Noninvasive venous testing in the diagnosis of pulmonary embolism: The impact on decisionmaking

Purpose: To characterize the use and utility of lower extremity noninvasive venous testing (NIVT) in the diagnosis of pulmonary embolism (PE).Methods: The study is a retrospective case series of consecutive patients in whom PE was suspected who were referred to a large, urban tertiary care center for NIVT. The main outcome measures of the study were the rate of positive results of NIVT, the amount of new information provided by NIVT, and the frequency of management changes that were attributable to NIVT.Results: Forty-one of 450 patients (9%) had deep venous thrombosis (DVT) by NIVT. The prevalence of DVT by NIVT among patients not evaluated by ventilation/perfusion (V/Q) scanning was 8%. The prevalence of DVT by NIVT among patients with a high-probability V/Q scan result before NIVT was 39%, but no management decisions in this group were based on a positive NIVT result and only two decisions were based on negative NIVT results. The prevalence of DVT according to NIVT among patients who had a negative “diagnostic” (low, or very low probability, or normal) result of V/Q scan before NIVT was 2%. The overall frequency of management changes attributed to NIVT was only 2.5%. In the remaining 97% of patients, management was determined by the result of V/Q scanning or of subsequent pulmonary arteriography.Conclusions: In patients in whom PE is suspected, results of NIVT are usually negative for acute DVT. Management decisions are almost always based on V/Q scan or results of pulmonary arteriography and not on NIVT. The utility of NIVT to identify DVT in these patients appears limited, and a more selective approach to its application for the diagnosis of PE should be considered. (J Vasc Surg 1997 26:757-63.)     

Asymptomatic pulmonary embolism in patients with deep vein thrombosis. Is it useful to take a lung scan to rule out this condition?

One hundred and sixteen patients with proximal deep venous thrombosis (DVT) confirmed venographically had perfusion and ventilation lung scans performed 48 hours after admission to assess the incidence of asymptomatic pulmonary embolism (PE). Sixty-six patients had normal lung scans, 29 had high-probability defects suggestive of PE, and 21 had indeterminate-probability of PE. Chest X-ray, electrocardiogram and arterial blood gases were of no value in assessing the lung scan results. Six out of 29 patients with a baseline lung scan of high probability of PE experienced acute signs and/or symptoms suggestive of pulmonary embolism while on heparin therapy. A repeated scan this time did not disclose new perfusion defects in any patients. In the absence of a baseline study, these scans may be interpreted as demonstrating pulmonary embolism on treatment and lead to unnecessary caval interruption procedures for failed heparin therapy.     

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.     

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.     

Multi-institutional study of symptomatic deep venous thrombosis and pulmonary embolism in prostate cancer patients undergoing laparoscopic or robot-assisted laparoscopic radical prostatectomy

OBJECTIVES: The true incidence of symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE) in patients undergoing laparoscopic radical prostatectomy is unknown. Our aim was to determine the incidence of symptomatic DVT and PE and the risk factors for these complications. METHODS: Fourteen surgeons from 13 referral institutions from both Europe and the United States provided retrospective data for all 5951 patients treated with laparoscopic radical prostatectomy (LRP), with or without robotic assistance, since the start of their institution's experience. Symptomatic DVT and PE within 90 d of surgery were regarded as venous thromboembolism (VTE). DVT was diagnosed mostly by Doppler ultrasound or contrast venography and PE by lung ventilation/perfusion scan or chest computed tomography or both. Statistical analysis included evaluation of incidence of symptomatic DVT and PE and risk factors as determined by exact methods and logistic regression. RESULTS: Of 5951 patients in the study, 31 developed symptomatic VTE (0.5%; 95% confidence interval [CI], 0.4%, 0.7%). Among patients with an event, 22 (71%) had DVT only, 4 had PE without identified DVT, and 5 had both. Two patients died of PE. Prior DVT (odds ratio [OR]=13.5; 95%CI, 1.4, 61.3), current tobacco smoking (OR=2.8; 95%CI, 1.0, 7.3), larger prostate volume (OR=1.18; 95%CI, 1.09, 1.28), patient re-exploration (OR=20.6; 95%CI, 6.6, 54.0), longer operative time (OR=1.05; 95%CI, 1.02, 1.09), and longer hospital stay (OR=1.05; 95%CI, 1.01, 1.09) were associated with VTE in univariate analysis. Neoadjuvant therapy, body mass index, surgical experience, surgical approach, pathologic stage, perioperative transfusion, and heparin administration were not significant predictors. CONCLUSIONS: The incidence of symptomatic VTE after LRP is low. These data do not support the administration of prophylactic heparin to all patients undergoing LRP, especially those without risk factors for VTE.     

