Is venous duplex imaging an appropriate initial screening test for patients with suspected pulmonary embolism?

Noninvasive tests for deep venous thrombosis (DVT) are helpful in evaluating patients with suspected pulmonary embolism (PE) who have non-high-probability ventilation/perfusion (V/Q) lung scans. Based on the enthusiasm for these noninvasive tests, venous duplex imaging (VDI) has evolved as the initial screening test for patients with clinically suspected PE in some centers. This study evaluates the utility of VDI as the initial test in a diagnostic algorithm for patients with suspected PE. A total of 306 consecutive patients who underwent VDI as the initial screening test for clinically suspected PE during the past 24 months were reviewed; 121 patients were subsequently evaluated with V/Q scans and 20 underwent pulmonary arteriography. VDI demonstrated DVT in 10% (23/216), with 7% (22/306) having proximal DVT and 3% (9/306) having isolated calf DVT. In 25 patients with unilateral leg symptoms, DVT was found in 40% (10/25); however, among the 281 without unilateral leg symptoms, results of VDI were abnormal in only 5% (15/281). V/Q scans were obtained in 40% (121/306), with only 16% (19/121) of scans showing a high probability of PE. DVT was found in 25% (5/19) of patients with high-probability V/Q scans and in 25% (26/102) with non-high-probability scans. In patients with clinically suspected PE the incidence of detectable infrainguinal DVT is low. VDI appears to be a reasonable initial screening test in patients with clinically suspected PE and unilateral leg symptoms. However, in patients without unilateral leg symptoms, the diagnostic yield is low and an alternative diagnostic approach appears justified.Supported in part by NIH grant 1 K07HL02658-01.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995.     

Current diagnostic techniques for pulmonary embolism

The diagnosis of venous thromboembolism (VTE) includes deep venous thrombosis (DVT) and pulmonary embolism (PE) and requires objective testing. The clinician uses a combination of risk factors and nonspecific clinical findings to identify patients who warrant such an evaluation. The recommended approach begins with ventilation/perfusion (V/Q) lung scans or lower extremity noninvasive studies by compression ultrasonography. Nondiagnostic V/Q scans or negative noninvasive studies require further testing. A high-probability V/Q scan or a positive noninvasive study warrant treatment. A normal V/Q scan excludes the diagnosis of PE. Helical computed tomography (CT) can diagnose PE of major vessels but is not sufficiently sensitive to exclude PE because of its poor sensitivity for subsegmental pulmonary vessels. Newer D-dimer assays have a high negative predictive value, but results vary with the specific assay and do not perform well in patients with cancer. Future studies are needed to validate magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA).     

Role of venous duplex scanning in patients with suspected pulmonary embolism

Purpose: We examined the use of venous duplex scanning (VDS) in the diagnosis of pulmonary embolism (PE) at our institution.Methods: Patients undergoing lower extremity VDS from October 1988 through June 1995 were cross-referenced with those who underwent ventilation perfusion (V/Q) scans and pulmonary angiography (PA) for PE.Results: A total of 664 of 3534 VDS were for “rule out PE.” Deep venous thrombosis was found in 13%. A total of 256 VDS were in conjunction with V/Q scans in 249 patients, with only 8% undergoing PA. Deep venous thrombosis was present in 18% for those with both V/Q and VDS compared with 10% ( p < 0.01) for those with VDS as the sole study. The order in which V/Q, VDS, and PA were obtained and the relationship of positive studies was examined.Conclusion: We found no pattern to the sequence of tests ordered. V/Q scan rather than VDS should be the first study in the evaluation of PE. PE was diagnosed or excluded in nearly one third of patients based on V/Q as the initial study. A total of 29% of VDS could have been avoided. Treatment could be determined on the basis of VDS as the initial study in only 13%. We found only 14% incidence of positive PA in patients with nondiagnostic V/Q scans. We advocate judicious use of diagnostic tests in a stepwise fashion to appropriately treat patients with suspected PE. (J Vasc Surg 1996;24:768-73.)     

