Early Pulmonary Embolism Research Articles

Safety and efficacy of thrombolytic therapy in the treatment of early pulmonary embolism after thoracic surgery.

The incidence and mortality rates of early pulmonary embolism (PE) after thoracic surgery are high. Thrombolytic therapy is the basic treatment of PE. The aim of this study is to explore the safety and efficacy of thrombolytic therapy for patients with early postoperative PE. Data of forty patients excluding three patients with sudden death were analyzed. The included patients were divided into: thrombolysis + anticoagulation (group A, 21 cases) and anticoagulation (group B, 16 cases). Twenty patients had esophageal cancer and 17 had lung tumors. Bleeding, drainage volume, pulmonary infection, and perioperative mortality were compared between the groups. Factors related to perioperative mortality were analyzed by multivariate logistic regression. The mortality rates of group A (19.0%) and B (81.3%) differed significantly. No massive hemorrhage or significant drainage volume differences were observed. Group A's D-dimer (D-D) level decreased, group B's D-D level increased, and was significantly different between after surgery and on the fourth day of treatment. Group B's partial oxygen pressure was significantly different between the third and fourth day of treatment, it gradually increased in group A, and remained unaltered in group B. Multivariate logistic regression supported a significant survival rate improvement. Thrombolytic therapy is safe and effective for PE early after thoracic surgery in the absence of absolute contraindications for anticoagulation and thrombolysis, and it can reduce mortality in patients.

A case of early pulmonary embolism following blunt trauma to chest and a long bone fracture: a case report

BackgroundAfter substantial trauma, pulmonary embolism (PE) carries a high risk of morbidity and mortality. Early post-traumatic PE in the absence of deep vein thrombosis (DVT) is a distinct entity that might be connected to rare mechanisms or unidentified biochemical processes.Case presentationA driver of a car was presented with worsening chest pain and shortness of breath (SOB) following a road traffic accident in which he suffered an impact on the chest against the steering wheel and a closed fracture of the right femur. Radiological investigations revealed a pulmonary embolism in the left posterior segment pulmonary artery, without evidence of internal chest injuries or DVT within 12 h from the incident. D-dimer, troponin I, and creatinine kinase were elevated without evidence of myocardial infarction or myocardial injury. Other parameters were within the normal range.ConclusionsPossibilities of early PE in the absence of detectable DVT could be due to hyper-coagulability states, clots from the lower extremity completely getting detached and embolizing to the pulmonary circulation, screening errors, and “de novo” thrombi in the pulmonary circulation. Chest trauma is an identified risk factor for early or late pulmonary embolism. Action of the post-traumatic adrenergic response causing vascular endothelial inflammation and the synthesis of circulating adhesion molecules leading to localized thrombosis have also been suggested as causes for this phenomenon. A greater understanding of rare risk factors for early PE and the possibility of rare complications of chest trauma is useful in detecting and treating them in time, reducing morbidity and mortality.

Machine Learning-Based Screening of Risk Factors and Prediction of Deep Vein Thrombosis and Pulmonary Embolism After Hip Arthroplasty.

Prophylactic anticoagulation is a standard strategy for patients undergoing total hip arthroplasty (THA) to prevent deep venous thromboembolism (DVT) and pulmonary embolism (PE). Nevertheless, some patients still experience these complications during their hospital stay. Current risk assessment methods like the Caprini and Geneva scores are not specifically designed for THA and may not accurately predict DVT or PE postoperatively. This study used machine learning techniques to establish models for early diagnosis of DVT and PE in patients undergoing THA. Data were collected from 1481 patients who received perioperative prophylactic anticoagulation. Model establishment and parameter tuning were performed using a training set and evaluated using a test set. Among the models, extreme gradient boosting (XGBoost) performed the best, with an area under the receiver operating characteristic curve (AUC) of 0.982, sensitivity of 0.913, and specificity of 0.998. The main features used in the XGBoost model were direct and indirect bilirubin, partial activation prothrombin time, prealbumin, creatinine, D-dimer, and C-reactive protein. Shapley Additive Explanations analysis was conducted to further analyze these features. This study presents a model for early diagnosis DVT or PE after THA and demonstrates bilirubin could be a potential predictor in the assessment of DVT or PE. Compared to traditional risk assessment, XGBoost has a high sensitivity and specificity to predict DVT and PE in the clinical setting. Furthermore, the results of this study were converted into a web calculator that can be used in clinical practice.

