2011 Jul 20;93(14):e8121792484
To determine the pharmacologic and physical modalities used by orthopedic surgeons in Canada to prevent venous thromboembolism (deep venous thrombosis and pulmonary embolism) after total hip or knee arthroplasty.
Mail survey sent to all members of the Canadian Orthopaedic Association.
A nation-wide study.
A total of 828 questionnaires, designed to identify the type and frequency of prophylaxis against venous thromboembolism that were used after hip and knee arthroplasty were mailed to orthopedic surgeons.
Demographic data and the frequency and type of thromboprophylaxis.
Of the 828 surveys mailed 445 (54%) were returned, and 397 were included in this analysis. Of the respondents, 97% used prophylaxis routinely for patients who undergo total hip or knee arthroplasty. Three of the 397 (0.8%) did not use any method ofprophylaxis. Warfarin was the most common agent used (46%), followed by low-molecular-weight heparin (LMWH) (36%). Combination therapy with both mechanical and pharmacologic methods were used in 39% of patients. Objective screening tests were not frequently performed before discharge. Extended prophylaxis beyond the duration of hospitalization was used by 36% of physicians.
Prophylaxis for venous thromboembolism with warfarin or LMWH has become standard care after total hip or knee arthroplasty in Canada.