Pulmonary thromboembolism

Pulmonary embolism (PE) is a serious complication of chronic obstructive pulmonary disease (COPD). Retrospective studies on patients with COPD treated in the intensive care unit (ICU) were performed to determine: 1) the frequency of PE; 2) the clinical course of PE in cases of COPD in the ICU; and 3) the frequency of PE as a cause of death in the studied group. The frequency of PE was 10.9% in COPD patients. In the group analysed, clinical presentation of PE was characterized by acute severe, life-threatening complications leading to death in 86.7% of cases. PE was the most frequent cause of death (40.6%) in COPD patients in the ICU. The results of treatment of pulmonary embolism in chronic obstructive pulmonary disease are poor and mortality in this group of patients is very high. We believe that improvement of management can be achieved by antithromboembolic prophylaxis, which should be instituted as soon as possible in all patients with chronic obstructive pulmonary disease in the intensive care unit.     

Thrombolytic therapy for venous thromboembolism. Utilization by practicing pulmonologists

BACKGROUND: Pulmonary embolism (PE) is a potentially life-threatening condition for which thrombolytic therapy may be useful, although the appropriate setting, agent, and duration of therapy remain controversial. Deep venous thrombosis (DVT) can cause substantial morbidity and can be complicated by PE. METHODS: A questionnaire was submitted to 100 randomly selected practicing pulmonary physicians in 10 southeastern states. We sought to determine how physicians use thrombolytic therapy in PE and DVT. Characteristics of physicians, such as practice setting and the number of cases of PE and DVT treated in the last 2 years, were obtained. Physicians were asked if they would strongly consider the use of these agents in a variety of PE or DVT scenarios. RESULTS: Responses were tabulated from 56 practicing pulmonary physicians. Thirty-eight (70%) of responding physicians were in private practice. Fifty-four percent of physicians had used thrombolytic agents for acute PE, while only 28% had used them for DVT. All physicians who responded favored treating massive PE associated with hypotension with thrombolytic therapy, and 73% would strongly consider this treatment for acute PE associated with severe hypoxemia. Agreement on treatment in other scenarios was less uniform. CONCLUSIONS: Pulmonary physicians strongly favored thrombolytic therapy for massive PE associated with hypotension in the absence of absolute contraindications. A majority favored their use in PE associated with severe hypoxemia in the absence of hypotension or in massive proximal DVT present less than 7 days. Further prospective, multicenter, randomized trials appear indicated. Examining crucial end points, such as mortality, may help to unify therapeutic strategies and further refine the guidelines for the use of these agents in venous thromboembolism.     

Acute right ventricular dilatation: a new helical CT sign of massive pulmonary embolism

Acute right heart failure is a principal cause of circulatory collapse and death in patients with massive pulmonary embolism (PE). The purpose of this study was to investigate if helical computed tomography (CT) could contribute to the assessment of the right ventricle (RV) in those with massive PE. Over an 8-month period 79 helical CT pulmonary angiograms were performed to investigate suspected PE. Emboli were demonstrated in 28 (35%) patients and seven (9%) were considered to have had a major thromboembolic event. The CT scans of all patients were evaluated using parameters derived in the axial plane (maximum minor axis RV and LV dimensions, RV:LV minor axis ratio and RV wall thickness). Acute right ventricular dilatation with an RV:LV ratio> 1.5:1 (range 1.6:1-2.3:1, mean 2:1) was found in all seven patients who had sustained major PE. In the remaining group of 21 with lesser degrees of embolism no patient had an RV:LV ratio > 1.1:1 (range 0.8-1.1, mean 1.0). To our knowledge, this CT sign has not been described before. CONCLUSION: Helical CT can identify acute RV dilatation in addition to making the primary diagnosis in patients with massive PE. This observation may help identify those at greatest risk of a second fatal event and facilitate therapeutic strategy.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.     