79 PERCUTANEOUS TREATMENT OF HIGH-MODERATE RISK PULMONARY EMBOLISM SUCCESSFULLY TREATED WITH LOCAL ULTRASOUND-ASSISTED THROMBOLYSIS

Abstract Objective A 74 y/o female presented at our emergency department with syncope and head trauma. At the physical examination she was dispnoic and tachycardic. Laboratory analysis showed elevated troponin and NT-proBNP. The TTE showed a dilated and dysfunctional right ventricle, 60/60 sign, elevated PAPs with flattening of interventricular septum. CT angiography showed massive pulmonary embolism (PE) affecting both branches of the pulmonary artery. The lower extremity venous ultrasound showed a long thrombus in the left distal tract of the common femoral vein, superficial femoral vein and popliteal vein. Methods The patient was admitted to the cardiac intensive care unit. Due to her worsening respiratory condition and her moderate-high early mortality risk PE with high risk of bleeding due to recent trauma, we decided to treat her with local ultrasound-assisted thrombolysis (Ekos). This combines ultrasound fragmentation of the thrombus with in situ reduced-dose thrombolysis. Two catheters were placed in the two pulmonary arteries through two right femoral venous accesses. The Ekos catheters were left on site for 6 hours and then removed without complications. Results The treatment was immediately effective and the clinical conditions improved within 24-48 hours. The follow up TTE showed improved right ventricle function with attenuated signs of PE. CT angiography at one week showed resolution of the vascular thrombosis. Our patient was discharged in good clinical conditions and with prescription of a NOAC. The monthly follow up was normal and any complication was referred. Conclusions A local thrombolysis technique is useful in intermediate-high risk patients at elevated bleeding risk. Future studies will shed light on the comparison between these catheter directed treatments and standard of care.

Clinical Characteristics and Risk Factors for Early versus Late Pulmonary Embolism in Trauma Patients: A Retrospective, Observational Study.

BackgroundWe sought to evaluate the clinical characteristics and risk factors for early versus late pulmonary embolism (PE) in trauma patients.MethodsThis was a retrospective analysis of injured patients who presented with a confirmed PE between 2013 and 2019. Data were analysed and compared for patients with early PE (≤4 days) versus late PE (>4 days post-trauma).ResultsThe study included 82 consecutive trauma patients with confirmed diagnosis of PE. The mean age of patients was 42.3 ± 16.2 years. The majority were males (79.3%) and the median time from injury to PE was 10 days. Of the PE cases, 24 (29.3%) had early PE, while 58 (70.7%) had late PE. The early PE group had higher rates of surgical intervention within 24 hours of admission than the late PE group (p = 0.001). Also, the rate of sub-segmental thrombi was significantly higher in the early PE group (p = 0.01). The late PE group sustained more moderate-to-severe injuries ie, GCS ED <13 (p = 0.03) and the median time from injury to PE diagnosis was 15 days (p = 0.001). After adjusting for the potential covariates, surgery within 24 hours of admission [adjusted odds ratio 37.58 (95% confidence interval 3.393–416.20), p = 0.003] was found to be significant independent predictor of early PE in trauma patients.ConclusionOne-third of post-trauma PEs occurs early after trauma and the surgical intervention within the first 24 hours of admission is a major risk factor. A prospective study is needed to develop an objective risk assessment for the prevention and detection of early and late PE post-trauma.

Risk stratification to optimize the management of acute pulmonary embolism

Introduction Pulmonary embolism (PE) is a life-threatening disease. Risk stratification in patients with acute PE can guide clinical decisions. Clinical assessment, including hemodynamics, respiratory parameters, patient history, and right ventricle evaluation, has a pivotal role in this scope. Areas covered This review aims to describe: i) the role of individual tools for prognostic stratification, from simple clinical parameters to the models suggested by international guidelines; ii) the implications of risk stratification in terms of patient disposition and treatment. The bleeding risk assessment in acute PE was also reviewed. The literature search was performed in PubMed and Embase to address these issues. Expert opinion Prognostic assessment is essential to proceed with life-saving treatments in hemodynamically unstable patients and consider home treatment or short hospital stay in patients at low risk for death. In hemodynamically stable patients, risk stratification allows the implementation of personalized treatment pathways to reduce the risk of death, early PE recurrence, and bleeding. With the aim of optimizing healthcare resources, risk stratification may suggest appropriate patient disposition.

