Clinical Features Of Pulmonary Embolism Research Articles

Clinical features of pulmonary embolism in patients with previous recent COVID-19 infection

BACKGROUND: Pulmonary embolism (PE) is one of the most significant thromboembolic complications of coronavirus disease 2019 (COVID-19). Several studies have demonstrated the clinical features of PE in patients in the acute phase of COVID-19. The features of the course of PE diagnosed after an acute infection have not been sufficiently studied.
 AIM: To study the clinical picture of PE that occurred within 3 months after COVID-19.
 METHODS: A retrospective study was completed. Patients were hospitalized with a diagnosis of PE between January 2020 and December 2021. Two subgroups were formed: with a history of recent (up to 3 months) COVID-19 infection and without a history of COVID-19.
 RESULTS: Of the 278 patients hospitalized with PE, 44 had anamnesis of COVID-19, and 69 had no anamnesis of infection. In the remaining 165 patients with PE, determining the presence or absence of a history of COVID-19 was impossible. In the analysis of the clinical picture and examination results of 44 patients with COVID-19, distal localization of thrombotic lung lesions was predominant, the incidence of deep vein thrombosis of the lower extremities was lower, and right heart lesions were noted. A tendency toward the presence of diabetes mellitus, anemia, and thrombocytopenia was found.
 CONCLUSION: Patients with PE and history of COVID-19 have features of clinical presentation. The identified signs are consistent with the results of studies that have evaluated the course and clinical signs of PE in the acute period of COVID-19. Similar manifestations may indicate a significant effect of COVID-19 on PE signs both during and after the acute period of COVID-19. Clinical features were determined by the severity of the previous infection.

The incidence and clinical characteristics of pulmonary embolism in oncologic patients

BackgroundFor various types of cancer in oncologic patients, the clinical features of pulmonary embolism (PE) are unknown. The purpose of the study is to identify pulmonary embolism incidence and type among oncologic patients along with evaluating any associated clinical variables.Patients and methodsA prospective cohort study was conducted on 540 patients who had various types of cancers and attended to a 1-day care unit of oncology in King Fahd Hospital, Kingdom of Saudi Arabia. Chest CT with contrast and CT pulmonary angiography was applied when indicated.ResultsThis study was conducted on 540 patients who have different types of cancers; among them, 24 (4.44%) developed PE. Pulmonary embolism was reported in 50% of patients who had seminoma and germ cell tumor, while in cancer larynx, it was represented in 33.4% of them. Moreover, PE was less common among patients who had cancer colon, prostate, and breast (6.68%, 4.7%, and 2.54%, respectively). Seven patients with PE (1.3%) were diagnosed incidentally during cancer staging, while 17 patients (3.14%) had symptomatic PE. Eighty-four percent of the PE cases were diagnosed within the first 6 months of cancer diagnosis, while 4/24 (16%) of the PE cases were diagnosed throughout patient follow-up within the first year of diagnosis. Chest pain and dyspnea were the common presentations in confirmed PE either symptomatic or incidental group.ConclusionsLow-risk PE was the most frequent degree; massive and sub-massive PE was uncommon in oncologic patients. Dyspnea and chest discomfort are concerning signs of PE in cancer. Meticulous care during the first 6 months for cancer patients to pick up pulmonary embolism is recommended.

The prevalence and clinical features of pulmonary embolism in patients with AE-COPD: A meta-analysis and systematic review.