Usefulness of arterial blood gas analysis and D-dimer measurement in the assessment of pulmonary embolism after orthopedic surgery

Background Deep venous thrombosis (DVT) and pulmonary embolism (PE) after spinal or lower extremity surgery are well recognized as common complications. Since 1995 we have investigated the incidence of PE after orthopedic surgery using ventilation-perfusion (V/Q) lung scans, and the prevalence of PE was about 10%. With a view to detecting early-stage PE by simple examinations, we evaluated the use of both the blood gas analysis and the D-dimer measurement after spinal or lower extremity surgery. Methods Altogether, 85 patients who underwent spinal or lower extremity surgery were eligible for the study. Pneumatic sequential leg compression devices (PSLCDs) were utilized continuously both intra- and postoperatively. Arterial blood gas analysis and D-dimer measurement were performed pre- and postoperatively on days 3 and 7. We set lung scan criteria as follows: postoperative decrease in Pao2 (ΔPao2) by ≥10 torr (group G), postoperative D-dimer of ≥1μg/ml (group D), or both. Patients with the criteria went on to undergo lung scans, and PE was diagnosed by the existence of any mismatch between ventilation-perfusion (V/Q) lung scans. Results A total of 44 (51.8%) patients met the lung scan criteria and underwent perfusion lung scans, 10 (11.7%) of whom were diagnosed as PE. In groups G and D, about 30% showed PE. Moreover, six (85.7%) of the seven patients with both criteria showed a significant increase (83.7%) in the prevalence of PE. Conclusions Patients with the above criteria showed a high prevalence of PE. Moreover, 10 (11.7%) of the 85 patients were diagnosed as having PE, which corresponded to the prevalence in our former studies where lung scans were performed in all patients. The blood gas analysis and the D-dimer measurement may be utilized as the first screening examinations.     

Pulmonary embolism: a frequent occurrence in Indian patients with symptomatic lower limb venous thrombosis

OBJECTIVE: Pulmonary embolism (PE) is the most severe complication of deep venous thrombosis (DVT). There have been very few studies to assess the prevalence of PE in Asian patients. The objective of this study was to define the prevalence of PE in patients presenting with suspected lower limb DVT. METHODS: This was a prospective cohort study at Sir Ganga Ram Hospital, a large multispecialty hospital in New Delhi, India. From January 2001 to July 2004, 1,552 consecutive inpatients and outpatients who presented with clinically suspected lower limb DVT were enrolled in the study. Combined ascending radionuclide venography and lung perfusion scan was performed in all patients. Patients with evidence of pulmonary perfusion defects underwent ventilation lung scan. RESULTS: Radionuclide venography-detectable DVT was noted in 744 patients, of whom 521 (70%) had suprapopliteal DVT. Of patients with DVT, 294 (39.5%) showed a high-probability lung scan and 135 (18.1%) had an intermediate-probability lung scan. Overall, 47% of patients with a high-probability scan had no clinical manifestations suggestive of PE. CONCLUSION: PE occurs frequently in Indian patients with symptomatic DVT. Increasing awareness will provide us with clearer ideas about the prevalence of venous thromboembolism in Asian countries.     

Detection of Pulmonary Embolism in the Postoperative Orthopedic Patient Using Spiral CT Scans

Orthopedic surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). This study was performed to compare the clinical presentations of a suspected versus a documented PE/DVT and to determine the actual incidence of PE/DVT in the post-operative orthopedic patient in whom CT was ordered. All 695 patients at our institution who had a postoperative spiral CT to rule out PE/DVT from March 2004 to February 2006 were evaluated and information regarding their surgical procedure, risk factors, presenting symptoms, location of PE/DVT, and anticoagulation were assessed. Statistical analysis was performed using an independent samples t test with a two-tailed p value to examine significant associations between the patient variables and CT scans positive for PE. Logistic regression models were used to determine which variables appeared to be significant predictors of a positive chest CT. Of 32,854 patients admitted for same day surgery across all services, 695 (2.1%) had a postoperative spiral CT based on specific clinical guidelines. The incidence of a positive scan was 27.8% (193/695). Of these, 155 (22.3%) scans were positive for PE only, 24 (3.5%) for PE and DVT, and 14 (2.0%) for DVT only. The most common presenting symptoms were tachycardia (56%, 393/695), low oxygen saturation (48%, 336/695), and shortness of breath (19.6%, 136/695). Symptoms significantly associated with DVT were syncope and chest pain. A past medical history of PE/DVT was the only significant predictor of a positive scan. Patients who have a history of thromboembolic disease should be carefully monitored in the postoperative setting.     

