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PubMed1998

[Rolled atelectasis and asbestosis. Apropos of 26 patients].

Round atelectasis (AE) is a benign form of respiratory problem which develops due to fixing of the visceral pleura. This lesion for which the principal cause is exposure to asbestos may pose problems of differential diagnosis with bronchopulmonary cancer. In a cohort of 286 patients suffering from benign asbestos related pleural disease the diagnosis of round atelectasis was made on computerized tomography in 26 patients (31 AE) on the following criteria: rounded opacities of less than 7 cm in diameter situated at the periphery of the lung in contact with a thickened pleura with an acute angle linking the pleura and the opacity, a reduction of lung volume on the side of the atelectasis and the presence of a "comet tail sign". These patients were investigated to specify the circumstances of the occurrence, including their symptomatology, the changes in lung function, the topography of the round atelectasis and the associated radiological signs. Intense exposure to asbestos either continuous or discontinuous was found in 19 patients; 20 patients presented with some respiratory symptoms (dyspnoea 15/26, cough 11/26 and chest pain 9/26) but the reduction in lung function was moderate (7 had restrictive ventilatory trouble, 4 obstructive problems and a mixed problem in 1). The preferred localisation for round atelectasis was in the inferior lobes in the posterior basal lateral vertebral area (26/31) which may explain their being frequently missed on the standard radiograph (only one case of round atelectasis was visible on the straight chest radiograph in our study). An understanding of the pathology and the computered tomographic characteristics are now well defined and should enable an unnecessary diagnostic thoracotomy to be avoided which besides has no justification from the functional point of view.

Asbestosis↗
PubMed1984

The effects of pulmonary atelectasis and reexpansion on lung cellular immune defenses.

Pulmonary atelectasis predisposes the lung to infection. This condition may be partly due to impaired cellular immune response of the collapsed lung segment. We postulated that atelectasis may affect alveolar macrophage (AM) antibacterial function. To test this hypothesis, atelectasis was induced in the right upper lobes of piglet lungs. Alveolar macrophages harvested by bronchoalveolar lavage of collapsed segments for up to 24 hours showed progressive depression of their phagocytic activity against Pseudomonas aeruginosa in vitro. However, their intracellular bactericidal activity did not change. Reexpansion of the atelectatic lobes with mechanical ventilation and 100% oxygen supplementation for four hours after six hours of atelectasis resulted in reversal of the impaired AM phagocytic activity. These observations presented insight into the mechanisms of susceptibility to lung infection in pulmonary atelectasis and the potential for its reversal.

Animals↗
PubMed1992

Rounded atelectasis: diagnosis by fine-needle aspiration cytology.

Rounded atelectasis, a rare, benign mass lesion, is most often seen in association with asbestos-related pleural changes. Often a presumptive diagnosis can be made on the basis of characteristic CT and chest radiographic findings. However, not infrequently radiographic imaging fails to differentiate rounded atelectasis from primary bronchogenic carcinoma, a disease which is seen with increased frequency in patients with asbestos exposure. We describe two cases where the diagnosis of rounded atelectasis was made by fine-needle aspiration (FNA) cytology. The cytologic features included abundant pulmonary parenchymal material with thickened alveolar walls containing pulmonary macrophages and connective tissue. It is important to realize that this is a useful positive finding indicating rounded atelectasis, rather than a negative finding suggesting the absence of neoplasm. Needles with a cutting action may be necessary to obtain sufficient material to make the diagnosis of rounded atelectasis.

Aged↗
PubMed1986

The response of atelectasis from lung cancer to radiation therapy.

Between January 1981 and June 1983, 33 newly diagnosed patients with lung cancer presented with radiological findings of atelectasis. These patients were treated by primary radiation therapy, with doses ranging from 1200 to 6000 cGy. The response of atelectasis to radiation therapy was established on the basis of follow-up chest roentgenograms. Of the 28 patients with non-small cell carcinoma of lung, there were 17 (61%) who had improvement of the atelectasis. Among these, 13 patients were treated with doses ranging from 5000 to 6000 cGy in 5 to 8 weeks; 9 of these (70%) responded. By histological subtype, the numbers, though small, show that three of eight patients with adenocarcinoma responded, as compared to 2 out of 4 with large cell undifferentiated carcinoma and 12 of 16 patients with squamous cell carcinoma. In patients treated by more than 5000 cGy, four of eight (50%) patients with squamous cell carcinoma had a complete response and three (37.5%) had a partial relief of atelectasis, for a total response of 87.5%. The study indicates the importance of radiation therapy in the management of atelectasis caused by primary lung cancer.