BackgroundThe prevalence of pulmonary embolism (PE) in the acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) is highly controversial. We conducted a systematic review and meta-analysis to summarize the epidemiology and characteristics of PE with AE-COPD for current studies.MethodsWe searched the PubMed, EMBASE, Cochrane Library and Web of Science databases for studies published prior to October 21, 2020. Pooled proportions with 95% confidence intervals (95% CIs) were calculated using a random effects model. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals were used as effect measures for dichotomous and continuous variables, respectively.ResultsA total of 17 studies involving 3170 patients were included. The prevalence of PE and deep vein thrombosis (DVT) in AE-COPD patients was 17.2% (95% CI: 13.4%-21.3%) and 7.1% (95% CI: 3.7%-11.4%%), respectively. Dyspnea (OR = 6.77, 95% CI: 1.97–23.22), pleuritic chest pain (OR = 3.25, 95% CI: 2.06–5.12), lower limb asymmetry or edema (OR = 2.46, 95% CI:1.51–4.00), higher heart rates (MD = 20.51, 95% CI: 4.95–36.08), longer hospital stays (MD = 3.66, 95% CI: 3.01–4.31) were associated with the PE in the AE-COPD patients. Levels of D-dimer (MD = 1.51, 95% CI: 0.80–2.23), WBC counts (MD = 1.42, 95% CI: 0.14–2.70) were significantly higher and levels of PaO2 was lower (MD = -17.20, 95% CI: -33.94- -0.45, P<0.05) in the AE-COPD with PE group. The AE-COPD with PE group had increased risk of fatal outcome than the AE-COPD group (OR = 2.23, 95% CI: 1.43–3.50).ConclusionsThe prevalence of PE during AE-COPD varies considerably among the studies. AE-COPD patients with PE experienced an increased risk of death, especially among the ICU patients. Understanding the potential risk factors for PE may help clinicians identify AE-COPD patients at increased risk of PE.Prospero registration numberCRD42021226568.

Clinical features of pulmonary embolism in patients with lung cancer: A meta-analysis.

BackgroundPulmonary embolism (PE) is correlated with increased mortality among patients with lung cancer (LC). The characteristics of patients with LC presenting with PE have not been fully established, and our meta-analysis aims to comprehensively investigate the clinical characteristics associated with PE in patients with LC to help physicians identify PE earlier in these patients.MethodsMultiple databases were searched, including PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure and Wanfang. Odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (95% CIs) were used as effect measures for dichotomous and continuous variables, respectively. Moreover, Egger’s test, Begg’s test and a sensitivity analysis were performed to assess the publication bias and reliability of the articles.ResultsIn total, 16 studies were included in our meta-analysis. The results indicated that history of chronic obstructive pulmonary disease (OR = 2.59, 95% CI: 1.09, 6.15; P = 0.03), adenocarcinoma (OR = 2.28, 95% CI: 1.88, 2.77; P < 0.01), advanced tumour stage (TNM III-IV vs. I-II, OR = 2.38, 95% CI: 1.99, 2.86; P < 0.01), history of central venous catheter (OR = 1.95, 95% CI: 1.36, 2.78; P < 0.01), history of chemotherapy (OR = 2.32, 95% CI: 1.80, 2.99, P < 0.01), high levels of D-dimer (WMD = 4.31, 95% CI: 2.53, 6.10; P < 0.01) and carcinoembryonic antigen (WMD = 10.30, 95% CI: 9.95, 10.64; P < 0.01) and a low level of partial pressure of oxygen (WMD = -25.97, 95% CI: -31.31, -20.62; P < 0.01) were clinical features of LC patients with PE compared to those without PE.ConclusionsThese results reveal that LC patients with PE have specific clinical features, including but not limited to several cancer- and treatment-related factors, that may help their early identification.

Interval Hysterectomy for Placenta Percreta - a Case Report.