Diagnosis and treatment of shock due to massive pulmonary embolism: approach with transesophageal echocardiography and intrapulmonary thrombolysis

STUDY OBJECTIVES: To evaluate the diagnostic value of transesophageal echocardiography (TEE) as an initial diagnostic tool in shocked patients. The second objective was to study therapeutic impact of intrapulmonary thrombolysis in patients with diagnosed massive pulmonary embolism. DESIGN: Prospective observational study. SETTING: Medical ICU in 800-bed general hospital. PATIENTS: Twenty-four consecutive patients with unexplained shock and distended jugular veins. MEASUREMENTS AND MAIN RESULTS: In 18 patients, right ventricular dilatation with global or segmental hypokinesis was documented. In addition, central pulmonary thromboemboli (12 patients), reduced contrast flow in right pulmonary artery (one patient), and right ventricular free wall akinesis (one patient) were found. No additional echocardiographic findings were apparent in four patients. According to pulmonary scintigraphy or autopsy, sensitivity of TEE for diagnosis of massive pulmonary embolism (MPE) in patients with right ventricular dilatation was 92% and specificity was 100%. In patients without right ventricular dilatation, left ventricular dysfunction (four patients) or cardiac tamponade (two patients) was confirmed. Intrapulmonary thrombolysis was evaluated in 11 of 13 patients with MPE. Two patients died prior to attempted thrombolysis. Three patients received streptokinase and eight received urokinase. Twenty-four hours after beginning of treatment, total pulmonary resistance index significantly decreased for 59% and mean pulmonary artery pressure for 31%. Cardiac index increased for 74%. Nine of 11 patients receiving thrombolysis survived to hospital discharge. CONCLUSION: Bedside TEE is a valuable tool for diagnosis of MPE. It enables immediate intrapulmonary thrombolysis, which seems to be an effective therapeutic alternative in our group of patients with obstructive shock.     

Minimally invasive cardiac surgery: current status and perspective

This study investigated the features of calf deep vein thrombosis (DVT) as a pulmonary embolic source. Fifty-eight lower limbs in 29 patients who were suspected of having DVT distal to the popliteal vein were screened by ultrasonography. Then, ascending venography was performed to confirm the diagnosis. Pulmonary embolism (PE) was diagnosed in suspected patients by use of pulmonary perfusion scanning or pulmonary angiography. Venography revealed calf DVT in 33 limbs in 28 patients. Of 28 patients, six had symptomatic PE. Thrombosis was found in the muscle veins in 18 limbs, the trunk veins in 11, and both veins in four. Isolated single vein thrombosis was found in the soleal vein in 14 limbs (42%), the posterior tibial vein in eight, the peroneal vein in two, and the gastrocnemius vein in two. The overall percentage of soleal vein thrombi was 61%. All six patients with symptomatic PE had isolated soleal vein thromboses. Calf DVT was a pulmonary embolic source when isolated thrombosis of the large soleal vein was more than 7 mm in diameter. Soleal veins were the most frequent and important location of calf DVT, suggesting that these were an occasional embolic source of critical PE.     

Autopsy evidence of pulmonary thromboembolism

OBJECTIVE: To determine the prevalence of pulmonary thromboembolism (PE) and underlying risk factors at autopsy, compared with clinical diagnosis. DESIGN: Retrospective review of autopsy records, death certificates and medical histories. PATIENTS AND SETTING: All 132 patients who underwent autopsy at St Vincent's Hospital, Melbourne, in 1992. RESULTS: Sixteen cases (12% of autopsies) of PE were found at autopsy. In only two had PE been recorded on the death certificate; in one other, diagnosis had been made before death. Associated pulmonary infarction and/or haemorrhage was found in only six patients with PE. All 16 had at least one underlying risk factor: advanced age, cancer, heart disease, or recent pelvic or abdominal surgery. In four patients with missed PE, clinical records showed episodes consistent with PE. There were four false-positive diagnoses. CONCLUSIONS: Significant undiagnosed pulmonary embolism is not uncommon at autopsy. Many episodes are clinically silent, but the diagnosis should be suspected in at-risk patients with unexplained episodes of dyspnoea and tachycardia.     