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.     

Experience with external pneumatic calf compression in neurology and neurosurgery

This report reviews our experience with external pneumatic compression (EPC) therapy in preventing clinically evident deep venous thrombosis (DVT) and pulmonary emboli (PE) in neurological and neurosurgical patients. A total of 523 patients admitted to the Departments of Neurology and Neurosurgery at the Massachusetts General Hospital from December 1980 through January 1984 are included. The incidence of DVT despite EPC use was 2.3%. The incidence of PE diagnosed by lung scan and usually confirmed by angiography was 1.8%. In conjunction with previously published reports of the incidence of DVT and PE, these data suggest that EPC may be efficacious in decreasing the incidence of DVT but may not prevent PE in neurological and neurosurgical patients.     

The role of surveillance duplex scanning in preventing venous thromboembolism in trauma patients

BACKGROUND: This study was performed to determine the role of duplex scanning in preventing pulmonary embolism (PE), the correlation of venous thromboembolism (VTE) risk score with the incidence of deep venous thrombosis (DVT), and patients who may benefit from surveillance duplex scanning. METHODS: Age, sex, Injury Severity Score (ISS), VTE score, length of stay, diagnoses, and bleeding risk were recorded from the trauma registry in patients who had a duplex scan from 1995 to 2000. RESULTS: There were 1,513 duplex scans obtained (10,141 trauma admissions), 253 (2.5%) cases of DVT (52% above-knee, 8% upper extremity), and 30 cases of PE (0.3%). Only 5 of 21 duplex scans were positive in PE patients. DVT patients were older (52.9 vs. 46.7 years), with higher ISS (24.0 vs. 20.8) than patients without DVT. Regression analysis showed poor correlation between VTE score and DVT incidence (r2 = 0.27). Univariate analysis identified age, ISS, and VTE score as risk predictors for DVT. CONCLUSION: Adherence to an evidence-based VTE prophylaxis protocol is more important than surveillance duplex scanning in preventing VTE in trauma patients.     

Thromboembolism following multiple trauma.

The true incidence of thromboembolic complications following multiple trauma is unknown, and no method of prophylaxis has been shown to be both safe and effective in managing seriously injured patients. In this prospective study, 113 trauma patients were assigned on admission to receive either low-dose heparin (LDH), (5,000 U subcutaneously every 12 hours) or to wear sequential compression devices (SCDs) as prophylaxis against the development of deep venous thrombosis (DVT). Both groups of patients were serially studied with duplex venous ultrasound imaging to detect thrombus in the veins of the thigh. Ventilation-perfusion lung scans and pulmonary angiograms were performed when pulmonary embolism (PE) was suspected clinically. There were 12 patients who had thromboembolic complications, including 9 of 76 in the SCD group (12%) and 3 of 37 in the LDH group (8%). Five patients had DVT only, four had PE without detectable DVT, and three had both DVT and PE. None of the patients with PE died, and there were no major complications associated with either method of prophylaxis. Compared with the patients who did not develop DVT/PE, those with thromboembolic complications were older (49 +/- 23 vs. 36 +/- 17 years, p less than 0.02), spent more hospital days immobilized (24 +/- 15 vs. 10 +/- 13 days, p less than 0.001), received more transfusions (11 +/- 12 vs. 3 +/- 5 U, p less than 0.001) and had clotting abnormalities on admission, as demonstrated by prolonged PTT values (39 +/- 28 vs. 26 +/- 5 seconds, p less than 0.001). It appears that there is an identifiable subgroup of injured patients at highest risk for PE who warrant both prophylaxis and close surveillance for DVT.     