IntroductionPlacenta percreta is an abnormality of placentation where it invades the serosa and can go beyond it. Complications include massive hemorrhage, bladder dysfunction, and severe infections during delivery. The aim of this study is to report a complex case of placenta percreta managed by interval hysterectomy.Case presentationPre-operative: 34 years old patient with previous three cesarean sections was followed in antenatal clinic. She came with repeated bouts of vaginal bleeding at 30–31 weeks. At 32 weeks and 4 days classical cesarean section was done with placenta left in situ. Prophylactic bilateral internal iliac artery balloon was inserted. Post cesarean section, uterine artery embolization was performed. Post-operative: Clinical features of pulmonary embolism (PE) developed about 4 hours later. Post-Operative Day 13: Total abdominal hysterectomy was done. After few days of discharge, the patient presented to the emergency department with shortness of breath. She was consequently diagnosed with chronic pulmonary embolism and treated with warfarin.ConclusionThis is a case of placenta percreta managed by interval hysterectomy. However, the most widely accepted method of management is cesarean hysterectomy. In this case, interval hysterectomy was done due to the possibility of bladder invasion by placenta, to decrease the amount of blood loss and to reduce the number of days stayed in hospital. Appropriate management for the patient must be personalized, whether it is by cesarean hysterectomy or interval hysterectomy, as each has risks and benefits.

Dilemmas in the management of venous thromboembolism in older patients.

Venous thromboembolism most commonly affects older patients. Despite the high incidence in this population, challenges remain in terms of the understanding of its presentation, diagnosis and management. Old age is associated with multi-morbidities which may complicate the diagnosis of venous thromboembolism as signs or symptoms may be attributed to underlying medical conditions. The presence of certain comorbidities (such as congestive cardiac failure and chronic obstructive pulmonary disease) also increases the risk of venous thromboembolism, but could mimic the clinical features of pulmonary embolism. In addition, the physiological processes associated with ageing and factors such as immobility and malignancy, which are more common in older people, will further increase the thrombotic risk. Dilemmas also exist with treatment decisions because of the concomitant increased risk of bleeding, comorbidities, polypharmacy, frailty and the risk of falls.

0231 : Clinical features of pulmonary embolism in elderly

The aim of this study was to determine the clinical features of pulmonary embolism in elderly patients (≥70 years). All patients hospitalized for PE in our cardiology department from January 2013 to December 2014 were included in the study. The aim was to compare the features of pulmonary embolism in elderly patients (≥70 years) (Group 1) to those of patients younger than 70 years (Group 2). The following data were recorded: past medical history, risk factors for venous thrombo-embolism (VTE), clinical features, and echocardiographic data. The population was composed of 50 patients (women 78%) with a median age of 55,4 years ± 15,8. There was no statistical difference for risk factors of VTE. Syncope/faintness was more frequent in elderly patients (21% versus 0%, P=0.019). On admission we note the predominance of shock in group 1 (42% versus 11%, p=0.020). The diagnosis of PE was often mentioned and even confirmed by Transthoracic echocardiography allowing us to start thrombolysis without waiting for confirmation by chest CT. TTE has shown a thrombus in the right cavities in 35% of patients in Group 1 against only 2.7% of patients in group 2 (P=0.005) and right ventricular (RV) dysfunction in 85% of group 1 versus 25% group 2 (P <0.0001), as well as RV dilatation, the paradoxical septum and pulmonary hypertension who were more frequently found in elderly subjects (100% vs 63% P = 0.010; 92% vs 61% P=0.039 and 71% vs 38% P=0.039 respectively). Was used to thrombolysis in 6 patients (42%) in group 1 vs 3 patients (8%) in group 2 (P=0.009). Our work emphasizes the seriousness of pulmonary embolism in the elderly. We confirm the difficulty of diagnosis of PE in this population. The author hereby declares no conflict of interest

Clinical characteristics of pulmonary embolism with concomitant pneumonia.