Incidence of pulmonary embolism after total knee arthroplasty with low-dose coumadin prophylaxis

The incidence of pulmonary embolism (PE) in osteoarthritic patients prophylaxed with low-dose coumadin after cemented total knee arthroplasty (TKA) was investigated prospectively. Each patient had a preoperative perfusion scan and a ventilation-perfusion scan on the seventh postoperative day. Pulmonary embolism was diagnosed by a high probability ventilation-perfusion scan or positive arteriogram. Patients with a moderate probability scan had an arteriogram to rule out PE. Pulmonary embolus was identified in 48 (5.6%) of 852 TKAs in 755 patients. Of these, six (0.7%) were symptomatic, and no fatal PE was identified. Age, gender, and weight did not show statistical differences comparing the PE and non-PE groups, nor did the incidences of previous PE, contralateral phlebitis, malignancy, and diabetes. A history of ipsilateral phlebitis increased the risk of PE from 5.2% to 13%, and a history of cardiac disease decreased the risk from 7.8% to 4.2%. Type of anesthesia, blood loss, tourniquet time, and prosthesis type were not significant factors. With the exception of previous contralateral phlebitis, traditional risk factors for PE were not found to increase risk of PE with low-dose coumadin prophylaxis. Spinal anesthesia that has been shown to be protective in total hip surgery was not a significant factor in this study.     

Fragmentation of massive pulmonary embolism using a pigtail rotation catheter

STUDY OBJECTIVES: The purpose of this study was the evaluation of the efficacy and safety of mechanical fragmentation of acute massive pulmonary emboli with a rotatable pigtail catheter. MATERIAL AND METHODS: Ten patients (4 female, 6 male, age 53.8+/-9.5 years) with acute massive pulmonary embolism with hemodynamic impairment were included in the study. The fragmentation catheter device (William Cook Europe A/S; Bjaerverskov, Denmark) consisted of a 5F catheter embedded in a flexible 5.5F sheath. Pulmonary emboli were fragmented by mechanical action of the recoiled rotating pigtail, while the guide wire was exiting an oval side hole proximal to the pigtail tip. In eight cases, an additional thrombolysis was performed. RESULTS: Fragmentation was successful in 7 of 10 patients. Average percentage of recanalization by fragmentation was 29.2+/-14.0%, and 36.0+/-10.0% exclusively of the seven successful cases. Average shock index decreased significantly prefragmentation to postfragmentation from 1.52 to 1.22 (p = 0.03) and to 0.81 48 h later (p < 0.001). Decrease of the average mean arterial pulmonary pressure prefragmentation to postfragmentation was insignificant (from 33 to 31 mm Hg, p = 0.14); further decrease within the 48 h follow-up was highly significant (from 31 to 21 mm Hg, p < 0.001) due to a synergy of fragmentation and thrombolysis (average dose 63+/-25 mg plasminogen activator). There were no procedure-related complications. Overall mortality rate was 20%. CONCLUSION: Fragmentation of massive pulmonary emboli with the pigtail rotation catheter achieved rapid partial recanalization in most cases, with ease of instrumentation, and without complications. Hemodynamic stabilization was completed in synergy with thrombolysis.     