Role of spiral volumetric computed tomographic scanning in the assessment of patients with clinical suspicion of pulmonary embolism and an abnormal ventilation/perfusion lung scan.

BACKGROUND: A study was carried out to evaluate the potential place of spiral volumetric computed tomography (SVCT) in the diagnostic strategy for pulmonary embolism. METHODS: In a prospective study 249 patients with clinical suspicion of pulmonary embolism were evaluated with various imaging techniques. In all patients a ventilation/perfusion (V/Q) scan was performed. Seventy seven patients with an abnormal V/Q scan underwent SVCT. Pulmonary angiography was then performed in all 42 patients with a non-diagnostic V/Q scan and in three patients with a high probability V/Q scan without emboli on the SVCT scan. Patients with an abnormal perfusion scan also underwent ultrasonography of the legs for the detection of deep vein thrombosis. RESULTS: One hundred and seventy two patients (69%) had a normal V/Q scan. Forty two patients (17%) had a non-diagnostic V/Q scan, and in five of these patients pulmonary emboli were found both by SVCT and pulmonary angiography. In one patient, although SVCT showed no emboli, the angiogram was positive for pulmonary embolism. In one of the 42 patients the SVCT scan showed an embolus which was not confirmed by pulmonary angiography. The other 35 patients showed no sign of emboli. Thirty five patients (14%) had a high probability V/Q scan, and in 32 patients emboli were seen on SVCT images. Two patients had both a negative SVCT scan and a negative pulmonary angiogram. In one who had an inconclusive SVCT scan pulmonary angiography was positive. The sensitivity for pulmonary embolism was 95% and the specificity 97%; the positive and negative predicted values of SVCT were 97% and 97%, respectively. CONCLUSIONS: SVCT is a relatively noninvasive test for pulmonary embolism which is both sensitive and specific and which may serve as an alternative to ventilation scintigraphy and possibly to pulmonary angiography in the diagnostic strategy for pulmonary embolism.     

Pulmonary Embolism and Deep Venous Thrombosis Following Bariatric Surgery

Background

The contribution of obesity to the thromboembolic risks of surgery suggests that patients undergoing bariatric surgery would have a particularly high risk of postoperative pulmonary embolism (PE) and/or deep venous thrombosis (DVT). This study aimed to assess the prevalence of in-hospital PE, DVT, and venous thromboembolism (VTE) following bariatric surgery in the USA from 2007 to 2009.

Methods

We used the database of the Nationwide Inpatient Sample.

Results

The prevalence of PE was 4,500 of 508,230 (0.9 %). The prevalence of DVT not accompanied by PE was 6,480 of 508,230 (1.3 %) and VTE (either PE or DVT) occurred in 10,980 of 508,230 (2.2 %). In-hospital death among patients with PE was 130 of 508,231 (0.03 %). Vena cava filters were inserted in 1,515 of 508,230 (0.3 %) patients who underwent bariatric surgery. Among patients who had VTE, filters were inserted in 1,150 of 10,980 (10.5 %). Among patients who had neither PE nor DVT, prophylactic vena cava filters were inserted in 365 of 497,250 (0.07 %). Among patients with PE, in-hospital mortality was 25 of 635 (3.9 %) with a filter compared with 105 of 3,865 (2.7 %) (NS) without a filter. However, among patients with DVT alone, in-hospital mortality was 0 of 510 (0 %) with a filter compared with 80 of 5,970 (1.3 %) (P?=?0.009) without a filter.

Conclusions

This investigation establishes a baseline for the incidence of venous thromboembolic complications following bariatric surgery in recent years. Determination of the present in-hospital rate of PE and DVT may contribute to antithrombotic prophylactic considerations.     

Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans

Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004–February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.     

