SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A 6-year-old girl with an inflammatory myofibroblastic tumour of the lung is presented. The radiological features of this lesion are often atypical, as in this case, presenting as progressive atelectasis. The differential diagnosis is extensive and can be difficult, despite modern imaging techniques.
Six dogs anesthetized with 30 mg/kg pentobarbital were ventilated after differential cannulation of the main stem bronchi. Following sternotomy, blood flow was monitored by electromagnetic flow probes on the left pulmonary artery (QL) and on the pulmonary trunk or aorta (QT). Following 10 min of bilateral 100% O2, QL was 37.4 +/- 5.8% of QT. When left lung atelectasis was induced while the right lung remained on 100% O2, PaO2 remained above 75 mm Hg and QL fell to 26.1 +/- 5.0% of QT. However, when the right lung was ventilated with room air while the left lung remained atelectatic, PaO2 fell to 50.0 +/- 2.6 mm Hg and QL rose to 36.7 +/- 6.2% of QT. Six dogs which had undergone peripheral chemoreceptor denervation prior to these experiments showed a similar decrease in perfusion of the atelectatic left lung when the right lung was ventilated with 100% O2, but did not increase blood flow to the atelectatic lung during systemic hypoxemia. Thus, the increased blood flow to the atelectatic lung which occurs during systemic hypoxemia appears to be mediated by the arterial chemoreceptors.
We studied the effects of positive end expiratory pressure (PEEP) on vascular pressure flow relationships in atelectatic lobes in the closed-chest pigs and compared our results to measurements we previously obtained in sublobar atelectasis. Regional hemodynamic responses to lung inflation were significantly different between lobes and sublobar regions. PEEP caused marked increase in the fraction of cardiac output perfusing the atelectatic lobe from 16.5 +/- 2.0% (SE) to 32.5 +/- 2.0% at similar pulmonary vascular transmural pressures. In contrast, similar levels of PEEP failed to redistribute blood flow to the atelectatic sublobar regions. We propose that distortion of the sublobar region with inflation of the surrounding lung may be responsible for the failure of redistribution of pulmonary blood flow with application of PEEP.
Computed tomography (CT) of the chest is often variable in the evaluation of pulmonary masses. Our case demonstrated characteristic findings on CT that aided in the diagnosis of round atelectasis.
A case of rounded atelectasis of the lung is presented in which the diagnosis was made following computed tomography. This imaging technique enabled differentiation of this benign condition from other causes of lung masses. In certain cases where diagnosis is difficult by conventional means, CT may prove helpful and prevent unnecessary surgery.
Rounded atelectasis of the lung (RA) is a lesion well described in the medical literature, yet often very difficult to diagnose. In recent years, the widespread use of high-resolution imaging modalities employed in the struggle against cancer, coinciding with the peak of the asbestos epidemic, have boosted the detection frequency of RA. However, its differential diagnosis still poses a challenge to the pulmonary specialist and the radiologist, as little is known about its pathogenesis. Furthermore, the multifactorial etiology of RA and its occasional coexistence with lung cancer make the task of confidently ruling out malignancy sometimes daunting. This article attempts to provide an update on RA's etiology, radiological evaluation, clinical management, and prognosis based on recent advances in broadly available diagnostic modalities and minimally invasive interventional procedures. An exemplary case of post-tuberculous RA is illustrated, as RA often presents as an unusual finding of a fairly common disease.
Rounded atelectasis developed in two patients after coronary artery bypass grafting. Although both lesions led to the suspicion of a primary pulmonary tumor on initial assessment, malignancy was excluded by biopsy and radiologic observation in the first patient and excision biopsy in the second.