Adenocarcinoma↗
PubMed1979

Postextubation atelectasis: a retrospective review and a prospective controlled study.

To determine the role of chest physiotherapy in the prevention of postextubation atelectasis in neonates intubated for greater than 24 hours, a retrospective survey compared the incidence of this complication in a newborn intensive care unit prior to and following the institution of a routine of chest physiotherapy. Eight of 23 infants extubated developed atelectasis in the "pre-physio" period, whereas only one collapse occurred in 20 infants treated with a routine of physiotherapy at extubation (P less than 0.025). Subsequently a prospective controlled trial compared the use of a routine of physiotherapy at extubation with no physiotherapy. Eight of 21 infants not receiving physiotherapy developed postextubation atelectasis and none of 21 infants receiving physiotherapy developed atelectasis (P less than 0.01). Seventy-six percent of the collapses involved the right upper lobe. A vigorous program of chest physiotherapy, including postural drainage emphasizing the positions of the right upper lobe and chest vibrations, will significantly reduce the incidence of postextubation atelectasis.

Drainage↗
PubMed1995

Lobar emphysema and atelectasis syndrome, a nosological unity.

Shrinking and atelectatic pulmonary processes--atelectasis syndrome--and lobar emphysema show morphological similarities: congenital malformations of the bronchial structure, external compression of the bronchi as well as inflammatory processes. Ventilation mechanics determine whether in the described processes an atelectasis or an emphysema manifests itself clinically. Usually, one finds over-expansions in connection with atelectasis syndrome and atelectases together with lobar emphysema. Both processes can be reversible, if we are not dealing with bronchial malformations. Longer lasting processes as well as acute, life threatening forms require operation. The belief that atelectasis syndrome and lobar emphysema constitute a nosological unity is illustrated by our cases of 9 patients with atelectasis syndrome and 16 patients with lobar emphysema.

Bronchi↗
PubMed2003

Effects of recruitment maneuver on atelectasis in anesthetized children.

BACKGROUND: General anesthesia is known to promote atelectasis formation. High inspiratory pressures are required to reexpand healthy but collapsed alveoli. However, in the absence of positive end-expiratory pressure (PEEP), reexpanded alveoli collapse again. Using magnetic resonance imaging, the impact of an alveolar recruitment strategy on the amount and distribution of atelectasis was tested. METHODS: The authors prospectively randomized 24 children who met American Society of Anesthesiologists physical status I or II criteria, were aged 6 months-6 yr, and were undergoing cranial magnetic resonance imaging into three groups. After anesthesia induction, in the alveolar recruitment strategy (ARS) group, an alveolar recruitment maneuver was performed by manually ventilating the lungs with a peak airway pressure of 40 cm H2O and a PEEP of 15 cm H2O for 10 breaths. PEEP was then reduced to and kept at 5 cm H2O. The continuous positive airway pressure (CPAP) group received 5 cm H2O of continuous positive airway pressure without recruitment. The zero end-expiratory pressure (ZEEP) group received neither PEEP nor the recruitment maneuver. All patients breathed spontaneously during the procedure. After cranial magnetic resonance imaging, thoracic magnetic resonance imaging was performed. RESULTS: The atelectatic volume (median, first and third standard quartiles) detected in the ZEEP group was 1.25 (0.75-4.56) cm3 in the right lung and 4.25 (3.2-13.9) cm3 in the left lung. The CPAP group had 9.5 (3.1-23.7) cm3 of collapsed lung tissue in the right lung and 8.8 (5.3-28.5) cm3 in the left lung. Only one patient in the ARS group presented an atelectasis of less than 2 cm3. An uneven distribution of the atelectasis was observed within each lung and between the right and left lungs, with a clear predominance of the left basal paradiaphragmatic regions. CONCLUSION: Frequency of atelectasis was much less following the alveolar recruitment strategy, compared with children who did not have the maneuver performed. The mere application of 5 cm H2O of CPAP without a prior recruitment did not show the same treatment effect and showed no difference compared to the control group without PEEP.