The management and outcome of acute venous thromboembolism: a prospective registry including 4011 patients

OBJECTIVE: To obtain a realistic overview of management and clinical outcomes of patients with venous thromboembolism (VTE) in Spain on the basis of data from a national multicenter registry. METHODS: A prospective registry was initiated in Spain in March 2001. Data were collected from patients with objectively confirmed deep vein thrombosis (DVT) and/or pulmonary embolism (PE) and entered into the online registry by physicians who were responsible for the management of these patients. RESULTS: As of August 2002, 4011 patients with confirmed VTE were included in the registry: 60% with DVT, 23% with PE, and 17% with both DVT and PE. Diagnostic methods for VTE included compression ultrasonography (86%), venography (10%), V/Q lung scans (42%), computed tomography scan (28%), and pulmonary angiography (0.9%). D-dimer testing was performed in 61% of cases and was positive in 92% of patients with confirmed VTE. The majority of DVT (95%) were located in the lower extremities (82% proximal and 4% bilateral), while 4.8% were located in the upper extremities or neck veins. Most patients (90.5%) were admitted to hospital. In the acute phase, treatment consisted of low molecular weight heparin (LMWH) in 88%, unfractionated heparin (UFH) in 11%, and fibrinolysis in 0.8%. Cava filters were inserted in 2% of patients, mainly because of active bleeding (13%), increased hemorrhagic risk (38%), or recurrent VTE (29%). Absolute bed rest was recommended to 63% of patients. Secondary prevention of VTE included oral anticoagulants (75%) and LMWH (24.5%). Therapeutic compression stockings were prescribed to 53% of patients at the time of hospital discharge. Regarding the main clinical outcomes during an average (+/-SD) follow-up period of 156 +/- 95 days, 19% had adverse events: 12.5% of patients died, 5.5% had clinically confirmed VTE recurrence, and 9.8% suffered bleeding complications (44% with major bleeding). CONCLUSIONS: This prospective observational multicenter registry provides a large database reflecting the actual day-to-day clinical practice regarding VTE management in a European country. The most important findings were the increasing use of spiral computed tomography for PE diagnosis, the unexpectedly high proportion of patients admitted to hospital despite the use of LMWH in almost 90% of cases in the acute phase, and the utilization of LMWH for secondary prevention in almost 25% of cases. On the other hand, this large-scale prospective registry permits on-line consultation of high-risk situations to assess how difficult cases were treated and what their outcomes were. This will provide a most useful tool for the practicing physician responsible for the management of VTE patients.     

Frequency of pulmonary embolism in patients who have iliofemoral deep vein thrombosis and are treated with once- or twice-daily low-molecular-weight heparin

Purpose: The purpose of this study was to compare the efficacy and safety of treating mobile iliofemoral patients with deep venous thrombosis (DVT) with subcutaneous low-molecular-weight heparin (dalteparin sodium) either 200 IU/kg once-daily (group 1) or 100 IU/kg twice-daily (group 2).Methods: Consecutive patients with suspected iliofemoral DVT diagnosed by duplex ultrasonography and verified by radionuclide venography were randomized to one of the two low-molecular-weight heparin (LMWH) regimens. Perfusion and when necessary ventilation scans were performed for diagnosis of pulmonary emboli (PE) in all patients immediately after admission and were repeated after approximately 10 days, whereupon oral anticoagulation was started unless contraindicated. Minimal and maximal anti-factor Xa activity was measured after 2 to 3 days of therapy. All patients were kept mobile with compression bandages. The primary end point was reduction in frequency of PE as assessed on the second lung scan.Results: A total of 140 patients with confirmed DVT were randomized, 76 to group 1 and 64 to group 2. The two groups were comparable in their baseline clinical characteristics. In the initial lung scans 36 (47.4%) patients in group 1 and 29 (45.3%) patients in group 2 had objectively verified PE, but only 11 (14.5%) and 8 (12.5%) patients, respectively, had symptoms. After dalteparin treatment PE disappeared in two patients in group 1, but in two other cases new PEs occurred, (NS). In group 2 a resolution of PEs was observed in eight patients, whereas only one new PE could be detected. This change reflects the efficacy of therapy as defined by resolution of existing PEs and by the occurrence of new PEs and is statistically significant according to Mc Nemar's χ ² test with the exact binomial method pair procedure ( p < 0.05). Symptomatic PE was reduced from 14.5% to 5.3% in group 1 (96% to CI for the difference, -1.5% to +17.3%) and from 12.5% to 1.6% in group 2 (95% CI for the difference 0.7% to 18%, p < 0.05). There was one single fatal PE, one serious and three minor bleeding episodes in group 1, and one minor bleeding episode in group 2 (95% CI for the difference: -3.6% to + 8.1%).Conclusions: Treatment of ambulant iliofemoral patients with DVT with 100 IU/kg dalteparin twice-daily appears to be more safe and effective than 200 IU/kg given once-daily. Bed rest is not necessary for treating mobile patients. (J Vasc Surg 1996;24:774-82.)     