A pig model with aerosolized pneumococcal bacteria was used to establish that bacterial clearance in a collapsed lung in the perioperative period was decreased compared with the opposite, aerated lung. Cannulation of the right lymphatic duct revealed a significant increase in both lymph flow and ratio of lymph to plasma protein, indicating the development of a high-permeability edema in the collapsed, infected lung. Only 22% of the efferent lymph and blood was positive for the infecting organism. Examination of the T cells obtained by bronchopulmonary lavage showed an initial fall in the numbers of alveolar macrophages at 6 hours after collapse and infection, relative to the opposite, control lung. However, at 24 hours, the collapsed lung had replenished its alveolar macrophage population to such a degree that it was greater than the control. Electron microscopy revealed that the macrophages in the collapsed lung were more activated with increased lysosomal and pseudopodial activity. The in vitro chemotactic function of the macrophages appeared depressed, but phagocytosis and intracellular bactericidal activity were increased in the atelectatic lung. We conclude that there is a decreased bacterial clearance capacity in atelectasis. This finding indicates that impaired mucociliary clearance plays the dominant role in susceptibility to infection.
A patient presented with recurrent episodes of apnea and segmental pulmonary atelectasis. These episodes persisted following repair of esophageal atresia and tracheoesophageal fistula and repair of vascular ring causing tracheal compression. A tracheal diverticulum was identified and resected. The patient's symptoms disappeared following surgery.
To develop a reproducible model of atelectasis, 15 mechanically ventilated Wistar rats were wrapped around the thorax/abdomen with a sphygmomanometer. The cuff was inflated to transpulmonary pressures (PL) of -4 cmH2O (group A) and -8 cmH2O (group B) for 5 sec. Group C was not compressed. Airflow, volume, tracheal and oesophageal pressures were registered. Respiratory system (rs), lung (L), and chest wall resistive (DeltaP1), viscoelastic/inhomogeneous pressures (DeltaP2), DeltaPtot (=DeltaP1 + DeltaP2), static (Est) and dynamic (Edyn) elastances, and DeltaE (=Edyn - Est) were determined before and after compression. In A, respiratory mechanics remained unaltered. In B, Est,rs (+99%), Est,L (+111%), DeltaE,rs (+41%), DeltaE,L (+73%), DeltaP1,rs (+45%), DeltaP1,L (+44%), DeltaP2,rs (+41%), DeltaP2,L (+69%), DeltaPtot,rs (+40%), and DeltaPtot,L (+58%) increased after compression. Mean alveolar diameter and bronchiolar lumen decreased in A, and were even smaller in B. In conclusion, chest wall compression with PL of -8 cmH2O yielded a reproducible alveolar collapse, which resulted in increased elastic, resistive and viscoelastic/inhomogeneous pressures.
Variations in mortality attributed to birth injury and atelectasis in the 10 years 1958-67 have been investigated for each county borough of England and Wales. It became evident that diagnostic difficulties in separating these two causes must have been such that for statistical purposes they should be combined in a single rate.Variables likely to affect the local rates such as the sex ratio of births, and rates of illegitimacy and immaturity as an ill-defined cause of death appeared to affect the mortality levels in certain towns but not sufficiently to account for the wide variations apparent in those levels. It is concluded that local surveys are necessary in the towns with highest rates to uncover differences in numbers of births in hospital, in obstetric techniques and in quality of medical care.
To evaluate diaphragm movement, 18 consecutive patients undergoing surgery under general anaesthesia were allocated to Group 1 (n = 9: no neuromuscular paralysis) or Group 2 (n = 9: neuromuscular paralysis achieved with pancuronium). Spiral computerised tomography was performed awake and during anaesthesia at end-expiratory level and, additionally, in four patients (Group 2) at end-inspiration for subsequent analysis. There was a significant cephalad displacement of the most cephalad point of the diaphragm dome at functional residual capacity, particularly in its dependent portion, in the pancuronium group. During anaesthesia with no persisting muscle paralysis, there was only a minor and insignificant cephalad shift of the diaphragm dome. However, regional analysis showed that the most dorsal part of the diaphragm was significantly displaced cephalad. Compared with conscious, spontaneous breathing, mechanical ventilation decreased the inspiratory displacement of the dependent part of the muscle. This minor movement of the diaphragm may play an additional role in atelectasis formation.