Although pneumonia is associated with an increased risk of venous thromboembolism, patients with pulmonary embolism and concomitant pneumonia are uncommon. The aim of the present study was to investigate the clinical features of pulmonary embolism with coexisting pneumonia. We retrospectively compared clinical, radiologic and laboratory parameters between patients with pulmonary embolism and concomitant pneumonia (pneumonia group) and those with unprovoked pulmonary embolism (unprovoked group), and then between the pneumonia group and those with pulmonary infarction (infarction group). Of 794 patients with pulmonary embolism, 36 (5%) had coexisting pneumonia and six (1%) had no provoking factor other than pneumonia. Stroke was significantly more common in the pneumonia group, than either the unprovoked group or the infarction group. In the pneumonia group, fever was significantly more common and serum C-reactive protein levels were significantly higher. By contrast, central pulmonary embolism and right ventricular dilation on computed tomography were significantly less frequent in the pneumonia group. In addition, an adverse outcome due to pulmonary embolism was less common in the pneumonia group than in either of the other two groups. The coexistence of pulmonary embolism and pneumonia is rarely encountered in clinical practice, especially without the presence of other factors that could provoke venous thromboembolism and is commonly associated with stroke. It is characterized by lower incidences of central pulmonary embolism and right ventricular dilation and by a lower rate of adverse outcomes due to pulmonary embolism itself.

Reproducibility of Pretest Assessment in Suspected Pulmonary Embolism

Pulmonary embolism (PE) is a leading cause of mortality in North America. Prompt recognition and treatment of PE with anticoagulant therapy reduces the risk of mortality from 30% to 1.5%. Unfortunately, timely diagnosis of PE can be difficult because the clinical features of PE, such as chest pain and rapid heart rate, are not unique to PE. Although clinical assessment alone cannot confirm or exclude PE, it can be used to stratify patients according to their likelihood of having PE before diagnostic tests are performed (ie, pretest probability). This paper will review the role of clinical assessment in the diagnosis of PE, provide an overview of validated clinical prediction rules for PE, and discuss the reproducibility of clinical pretest probability assessment in suspected PE.

A cohort study on the incidence and outcome of pulmonary embolism in trauma and orthopedic patients

BackgroundThis study aims to determine the incidence of pulmonary embolism (PE) in trauma and orthopedic patients within a regional tertiary referral center and its association with the pattern of injury, type of treatment, co-morbidities, thromboprophylaxis and mortality.MethodsAll patients admitted to our institution between January 2010 and December 2011, for acute trauma or elective orthopedic procedures, were eligible to participate in this study. Our cohort was formed by identifying all patients with clinical features of PE who underwent Computed Tomography-Pulmonary Angiogram (CT-PA) to confirm or exclude the clinical suspicion of PE, within six months after the injury or the surgical procedure.Case notes and electronic databases were reviewed retrospectively to identify each patient’s venous thromboembolism (VTE) risk factors, type of treatment, thromboprophylaxis and mortality.ResultsOut of 18,151 patients admitted during the study period only 85 (0.47%) patients developed PE (positive CT-PA) (24 underwent elective surgery and 61 sustained acute trauma). Of these, only 76% of the patients received thromboprophylaxis. Hypertension, obesity and cardiovascular disease were the most commonly identifiable risk factors. In 39% of the cases, PE was diagnosed during the in-hospital stay. The median time of PE diagnosis, from the date of injury or the surgical intervention was 23 days (range 1 to 312). The overall mortality rate was 0.07% (13/18,151), but for those who developed PE it was 15.29% (13/85). Concomitant deep venous thrombosis (DVT) was identified in 33.3% of patients. The presence of two or more co-morbidities was significantly associated with the incidence of mortality (unadjusted odds ratio (OR) = 3.52, 95% confidence interval (CI) (1.34, 18.99), P = 0.034). Although there was also a similar clinical effect size for polytrauma injury on mortality (unadjusted OR = 1.90 (0.38, 9.54), P = 0.218), evidence was not statistically significant for this factor.ConclusionsThe incidence of VTE was comparable to previously reported rates, whereas the mortality rate was lower. Our local protocols that comply with the National Institute for Health and Clinical Excellence (NICE) guidelines in the UK appear to be effective in preventing VTE and reducing mortality in trauma and orthopedic patients.

Normal blood D-dimer concentrations: do they exclude pulmonary embolism?

