Acute pulmonary thromboembolism (APTE) is a highly prevalent condition (104-183 cases per 100,000 person-years) and is potentially fatal. Approximately 20% of patients with APTE are hypotensive, being considered at high risk of death. In such patients, immediate lung reperfusion is necessary in order to reduce right ventricular afterload and to restore hemodynamic stability. To reduce pulmonary vascular resistance in APTE and, consequently, to improve right ventricular function, lung reperfusion strategies have been developed over time and widely studied in recent years. In this review, we focus on advances in the indication and use of systemic thrombolytic agents, as well as lung reperfusion via endovascular and classical surgical approaches, in APTE.

Keywords: Embolism; Shock; Hypotension; Thrombolytic therapy; Reperfusion; Hemorrhage.

The diagnosis of acute pulmonary thromboembolism is based on the clinical probability, use of D-dimer (when available) and imaging. The main imaging modalities used in the diagnosis are ventilation-perfusion (V/Q), angiography, and computed tomography (CT). In the last decade several studies have demonstrated that spiral CT has a high sensitivity and specificity in the diagnosis of acute pulmonary thromboembolism. The evaluation of the pulmonary arteries has further improved with the recent introduction of multidetector spiral CT scanners. Various investigators have suggested that spiral CT pulmonary angiography should replace scintigraphy in the assessment of patients whose symptoms are suggestive of acute PE. This article discusses the role of the various imaging modalities in the diagnosis of acute pulmonary thromboembolism with emphasis on the role of spiral CT.

Keywords: Diagnostic imaging. Pulmonary embolism./diagnosis. Angiography. Lung diseases/radionuclide imaging. Tomography, emission-computed single-photon/methods.

Pulmonary thromboembolism and exacerbation of chronic obstructive pulmonary disease are common conditions. Chronic obstructive pulmonary disease is a clinical risk factor for pulmonary thromboembolism. The presentation of acute pulmonary thromboembolism and acute exacerbation of chronic obstructive pulmonary disease often mimic each other so closely that they cannot be distinguished clinically. The structural abnormalities of the lungs in chronic obstructive pulmonary disease make also difficult to interpret the results of noninvasive tests like ventilation-perfusion lung scans. Therefore, diagnosing acute pulmonary thromboembolism in patients with underlying chronic obstructive pulmonary disease is a challenging task. In order to update knowledge of the subject and offer suggestions regarding conduct, we evaluated various studies addressing this theme, including case reports and case series. In addition, we reviewed diagnostic approaches to acute pulmonary thromboembolism, and we reflect upon that topic. The clinical probability of pulmonary thromboembolism concomitant to chronic obstructive pulmonary disease is typically intermediate, as is positivity on the ventilation-perfusion lung scan. Diagnostic algorithms should take that into consideration.

Keywords: Pulmonary disease, chronic obstructive/complications; Pulmonary embolism/diagnosis; Pulmonary embolism/epidemiology; Ventilation-perfusion ratio

Pulmonary thromboembolism is a common condition. Its diagnosis usually requires pulmonary scintigraphy, computed angiotomography, pulmonary arteriography and, in order to rule out other diagnoses, the measurement of D-dimer levels. Due to the fact that these diagnostic methods are not available in most Brazilian hospitals, the validation of other diagnostic techniques is of fundamental importance. We describe a case of a woman with chronic pulmonary hypertension who experienced a pulmonary thromboembolism event. Pulmonary scintigraphy, computed angiotomography and pulmonary arteriography were used in the diagnosis. The D-dimer test result was positive. Volumetric capnography was performed at admission and after treatment. The values obtained were compared with the imaging test results.

Keywords: Thromboembolism; Hypertension, pulmonary; Capnography; Schistosomiasis.

Introduction: Surgical procedures requiring aortic occlusion have been associated with pulmonary reperfusion injury. The authors studied the pulmonary edema in a reperfusion injury model by aortic occlusion in rats. Material and methods: Thirty-three Wistar rats were anesthetized with intraperitoneal injection of sodium pentobarbital (20 mg/kg). Using a midline abdominal incision, the infra-renal aorta was isolated and the animals were randomized into three groups. Ischemia-reperfusion group (IRG, n = 5): rats that underwent 30 min of aorta occlusion and were followed during 120 min of reperfusion. Ischemia group (IG, n = 5): rats that underwent 30 min of aorta occlusion. Control group (CG, n = 5): rats that underwent sham operations without aorta occlusion and were followed during 150 min. Histopathologic examination of the right lung was performed. The pulmonary edema was studied by morphometric analysis and so was the leukocytes infiltration. Eighteen rats (6 rats in each group) were studied with respect to lung fresh/dry weight ratio. ANOVA was used to analyze the morphometric results and the lung fresh/dry weight ratio, with Bonferroni adjustment for paired multiple comparisons. Animals of the IRG presented more pulmonary edema than those of the IG and CG (0.24 vs. 0.17 and 0.17, p < 0.001). There was no difference between the groups regarding the lung fresh/dry weight ratio. There were more inflammatory cells in the lungs of the rats submitted to ischemia-reperfusion. The authors concluded that infra-renal abdominal aorta cross-clamping and unclamping are associated with pulmonary edema. This edema is not induced by elevation of the hydrostatic pressure due to the aortic occlusion, since it was not seen in animals that were only submitted to ischemia.