Retrievable inferior vena cava filter for primary prophylaxis of pulmonary embolism in at-risk trauma patients: A feasibility trial

To determine if insertion of rIVCF for PE prophylaxis in high risk trauma patients could result in a clinically meaningful reduction (>24h) in time that patients are left unprotected from PEs SUMMARY AND BACKGROUND DATA: Trauma patients are at high risk for the development of pulmonary embolism (PE). Early pharmacologic PE prophylaxis is ideal, however many patients are unable to receive prophylaxis due to concomitant injuries. Current guidelines are conflicting on the role of prophylactic retrievable inferior vena cava filters (rIVCF) for PE prevention in this patient population, and robust data to guide clinicians is lacking. In this single center, randomized control trial of adult (age > 18 years) trauma patients at high risk for PE by EAST criteria and unable to receive pharmacologic prophylaxis for at least 72h, we randomized 42 patients to receive a rIVCF or to not have a rIVCF placed. Our primary endpoints were time left unprotected to PE development and feasibility. The median patient age was 53 years, with a median Injury Severity Score of 33. Randomization to rIVCF reduced the time left unprotected to PE (Control: 78.2h [53.6-104]; rIVCF: 25.5h [9.8-44.6], p=0.0001). Two pulmonary embolisms occurred in the control group, and one in the rIVCF group. Seven deaths occurred in the control group, and 8 in the rIVCF group. This feasibility study demonstrates a clinically meaningful reduction in time left unprotected to PE. Further investigations powered to demonstrate a reduction in PE incidence are required. Level 1 Evidence randomized controlled trial.

A 10-fold and greater increase in D-dimer at admission in COVID-19 patients is highly predictive of pulmonary embolism in a retrospective cohort study.

Background:COVID-19 patients present with both elevated D-dimer and a higher incidence of pulmonary embolism (PE). This single-centre retrospective observational study investigated the prevalence of early PE in COVID-19 patients and its relation to D-dimer at presentation.Methods:The study included 1038 COVID-19-positive patients, with 1222 emergency department (ED) attendances over 11 weeks (16 March to 31 May 2020). Computed tomography pulmonary angiogram (CTPA) for PE was performed in 123 patients within 48 h of ED presentation, of whom 118 had D-dimer results. The remaining 875 attendances had D-dimer performed.Results:CTPA performed in 11.8% of patients within 48 h of ED presentation confirmed PE in 37.4% (46/123). Thrombosis was observed at all levels of pulmonary vasculature with and without right ventricular strain. In the CTPA cohort, patients with PE had significantly higher D-dimer, prothrombin time, C-reactive protein, troponin, total bilirubin, neutrophils, white cell count and lower albumin compared with non-PE patients. However, there was no difference in the median duration of inpatient stay or mortality. A receiver operator curve analysis demonstrated that D-dimer could discriminate between PE and non-PE COVID-19 patients (area under the curve of 0.79, p < 0.0001). Furthermore, 43% (n = 62/145) of patients with D-dimer >5000 ng/ml had CTPA with PE confirmed in 61% (n = 38/62), that is, 26% of >5000 ng/ml cohort. The sensitivity and specificity were related to D-dimer level; cutoffs of 2000, 3000, 4000, and 5000 ng/ml, respectively, had a sensitivity of 93%, 90%, 90% and 86%, and a specificity of 38%, 54%, 59% and 68%, and if implemented, an additional 229, 141, 106 and 83 CTPAs would be required.Conclusion:Our data suggested an increased PE prevalence in COVID-19 patients attending ED with an elevated D-dimer, and patients with levels >5000 ng/ml might benefit from CTPA to exclude concomitant PE.

Systemic thrombolysis and anticoagulation improved biomarker measurements in massive-like pulmonary embolism and severe COVID-19 pneumonia: a case report.