Background Although pulmonary embolism (PE) with normal blood D-dimer (DD) concentrations is considered rare, in practice the incidence may be greater than is generally believed. Overlooking PE is potentially dangerous. The aim of this study was to explore the incidence and clinical features of PE with normal DD concentrations. Methods We retrospectively analyzed the records of 29 patients with PE and normal DD concentrations from the past seven years. We here compare relevant clinical characteristics of these patients with those of patients with PE and abnormal DD concentrations. We evaluated the probabilities of differences by computing pretest probability scores (Wells score and revised Geneva score). Results The frequency of normal DD concentrations in patients with PE was 4%. Previous episode(s) of PE were more common in patients with normal DD concentrations than in those with abnormal DD concentrations (P=0.001). Fever, tachycardia, and tachypnea occurred less frequently in the former group (P&lt;0.05) and time between onset of symptoms and DD testing was longer (P=0.001). The diagnosis of PE was delayed in 22 of the 29 cases. Nineteen and seven cases with normal DD concentrations were classified according to pretest scores as intermediate and low risk, respectively. Conclusions PE with normal DD concentrations is uncommon. Although most diagnoses of PE are ruled out by normal DD values, a small number of cases with PE are missed. A combination of pretest probability score and normal DD concentration increases the probability of making the correct diagnosis, but cannot completely exclude patients with suspected PE. When the clinical manifestations cannot be otherwise explained, clinicians should be alert to the possibility of PE with normal DD concentrations in patients with previous episode(s) of PE or a long interval between onset of symptoms and DD testing.

Complications During Clinical Evolution in Lung Transplantation: Pulmonary Embolism

Background Medical complications after lung transplantation (LT) are frequent despite the advances in management. The objectives of this study were to evaluate the incidence and clinical features of pulmonary embolism (PE) among LT recipients in our center. Patients and Methods We performed a retrospective descriptive study of 280 patients who underwent LT between June 1999 and December 2009. Results Five patients with PE (1.78%) had undergone single LT due to idiopathic pulmonary fibrosis (IPF). PE developed in the transplanted lung and was bilateral in 2 cases. The only associated risk factor was obesity in 3 patients. The clinical presentation was nonspecific; the most frequent symptom being dyspnea. Computed tomography (CT) angiography and ventilation-perfusion scan were used for diagnosis. Patients underwent treatment with low–molecular weight heparin followed by oral anticoagulation. Conclusions Our study showed a low incidence of PE (1.78%), although we focused exclusively on this condition, excluding other entities such as deep vein thrombosis. All PE events occurred in the subpopulation of IPF transplant recipients. Possibly some factors predisposed these patients to PE, although they remain unclear. Because PE can cause significant morbidity in LT recipients, it is important to include PE in the differential diagnosis among LT patients presenting with dyspnea, hypoxia, or clinical deterioration.

Antenna Reflector Surface Fitting Algorithm Based on Rigid Body Displacement Principle

Pulmonary embolism, a potentially fatal event, occurs more frequently in cancer patients than in the general population. To offer an accurate diagnosis and effective treatment to such patients in China, we analyzed the incidence rate and clinical features of pulmonary embolism in patients with solid tumor hospitalized in the Peking Union Medical College (PUMC) Hospital. A retrospective analysis was made of the hospitalized patients with solid malignancies complicated with pulmonary embolism who had been admitted into the PUMC Hospital from January 2002 to December 2008. The incidence of pulmonary embolism in hospitalized patients with solid malignancies was 0.27% (120/43 967). The median age at diagnosis was 57.5 years. The male to female ratio was 1.0:1.4 (49:71). Patients with non-small-cell lung cancer (NSCLC) constituted the largest proportion of the 120 patients (37.5%), followed by patients with breast (9.2%), ovarian (8.3%), pancreatic (6.7%), and liver cancer (6.7%). Eighty patients (66.7%) had stage IV cancer. Bone was the most common site of distant metastasis (46.3%). D-dimer level was elevated in 90.9% of the 66 tested patients. The incidence of bleeding due to anti-coagulation therapy was 3.6%. Thirty-six (30.0%) of the 120 patients had concurrent deep venous thrombosis in the lower extremities. Seventeen patients developed acute pulmonary embolism within 2 weeks after surgery, 3 of whom died suddenly. Four patients presented with deep venous thrombosis and 1 with pulmonary embolism prior to the identification of malignancy. Patients with cancer of the lung, ovarian, breast, pancreas, and liver are more likely to be complicated with pulmonary embolism than those with other types of solid tumors. Patients with distant metastasis are at a higher risk of pulmonary embolism. Pulmonary embolism without concurrent deep venous thrombosis is more frequently observed than concurrence of both disorders in the clinical setting.