Anesthesia, General↗
PubMed2005

Effect of carbon dioxide pneumoperitoneum on development of atelectasis during anesthesia, examined by spiral computed tomography.

BACKGROUND: Anesthesia per se results in atelectasis development in the dependent regions of the lungs. The effect of pneumoperitoneum on atelectasis formation is not known. The aim of the current study was to measure by spiral computed tomography the effect of carbon dioxide pneumoperitoneum for laparoscopic surgery on the development of atelectasis, overall lung volume, and regional tissue volumes of gas and tissue. METHODS: Seven patients (American Society of Anesthesiologists physical status I), scheduled to undergo laparoscopic cholecystectomy, were observed. After induction of anesthesia, the patients were mechanically ventilated and positioned supine on the computed tomography table. Tomography of the lungs (10 mm spiral) was performed before and 10 min after induction of carbon dioxide pneumoperitoneum at an intraabdominal pressure of 11-13 mmHg. The Student t test was used for statistical analysis. A P value less than 0.05 was considered significant. RESULTS: Induction of pneumoperitoneum increased the mean atelectasis volume in the dependent lung regions by 66% (range, 11-170%). The overall lung volume and gas as well as tissue volume significantly decreased. Relative to the total lung volume, lung tissue volume increased, while gas volume decreased significantly. Both upper and lower lobes reacted the same way. A cranial displacement of the diaphragm between 1 and 3 cm (mean, 1.9 cm) was registered. CONCLUSION: Pneumoperitoneum at an intraabdominal pressure level of 11-13 mmHg increased the volume of atelectasis. Because lung tissue volume increased in the lung, there may have been an opening of previously closed vessels, which could explain previously seen increase in arterial oxygenation after induction of pneumoperitoneum.

Adult↗
PubMed1993

Rounded atelectasis and fibrotic pleural disease: the pathologic continuum.

Although rounded atelectasis was recognized in 1928, its relationship to fibrotic pleural disease almost has gone unnoticed. We present four cases of lobar rounded atelectasis that help to clarify this relationship. Rounded atelectasis is part of the spectrum of fibrous pleural disease. Any portion of lung may become entrapped by the pleural process. When focal areas are involved rounded atelectasis results. When a larger portion of the thorax is involved with this process, lobar rounded atelectasis may occur. Very extensive disease is recognized as fibrothorax.

Adult↗
PubMed1985

Plate atelectasis.

Postmortem examination was performed in 15 patients who had plate atelectasis (PA) on their last antemortem radiograph. In 10 patients, corresponding abnormalities were found in the lungs. In all 10, there was peripheral subpleural linear collapse combined with invagination of the overlying pleura; prominent interlobular septa were observed within or bordering the linear atelectasis in nine. The atelectasis and the invaginated pleura both contributed to the linear radiographic density. The bronchi supplying the areas of PA showed no obstruction nor rearrangement. Despite a frequent association with pulmonary embolism (6/10), there was no evidence that PA directly represented thrombosed vessels or infarcts. The findings suggest that PA represents one (radiographically visible) form of peripheral atelectasis. In persisting low-volume states, the dependent subpleural lung appears to buckle and fold in. The frequent association of PA with congenital pleural clefts, indentations, scars, and incomplete fissures suggests that this process may preferentially occur at sites of pre-existing pleural invagination. PA frequently indicates more widespread peripheral atelectasis than is radiologically apparent; it also may indicate the presence of some other (more serious) abnormality in the chest or abdomen.

Aged↗
PubMed1981

Ventilation-perfusion relationships with high cardiac output in lobar atelectasis.