BackgroundFrom asymptomatic patients to severe acute respiratory distress syndrome, COVID-19 has a wide range of clinical presentations, and venous thromboembolism has emerged as a critical and frequent complication.Case summaryWe present a case of a 69-year-old man with a clinical presentation of massive-like pulmonary embolism (PE) overlapping with severe COVID-19 pneumonia. The diagnosis was made based on hypotension, severe oxygen desaturation (33%), and right ventricular dysfunction (RVD). We used alteplase and low-molecular-weight heparin, obtaining immediate clinical improvement. Also, we identified an extremely elevated D-dimer (31.2 mcg/mL), and computed tomography pulmonary angiography (CTPA) revealed an unexpected low thrombus burden and a crazy-paving pattern. Considering this, we decided to discontinue the alteplase. Therefore, the mechanisms of pulmonary hypertension and RVD could be multifactorial. Despite the patient’s respiratory status worsening and ongoing mechanical ventilation, biomarkers kept lowering to normal ranges. It appears a favourable outcome was related to early PE diagnosis and a multimodal therapeutic approach.DiscussionPhysicians in the ER should be warned about extremely high D-dimer measurements and severe oxygen desaturation as possible markers of severe COVID-19 pneumonia in patients with high-clinical suspicion of PE. Although ESC guidelines recommend immediate reperfusion in cardiogenic shock secondary to PE, we suggest initial CTPA in patients with high-clinical suspicion of severe COVID-19.

Timing of pulmonary embolisms in femur fracture patients: Incidence and outcomes.

Femur fracture is a well-recognized risk factor for pulmonary embolism (PE). Despite recent reports of early PE after major trauma, the incidence and outcomes of PE in femur fracture patients are unknown. The aims of the study were to determine the incidence of PE after a femur fracture and to evaluate its timing and clinical significance. We included all consecutive adult patients (≥18 years old) with femur fracture admitted to our emergency department from January 2010 to December 2014 who underwent subsequent PE computed tomography within 72 hours. Of 453 stable patients, 28 with a confirmed diagnosis of acute PE were compared against those without PE. Of 1,301 femur fracture patients who presented at our hospital, 453 were included in our present analysis, of whom 28 developed PE (2.2%). Proximal PE, defined as emboli located within the main or lobar arteries, constituted 78.6% and subsegmental PE constituted 21.4% of these 28 cases. The femur fracture sites were mainly intertrochanteric (50.3%) and the neck (43.9%). The median interval from injury to computed tomography was 13.0 hours (IQR, 9.0-24.0 hours). PE was detected in 57.1% (16 of 28) of patients in the first 24 hours after injury and in 89.3% (25 of 28) in the first 48 hours. Overall mortality was 0.7%, and no patient in the early PE group died of their injury. PE arises in femur fracture patients in the immediate period following injury and shows an incidence somewhat higher than commonly appreciated in other trauma events but is not fatal. Epidemiologic/prognostic study, level III.

Pulmonary embolism and gastrointestinal leak following bariatric surgery: when do major complications occur?

BackgroundComplications following bariatric surgery are uncommon but potentially life threatening. ObjectivesThe aim of this study was to assess the timing of gastrointestinal leaks (GIL) and pulmonary embolism (PE) in patients undergoing bariatric surgery. SettingRetrospective analysis of the nationwide American College of Surgeons National Surgical Quality Improvement Program database from 2006 to 2011. MethodsData on patient demographic characteristics, baseline co-morbidities, procedural events, and postoperative occurrences were analyzed. Thirty-day morbidity was assessed. Median (interquartile range) and frequencies are reported. ResultsWe identified 71,694 bariatric surgery patients; median age was 45 years (range 36–54 yr), and median body mass index was 44.8 kg/m2 (range 40.8–50.3 kg/m2). Laparoscopic Roux-en-Y gastric bypass was performed in 39,480 patients, laparoscopic adjustable band in 21,104, laparoscopic sleeve gastrectomy in 3225, open Roux-en-Y gastric bypass in 4243, duodenal switch in 1064, revisional surgery in 1182, and other procedures in 1396 patients. Of these patients, 95.2% had no complications. GIL was found in 441 (.6%), deep vein thrombosis in 184 (.3%), and PE in 134 (.2%). These complications occurred 10 (5–15), 13 (7–20), and 11 (4–19) days after surgery, respectively. GIL and PE developed after discharge in 275 (62.4%) and 96 (71.6%), respectively. Only 35 (26.1%) of the patients who developed PE had deep vein thrombosis. There were no differences in patient characteristics between the groups of early PE versus postdischarge PE. Patients diagnosed with in-hospital GIL were more obese with more severe systemic disease compared with patients with postdischarge diagnosis. ConclusionsThe majority of GILs and PEs after bariatric surgery occur after discharge. This finding goes against the routine use of contrast studies to rule out GIL. The risk of PE remains after discharge from bariatric surgery.