Role of inferior vena cava filter implantation in preventing pulmonary embolism

A retrospective review of all patients undergoing IVC filter implantation at Shifa International Hospital, Islamabad, from June 2004 to June 2006 was conducted to study the indications of inferior vena cava (IVC) filter use and impact on short-term morbidity/mortality. A total of 17 patients received IVC filters. Five patients were excluded due to data loss. One month clinical follow-up was available for 12 patients and 6 months follow-up was also available for 4 of 12 patients. The underlying disease was deep venous thrombosis (DVT) with pulmonary embolism (PE) in 6 (50%), DVT without PE in 4 (33.3%) and PE with negative duplex scan for DVT in 2 (16.6%) patients, respectively. Indications for IVC filter implantation were DVT and/or PE with contraindication to anticoagulation in 8 (66.7%) and DVT and/or PE with complications of anticoagulation in 4 (33.3%) patients. No procedure-related complications were noted in all 17 patients. Three patients (25%) died of non-PE related causes during the 1st month. There were no PE related mortalities at 6 months. This data set indicates that IVC filter implantation is a safe procedure with no short-term morbidity/mortality and potential long-term mortality benefit.     

Thermally injured patients are at significant risk for thromboembolic complications

BACKGROUND: The incidence of thromboembolic complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE) in thermally injured patients is considered sufficiently uncommon that routine prophylactic measures are not warranted. Nevertheless, the incidence of DVT/PE may be increasing. METHODS: The records of 1,300 patients admitted to our unit from January 1990 to June 1995 were reviewed. RESULTS: Twenty-three patients developed a clinically significant DVT, eight patients developed a PE, and two patients developed both a DVT and a PE, for an overall DVT/PE incidence of 2.9%. Four of 10 PEs were felt to be fatal. The DVT/PE patients were older (mean age, 42.6 vs. 28.7; p < 0.001) and had larger burns (37% vs. 18%, p < 0.001) than patients without evidence of DVT/PE. Body weight appeared to also influence DVT/PE rates, with obese patients (>30% over ideal body weight) having a higher incidence than patients with low or normal body weight (7.2 vs. 2.7%, p < 0.015). Age and total body surface area (TBSA) burn had a synergistic effect on DVT/PE risk, with the sum of age and TBSA burn exerting the strongest independent effect when discriminant function analysis was performed (p < 0.001). CONCLUSION: One can identify a population at increased risk of DVT/PE on the basis of the sum of age and TBSA burn, but prospective screening trials that assess all risk factors for DVT/PE should be performed before routine prophylaxis is used in thermally injured patients.     

Efficacy and Safety of Mechanical IVC Filtration for Preventing Pulmonary Embolism in High-Risk Orthopedic Patients Undergoing Total Hip or Knee Arthroplasty

BackgroundTo determine the efficacy and safety of inferior vena cava (IVC) filters in preventing pulmonary embolism (PE) in high-risk patients undergoing hip or knee arthroplasty.Methods2857 hip or knee arthroplasty procedures between January 2013 and December 2018 were retrospectively reviewed. Patients with a preoperative history of venous thromboembolism (VTE), either PE or deep venous thrombosis (DVT), were categorized as high-risk patients. The incidence of overall VTE, PE, and DVT were compared between patients with filters and those without. The subgroup analysis was also performed by patient risk, and filter status and the incidence of VTE, PE, and DVT were compared. Variables such as filter placement, history of hypercoagulability etcetra were evaluated as risk factors for the development of postoperative VTE.ResultsIn the high-risk group, the use of IVC filters was significantly associated with a lower incidence of pulmonary embolism (0.8% vs 5.5%, P = .028). When compared with the low-risk group, the high-risk group had significantly higher incidence of PE (3.8% vs 2.0%, P = .038), DVT (11.6% vs 5.3%, P < .001), and overall VTE (15.0% vs 6.8%, P < .001). The history of VTE was associated with postoperative VTE (P < .001), PE (P = .042), and DVT (P < .001). There was no significant correlation between filter placement and postoperative VTE, DVT, or PE in the low-risk group. Filter retrieval was successful in 100% (96/96) of attempted patients with no complications.ConclusionThe use of IVC filters is significantly associated with a lower incidence in pulmonary embolism in high-risk arthroplasty patients. High-risk patients demonstrated an incidence of postoperative VTE over two times greater than other patients. Prophylactic placement of IVC filters in hip/knee arthroplasty is safe.     