Keywords: ischemia, reperfusion, pulmonary edema, inbred strains rats

Pulmonary thromboembolism (PTE) should be suspected in patients with risk factors for deep venous thrombosis (DVP) who present, either isolated or in association, malaise, dyspnea/tachypnea, sudden collapse or pulmonary hemorrhage syndrome. The diagnostic approach starts with basic tests (chest X-rays electrocardiographs, and arterial blood gas tensions) the results of which associated to medical history and to physical examination allow the classification of clinical suspicion as high, intermediate or low probability. This phase is important, both to support clinical suspicion of PTE and to exclude alternative diagnoses. In order to confirm or exclude PTE, one or several sophisticated imaging exams (lung isotope scanning, leg imaging, and pulmonary angiography) should be performed next, according to the findings of the chest X-ray. If there is undue delay in arranging investigations for patients with high clinical probability, heparin should be started, unless high risk to anticoagulation is present. In this review the diagnostic methods are discussed and some strategies for rapid investigation of PTE are shown with the main purpose of adapting them to Brazilian reality.

Keywords: Pulmonary thromboembolism. Diagnosis. Management strategy.

Background: Pulmonary thromboembolism (PTE) is still an enigmatic disorder in many epidemiological and clinical features, remaining one of the most commonly misdiagnosed disorders. Objective: To describe the prevalence and pathological findings of PTE in a series of autopsies, to correlate these findings with underlying diseases, and to verify the frequency of PTE clinically suspected before death. Method: The reports on 5261 consecutive autopsies performed from 1979 to 2002 in a Brazilian tertiary referral medical school were reviewed for a retrospective study. From the medical records and autopsy reports of the patients found with macroscopically and/or microscopically documented PTE, were gathered data on demographics, underlying diseases, antemortem suspicion of PTE, and probable PTE site of origin. Results: The autopsy rate was 42.0% and PTE was found in 544 patients. In 225 cases, PTE was the main cause of death (fatal PTE). Infections (p=0.0003) were associated with nonfatal PTE and trauma (p=0.007) with fatal PTE. The rate of antemortem unsuspected PTE was 84.6% and 40.0% of these patients presented fatal PTE. Diseases of the circulatory system (p=0.0001), infections (p<0.0001), diseases of the digestive system (p=0.0001), neoplasia (p=0.024) and trauma (p=0.005) were associated with unsuspected PTE. The most frequent PTE site of origin was the lower limbs (48.9%). Probable PTE sites of origin such as right-sided cardiac chambers (p=0.012) and pelvic veins (p=0.015) were associated with fatal PTE. Conclusion: A large number of cases do not have antemortem suspicion of PTE. Special attention should be paid to the possibility of PTE in patients with diseases of the circulatory system, infections, diseases of the digestive system, neoplasia, and trauma.

Keywords: Autopsy. Epidemiology. Pulmonary Thromboembolism.

Objectives: The purpose of this study is to establish the prevalence of pulmonary thromboembolism (PTE) in autopsies and its rate of antemortem suspicion at Hospital de Clínicas de Porto Alegre (HCPA). Design: Cohort study with historical data. Setting: School hospital with 728 beds. Patients and methods: The adult autopsy reports were studied from 1985 to 1995 as well as the records of patients whose autopsies diagnosed PTE. Antemortem suspicion of PTE was considered from explicit notes on patients records, from requests of lung scan, or from full anticoagulation. Results: In the period mentioned, 9,607 deaths occurred, and 767 (7.98%) autopsies were performed. Significant PTE (> 1 pulmonary subsegment) in 30 (3.9%) patients. In 3 (10%) patients, PTE was considered the effective cause of death. Clinic suspicion was present in 5 (16.6%) patients; in 25 (83.4%) patients, there were only postmortem findings. Conclusion: PTE rates in autopsies were similar to those found in international literature. The rates of clinical suspicion were half of the ones mentioned in school hospitals in the United States and Europe. PTE was subsuspected in life in patients hospitalized at HCPA.