Early placement of prophylactic vena caval filters in injured patients at high risk for pulmonary embolism

OBJECTIVE: Pulmonary embolism (PE) is a major problem in patients with multiple injuries. We present our experience with early placement of prophylactic vena caval filters (VCFs). DESIGN: Prospective study group with historical control. MATERIALS AND METHODS: From March 1993 to December 1993, VCFs were placed in 40 consecutive patients with three or more risk factors for PE and had demographic, physiologic, venous thromboembolic prophylaxis, and outcome data collected prospectively (VCF group). They were compared to 80 injured patients admitted between November 1991 and February 1993 who survived > 48 hours and who were matched with the VCF group for mechanism of injury and risk factors for PE (NO VCF group). MEASUREMENTS AND MAIN RESULTS: VCF placement affected a significant reduction in the incidence of PE (2.5% vs. 17%) and a clinical reduction in PE-related mortality. Embolic trapping was suggested by a 10% incidence of documented vena caval thrombi and although two patients developed significant venous stasis disease, no other VCF-related morbidity was noted. CONCLUSIONS: In spite of long-term morbidity, early prophylactic VCF placement is safe and should be considered in the prophylaxis of PE in the high-risk injured patients. This intervention may be effective in eliminating PE as a major cause of posttrauma morbidity and mortality.     

Clinical and instrumental diagnosis of pulmonary embolism

Pulmonary embolism shows a high mortality especially for the difficulty in establishing an early correct diagnosis. The pathophysiology and thus the clinical manifestations of pulmonary embolism (PE) are essentially conditioned by three factors: the size of the embolus, the pre-existing cardiorespiratory condition, the release caused by the embolus, of some substances or the activation of reflexes which tend to worsen the purely mechanical consequences of PE. The clinical manifestations resulting from the combination of these factors result in three clinical patterns: acute cor pulmonare, pulmonary infarction, acute dyspnea. PE symptoms may be absent in a moderate percentage of cases and if present, they are nonspecific. Some laboratory tests were shown to be of no diagnostic accuracy, as enzyme determination, a sign of necrosis, blood gas analysis, and determination of alveolar arterial oxygen gradient. Among blood coagulation tests, D-dimer determination was shown to be of some relevance. However, at present, it cannot be used to confirm the diagnostic suspicion of PE. Among the instrumental cardiologic procedures, while ECG has a poor diagnostic reliability, transesophageal echocardiography in central embolism may be able to visualize the embolus and to accurately assess the hemodynamic effects, supplying sufficient information for PE therapy. Even if imaging procedures as pulmonary angiography and more recently CT or MRI are the most reliable diagnostic tools, the diagnostic suspicion of PE in subjects at risk, the use of the examined methods and the search in these patients for the presence of lower limb deep vein thrombosis, often asymptomatic, may increase the number of treated patients thus decreasing the mortality of this disease.     

Prophylactic Greenfield filters: acute complications and long-term follow-up

The efficacy of prophylactic vena caval filters (VCF) in reducing morbidity and mortality from pulmonary embolism (PE) in high-risk trauma patients has been shown, but minimal follow-up data is currently available. VCFs were prophylactically placed in 110 patients between August 1991 and June 1995. There was an early VCF complication rate of 7%. Twenty-two patients died; the remaining 88 patients formed the basis for the follow-up study. Forty-five patients were located and interviewed by phone, and 30 of these patients (34%) returned for evaluation. The mean follow-up time was 18 months (range, 4-42 months). There was no incidence of caval thrombosis on follow-up. Eleven patients had physical findings, and duplex evidence consistent with postphlebitic syndrome. An additional three patients had evidence of old deep venous thrombosis (DVT) by duplex, but no significant symptomatology. VCF are effective in preventing PE related deaths and have few major complications. The long-term morbidity associated with posttraumatic venous thrombosis is significant. This morbidity is related not to PE or VCF, but to the underlying DVT. Improved strategies against DVT are necessary.     

The delivery of oxygen by a venturi T piece

Thromboembolic events such as deep vein thrombosis (DVT) and pulmonary embolism (PE) are very uncommon in the pediatric age group; even more rare is the white clot syndrome. We present the case of a 13-year-old girl who presented with no known risk factors for thromboembolic disease or cardiopulmonary complaints, yet was found to have extensive lower extremity DVT and PE. This patient also suffered the rare but potentially devastating complication of heparin therapy referred to as the white clot syndrome, resulting in amputation of the lower extremity. Greater awareness of both thromboembolic disease in children and the white clot syndrome may lessen the morbidity and mortality associated with these entities.     

