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PubMed1990

Treatment of atelectasis of upper lung lobes. Selective bronchial suctioning with J-shaped catheter tip and guide mark.

We developed a technique for blind bronchial suction using a curved-tip catheter with a guide mark, for the treatment of atelectasis of the lower and middle lobes of the lung. Suction of the upper lobe bronchi could not be performed because of the combination of the peculiar anatomy of the upper lobe bronchi with catheter design. We treated successfully two cases of atelectasis of the right upper lobes using a Rusch Metras bronchography catheter with a guide mark which is not readily available. Therefore we devised a J-shape tipped catheter with a guide mark. We have successfully treated 13 episodes of atelectasis of the right upper lobe in 10 patients and one episode in the left upper lobe in one patient with this new catheter.

Bronchi↗

PubMed1997

Bilobar atelectasis after difficult tracheal intubation.

Acute intra-operative collapse of a lobe without apparent cause is rare. We report a case of transient bilobar atelectasis that developed without any apparent cause after a difficult tracheal intubation in a healthy young patient. Intrabronchial obstruction was ruled out by bronchoscopy. The bilobar atelectasis developed acutely and resolved quickly with mechanical ventilation. The characteristics of the lung collapse were atypical, suggesting either its reflex nature or acute reduction of lung volume owing to intubation-induced coughing. We present a review of the mechanisms of atelectasis.

Acute Disease↗

PubMed1987

Constitutional factors promoting development of atelectasis during anaesthesia.

The extent of atelectasis was correlated to constitutional factors in 38 patients who underwent computed tomography prior to and during general anaesthesia with halothane. All patients but two developed atelectasis in dependent regions of both lungs immediately after induction of anaesthesia prior to surgery. The transverse area of the densities ranged from 0 to 27 cm2, and there were no significant differences between patients of different age or sex, or with different smoking habits. A significant linear regression was found between Broca's index weight (kg)/height (cm)-100 and the area of the densities, and also between an index describing the shape of the thorax and the density area. Thus, patients who were overweight and/or had a low and wide thorax tended to develop more extensive atelectasis during anaesthesia. This finding might partly explain why overweight patients develop postoperative pulmonary complications more often than non-obese patients.

Adult↗

PubMed1988

Minitracheotomy in the treatment of postoperative sputum retention and atelectasis.

Minitracheotomy (MT) is a new method for the treatment of sputum retention and atelectasis. Through a 1-cm incision in the cricothyroid membrane (coniotomy), a specially designed tube is placed in the trachea, allowing suction to be performed. Fifteen patients, aged 37-78 years (median 62 years), with postoperative sputum retention, atelectasis and imminent respiratory failure, were treated with suction by MT. Thirteen of the patients recovered from their respiratory problems, while two patients had to be treated with intermittent positive pressure ventilation (IPPV). During insertion, one case of external bleeding and one case of subcutaneous and mediastinal emphysema were seen, while no complications were seen during cannulation. The duration of cannulation was 4-38 days (median 10 days). Following decannulation the incisions were airtight within 1 day and healed within 3 days. Ten patients left hospital in good health and five died because of surgical complications and/or cardiovascular failure. MT seems to be effective in the treatment of sputum retention and atelectasis. Advantages over other invasive methods make it a method of first choice. The method involves few complications and is often so effective that avoidance of intubation and IPPV is possible.

Adult↗

PubMed1990

The influence of body position and differential ventilation on lung dimensions and atelectasis formation in anaesthetized man.

The effects of body position and anaesthesia with mechanical ventilation on thoracic dimensions and atelectasis formation were studied by means of computerized tomography in 14 patients. Induction of anaesthesia in the supine position reduced the cross-sectional area for both lungs and caused atelectasis formation in dependent lung regions in 4/5 patients. Conventional ventilation with positive end-expiratory pressure (PEEP) increased thoracic dimensions and reduced, but did not eliminate, the atelectatic areas. The vertical diameters of both lungs were smaller in the lateral position as compared to the supine position (16.7 vs 10.4 cm in the left lung and 17.3 vs 12.8 cm in the right lung). The lateral positioning also caused a large reduction of the atelectatic area in the non-dependent lung. Differential ventilation with selective PEEP to the dependent lung eliminated (3/8 patients) or reduced (5/8 patients) dependent lung atelectasis. It can be concluded that lung geometry is altered in the lateral position: the shape of the lung makes the vertical diameter of each lung less in the lateral position, compared to the supine position. The atelectatic areas are mainly located in the dependent lung in the lateral position, and these atelectatic areas could be further reduced by selective PEEP to this lung.

Adult↗

PubMed1995

Reexpansion of atelectasis during general anaesthesia may have a prolonged effect.