Factors Associated with Pulmonary Embolism Within 72 Hours of Admission after Trauma: A Multicenter Study

Recent studies using thromboelastography indicate that patients are at risk for hypercoagulability early after injury. Pulmonary embolism (PE) is also well known to cause significant morbidity and mortality after injury and can occur within 72 hours of admission (early PE). Despite this risk, prophylactic anticoagulation is often delayed in patients with certain injuries due to concerns about bleeding. This was a retrospective study of injured patients with a PE from 2007 to 2013 at 3 level I trauma centers. Data collected included patient demographics, injury patterns, length of stay, timing of prophylaxis for deep vein thrombosis (DVT), and diagnosis of PE. Patients with early PE (≤ 3 days) were compared with those with late PE (>3 days) using bivariate and multivariable analysis. A total of 54,964 patients were admitted to the 3 centers during the study period, and 144 (0.26%) were diagnosed with a PE. Eleven were excluded from the study due to a lack of critical data, leaving 133 patients (43% early PE). Factors associated with early PE included long bone fractures in the lower extremity and an Abbreviated Injury Score (AIS) Extremity ≥ 3. Higher Injury Severity Score, severe chest and head trauma (AIS ≥ 3), and not receiving DVT prophylaxis within 48 hours of hospital admission were not associated with early PE. Early PE is a significant clinical entity occurring in nearly half the patients who suffered a PE. Early PE is associated with long bone fractures and severe extremity trauma, but not severe thoracic injury. Timing of prophylactic anticoagulation had no impact on early PE. If further studies confirm this incidence of unsuspected early PE, all admitted trauma patients should be assessed for a hypercoagulable state after injury.

Angel® Catheter — A Solution to Pulmonary Embolism Prophylaxis in the Critically Ill Patient

Pulmonary embolism (PE) is a serious complication among critically ill patients. Despite the recommended and effective use of prophylactic anticoagulation, new options are required, particularly for critically ill patients with absolute or temporary contraindications to the use of anticoagulation. The Angel® Catheter (BiO2 Medical, Inc. San Antonio, Texas) is intended for these critically ill patients, allowing early PE prophylaxis without additional bleeding risk. The device is inserted at the bedside, provides both central venous access and inferior vena cava filtration, and can be successfully removed in all instances. Clinical experience and ongoing research will help define the role of the Angel Catheter in PE prophylaxis for critically ill patients.

Early pulmonary embolism after injury: A different clinical entity?

BackgroundWe sought to characterize pulmonary embolism (PE) occurring early after injury. We hypothesized that early PE may represent a different clinical entity than those occurring later in the post-injury period. MethodsAll trauma patients diagnosed with PE from 2005 to 2010 were examined. PEs diagnosed within 72h of admission were compared against those occurring later. Results19 out of 54 PEs were diagnosed early. Early PE patients had a higher rate of lower extremity fractures, a lower mean injury severity score, and a lower average length of stay. Early PE patients had a shorter average time to start of chemical prophylaxis, were less likely to have had a femoral line, and less likely to have operative intervention under general anaesthesia. ConclusionsEarly PE after trauma may occur with different underlying pathophysiology than previously thought. Further study is indicated as this has implications concerning the prevention of PE in trauma patients.