不同治疗方法对下肢深静脉血栓发生肺栓塞影响的对比研究

目的 对比不同治疗方法对下肢深静脉血栓形成发生肺栓塞的影响.方法 回顾性分析2002年8月至2008年6月201例下肢深静脉血栓形成患者,男性97例,女性104例;年龄24～83岁,平均60.4岁.其中血栓发生于左侧肢体174例,右侧24例,双侧3例.所有患者发病≤7 d,入院时无肺栓塞,且均获得随访.按治疗方法分为:单独溶栓抗凝组,手术取栓后溶栓抗凝组及置入下腔静脉滤器后溶栓抗凝组.分别计算各组住院期间和随访期间3组肺栓塞的发生率.结果 单独溶栓抗凝组住院期间有症状肺栓塞发生率为2.8%(3/107),下腔静脉滤器组、手术组无肺栓塞发生,3组间差异无统计学意义(P=0.425).出院后随访6～72个月,平均24个月.随访期间单独溶栓抗凝治疗组及手术取栓组无肺栓塞发生,下腔静脉滤器组肺栓塞发生率为2.4%(1/42)且死于肺栓塞,3组间差异无统计学意义(P=0.656).结论 三种治疗方法对下肢深静脉血栓形成、发生有症状肺栓塞的影响并无差异,下腔静脉滤器的置入应严格掌握适应证.     

The prevalence of deep vein thrombosis in a cohort of patients with spinal cord injury following the Pakistan earthquake of October 2005

STUDY DESIGN: Prospective observational study. OBJECTIVES: To assess the prevalence of symptomatic deep vein thrombosis (DVT) in earthquake survivors with spinal cord injury (SCI). SETTINGS: Rawalpindi, Pakistan, in the months after the October 2005 earthquake. METHODS: Earthquake survivors (n=187) with acute SCI were enrolled after verbal informed consent. Information on mechanism of injury, mode of evacuation, associated injuries was gathered, and a detailed clinical and radiological assessment was performed. They were followed for 10 weeks for clinical signs and symptoms suggestive of DVT. Case with clinical suspicion of a DVT underwent a duplex scan of both legs to confirm the diagnosis. The influence of age, gender, American Spinal Injury Association (ASIA) grade and lower limb fractures on occurrence of DVT was determined. RESULTS: There were 80 men and 107 women with a mean age of 28.3+/-12.4 years. Seventeen patients were clinically suspected to have a DVT and ultrasound was positive in nine (4.8%). There was no influence of age (P=0.4), gender (P=0.4), ASIA grade (P=0.1) or presence of a lower limb fracture (P=0.6) on the occurrence of a DVT. CONCLUSION: This study adds further evidence to support the belief that the incidence of DVT in Southeast Asian patients with an SCI is lower than the reported incidence in the West. It may not be necessary to apply the recommendations for DVT prophylaxis in Caucasians with SCI to other groups, including Southeast Asians.     

Postoperative D-dimer predicts venous thromboembolism in patients undergoing urologic tumor surgery

Purpose

We examined the incidence of pulmonary thromboembolism (PE) and deep venous thromboembolism (DVT) in patients who underwent urologic tumor surgery. The aim of this study was to investigate the postoperative D-dimer for prediction of venous thromboembolism events (VTE), as well as to identify other risk factors associated with the occurrence of thromboembolisms.

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).     

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.     

Duplex scanning of central vascular access sites in burn patients.

Seventy-one burned patients requiring intensive care unit management underwent 570 central venous and 167 femoral arterial catheterizations. These patients were surveyed by repeated physical examinations and duplex scans for vascular-related complications. Catheter sites were rotated every 3 days. No arterial thrombi or occlusions were noted. Fourteen patients (19.6%) had 19 positive venous duplex scans. Five patients (7%) had symptomatic deep venous thrombosis (DVT) and nine (12.6%) had asymptomatic DVT. Mean number of venous cannulations before a positive scan was 4.3 (range 1 to 17). All five symptomatic patients had DVT that originated in the lower extremities. No patient had clinical evidence of a pulmonary embolus, or limb morbidity resulting from the DVT. Follow-up duplex scans in the five asymptomatic and three symptomatic patients showed complete resolution in each case. This study demonstrates the high incidence and natural history of central DVT in a group of critically ill burn patients.     