Oral Benadryl and Central Venous Catheter Abuse-A Potentially "Lethal Combination"

This article describes the potential for lethal abuse of central venous catheters in oncology patients and its effects especially on the cardiovascular system. Central venous catheters are frequently used to provide immediate vascular access allowing patients to obtain lifesaving therapy or have painless blood-drawing procedures. However, they may also serve as a vehicle for abuse and misuse of medications increasing the potential for morbidity and mortality. We present a unique instance where a pediatric patient attempted suicide by self-injecting crushed diphenhydramine (Benadryl) capsules into her central venous catheter. The patient developed acute but transient ST segment elevation and echocardiographic evidence of severe pulmonary hypertension. She was treated symptomatically with oxygen and diuretics over a period of weeks, while her pulmonary hypertension completely resolved. The injection of oral medications into the central circulation is typically associated with transient pulmonary hypertension and clinical features of pulmonary embolism, especially in preparations containing talc. Although the pulmonary hypertension can be transient, it could be fatal. Physicians must be alert to the potential for abuse and misuse of central venous catheters especially in the chronically ill pediatric patients.

Diagnosis and Treatment of Pulmonary Embolism: An Overview

Pulmonary embolism (PE) is a common clinical condition with an estimated incidence of 0.5 cases per 1000 population/year (1). Once diagnosed, the treatment of PE in the early stage is usually straightforward and effective. Unfortunately, it is frequently missed or misdiagnosed until in the later stages of disease process where the outcome is poor and the therapeutic options are limited. Numerous post-mortem studies have shown that PE continues to be missed especially in the elderly and in patients with concurrent cardiorespiratory disease (2). This is due to the nonspecific clinical features of PE (often silent) and because the disease process itself commonly affects and complicates the course of severely ill patients, which makes interpretation of available diagnostic tests difficult. To date, there has been no international consensus on the most effective clinical protocol for the diagnosis, prophylaxis or treatment of pulmonary embolism. The clinical practices are highly variable between hospitals with some centres advocating aggressive management (e.g. thrombolysis) while others are more conservative. Unfortunately, this variability leads to confusion among practitioners. We sincerely hope that this article may shed some light on this complex disease.

Clinical Features of Pulmonary Embolism: Doubts and Certainties

The diagnosis of pulmonary embolism (PE) can be accurately made by perfusion lung scan and pulmonary angiography; however, when these diagnostic techniques are not promptly available, simple clinical procedures may be useful to identify patients with high probability PE. To this end, collection of clinical data through a standardized questionnaire and the use of findings from chest radiograph, ECG, and blood gas analysis may raise clinical suspicion and decide on therapeutic management. By reviewing published literature and our own experience, we found that unexplained dyspnea and chest pain are the most frequent symptoms, and sudden onset dyspnea and pleuritic chest pain are the most typical. Chest radiograph is abnormal in more than 80% of patients with PE, showing typical signs such as "sausage-like" descending pulmonary artery, Westermark sign, etc. The ECG may show findings characteristic of PE, such as tachycardia, T wave inversion in V1-V2, and PR displacement. Arterial blood gas data frequently demonstrate hypoxia and hypocapnia, being helpful in suspecting or excluding PE. Recent statistical techniques, such as discriminant or logistic analysis, may be applied to the above clinical assessment to refine and improve the noninvasive diagnosis of PE.