Dysfunction of airway surfactant is suggested as an important factor contributing to the pathogenesis of bronchoconstriction of patients with asthma. We report the case of a 59-year-old female who had an infect-exacerbation of her asthma complicated by a complete collapse of the left lower lung lobe. Only the local application of 150 mg of bovine surfactant resulted in a complete reexpansion of the lobe. Local therapy with replacement of surfactant may be a promising therapeutic approach in treatment of forms of atelectasis, which depend on a dysfunction or disturbed homeostasis of surfactant.
Severe thoracic trauma is always an important risk factor for the development of acute pulmonary failure. The course is often complicated by barotrauma or volutrauma. We report on a 48-year-old patient who was transferred to us nine days after a bicycle accident because of a severe disturbance of gas exchange and atelectasis of the left lung refractory to therapy. The left lung could not be ventilated even after separate artificial ventilation on each side with positive end expiratory pressure. After administration of surfactant (50 mg Exosurf per kg body weight) and continued separate artificial ventilation on each side, there was a complete re-expansion of the left lung with an increase of the arterial pO2 value from 65 mm Hg to 416 mm Hg with a FIO2 of 1,0 and a decrease of the intrapulmonary venous admixture from 34% to 12% within a few hours. The extravascular pulmonary fluid was unaffected by the administration of surfactant (200 ml solution). The administration of surfactant preparations may be a new therapeutic approach in treatment of ARDS patients.
The rounded (helical) atelectasis is a benign alteration of the lung that can be diagnosed by radiography. Besides the criteria of the chest x-ray film and of the conventional tomogram (shadow close to the pleura, located mainly in the inferior lobe, with "comet-sign" and pleural thickening) the most important finding in computed tomography is the "octopus-sign".
a) For several reasons Sinner's paper calls for critical remarks: His term "Pleuroma" for a neither pleural nor tumorous but intrapulmonary and atelectatic mass lesion lacks any anatomical and histological basis and is misleading at that because it pretends a tumor of the pleura; his statement in the summary that atelectatic pseudotumors of the lung show a tumorcell-like cytoarchitecture is surprising without being further discussed by the author; he encourages risky invasive diagnostical procedures even in cases where the radiological diagnosis of round atelectasis is unmistakable; already known radiologic features of round atelectases are presented by him as hitherto undescribed; his conceptions of the formal development of round atelectases and of their most characteristic features can not be agreed with. b) The different forms of round atelectases and their residuals are presented with tomograms and with diagrams of their formal development from our point of view.
Total atelectasis of the left lung occurred in a 61-year-old woman after several weeks ventilator-assisted breathing following an operation for ileus, when the tracheal cannula was removed. It was quickly replaced and artificial ventilation resumed. But despite daily bronchoscopic suction for three weeks the patient's state failed to improve (vital capacity 39%, arterial pO2 47 mm Hg, pCO2 37 mm Hg). Mechanical ventilation with an "iron lung" was therefore instituted over a six month period, at first for two hours daily (as an in-patient) and then weekly (as out-patient). During this time her condition and general state clearly improved. On re-hospitalization to remove the tracheal cannula her vital capacity was 75%, pO2 78 mm Hg and pCO2 38 mm Hg.
In a prospective study, the functional and clinical effectiveness of active alveolar expansion was tested by means of an incentive spirometer on 30 patients each of a treatment and control group. All patients (average age 61 and 58 years, respectively) had undergone a transabdominal pelvic artery reconstruction. Pre-operatively active alveolar expansion significantly reduced intrapulmonary right to left shunting from 11.1% to 4.2% of cardiac output (P less than 0.01). Correspondingly, right to left shunting on the second to fifth postoperative day was reduced significantly (P less than 0.05) by 5-10% of cardiac output in the treatment group, cardiac output being significantly (P less than 0.05) reduced by 1 l/min average. Clinically and radiologically there was a definite reduction in pulmonary complications from 40% to 13%. Peri-operatively performed active alveolar expansion is thus an effective method for the reduction of postoperative functional atelectasis and pulmonary complications.