Usefulness of D-dimer, blood gas, and respiratory rate measurements for excluding pulmonary embolism

BACKGROUND: A study was undertaken to assess the usefulness of the SimpliRED D-dimer test, arterial oxygen tension, and respiratory rate measurement for excluding pulmonary embolism (PE) and venous thromboembolism (VTE). METHODS: Lung scans were performed in 517 consecutive medical inpatients with suspected acute PE over a one year period. Predetermined end points for objectively diagnosed PE in order of precedence were (1) a post mortem diagnosis, (2) a positive pulmonary angiogram, (3) a high probability ventilation perfusion lung scan when the pretest probability was also high, and (4) the unanimous opinion of an adjudication committee. Deep vein thrombosis (DVT) was diagnosed by standard ultrasound and venography. RESULTS: A total of 40 cases of PE and 37 cases of DVT were objectively diagnosed. The predictive value of a negative SimpliRED test for excluding objectively diagnosed PE was 0.99 (error rate 2/249), that of PaO2 of > or = 80 mm Hg (10.7 kPa) was 0.97 (error rate 5/160), and that of a respiratory rate of < or = 20/min was 0.95 (error rate 14/308). The best combination of findings for excluding PE was a negative SimpliRED test and PaO2 > or = 80 mm Hg, which gave a predictive value of 1.0 (error rate 0/93). The predictive value of a negative SimpliRED test for excluding VTE was 0.98 (error rate 5/249). CONCLUSIONS: All three of these observations are helpful in excluding PE. When any two parameters were normal, PE was very unlikely. In patients with a negative SimpliRED test and PaO2 of > or = 80 mm Hg a lung scan is usually unnecessary. Application of this approach for triage in the preliminary assessment of suspected PE could lead to a reduced rate of false positive diagnoses and considerable resource savings.     

抗凝、溶栓治疗下肢深静脉血栓对患者发生肺栓塞的影响

目的 探讨抗凝、溶栓治疗对下肢深静脉血栓(DVT)患者发生肺栓塞的影响.方法 回顾分析经抗凝、溶栓治疗并获随访的105例下肢深静脉血栓患者的临床资料,统计肺栓塞的发生率,并对患者的性别、年龄、血栓位置、血栓类型行单因素分析,探讨它们与肺栓塞发生的关系.结果 抗凝、溶栓治疗的患者住院期间有症状肺栓塞的发生率为2.86%(3/105),出院后随访无肺栓塞发生.肺栓塞的发牛率与性别、年龄、血栓位置、血栓类型无关(P=0.086,0.618,1.0,1.0).结论 对下肢DVT患者严格的抗凝、溶栓治疗可有效的降低其肺栓塞的发生率,故VCF的置入应严格掌握适应证.     

No correlation between lower extremity deep vein thrombosis and pulmonary embolism proportions in trauma: a systematic literature review

Purpose

To assess the effect of surveillance on deep vein thrombosis (DVT) and pulmonary embolism (PE) rates, the efficacy of chemoprophylaxis and mechanical prophylaxis, and the relationship between DVT and PE.

Methods

A 23 year, systematic literature review was performed in PubMed. Twenty publications with >?13,000 patients were reviewed. Analyzed traits included: DVT surveillance utilization, the total number of patients included in each study, the number of patients developing DVT and/or PE, chemoprophylaxis and mechanical prophylaxis utilization. When event proportions from individual studies were combined, a weighted mean proportion was computed based on the size of each individual cohort. Combined event proportions were compared with other combined event proportions, according to differences in intervention. Inter-group event proportions were compared using Chi-Square or Fisher’s exact test, as appropriate.