Pulmonary gas exchange was evaluated in 10 anesthetized mechanically ventilated dogs. Cardiac output (QT) was increased approximately 50% by opening peripheral arteriovenous fistulas. With both lungs ventilated, increasing QT increased mixed venous O2 both pressure (PO2) and pulmonary arterial pressure, but neither shunt fraction nor the distribution of ventilation-perfusion was consistently altered. During left lung atelectasis, increasing QT again increased mixed venous PO2 and pulmonary arterial pressure, but two different responses in shunt-like perfusion were measured. In four dogs, left lung atelectasis caused a shunt fraction of 46 +/- 6% that was not changed by high QT (P greater than 0.05). In six dogs, atelectasis caused a shunt fraction of 24 +/- 3% during normal QT that increased to 42 +/- 2% during high QT (P less than 0.001). Dogs whose shunt fraction during atelectasis was high and unchanged by QT had lower arterial pH (7.24 +/- 0.03) than dogs whose shunt fraction was initially lower and was increased with QT (7.36 +/- 0.02) (P less than 0.01). We conclude that increased QT can worsen shunt flow during lobar atelectasis when hypoxic vasoconstriction has been effective in limiting perfusion to the collapsed region at normal levels of QT.

Animals↗
PubMed1996

V/Q distribution and correlation to atelectasis in anesthetized paralyzed humans.

Regional ventilation and perfusion were studied in 10 anesthetized paralyzed supine patients by single-photon emission computerized tomography. Atelectasis was estimated from two transaxial computerized tomography scans. The ventilation-perfusion (V/Q) distribution was also evaluated by multiple inert gas elimination. While the patients were awake, inert gas V/Q ration was normal, and shunt did not exceed 1% in any patient. Computerized tomography showed no atelectasis. During anesthesia, shunt ranged from 0.4 to 12.2. Nine patients displayed atelectasis (0.6-7.2% of the intrathoracic area), and shunt correlated with the atelectasis (r = 0.91, P < 0.001). Shunt was located in dependent lung regions corresponding to the atelectatic area. There was considerable V/Q mismatch, with ventilation mainly of ventral lung regions and perfusion of dorsal regions. Little perfusion was seen in the most ventral parts (zone 1) of caudal (diaphragmatic) lung regions. In summary, shunt during anesthesia is due to atelectasis in dependent lung regions. The V/Q distributions differ from those shown earlier in awake subjects.

Adult↗
PubMed2005

Bronchoscopic surfactant administration in pediatric patients with persistent lobar atelectasis.

Persistent lobar atelectasis in pediatric patients on mechanical ventilation results in impaired gas exchange and lung mechanics and contributes to a further need for mechanical ventilation. The most common types of atelectasis in children are resorption atelectasis following airway obstruction, and atelectasis due to surfactant deficiency or dysfunction. We aimed to determine whether bronchoscopic suctioning and surfactant application to atelectatic lung segments would result in improved oxygenation, ventilation, chest X-ray scoring, and early extubation. Five children with heterogeneous lung diseases (aged between 7 months and 15 years) were treated with a diluted surfactant preparation (Curosurf) in a concentration of 5-10 mg/ml (total dose 120-240 mg) which was instilled into the affected segments. Outcome parameters were gas exchange, radiographic resolution of atelectasis and extubation. All mechanically ventilated patients could be extubated within 24 h following the intervention. Bronchoscopic surfactant application could be carried out without adverse effects and brought improvements in oxygenation, respiratory rate, and partial or complete resolution of atelectases without recurrence.

Adolescent↗
PubMed1995

What is the role of absorption atelectasis in the genesis of perioperative pulmonary collapse?

During anaesthesia the combination of breathing at low lung volume, the administration of nitrous oxide and high inspired oxygen concentrations produces conditions that favour absorption atelectasis. Measures such as adding nitrogen to the inspired mixture and avoiding high inspired oxygen concentrations would reduce the amount of perioperative atelectasis if gas absorption was important in the genesis of perioperative pulmonary collapse. Experimental results demonstrate that these measures do not protect against atelectasis. This indicates that absorption atelectasis does not play a significant role in the genesis of perioperative pulmonary collapse. Compression atelectasis may be the underlying mechanism.

Absorption↗
PubMed2005

DNase and atelectasis in non-cystic fibrosis pediatric patients.

