Experimentally induced nasal hypersecretion does not reduce the efficacy of intranasal levocabastine

Pulmonary tumor embolism is an often missed antemortem diagnosis in patients with cancer and respiratory failure. Although rare, this complication is an important cause of additional morbidity. Referred for radionuclide pulmonary perfusion and ventilation scintigraphy, a typical pattern of multiple subsegmental peripheral defects on perfusion lung scanning without matching ventilation defects, suggesting a high probability of pulmonary thromboembolism, often leads to false conclusions. We present a case of bilateral multiple subsegmental mismatched defects in lung ventilation perfusion scintigraphy, where autopsy confirmed the diagnosis of pulmonary tumor embolism, secondary to an undifferentiated ductal type adenocarcinoma of the pancreas. Pulmonary tumor embolism is an entity to keep in mind in patients treated for carcinoma presenting with (sub) acute dyspnea.     

Estimation of shunt flow in coronary-pulmonary fistula by lung perfusion scintigraphy with technetium-99m macroaggregated albumin

The shunt flow from the coronary artery to pulmonary arteries was evaluated in 6 patients with coronary-pulmonary fistula by lung perfusion scintigraphy with technetium-99m macroaggregated albumin. In 2 patients, whose degree of visualization of pulmonary arteries by coronary angiography was relatively high, lung perfusion scintigrams demonstrated the defects at the distal of coronary-pulmonary fistulas.     

Hyperlucent lung secondary to homocystinuria

At 23 months of age, one of a pair of monozygotic twins with radiographic unilateral hyperlucent lung was evaluated by radionuclide ventilation/perfusion pulmonary studies, which revealed a ventilation/perfusion mismatch of an entire lung. This twin died, and autopsy revealed pulmonary arterial thrombosis and histological changes compatible with homocystinuria, which was subsequently shown to be present in the surviving twin as well. A ventilation/perfusion lung scan of the surviving twin revealed multiple ventilation/perfusion mismatched defects, suggestive of pulmonary embolism. The presenting manifestation of homocystinuria in these patients was the pulmonary thrombotic disease. Neither twin had any other stigmata of homocystinuria at the time of initial presentation.     

A case of meningioma appearing as a cyst with solid parietal nodule. Evaluation using computerized tomography and magnetic resonance

Bilateral sequential lung transplantation was complicated by pulmonary artery anastomotic stenosis and bilateral pulmonary thromboemboli. Pulmonary artery thrombus was eliminated by intrathrombotic but not by systemic administration of urokinase. The pulmonary emboli resulted in localized pulmonary infarctions, supporting the need for thrombolytic intervention to restore pulmonary perfusion in the absence of collateral bronchial blood flow after lung transplantation. Pulmonary artery stenosis was relieved by endovascular stenting, avoiding an early reoperative procedure. This case suggests that direct administration of thrombolytic agent may be superior to intravenous administration in the treatment of pulmonary thromboemboli. Pulmonary arterial anastomotic stenoses after lung transplantation can be relieved by endovascular procedures.     

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.     

Asymmetric distribution of the pulmonary blood flow between the right and left lungs in d-transposition of the great arteries

Pulmonary angiograms, radionuclide lung images and chest roentgenograms were evaluated regarding the incidence, magnitude and natural evolution of maldistribution of the pulmonary blood flow between the lungs in 63 patients with dextrotransposition of the great arteries. Approximately half of these patients had some degree of greater perfusion of the right relative to the left lung. A significant correlation was demonstrated between the incidence of this maldistribution of blood flow and the angulation between the main and the right pulmonary arteries. For any given angulation between these vessels, additional pulmonary stenosis increased the incidence of disparity in perfusion. Our observations suggest the following developmental mechanisms: The maldistribution in flow results from the abnormal rightward inclination of the main pulmonary artery in the transposition malformation which straightens the flow axis from the main to the right pulmonary artery. Under these circumstances the momentum of the blood in the main pulmonary artery carries the blood preferentially into the right pulmonary artery. This momentum is increased when there is stenosis of the left ventricular outflow tract. Consequent differences in the mechanical properties of the two pulmonary vascular beds can increase this maldistribution. The disparity in perfusion between the lungs is not present in newborns with d-transposition, appears to be progressive in severity and in time may result in almost complete cessation of effective perfusion of the left lung. The effect of the Mustard operation on this abnormality of flow is discussed.     