Pulmonary atelectasis, as found during general anaesthesia, may be reexpanded by hyper-inflation of the lungs. The purpose of this study was to determine whether such a recruitment is maintained and whether this is accompanied by an improved gas exchange. We studied a consecutive sample of twelve lung healthy adults, scheduled for elective surgery. After induction of intravenous anaesthesia, the lungs were hyperinflated manually. The ventilationperfusion relationship (VA/Q) was estimated with the multiple inert gas method, and in six patients atelectasis was assessed by computed x-ray tomography. The mean pulmonary shunt was 7.5% of cardiac output after induction of anaesthesia and this decreased to 1.0% and 2.8% at 20 and 40 min after the recruitment manoeuvre. Perfusion of poorly ventilated lung regions (low VA/Q), however, increased from 3.7% to 10.6% and 7.8% at 20 and 40 min after the recruitment, respectively. The mean alveolar-arterial oxygen tension difference (PA-aO2) was 14.3 kPa after induction of anaesthesia and 11.1 kPa immediately after recruitment. Forty minutes later PA-aO2 was still 2.0 kPa lower than after induction of anaesthesia (95% confidence interval [CI] 0.3 to 3.8 kPa). PA-aO2 decreased more in obese patients. The mean area of atelectasis decreased from 9.0 cm2 after induction of anaesthesia to 0.1 cm2 immediately after recruitment, and there was a slow increase to 1.9 cm2 (95% CI 0.0 to 3.9 cm2) 40 min later. During general anaesthesia in lung healthy patients, most of the reexpanded atelectatic lung tissue remains inflated for at least 40 min. The recruitment manoeuvre decreases pulmonary shunt, but increases low VA/Q. The net effect on gas exchange is a small reduction of PA-aO2.

Adult↗

PubMed2005

Pulmonary abnormalities after cardiac surgery are better explained by atelectasis than by increased permeability oedema.

BACKGROUND: Cardiac surgery can be complicated by pulmonary abnormalities, but it is unclear how various manifestations interrelate. METHODS: A prospective study in the intensive care unit was performed on 26 mechanically ventilated patients without cardiac failure within 3 h after elective cardiac surgery involving cardiopulmonary bypass. Oedema (extravascular lung water, EVLW) was measured by the thermal-dye technique and permeability by a dual radionuclide technique, yielding a pulmonary leak index (PLI). Radiographic, mechanical and gas exchange features were used to calculate the lung injury score (LIS), ranging between 0 and 4. Evidence for left lower lobe atelectasis was obtained from plain radiographs. The plasma colloid osmotic pressure (COP) was measured by an oncometer. RESULTS: The EVLW (normal, <7 ml/kg) was elevated in 36% of patients and the PLI (normal, <14.1 x 10(-3)/min) in 44%, but the variables did not interrelate directly. Patients with a supranormal EVLW had a lower COP than patients with normal EVLW. The duration of mechanical ventilation was prolonged in patients (20%) with EVLW > 10 ml/kg. There was no difference in EVLW and PLI in patients with LIS < 1 and LIS > 1 (31% of patients). In patients with radiographic evidence for atelectasis (46%), the positive end-expiratory pressure and inspiratory O2 fraction to maintain oxygenation were higher than in those without. CONCLUSIONS: After cardiac surgery, mild pulmonary oedema is relatively common, even in the absence of high filling pressures, and is mainly attributable to a low COP, irrespective of increased permeability in about one-half of patients. It may prolong mechanical ventilation at EVLW > 10 ml/kg. However, pulmonary radiographic and ventilatory abnormalities may result, at least in part, from atelectasis rather than increased permeability oedema.

Adult↗

PubMed1985

Exogenous particles in lymph nodes in patients with shrinking pleuritis with atelectasis.

Shrinking pleuritis with atelectasis is a disease in which a compression atelectasis of the lung is caused by shrinking of the inflamed visceral pleura. This reaction has been attributed to asbestos. By means of scanning electron microscopy, with computerised x ray spectrophotometry and x ray diffraction analysis, tissue samples from the lymph nodes of patients with the disease and control subjects were examined for other particles of possible aetiological importance. The results would suggest, however, that asbestos is the most important factor in the aetiology of shrinking pleuritis with atelectasis.

Asbestos↗

PubMed1990

Atelectasis affects the rate of arterial desaturation during obstructive apnea.