Prospective evaluation of a screening protocol to exclude deep vein thrombosis on the basis of a combination of quantitative D-dimer testing and pretest clinical probability score

BACKGROUND: Clinical signs and symptoms such as swelling, pain, and redness are unreliable markers of deep vein thrombosis (DVT). Because of this venous duplex scanning (VDS) has been heavily used in DVT detection. The purpose of this study was to determine if a combination of D-dimer testing and pretest clinical score could reduce the use of VDS in symptomatic patients with suspected DVT. STUDY DESIGN: One hundred seventy-four consecutive patients with suspected DVT were prospectively evaluated using pretest clinical probability (PCP) score and D-dimer testing before VDS. After calculating clinical probability scores developed by Wells and associates, patients were divided into low risk (or=3 points) PCP. RESULTS: One hundred fifty-eight patients were enrolled. The prevalence of DVT in this study was 37%. Thirty-eight patients (24%) were classified as low risk, 64 (41%) as moderate risk, and 56 (35%) as high risk PCP. DVT was identified in only one patient (2.6%) with low risk PCP. In contrast, DVT was found in 22 (34%) with moderate risk, and 35 (63%) with high risk PCP. In the high and moderate risk PCP groups, positive scan patients had a markedly higher value of D-dimer assay than negative scan patients (p=0.0001 and p=0.0057, respectively). In the low risk PCP patients, D-dimer testing provided 100% sensitivity, 46% specificity, 4.8% positive predictive value, and 100% negative predictive value in the diagnosis of DVT. Similarly, in the moderate risk PCP, the D-dimer testing showed 100% sensitivity, 45% specificity, 49% positive predictive value, and 100% negative predictive value. In the high risk group, D-dimer testing achieved 100% sensitivity, 57% specificity, 80% positive predictive value, and 100% negative predictive value in the diagnosis of DVT. These results suggested that 36 of 158 patients who had a non-high PCP (low and moderate PCP) and a normal D-dimer concentration were considered to have no additional investigation, so VDS could have been reduced by 23% (36/158). CONCLUSIONS: A combination of D-dimer testing and clinical probability score may be effective in avoiding unnecessary VDS in suspected symptomatic DVT in the low and moderate PCP patients. The need for VDS could be reduced by 23% despite a relatively high prevalence of DVT.     

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.)     

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.     

Pulmonary embolism after spinal surgery: report of two cases

We present two cases of pulmonary embolism (PE) without deep venous thrombosis (DVT) after spinal surgery with an anterior approach. On the seventh day after surgery, the patients’ plasma D-dimer levels were high without symptoms, so computed tomography (CT) was performed from chest to lower limb, revealing PE without lower limb DVT. After the exam, we immediately started anticoagulation therapy with heparin and warfarin. The patients were discharged with no complications. Previous reports have documented that DVT causes most cases of PE; however, our cases had no lower limb DVT. Some reports hypothesize that anterior spinal surgery might have a differential pathogenesis of PE. Simple mechanical prophylaxis for DVT may not protect these patients. On the other hand, the administration of chemical anticoagulants therapy after spinal surgery is controversial because of the risk of epidural hematoma. We should explain the risk of PE to patients undergoing spinal surgery with an anterior approach.     

Incidence of symptomatic venous thrombo-embolism following shoulder surgery

Purpose

This clinical study was performed to establish the incidence of symptomatic deep vein thrombosis and pulmonary embolism after shoulder surgery as the incidence of venous thrombo-embolism complicating shoulder surgery is poorly described in literature.

Methods

We reviewed retrospectively clinical records of 920 consecutive patients who had any surgical procedure performed on their shoulder in Glan Clwyd Hospital, North Wales and a further 1,421 consecutive patients who had surgery in Morriston and Singleton Hospitals, South Wales. Patients’ records were assessed for any admissions due to proven VTE; we investigated for any radiological results suggestive of venous thrombo-embolism and for deaths in the post-operative period.

Results

We analyzed data of 2,341 patients. There was one fatal PE in this group, whereby the patient died within 48 hours following reverse shoulder replacement, and post mortem revealed massive pulmonary embolism. There were a further three cases of symptomatic, non-fatal PE. There were six cases of symptomatic DVT of lower limb. All these cases were treated successfully with anticoagulation. No upper limb DVT was identified.

Conclusion

Recent studies suggest that DVT prevalence following shoulder arthroplasty is as high as 13 %. In our study we examined occurrence of symptomatic VTE only. According to our results the prevalence of symptomatic DVT following shoulder surgery is 0.26 %, symptomatic PE 0.17 % and combined prevalence of VTE is 0.43 %. We would advise careful thought about the risk of thrombosis and use mechanical prophylaxis in shoulder surgery, especially for longer procedures. We would not recommend routine pharmacological prophylaxis unless there are additional risk factors.