Keywords: Venous thromboembolism. Deep venous thrombosis. Pulmonary artery. Pulmonary infarction.

Objective: To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA) in patients with suspected pulmonary thromboembolism (PTE) who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods: This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results: On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%). Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%). Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%). Among those 75 cases, there were only 39 (20.4%) in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases). Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001). Conclusions: Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients.

Keywords: Pulmonary embolism/diagnosis; Pulmonary embolism/epidemiology; Angiography.

Due to the increasing number and improved survival of lung transplant recipients, radiologists should be aware of the imaging features of the postoperative complications that can occur in such patients. The early treatment of complications is important for the long-term survival of lung transplant recipients. Frequently, HRCT plays a central role in the investigation of such complications. Early recognition of the signs of complications allows treatment to be initiated earlier, which improves survival. The aim of this pictorial review was to demonstrate the CT scan appearance of pulmonary complications such as reperfusion edema, acute rejection, infection, pulmonary thromboembolism, chronic rejection, bronchiolitis obliterans syndrome, cryptogenic organizing pneumonia, post-transplant lymphoproliferative disorder, bronchial dehiscence and bronchial stenosis.

Keywords: Tomography, X-ray computed; Lung transplantation; Postoperative complications.

Objective: To evaluate the use of venous thromboembolism (VTE) prophylaxis in a general hospital. Methods: A cross-sectional cohort study at the Hospital Nossa Senhora da Conceição, located in the city of Porto Alegre, Brazil, involving a random sample of patients admitted between October of 2008 and February of 2009. We included patients over 18 years of age and hospitalized for more than 48 h. The exclusion criteria were anticoagulant use, pregnancy, puerperium, and a history of thromboembolic disease. The adequacy of prophylaxis was evaluated in accordance with a protocol created by the Hospital and principally based on the American College of Chest Physicians guidelines, eighth edition. Results: We included 262 patients. The mean age was 59.1 ± 16.6 years. The most common risk factors were immobilization (in 70.6%), infection (in 44.3%), cancer (in 27.5%), obesity (in 23.3%), and major surgery (in 14.1%). The risk of VTE was classified as high and moderate in 143 (54.6%) and 117 (44.7%) of the patients, respectively. Overall, 46.2% of the patients received adequate prophylaxis, 25% of those with ≥ three risk factors for VTE and 18% of those with cancer, the differences between these last two groups and their counterparts (patients with < three risk factors and those without cancer) being statistically significant (p < 0.001 for both). Conclusions: Our data reveal that nearly all patients at our hospital were at risk for VTE, and that less than half received adequate VTE prophylaxis, which is in agreement with the literature. It is surprising that inadequate prophylaxis is more common in high-risk patients.

Keywords: Venous thromboembolism/prevention and control; Venous thrombosis/prevention and control; Heparin.

Objective: To investigate the effects of N-acetylcysteine (NAC) and pentoxifylline in a model of remote organ injury after hind-limb ischemia/reperfusion (I/R) in rats, the lungs being the remote organ system. Methods: Thirty-five male Wistar rats were assigned to one of five conditions (n = 7/group), as follows: sham operation (control group); hind-limb ischemia, induced by clamping the left femoral artery, for 2 h, followed by 24 h of reperfusion (I/R group); and hind-limb ischemia, as above, followed by intraperitoneal injection (prior to reperfusion) of 150 mg/kg of NAC (I/R+NAC group), 40 mg/kg of pentoxifylline (I/R+PTX group), or both (I/R+NAC+PTX group). At the end of the trial, lung tissues were removed for histological analysis and assessment of oxidative stress. Results: In comparison with the rats in the other groups, those in the I/R group showed lower superoxide dismutase activity and glutathione levels, together with higher malondialdehyde levels and lung injury scores (p < 0.05 for all). Interstitial inflammatory cell infiltration of the lungs was also markedly greater in the I/R group than in the other groups. In addition, I/R group rats showed various signs of interstitial edema and hemorrhage. In the I/R+NAC, I/R+PTX, and I/R+NAC+PTX groups, superoxide dismutase activity, glutathione levels, malondialdehyde levels, and lung injury scores were preserved (p < 0.05 for all). The differences between the administration of NAC or pentoxifylline alone and the administration of the two together were not significant for any of those parameters (p > 0.05 for all). Conclusions: Our results suggest that NAC and pentoxifylline both protect lung tissue from the effects of skeletal muscle I/R. However, their combined use does not appear to increase the level of that protection.

Keywords: Skeletal muscle; Ischemia; Reperfusion injury; Lung injury; Acetylcysteine; Pentoxifylline.