Bronchial adenoma resection with relief of hypoxic pulmonary vasoconstriction

Experimental airway obstruction is known to cause reflex pulmonary artery constriction, but clinical documentation of reversible bronchial obstruction and vasoconstriction is rare. A soft bronchial adenoma obstructed the left main bronchus, and scans showed minimal ventilation and perfusion on the left. Gas aspirated from beyond the tumor was hypoxic. The adenoma was removed and the lung left intact by means of a skin graft in the bronchial wall. Four months later, pulmonary function was normal, and both ventilation and perfusion of the left lung were normal. Reflex pulmonary vasoconstriction resulting from alveolar hypoxia minimizes systemic hypoxemia and also minimizes alveolar tissue hypoxia in the lung itself. The reflex is seen most frequently in perfusion scans in patients with chronic airways disease. This case in important in that it documents reversal of vasoconstriction after ventilation was restored.     

Comparison of rest/exercise ECG, thallium-201 scans and radionuclide angiography in patients with suspected coronary artery disease

The results of rest and exercise ECG, 201Tl myocardial perfusion imaging and equilibrium radionuclide angiography were analyzed in 71 consecutive patients referred for diagnosis or evaluation of coronary artery disease (CAD). In 45 patients the diagnosis was established either by catheterization or typical history. In this group the overall sensitivity for rest/exercise ECG was 66%, for 201Tl scans 74%, for both combined 79% and for the ejection fraction response to exercise determined by radionuclide angiography 97%. If only the exercise response was considered, the corresponding sensitivity values were 58% (ECG), 50% (201Tl scans), 71% (ECG + 201Tl) and 97% (radionuclide angiography). The specificity for coronary artery disease was determined to be 71% for ECG, 86% for 201Tl scans and 42% for radionuclide angiography. All patients with false-positive results by radionuclide angiography had cardiomyopathies, thus this test has a high specificity for left ventricular dysfunction rather than for CAD alone. Criteria developed from the analysis of the test results in the 45 patients with definite diagnoses were then applied to the evaluation of 26 additional patients with atypical chest pain. A diagnosis could be made in all but 5 of them and radionuclide angiography was again the single most reliable test. Based on this study a new approach for the noninvasive evaluation of patients with suspected coronary artery disease is proposed.     

Effect of pulmonary artery stenoses on the cardiopulmonary response to exercise following repair of tetralogy of Fallot

Data from exercise tests, echocardiograms, and lung perfusion scans were analyzed to determine whether the excessive minute ventilation (VE) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery stenoses. Patients with branch PA stenoses had lower peak oxygen consumptions and higher VE during exercise than did patients without stenoses, and a strong correlation existed between the degree of pulmonary blood flow maldistribution on lung perfusion scan and the amount of excessive VE during exercise.     

Evaluation of the respiratory function by lung scintigraphy in patients candidates for pulmonary resection

Sixty-one patients undergoing pulmonary resection were studied pre- and post-operatively by spirometry, arterial gas determination, and quantitative ventilation/perfusion lung scanning. Our results showed that ventilation and/or perfusional scintigraphic scanning is currently the most reliable method in identifying patients at risk for postoperative respiratory insufficiency. Specifically, this technique was successful in detecting pulmonary areas other than those to be resected presenting ventilation or perfusional abnormalities. Therefore, the technique is particularly useful in predicting residual pulmonary function.     

Inhaled nitric oxide during anesthesia for bilateral single lung transplantation. Case report

Recently inhaled nitric oxide (iNO) has been used as pulmonary vasodilator without any effect on systemic hemodynamics. iNO has been also used in cardiac and thoracic surgery, involving lung transplantation. In this case report a patient, 41 years old female, affected by bronchiectasis, underwent bilateral sequential single lung transplantation and during one lung ventilation and pulmonary artery clamped iNO allowed to avoid cardiopulmonary bypass and to carry out the procedure successfully.     

Noninvasive diagnosis of pulmonary embolism

With the development of new methods for detecting pulmonary embolism, the need for angiography has been greatly reduced. Plasma D-dimer assays, lower-limb ultrasonography, and ventilation/perfusion lung scans in combination with the clinical assessment enable safe, cost-effective diagnoses.     

Post-traumatic ARDS--a potential indication for lung transplantation?