Pulmonary Embolism: Cause, consequences, prevention and treatment

Since Virchow introduced the doctrine of thromboembolism almost 120 years ago, “few conditions in medicine have been subjected to so much analysis with so little elucidation” (33). Indeed, the causes and exact frequency of pulmonary embolism remain uncertain. The majority of such emboli arise from veins in the lower extremities and pelvis, and important predisposing factors are trauma, congestive heart failure, phlebitis and immobility. The clinical features of pulmonary embolism are protean. They depend in part on the number and size of the emboli, the presence or absence of pulmonary infarction and the nature of any underlying disease (s). Dyspnea without orthopnea and pleuritic chest pain are important symtoms, and tachycardia and fever are common signs. If one waits for hemoptysis, cough, pleural friction rub or radiographic abnormalities to develop, most cases of pulmonary embolism will go undiagnosed. Roentgenograms of the chest in patients with pulmonary embolism or infarction show an extremely varied picture, and no radiologic finding is diagnostic. Similarly, the electrocardiogram may demonstrate no ab-normality or any one or more of a variety of changes. The differential diagnosis includes respiratory, cardiac, neurologic, psychiatric and upper abdominal disorders. Of these, myocardial infarc-tion and pneumonia are the most important and the ones with which pulmonary embolism and infarction most likely are to be confused. The ideal treatment of pulmonary embolism is prevention of the initial thrombus formation. Methods ordinarily employed to accomplish this are early, full ambulation, the use of elastic stockings and anticoagulant therapy. Once pulmonary embolism has occurred, the therapy will depend on the available facilities, the type(s) of associated disease and the physician's skill. Supportive measures always are indicated and often are sufficient. Anticoagulants are used frequently. In some patients with pulmonary embolism, surgical therapy is indicated, either for the prevention of further embolism or for the resuscitation and treatment of the patient with massive embolism. Among those procedures in the former category, ligation of the superficial femoral veins has been used extensively for many years. Now it is much less popular because of the high incidence of recurrent pulmonary emboli following such an operation. Venous ligation at the level of the inferior vena cava effectively prevents further pulmonary embolism, but the incidence of unfavorable sequelae following operation is higher than in those with more distal ligations. It generally is agreed that the inferior vena cava should be ligated in the presence of septic thrombophlebitis, failure of anticoagulants or contraindications to anticoagulation in patients with pulmonary embolism. Technics of inferior vena caval occlusion vary somewhat with the preference of the operator, and in recent years several ingenious procedures have been suggested in order to prevent the passage of large pulmonary emboli and at the same time maintain the flow of blood through the inferior vena cava. Pulmonary embolectomy for the treatment of acute massive pulmonary embolism was suggested by Trendelenburg more than 50 years ago. However, so few patients survived the procedure that the Trendelenburg operation was discarded almost completely. Recent experience with pulmonary embolectomy using temprary cardiopulmonary bypass has resulted in the survival of more than one third as many patients in 2 years as survived the procedure without cardiopulmonary bypass during the previous half-century. In certain instances, partial cardiopulmonary bypass from the femoral vein to the femoral artery for resuscitation should be employed prior to definitive embolectomy. The technic of embolectomy consists of an arteriotomy in the main pulmonary artery during total cardiopulmonary bypass followed by manual compression of both lungs in conjunction with extraction of the emboli through the pulmonary arteriotomy. Further improvements in the technical aspects of pulmonary embolectomy are foreseeable, and extensions of the procedure into other areas of pulmonary embolism should be forthcoming.

CLINICAL FEATURES OF PULMONARY EMBOLISM

CLINICAL FEATURES OF PULMONARY EMBOLISM