Value of perfusion lung scan in the diagnosis of pulmonary embolism: results of the Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISA-PED)

To assess the value of perfusion lung scan in the diagnosis of pulmonary embolism, we prospectively evaluated 890 consecutive patients with suspected pulmonary embolism. Prior to lung scanning, each patient was assigned a clinical probability of pulmonary embolism (very likely, possible, unlikely). Perfusion scans were independently classified as follows: (1) normal, (2) near-normal, (3) abnormal compatible with pulmonary embolism (PE+: single or multiple wedge-shaped perfusion defects), or (4) abnormal not compatible with pulmonary embolism (PE-: perfusion defects other than wedge-shaped). The study design required pulmonary angiography and clinical and scintigraphic follow-up in all patients with abnormal scans. Of 890 scans, 220 were classified as normal/or near-normal and 670 as abnormal. A definitive diagnosis was established in 563 (84%) patients with abnormal scans. The overall prevalence of pulmonary embolism was 39%. Most patients with angiographically proven pulmonary embolism had PE+ scans (sensitivity: 92%). Conversely, most patients without emboli on angiography had PE- scans (specificity: 87%). A PE+ scan associated with a very likely or possible clinical presentation of pulmonary embolism had positive predictive values of 99 and 92%, respectively. A PE- scan paired with an unlikely clinical presentation had a negative predictive value of 97%. Clinical assessment combined with perfusion-scan evaluation established or excluded pulmonary embolism in the majority of patients with abnormal scans. Our data indicate that accurate diagnosis of pulmonary embolism is possible by perfusion scanning alone, without ventilation imaging. Combining perfusion scanning with clinical assessment helps to restrict the need for angiography to a minority of patients with suspected pulmonary embolism.     

The traps of pulmonary embolism

The clinical diagnosis of pulmonary embolism (PE), even massive, remains difficult and perplexing. In our hospital, the percentage of exact clinical diagnoses has not significantly changed over recent years, with a false-negative rate of 78%, and a false-positive rate of 2%. In approximately 20% of cases, autopsy showed several emboli and pulmonary infarctions of various ages, indicating recurrent embolic episodes. The diseases most frequently associated were cardiac diseases (51%) and tumours (24%). Pneumonia considerably decreases the probability of an exact diagnosis of PE; hospitalisation in the Cardiology department or Intensive Care Unit increased the probability of this diagnosis. While the numerous diagnostic algorithms recently proposed have a limited value, the process integrating clinical and instrumental data in order to establish a prospective clinical probability, should facilitate identification of acute PE in live patients.     

Review of patients with infective endocarditis of native valves over a five-year period

The clinical characteristics, echocardiographic features, bacteriologic data, morbidity and mortality of patients who were admitted to our hospital with infective endocarditis of their native valves over a five-year period were reviewed. There were 32 patients with a mean age of 38.2 +/- 16.2 years (range: 17 to 71 years) in our study population; 24 patients had underlying valvular abnormalities, six patients had congenital heart disease and two patients had no structural cardiac abnormality. Echocardiography was performed for all patients. Vegetations were absent in three (9.4%) patients, single in 19 (59.4%) patients and multiple in ten (31.3%) patients. Of the 24 (75%) patients who had left-sided endocarditis, mitral valve disease was the commonest valvular abnormality (16 patients). Ventricular septal defect was the commonest underlying abnormality in patients with right-sided endocarditis. Blood cultures were positive in 26 (81.3%) patients; the commonest organism was streptococcal (16 or 50% patients). Complications were present in 13 (40.6%) patients, of which eight patients had evidence of embolism, four patients had cardiac failure and one patient had a paravalvular abscess. Four (12.5%) patients died, two as a result of refractory heart failure and two as a consequence of septic embolism. Advances in medicine have resulted in a better outcome for patients with infective endocarditis, however, it remains an important disease with significant morbidity and mortality.     