Posttraumatic adult respiratory distress syndrome (ARDS) still involves significant mortality, despite progress in management concepts. Current therapeutic strategies are briefly described, including kinetic therapy, high-frequency jet ventilation and extracorporeal membrane oxygenation. In addition, a spectacular case of the first successful lung transplantation for posttraumatic ARDS after failed ECMO (extracorporeal membrane oxygenation) support is reported. This young man with severe posttraumatic ARDS developed a potentially lethal bilateral pulmonary hemorrhage under treatment with ECMO, and on the basis of this bilateral pulmonary transplantation was considered to be indicated. The patient is alive and well 2 years after the procedure.     

Pulmonary embolization causes hypoxemia by redistributing regional blood flow without changing ventilation

To explore mechanisms of hypoxemia after acute pulmonary embolism, we measured regional pulmonary blood flow and alveolar ventilation before and after embolization with 780-micrometers beads in five anesthetized, mechanically ventilated pigs. Regional ventilation and perfusion were determined in approximately 2.0-cm3 lung volumes by using 1-micrometers-diameter aerosolized and 15-micrometers-diameter injected fluorescent microspheres. Hypoxemia after embolization resulted from increased perfusion to regions with low ventilation-to-perfusion ratios. Embolization caused an increase in perfusion heterogeneity and a fall in the correlation between ventilation and perfusion. Correlation between regional ventilation pre- and postembolization was greater than correlation between regional perfusion pre- and postembolization. The majority of regional ventilation-to-perfusion ratio heterogeneity was attributable to changes in regional perfusion. Regional perfusion redistribution without compensatory changes in regional ventilation is responsible for hypoxemia after pulmonary vascular embolization in pigs.     

V/Q mismatch without pulmonary emboli in children with histoplasmosis

In two children with histoplasmosis pulmonary perfusion and ventilation studies revealed mismatched abnormalities characterized by almost unilaterally absent perfusion but normal ventilation in the right lung. Chest roentgenograms demonstrated right hilar enlargement and pulmonary contrast angiograms revealed narrowing of the right pulmonary arteries by extrinsic fibrotic granulomata but no pulmonary emboli were present. Fibrosing mediastinitis due to histoplasmosis was found by mediastinoscopic examination in one of the patients. Non-embolic causes of V/Q mismatch lung imaging are discussed briefly, and the correlation with clinical findings is stressed for the diagnosis of pulmonary emboli.     

Effect of pulmonary microembolism on arteriovenous shunt flow

The effects of acute pulmonary hypertension on the fraction of cardiac output shunted through pulmonary arteriovenous communications have been studied in dogs as a possible cause of hypoxia following pulmonary embolization. Pulmonary artery pressure was increased twofold and then fourfold above control values by embolization of the pulmonary vascular bed with polystyrene microspheres. Quantitative measurements of arteriovenous shunt were determined from the fraction of 50 mu radioactively labeled microspheres injected into the inferior vena cava which passed through the pulmonary circulation into systemic vascular beds. There was no increase in the fraction of pulmonary blood flow passing through pulmonary arteriovenous connections, 50 mu in diameter or greater, with pulmonary microembolism when FIo2 was 1. There was a small increase in arteriovenous shunt fraction when pulmonary artery pressure was increased with an FIo2 of 0.21. Physiological shunt measured by the oxygen technique did not increase with pulmonary embolism, but total venous admixture rose significantly. Postmortem gravimetric measurements of lung water indicated pulmonary edema. We conclude that anatomic arteriovenous shunt channels have little physiological significance after pulmonary microembolism in the dog lung. The major cause of hypoxia immediately after pulmonary microembolism is ventilation/perfusion imbalance, probably caused by pulmonary edema.     

An experience of the modified Norwood's operation for hypoplastic left heart syndrome with aberrant origin of right subclavian artery and persistent left superior vena cava--the procedure without total circulatory arrest and cardiac arrest

We reported a successful case of the modified Norwood operation for a 21-day-old neonate with hypoplastic left heart syndrome (MS and AS) associated with an aberrant right subclavian artery and a persistent left superior vena cava. The modified Norwood operation was performed without total circulatory arrest and Cardiac arrest. A 4 mm Gore-Tex graft, which was anastomosed between the right carotid artery and the right pulmonary artery for systemic-pulmonary shunt, was used for cerebral perfusion during aortic arch reconstruction. Coronary perfusion was performed with a small cannula placed on the relatively large ascending aorta during anastomosis between the main pulmonary artery and the ascending aorta. Equine pericardial patch was used for aortic arch reconstruction and the ascending aorta was directly anastomosed to a part of the main PA. Postoperative course was uneventful and postoperative MRI revealed no stenosis of the aortic arch and the pulmonary artery.     