Results

DVT rates increase with surveillance (10.7% vs. 2.5%, p?<?0.001). PE rates were similar regardless of surveillance (p?=?1.0). Chemoprophylaxis lowered both DVT rates (8.2% vs. 10.7%; p?<?0.0001) and PE rates (1.2% vs. 1.9%; p?=?0.0050). Mechanical prophylaxis did not decrease DVT rates (10.2% vs. 11.5%; p?=?0.2980) or PE rates (1.7% vs. 1.6%; p?=?1.0). In patients with neither chemoprophylaxis nor mechanical prophylaxis, DVT rate was 11.5%, PE was 1.6%. When chemoprophylaxis and/or mechanical prophylaxis were given, DVT rate was 8.6% (p?<?0.0189) and PE was 1.3% (p?=?0.4462). PE proportions were not decreased with mechanical prophylaxis or surveillance. DVT and PE rates were not associated (p?=?0.7574).

Conclusions

The results suggest that PE is not associated with lower extremity DVT in adult trauma patients.

     

Chemical Thromboprophylaxis Is Not Necessary to Reduce Risk of Thromboembolism With Tranexamic Acid After Total Hip Arthroplasty

Background

The major concern with the use of tranexamic acid is that it may promote a hypercoagulable state and increase the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE), particularly when chemical thromboprophylaxis is not used. The objective of this study was to ascertain whether tranexamic acid reduces blood loss and transfusion amounts and increases the prevalence of DVT and PE in the patients undergoing primary cementless total hip arthroplasty (THA) without the use of routine chemical thromboprophylaxis.

Does repeat duplex ultrasound for lower extremity deep vein thrombosis influence patient management?

The clinical significance of lower extremity deep vein thrombus (DVT) propagation in the setting of anticoagulation therapy remains unclear. The purpose of this study is to compare results of thrombus outcome found with repeat duplex ultrasonography to the incidence of pulmonary embolism and mortality. During a recent 18-month period, 457 patients were diagnosed with lower extremity DVT with duplex ultrasonography and their data were retrospectively analyzed. Repeat examinations were available for review in 118 patients (51 men, 67 women). Results of repeat duplex exams were divided into 4 groups: resolved, improved, unchanged, or extended proximally. All patients received heparin and warfarin therapy. Ventilation-perfusion (V/ Q) scans were obtained only for signs and symptoms of pulmonary embolism (n=30). Mortality, the prevalence of high-probability V/ Q scans, frequency of intracaval filter insertion, gender, mean age, mean prothrombin time (PT), mean partial thromboplastin time (PTT), mean number of repeat ultrasounds per patient, and mean time over which the repeat ultrasounds took place were compared among the 4 groups. Patients who had proximal extension of DVT (19%) on repeat duplex ultrasound had an increased prevalence of pulmonary embolism (p<0.05). Also, patients whose DVT resolved were younger (p<0.05). There was no difference among the 4 groups in mortality, placement of Greenfield filters, mean PT, mean PTT, mean number of ultrasound exams per patient, or mean follow-up time over which the exams took place. Proximal extension of DVT documented by repeat duplex ultrasound is a significant risk factor for pulmonary embolism. Repeat duplex ultrasound can identify a group of patients who may benefit from insertion of an intracaval filter device.     

Non-invasive diagnosis of pulmonary embolism, anno 2005

Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but no longer for subsegmental PE, because the inter-observer agreement for angiographically documented subsegmental PE is only 60%. Two non-invasive tools exclude PE with a negative predictive value of >99% : a normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test. The positive predictive value is 85 to 88% for a high probability ventilation-perfusion lung scan (VP-scan) and >95% for helical spiral CT. The prevalence of PE in management studies of symptomatic patients with a non-diagnostic VP-scan is 20 to 24%. Helical spiral CT detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic VP-scan or a high probability VP-scan. Single-slice helical CT as the primary diagnostic test in patients with suspected PE in three retrospective studies and in two prospective management study indicate that the negative predictive value of a normal helical spiral CT, a negative compression ultrasonography of the legs (CUS) together with a low or intermediate pre-test clinical probability is >99%. Therefore, helical spiral CT can replace both the VP-scan and pulmonary angiography to safely rule in and out PE. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer followed by CUS will reduce the need for helical spiral CT by 40 to 50%.