Thromboembolic and Bleeding Events Following Elective Hip and Knee Arthroplasty Using Oral Factor Xa Inhibitor

AbstractAbstract 501 Introduction & Purpose:Rivaroxaban is an oral Factor Xa inhibitor which has been licensed in Canada since 2008 and the United States since 2011 for the prevention of thromboembolic events following total hip and total knee arthroplasties. Multicentre research trials have shown clinical efficacy for prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE). The aim of this study was to prospectively document the incidence and timing of thromboembolic and bleeding events in patients who received rivaroxaban as the primary prophylaxis in clinical practice. Methods:Prospective, observational study of patients given oral Factor Xa inhibitor (rivaroxaban) following primary and revision Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA). All patients were approached to participate and consent obtained. Patients treated with Rivaroxaban 10 mg po daily starting Post-Operative Day (POD) #1 and continued for 15 days. This protocol was approved for use at this institution and is NOT consistent with manufacturer’s recommended dosing. All participants were followed up at 6 weeks and 3 months. Doppler ultrasound or venograms used to diagnose symptomatic proximal DVT at or above the popliteal vein. Spiral CT angiogram, angiogram or ventilation/perfusion V/Q scan were used to diagnose PE. All Doppler Ultrasound reports were reviewed by a radiologist to confirm findings and all spiral CT, CT angiogram or ventilation/perfusion scans or images were reviewed (where possible) to verify findings. Bleeding complications were documented as ‘on prophylaxis' starting 2 hours after first dose of anticoagulant therapy until 24 hours after the 15thdose. All major and non-major bleeding events were reviewed by an internist to confirm severity of bleeding episode. Event rates are reported. Data reported on consented patients only. Research ethics approval was obtained for this study. Results:From June 2010 to Dec 2011, 2888 patients underwent total joint arthroplasty. Two thousand five hundred and thirty-five (88%) agreed to participate in the study. One hundred and fifty patients were treated with thromboprophylaxis other than rivaroxaban. Two thousand three hundred and forty-two were followed up at 3 months (98%). Forty-three patients were lost to follow-up. Complete data on 2342 patients is reported: 905 men, 1437 women with mean age 66 years. Total knees 1353 (primary 1229, revision 123, uni 1). Total hips 989 (primary 899, revision 90). DVT:Three DVT were reported at 6 weeks. Nine additional DVT's were reported at 3 months: 5 primary TKA and 6 Primary THAs 1 Rev THA. Total DVT= 12/2342= 0.5% (see Fig 1). PE:There were 7 confirmed PE during the first week post op: 6 primary TKA and 1 primary THA. Three additional PE's 6 weeks: 3 THA and 1 TKA. Five additional PE's reported at 3 months:4 THA and 1 TKA. Total PE 16/2342=0.7% (See Fig 2). Death:There have been 4 perioperative deaths. None were related to surgery, DVT, pulmonary embolism or bleeding. Bleeding:No major and 9 non-major surgical-site bleeds occurred. All but one were in primary THA. One major and 6 non-major non-surgical site bleeds occurred in patients who received rivaroxaban. Two additional major Non-surgical site bleeds occurred after having received rivaroxaban: one patient received only one dose of rivaroxaban and the other occurred 3–4 days after completion of treatment. Overall Major bleeds 0.04% and Non-Major bleeds 15/2342=0.6%. Transfusion:One hundred and fourteen patients (5%) received blood transfusions. Transfusion rates by procedure: unilateral THA 4%, Bilateral THA 40%, RTHA 27, unilateral PTKA 3%, bilateral TKA 16%,unicompartmental knee 0% and revision TKA 6%. No routine blood salvage or drains used for primary arthroplasties. Conclusions:The incidence of thromboembolic events within a period of 3 months was 12/2342=0.6% for DVT and 16/2342=0.7% for PE. The incidence of major bleeding was 0.04%. There were no deaths related to DVT, PE or bleeding. Preliminary results are surprising for the number of pulmonary emboli which occurred while patients were still in hospital and for the number of DVT's which occurred between 6 weeks and 3 months. The early PE's tended to occur in primary TKA. The late events tended to occur in primary THA and TKA. [Display omitted] [Display omitted] Disclosures:Murnaghan:Bayer Healthcare: Honoraria, Research Funding. Off Label Use: rivaroxaban is used for thromboprophylaxis after total joint replacement. our protocol gives first dose on day after surgery. Gollish:Bayer Healthcare: Honoraria, Research Funding.