INTRODUCTION: No evidence based treatment is available for atelectasis. We aimed to evaluate the clinical and radiologic changes in pediatric patients who received DNase for persistent atelectasis that could not be attributed to cardiovascular causes, and who were unresponsive to treatment with inhaled bronchodilators and physiotherapy. METHODS: All non-cystic fibrosis pediatric patients who received nebulised or endotracheally instilled DNase for atelectasis between 1998 and 2002, with and without mechanical ventilation, were analysed in a retrospective descriptive study. The endpoints were the blood pCO2, the heart rate, the respiratory rate, the FiO2 and the chest X-ray scores before and after treatment. RESULTS: In 25 of 30 patients (median [range] age, 1.6 [0.1-11] years) who met inclusion criteria, paired data of at least three endpoints were available. All clinical parameters improved significantly within 2 hours (P < 0.01), except for the heart rate (P = 0.06). Chest X-ray scores improved significantly within 24 hours after DNase treatment (P < 0.001). Individual improvement was observed in 17 patients and no clinical change was observed in five patients. Temporary deterioration (n = 3) was associated with increased airway obstruction and desaturations. No other complications were observed. CONCLUSION: After treatment with DNase for atelectasis of presumably infectious origin in non-cystic fibrosis pediatric patients, rapid clinical improvement was observed within 2 hours and radiologic improvement was documented within 24 hours in the large majority of children, and increased airway obstruction and ventilation-perfusion mismatch occurred in three children, possibly due to rapid mobilisation of mucus. DNase may be an effective treatment for infectious atelectasis in non-cystic fibrosis pediatric patients.

Administration, Inhalation↗
PubMed1985

Alterations in gas exchange associated with lobar atelectasis in young piglets.

Lobar atelectasis is common among infants and children with obstructive lung diseases. However, the effect of lobar collapse in the presence of diffuse lung disease on gas exchange in the pediatric age group has not been described. We developed an infant model of lobar atelectasis using piglets and tested the hypothesis that diffuse alveolar hypoxia increases shunt fraction (Qs/QT) associated with lobar atelectasis by redirecting pulmonary blood from the well-ventilated portion of the lung into the collapsed region. Shunt fraction was determined using the multiple inert gas elimination technique. The proportion of pulmonary blood flow perfusing the left lower lobe was measured with microspheres. Qs/QT increased significantly but by a variable amount to an average value (+/- SD) of 5.9 +/- 4.2% following lobar collapse. The percentage of cardiac output perfusing the left lower lobe fell by an average of 70 +/- 17% in response to lobar collapse. When animals were ventilated with 12% oxygen, shunt fraction increased to 18.7 +/- 7.1% and blood flow to the collapsed left lower lobe increased from 9 +/- 3 to 22 +/- 3% of cardiac output. Lobar atelectasis in conditions where diffuse alveolar hypoxia is present may be associated with a significantly greater intrapulmonary shunt than lobar atelectasis in children with otherwise normal lungs.

Animals↗
PubMed2001

Lobar atelectasis: diagnostic pitfalls on chest radiography.

This pictorial review looks at the pitfalls in the diagnosis of lobar atelectasis on chest radiographs. Lobar atelectasis with marked volume loss is hard to recognize and may be easily missed. Lobar atelectasis presenting as a mass-like opacity may be misdiagnosed as mediastinal or lung tumour. Lobar atelectasis in an unusual location may also be misdiagnosed as other entities. Familiarity with such manifestations and consideration of anatomical alterations as the signs of lobar atelectasis are important in making the correct diagnosis.

Adult↗
PubMed1993

Influence of atelectasis on pulmonary function after coronary artery bypass grafting.

The purpose of this study was to determine the influence of atelectasis on pulmonary function 6 days following coronary artery bypass grafting (CABG). After 6 days, 30 patients had normal chest radiographs, 38 had atelectasis, and 57 had pleural changes. In 11 patients, atelectasis only was observed in the radiograph, and in 27 it was in combination with pleural changes. The decrease in FVC and FEV1 in the patients with atelectasis was 33.4 and 33.5 percent in the SVG group and 34.8 and 34.3 percent in the IMA group, while in those patients with a normal radiograph, the decrements were 26.3 and 26.9 percent in SVG group and 26.1 and 26.9 percent in IMA group, respectively. Thus, patients with atelectasis on the 6th postoperative day have a larger decrement in pulmonary function post CABG than the patients with normal chest radiograph and this reduction reflects a higher degree of thoracic trauma.

Coronary Artery Bypass↗