Radionuclide angiographic diagnosis of bronchopulmonary sequestration

Bronchopulmonary sequestration (BPS), a congenital malformation that usually presents as a chest mass in childhood, may be identified by its characteristic primary derivation of pulmonary blood supply from the systemic circulation. Five children with BPS were evaluated by radionuclide angiography from 1970 to 1974. In each instance the systemic origin of the vascular supply was correctly indicated. In those lesions where the artery originates below the hemidiaphragm, the aberrant source, when identified as such, provides a characteristic radionuclide appearance of BPS. The scimitar syndrome may be indistinguishable from BPS with this technique.     

Two cases of Swyer-James syndrome

Case 1: 55-year-old male was admitted to our hospital for further examination of increased transparency of X-ray in the left lower lung. He had history of pneumonia in his childhood. Left bronchography revealed mild cylindrical bronchi-ectasia in the proximal bronchi but poor filling by contrast in the peripheral bronchi. Case 2: 61-year-old male was referred to our hospital with palpitation and dyspnea. Chest X-ray film revealed hyperlucency of the left lower lung. The ventilation scan showed a marked decrease in ventilation to the left lung and air trapping was present in the left lung. The perfusion scan showed a matched decrease in blood supply to the left lung. In both cases, pulmonary arteriogram showed narrowed and withered-tree-like left pulmonary arteries. From these clinical findings, we diagnosed these two cases as Swyer-James syndrome. We are reporting two cases of Swyer-James syndrome and describing the clinical feature, differential diagnosis and etiology of the syndrome.     

Doppler grid surface scanning applications for pulmonary subsurface parenchymal perfusion assessment

Subsurface perfusion to lung parenchyma underlying the pleura is difficult to assess in live ventilated animals. The purpose of this study was to assess applicability of a newly developed laser Doppler grid scanning imaging technology that measures perfusion of pleural subsurface lung regions in intact normal and abnormal animal lungs. Eighty-six Doppler grid perfusion measurements were performed in five New Zealand White Rabbits (3-5 kg); four with unilateral bullous lung disease, one normal control. Left upper lobe lung surface was exposed to 10 1-sec spot Nd:YAG exposures (70 W/cm2). One week following laser exposure, all rabbits underwent sequential bilateral open thoracotomy. Unaffected left lower lobes in these animals and all four lobes of a previously untreated rabbit were used as controls. Pleural subsurface perfusion measurements were recorded over a contiguous 900-pixel square surface grid using quantitative noncontact laser Doppler imaging during open thoracotomy procedures. Scans were obtained in a normal volume ventilation mode, at 30 cm of inspiratory hold airway pressure, and postinflation. A perfusion-pressure response curve was obtained in normal lung at 10-, 20-, and 30-cm static airway pressure. Post mortem measurements were used as 0 flow controls. Normal lung tissue was found to have relatively high pleural subsurface perfusion (1362 +/- 328 corrected units on a scale of 0-4095). Areas of atelectasis had decreased perfusion (659 +/- 512 U., 48.4 +/- 12.5% compared to normal lung, p < 0.02), but returned to normal levels after inflation of the lung (1253 +/- 363 U., p = 0.21 compared to normal). Pleural subsurface perfusion decreased uniformly and progressively as lung inflation pressure increased (p < 0.0001). Perfusion increased immediately to supranormal values following release of high inspiratory inflation pressure holds (1603 +/- 626 U., 117 +/- 18% compared to normal lung, p = 0.03). Bullae had markedly decreased perfusion (541 +/- 68 U.) that was not further reduced by increased inflation pressures. Noncontact laser Doppler grid perfusion imaging appears to provide a new tool for measuring pleural subsurface perfusion over a large area of lung surface in clinical experimental settings. Results are rapid, reproducible, and consistent. Sampling errors inherent in current point sampling Doppler flow techniques are reduced by the multiple contiguous measurements. We have used this technique to demonstrate inspiratory pressure-related reduction in pleural subsurface perfusion in normal lung, reversible decreased perfusion in atelectatic regions, and reduced perfusion in bullous and laser-treated lung regions.