Pulmonary emboli after blunt trauma: Timing, clinical characteristics and natural history

BackgroundVenous thromboembolism (VTE) frequently complicates the recovery of trauma patients, and contributes to morbidity and mortality. Recent studies showed an increase in diagnosis of pulmonary embolism (PE) mainly in the early or immediate period after trauma. The clinical significance of those incidental PEs is unclear. MethodsThe study cohort included all blunt trauma patients who had a contrast-enhanced CT of the chest performed as part of their initial trauma assessment from January 1, 2005 to January 31, 2007 in a large academic Canadian trauma centre. Patients diagnosed with PE at any point during admission were identified using our institutional trauma registry. All chest CT scans and electronic charts were reviewed. Patients were classified according to time of PE detection (immediate, early or late) and symptoms (asymptomatic or symptomatic). The clinical characteristics and hospital course of the patients who were diagnosed with immediate PE were described. Results1259 blunt trauma patients were reviewed. Six patients presented with immediate PE (0.5%); nine patients were found to have early PE (0.7%) and 13 had late PE (1.0%). All six of the patients with immediate PE were classified as asymptomatic. Five of the nine patients with early PE were symptomatic and all 13 patients who developed late PE were symptomatic. Amongst the six patients with immediate PE, five survived 24h hospitalisation. Four of them were managed with prophylactic low molecular weight heparin and no other thromboembolic events were observed during admission or after discharge. ConclusionsThe increased use of advanced CT technology in trauma patients has resulted in an increased diagnosis of incidental PEs that are asymptomatic. The clinical significance and management of these small, incidental PE are uncertain and further studies are needed to clarify the natural history of this controversial finding.

Early Lower Extremity Fracture Fixation and the Risk of Early Pulmonary Embolus: Filter Before Fixation?

Venous thromboembolism is a major cause of morbidity and mortality after injury. Prophylactic anticoagulation is often delayed as a result of injuries or required procedures. Those patients at highest risk in this early vulnerable window postinjury are not well characterized. We sought to determine those patients at highest risk for an early pulmonary embolism (PE) after injury. A retrospective analysis using data derived from a large state wide trauma registry (1997-2007) was performed. Patients with a documented PE and time of occurrence were selected (n = 712). Patients with fat emboli and lower extremity vascular injuries were excluded. Patients with a PE within the first 72 hours of admission (EARLY, n = 122) were compared with those with DELAYED presentation. Kaplan-Meier survival analysis was used to characterize the timing of death between the two groups. Backward stepwise logistic regression was used to determine independent risk factors for EARLY PE relative to those with DELAYED PE. EARLY and DELAYED groups were similar in age, gender, Glasgow Coma Scale, emergency department systolic blood pressure, and injury mechanism. The EARLY PE group had a lower Injury Severity Score but injuries more commonly included femur fracture. Kaplan-Meier analysis revealed that EARLY PE patients have a significantly higher risk of early mortality relative to DELAYED PE patients (p = 0.012). Regression analysis revealed that the only independent risk factor for EARLY PE was lower extremity/pelvic orthopedic fixation (<48 hours from injury). The risk of EARLY PE was more than threefold higher (odds ratios, 3.85; 95% CI, 1.9-7.6; p < 0.001) for those who underwent early lower extremity orthopedic fixation versus those who did not. Early lower extremity/pelvis orthopedic fixation is the single independent predictor of EARLY PE in this patient cohort. Venous thromboembolism/PE prevention strategies should be made a priority in this group of patients, including early preoperative institution of anticoagulation prophylaxis. These results suggest that those with contraindications to early anticoagulation may benefit from insertion of retrievable inferior vena cava filters preoperatively.

Recent respiratory infection and risk of venous thromboembolism: case-control study through a general practice database

Background The association between respiratory infection and risk of heart attacks and strokes is well established. However, less evidence exists for an association between respiratory infection and venous thromboembolism (VTE). In this article, we describe the associations between respiratory infection and VTE.Methods All cases aged ≥18 years of first-time diagnosis of deep-vein thrombosis (DVT) or pulmonary embolism (PE) were identified together with single-matched controls from a primary care general practice database. In addition to the matching characteristics, information was collected on other potentially important confounding factors.Results There were 457/11 557 (4.0%) DVT cases with respiratory infection in the year before the index date (73 in the preceding month) compared with 262/11 557 (2.3%) controls (24 in the preceding month). There was an increased risk of DVT in the month following infection [adjusted odds ratio (OR) = 2.64, 95% confidence interval (95% CI) 1.62–4.29] which persisted up to a year. There were 180/5162 (3.5%) PE cases with respiratory infection in the year before the index date compared with 94/5162 (1.8%) controls excluding those in the preceding month to avoid the possible misdiagnosis of early PE. There was an increased risk of PE in the 3 months following infection (adjusted OR = 2.50, 95% CI 1.33–4.72) which may have persisted up to a year.Conclusions There are strong associations between recent respiratory infection and VTE. There should be less distinction between venous and arterial events in decisions about preventing or aborting infections, especially in high-risk patients.

