Single Pulmonary Embolism Research Articles

Anticoagulation prophylaxis patterns following retroperitoneal lymph node dissection for testis cancer

IntroductionRetroperitoneal lymph node dissection (RPLND) is the standard of care for testicular cancer in various disease settings. Deep vein thrombosis (DVT) complications have been reported to occur in <1% of primary RPLND cases and up to 3% of postchemotherapy (PC-RPLND) cases. While prophylactic anticoagulation (AC) has been well-documented to reduce DVT rates in patients undergoing surgery in general, the benefit of prophylactic AC in RPLND has not been assessed. In this retrospective cohort study, we seek to address this unmet need by evaluating the rates and associated risk factors of DVT and pulmonary embolism (PE) with a national and institutional database, assess the changing patterns in DVT prophylaxis with postoperative AC following RPLND, and quantify the potential benefit of prophylactic AC in patients who have undergone RPLND using a risk-stratified approach. MethodsThe National Surgical Quality Improvement Program (NSQIP) database was queried for patients who underwent RPLND during the 10-year period from 2011 to 2021. An institutional database was queried for all patients undergoing RPLND from 2013 to 2022. Patient characteristics and operative outcomes were compared between the NSQIP and the institutional database. The institutional database was stratified by prior oncologic treatment (i.e., primary RPLND vs. PC-RPLND) and outcomes were compared. Postoperative AC rate was determined and trended by year. The use of postoperative AC and PE events were stratified by clinical stage. The absolute risk reduction (ARR) of AC prophylaxis on PE events and the number needed to treat (NNT) with AC prophylaxis to prevent a single PE event was determined. ResultsIn total, the NSQIP database query resulted in 779 patients and our institutional database query resulted in 188 patients. The rate of DVT and PE was 1.2% and 0.5% vs. 2.1% and 1.6% in the NSQIP and institutional cohort, respectively. The rate of postoperative AC following RPLND in patients from the institutional database increased from 5% in 2013 to 43% in 2022 (P = 0.01). There were no statistically significant differences in complication rates, including bleeding events, chyle leaks, or hospital readmissions amongst patients who were prescribed AC at discharge and those who were not. No stage I patients developed PEs and no stage I patients were prescribed AC. The ARR for AC prophylaxis for development of PE was found to be 0.023 for the clinical stage II and stage III cohorts. The NNT to prevent a single PE with AC was 44 and 43 for the stage II and stage III cohorts, respectively. ConclusionsAC appears beneficial with minimal risk of harm after RPLND, especially in patients with higher risk of developing DVT/PE, highlighting the safety and efficacy of this regimen. There was a significant increase in the rate of AC prophylaxis at discharge amongst patients undergoing RPLND in the institutional database from 2013 to 2022. A risk-stratified protocol of postoperative AC following RPLND appears reasonable, and further prospective trials are warranted to formally confirm this recommendation.

External Validation of ASPECT (Algorithm for Suspected Pulmonary Embolism Confirmation and Treatment).

Administrative health care databases are increasingly being used to study pulmonary embolism (PE), but the validity of single PE codes is variable. Using data from Quebec, Canada, we developed ASPECT (Algorithm for Suspected Pulmonary Embolism Confirmation and Treatment), combining 3 components to ascertain confirmed PE: emergency department (ED) diagnoses, imaging codes, and dispensed prescriptions or hospital diagnoses. Herein, we used unrelated administrative health care databases to externally validate ASPECT. We used ED electronic health records (ED-EHRs) to identify all residents of Calgary (Alberta, Canada) with PE codes between January and June, 2016. We applied ASPECT by identifying imaging studies in the ED-EHR, admission diagnoses in linked discharge abstract database and filled prescriptions in linked pharmacy information. Confirmed PE in ASPECT was validated against chart review in the ED-EHR. The cohort included 498 patients. Overall, 258 (51.9%) were managed as outpatients and 327 were adjudicated to have confirmed PE; the positive predictive value (PV) of single PE codes was 65.6%. With ASPECT the positive PV was 96.5% [95% confidence interval (CI), 94.4-98.5%] and positive likelihood ratio was 10.9 (95% CI, 6.8-15.1). The negative PV and negative likelihood ratio were 85.1% (95% CI, 80.0-90.2%) and 0.1 (95% CI, 0.0-0.1), respectively. Overall agreement of ASPECT with confirmed PE was 92.2%. Further, ASPECT was similarly robust in inpatients and outpatients and was more precise than any 2-component combination of ASPECT. Our findings reiterate the limitations of using single administrative codes for PE and suggest ASPECT as an acceptable tool to study PE.

Radiologist Performance in the Detection of Pulmonary Embolism

This study aimed to assess the factors contributing toward accurate detection and erroneous interpretation of pulmonary embolism (PE). Over 13 months, all computed tomography pulmonary angiography studies were retrospectively rereviewed by a chest radiologist. Two additional chest radiologists assessed cases with disagreement between the first interpretation and rereview. The number, extent, and location of PE and specialty training, experience, time of study, kV, resident prelim, use of iterative reconstruction, signal to noise ratio (SNR), and reports describing the study as "limited" were recorded. Parametric and nonparametric statistical testing was performed (significance P<0.05). Of 2555 computed tomography pulmonary angiography cases assessed, there were 230 true positive (170 multiple, 60 single PE), 2271 true negative, 35 false-negative (15 multiple and 20 single PE), and 19 false-positive studies. The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of radiologists was 86.8%, 99.2%, 92.4%, 98.5%, and 97.9%. Sensitivity for the detection of multiple and central PE was significantly higher than the detection of single and peripheral PE, respectively (P<0.01 for both). The sensitivity of thoracic radiologists (91.7%) was higher than nonthoracic (82.8%) and reached significance for single PE (89.2% vs. 61.4%, P<0.02). Errors were more likely in cases with lower SNR (P=0.04) and those described as limited (P<0.001). Misses occurred more frequently in the upper lobe posterior and lower lobe lateral segments and subsegments (P=0.038). The accuracy for PE detection is high, but errors are more likely in studies with single PE interpreted by nonthoracic radiologists, especially when located in certain segments and in cases with low SNR or described as limited.