The postoperative lumbar spine: evaluation of epidural scar over a 1-year period

BACKGROUND: Results of antituberculous chemotherapy for Mycobacterium avium complex disease remain disappointing. Pulmonary resection during an early stage of the disease, therefore, may be beneficial to patients whose disease is localized and who can tolerate a resectional operation. METHODS: Thirty-three patients with localized M avium complex disease underwent 33 pulmonary resections between 1979 and 1996. There were 17 males and 16 females, with a mean age of 50 years (range, 30 to 69 years). Lobectomy was performed in 26 patients, pleuropneumonectomy in 1, segmentectomy in 5, and wedge resection in 1. RESULTS: There was no operative mortality. After pulmonary resection, 31 (94%) patients attained sputum-negative status. Bronchopleural fistula occurred in one patient who underwent a right upper lobectomy. There were two late deaths. A patient with bronchopleural fistula died of respiratory failure two years postoperatively. Another patient died of an unknown cause 12 years postoperatively. Of the 31 patients with negative sputum status postoperatively, only 2 patients (6%) had relapse at 1 and 9 years after operation. CONCLUSIONS: We recommend that patients with this disease be considered for pulmonary resection as early as possible.     

Acute digitoxin intoxication treated by intracardiac pacemaker: experience in sixty-eight patients

Out of 124 patients who had taken massive doses of digitoxin in attempted suicide, emergency endocardial pacing was performed in the 68 with the worst prognosis. The mortality (13%) in the 124 patients compared favorably with the mortality (20%) in a previous series of 70 similar patients none of whom were paced. Sixteen (23%) of the 68 paced patients died. The causes of death were: asystole (two); cardiogenic shock (two); septicemia (one); and ventricular fibrillation (eleven). Ventricular fibrillation occurred during introduction of the pacing catheter in two patients, as a result of electrode displacement in these patients, because of premature withdrawal of the catheter in one patient, and for no detectable reason, during normally proceeding pacing, in five patients. Endocardial pacing has a place in the emergency treatment of massive digitoxin poisoning. Its chief hazards are mechanical, and one of the commonest is electrode displacement.     

Group A streptococcal bacteremia. A 10-year prospective study

In this paper we present a prospective evaluation of 100 patients with Group A Streptococcal (GAS) bacteremia evaluated in our hospital over a 10-year period. Sixty-two patients were intravenous drug users (IVDU); all but 1 of these had an obvious cutaneous portal of entry related to the injection of illicit drugs. Twenty-seven patients had infectious metastasis, and the presence of septic pulmonary embolism was associated with suppurative phlebitis. Four of these patients had endocarditis. In the non-IVDU group, 24 patients had an underlying disease, and 12 were immunosuppressed. In 14 cases the infection was of hospital acquisition; in 35% infection was related to medical manipulations. Comparing the IVDU and non-IVDU groups, GAS bacteremia in IVDU patients is associated with a more benign outcome, a longer time of evolution before diagnosis, and a lower frequency of septic shock and mortality than in non-IVDU patients. Although in the univariate analysis GAS bacteremia was associated with several variables, in the multivariate analysis only the presence of shock and nosocomial acquisition of the infection were independently associated with a fatal outcome. Fifty-two patients were infected with human immunodeficiency virus (HIV); 5 of these were in the non-IVDU group. During the last 5 years of study, GAS bacteremia in our hospital was 39 times more frequent in HIV-infected patients than in patients without HIV. Nine patients presented clinical criteria corresponding to Streptococcal toxic shock syndrome (STSS), although its incidence was lower in the IVDU group. In the non-IVDU group, STSS was more frequent in patients with a necrotizing portal of entry, an age between 20 and 40 years, women, and when the origin of the infection was the skin or soft tissue. Six patients with STSS died, and death was associated with the presence of necrotizing lesions and lower counts of white cells, platelets, or hemoglobin.