Pulmonary Embolism After Injury: More Common Than We Think?

We have previously demonstrated that pulmonary embolism (PE) can occur early and explain hypoxia immediately after injury. We hypothesized that an increased awareness of early PE would result in an increased incidence, an earlier diagnosis, and a decreased mortality of PE after injury. The trauma registry identified patients diagnosed with a PE between time period (TP) 1 (June 1999 and December 2004) and TP 2 (January 2005 and December 2006). Demographics, injury specific data, time from injury to diagnosis, diagnostic modality, and mortality were compared with a t test for the two TPs. There were 35,424 and 15,022 patients, respectively, treated in our trauma center during the two study periods. During TP1, 94 (0.27%) patients were diagnosed with PE. Mean age was 45 years (+/-18.5) and mean Injury Severity Score (ISS) was 23 (+/-11.4); 81.9% were men and 91.6% sustained blunt trauma. Eighty-three (0.55%) patients in TP2 were identified with a PE. Mean age was 43 years (+/-17.4) and mean ISS was 23 (+/-13.0); 78.3% were men and 86.7% sustained blunt trauma. In TP1, the diagnosis was confirmed by a computed tomography (CT) in 76 of 94 (80.9%) patients. In TP2, the CT scan diagnosed 80 of 83 (96.4%) patients. Time to diagnosis was postinjury day 11.8 (+/-14) in TP1 and 9.2 (+/-11.5) in TP2. Mortality in patients diagnosed with PE was 10.6% in TP1 and 9.6% in TP2. Our incidence of PE has doubled from 0.27% to 0.55% in a 6-year TP when mean ISS and thromboembolic prophylaxis protocols have remained the same. We attribute this increase in incidence to heightened awareness through recent publications, as well as 24 hour availability of multiple multidetector-row spiral CT scanners and not necessarily an increase in prevalence of PE.

Impact of Thrombophilic Genetic Factors on Pulmonary Embolism: Early Onset and Recurrent Incidences

The importance of genetic thrombophilic factors in the development of venous thromboembolism has been increasingly recognized. Factor V Leiden (FVL), prothrombin gene mutation G20210A (FII G20210), genetic variant C677T of the methylentetrahydrofolate reductase (MTHFR), as well as the polymorphism A2 (PlA2) in platelet glycoprotein IIb/IIIa were recently discussed. We analyzed the contribution of genetic thrombophilic factors to the pathogenesis of pulmonary embolism (PE) and their association with the early onset and recurrence of PE using DNA analysis methods. In this case control trial we found thrombophilic genetic variants in 58.8% of 51 patients with PE. FVL was found in 23.5% of the patients versus 7.1% of the 98 controls (p=0.01), PlA2 IIb/IIIa was found in 35.3% vs. 14.3% (p=0.03), and FII G20210A was found in 5.9% vs. 2.0% (NS). Patients with recurrent PE had a very high prevalence of genetic factors, 70.4%. High prevalence of FVL was found in patients under 45 years of age: 39.3% (OR=14.23, 95% CI=1.58-330.03, p=0.01) as well as in patients with recurrent incidence (37%, OR=7.647, 95% CI=2.27-26.44, p=0.001). FVL was also significantly higher in the subgroup of patients with PE combined with deep venous thrombosis (OR=6.500, 95% CI=1.81-23.76, p=0.002) in comparison with patients with isolated PE (OR=2.261, 95% CI=0.50-9.69). The carriers of FVL are at higher risk for early and recurrent PE events. High prevalence of PlA2 in PE patients evidently shows the impact of this polymorphism in PE development. A different treatment should be considered in carriers of thrombophilic defects.