Management and outcomes of single subsegmental pulmonary embolus: a retrospective audit at North Shore Hospital, New Zealand.

It is unknown whether filling defects in subsegmental arteries on multidetector computed tomography pulmonary angiography correlate with clinically relevant subsegmental pulmonary embolism (PE) on pulmonary angiography. Current guidelines do not differentiate between PE in segmental and subsegmental vessels, and many patients receive at least 3 months anticoagulation. The strategy employed at North Shore Hospital in haemodynamically stable patients with single subsegmental PE is to perform bilateral lower leg compression ultrasound (CUS). Anticoagulation is withheld if CUS is negative; a bilateral CUS is repeated in 7-10 days. The aim of this retrospective audit was to ensure our current management strategy is safe. All diagnoses of single subsegmental PE between June 2005 and June 2013 were included. The primary outcome was the rate of venous thromboembolism (VTE) recurrence within 3 months of single subsegmental PE diagnosis. Secondary outcomes were rates of major/minor bleeding and all-cause mortality. Thirty-two patients were included - 20 were treated with anticoagulation; 12 were managed with observation/serial bilateral lower limb CUS. None of the patients in either group had VTE recurrence by 3 months. No bleeding episodes were observed in the observation group; there was a 10% major bleeding rate (n = 2) in the treatment group. One death occurred in each group, neither of which was attributed to VTE. Withholding anticoagulation in patients with single subsegmental PE and negative serial bilateral CUS appears to be a safe and effective management strategy, with a low risk of VTE recurrence.

The Rate and Mortality of Postoperative Venous Thromboembolism of Moderate Risk Surgery in Asian Patients without Thrombo‐prophylaxis: Systematic Review with Meta‐analysis

The general gynecologic and neurologic surgeries are regard as carrying moderate risk for postoperative venous thromboembolism (VTE). This review analyzed the postoperative VTE rate of these surgeries in Asia. Inclusion criteria were: prospective study; deep vein thrombosis (DVT) diagnosed by venography, ultrasonography, or radionucleotide scan; and no thromboprophylaxis. The pooled proportion was back calculated from Freeman-Tukey variant transformation, using a random effect model. Medline, EMBASE, Cochrane Library, and KoreaMed were searched. Fourteen studies (total population of 1,625) published from 1974 to 2008 were included. In general surgery, the pooled rate of all-sites proximal, isolated distal DVT was 13.4, 2.1, and 11.8 % (radionucleotide scan). The cancer patients carried a higher all-sites DVT rate (19.7 % radionucleotide scan and 17.4 % ultrasound). Gynecologic and neurologic surgery had 3.1 % (ultrasound) and 3.8 % (radionucleotide scan) all-sites DVT rate. For general, gynecologic, and neurologic patients, the pooled rates of symptomatic DVT were 1.5, 0.2, and 1.0 % respectively. The pooled rate of symptomatic pulmonary embolism (PE) was 0.4 % for general surgery. No patients died from PE (pooled rate 0.2 %); however, a single PE death was reported in the excluded study. Postoperative symptomatic VTE was relatively low in Asia. Further study is required to stratify VTE risk and the need for thromboprophylaxis in individual patients.

Differential diagnosis of pulmonary embolism in outpatients with non-specific cardiopulmonary symptoms

Most cardiopulmonary diseases share at least one symptom with pulmonary embolism (PE). The aim of this study was to identify the most common acute causes of dyspnea, chest pain, fainting or palpitations, which diagnostic procedures were performed and whether clinicians investigate them appropriately. An Italian multicenter collaboration gathered 17,497 Emergency Department (ED) records of patients admitted from January 2007 to June 2007 in six hospitals. A block random sampling procedure was applied to select 800 hospitalised patients. Results of the overall 17,497 patients were obtained by weighting sampled cases according to the probability of the randomisation block variables in the whole population. The case-mix of enrolled patients was assessed in terms of cardiopulmonary symptoms, and the prevalence of acute disorders. The actual performance of procedures was compared with a measure of their accuracy as expected in the most common clinical presentations. PE occurred in less than 4% of patients with cardiopulmonary symptoms. Acute heart failure, pneumonia and chronic obstructive pulmonary disease exacerbation were the most likely diagnoses in patients with dyspnea. Acute myocardial infarction was present in roughly 10% of patients with chest pain. Atrial fibrillation was the prevalent diagnosis in patients with palpitations. Echocardiography, computed tomographic pulmonary angiography, perfusion lung scan, D-dimer test and B-type natriuretic peptide were performed less than expected from their accuracy. Diagnostic strategies, starting from non-specific symptoms and coping with the eventuality of PE, are likely to benefit from an increased awareness of the examination's accuracy in discriminating among several competing hypotheses, rather than in testing the single PE suspicion.