Chronic hemodynamic disturbances are more profound in patients with obstructive sleep apnea when underlying lung disease with abnormal gas exchange (low arterial PO2) is present. Previous studies suggest that pulmonary gas exchange could influence the rate of fall of arterial oxygen saturation (dSaO2/dt) in obstructive sleep apnea. We postulated that abnormal gas exchange in the form of atelectasis would steepen dSaO2/dt and thereby lower nadir arterial oxyhemoglobin saturation (SaO2) for the same duration of apnea. Apneas were created by clamping an indwelling cuffed endotracheal tube at end expiration in eight spontaneously breathing adult baboons. Apneas of the same duration were then repeated during temporary endobronchial occlusion of one lobe of the lung. SaO2 and mixed venous O2 saturation were continuously monitored, and cardiac output was calculated. Worsening of pulmonary gas exchange during atelectasis was documented by an increase in calculated venous admixture from 10.5 +/- 0.8 to 25.0 +/- 0.7% (P less than 0.001). The dSaO2/dt was independent of apnea duration at 30, 45, and 60 s. During endobronchial occlusion, apnea dSaO2/dt increased 20%, and nadir SaO2 was significantly lower. Possible mechanisms for steepening of dSaO2/dt during atelectasis are discussed.

Animals↗

PubMed1991

Effect of atelectasis and surface tension on pulmonary vascular compliance.

The effects of atelectasis and surface tension on the vascular volume and compliance in an isolated perfused dog lung lobe were studied using vascular occlusion and indicator-dilution methods. Measurements were made during atelectasis and again after the lobes were inflated with either a gas mixture (air) or 0.9% saline. Inflation with air resulted in a 20% increase in vascular volume (P less than 0.02), whereas saline inflation had no effect on vascular volume. Inflation with either air or saline increased static vascular compliance by approximately 58% (P less than 0.001) and dynamic vascular compliance by approximately 85% (P less than 0.001). The larger dynamic compliance in the inflated lobes appears to have been mainly due to a larger microvascular compliance. The results suggest that atelectasis can result in a stiffer pulmonary capillary bed. This effect appears to be due primarily to the reconfiguration of the lung tissue structure, because replacing the air with an incompressible fluid did not have the same effect.

Animals↗

PubMed1984

Round atelectasis.

Round atelectasis is a little-known form of peripheral pulmonary collapse which may mimic a neoplastic tumor. Usually the atelectasis forms a well-demarcated round or oval intrapulmonary pleural-based mass at the basal, posterior or interlobar pleura. It is thought to be a sequela of a pleural effusion. If the radiographic features are characteristic, and fine-needle biopsy finding negative, the diagnosis of round atelectasis can be made with assurance, and unnecessary procedures such as thoracotomy and pulmonary resection can be avoided. In this paper experiences of 11 patients with this condition are presented. In 4 the diagnosis was established by surgery and in 7 a long-term follow-up confirmed the diagnosis of a nonmalignant intrapulmonary lesion. The pathogenesis, clinical and radiological features, and the diagnostic workup are discussed.

Adult↗

PubMed1975

Stress, deformation, and atelectasis of the lung.

The lung parenchyma as a tissue has a rather unusual stress-strain relationship. A theoretical derivation of this relationship is presented which connects the surface tension and the tissue elastic stress in the alveolar septa with the alveolar geometry. The mathematical expression contains a few meaningful physical constants which can be determined by in vitro and in vivo experiments. With this stress-strain relationship, the general equations of lung mechanics are formulated, and solutions to some simpler problems are presented. First, the equilibrium of a lung subjected to a uniform inflation pressure (definition: alveolar air pressure - intrapleural pressure - pleural tension X mean curvature of pleura) is analyzed, and the stability of the equilibrium states with respect to small perturbations is examined. Second, an exact solution for a lung in a chest under the influence of gravity is presented; the solution is "exact," of course, for only a particular lung, but it can serve as a standard to check numerical procedures being developed in many laboratories. Finally, three types of possible atelectasis-planar, axial, and focal-are analyzed. The planar type can exist in a normally inflated lung, provided the layers of alveoli are forced to collapse toward a plane by some external agent. But axial atelectasis (alveoli collapse into a cylinder) can occur only if the dimension (at which the elastic tension in the alveolar septa vanishes). Similarly, focal atelectasis can occur only if the entire lung is smaller than the resting volume.

Elasticity↗

PubMed1978

Treatment and prognosis of lobar and segmental atelectasis in cystic fibrosis.

Lobar atelectasis occurred in 30 (4.1 per cent) and segmental atelectasis occurred in 6 (0.8 per cent) of 728 patients with cystic fibrosis. The right lung was involved in all 11 patients less than 5 years of age and in 18 of 26 episodes in 19 older patients. Five of the younger patients died within 5 years of the initial episode. Bronchoscopy (with or without local lavage) performed in addition to intensified medical therapy did not appear to improve the outcome. Future studies of therapeutic measures (including bronchoscopy) for treatment of atelectasis complicating cystic fibrosis must include appropriate control patients who receive only medical therapy.

Adolescent↗

PubMed1985

Distribution of pulmonary blood flow in relation to atelectasis in premature ventilated lambs.

To investigate the ability of the preterm, ventilated lung to redirect blood flow away from atelectatic regions, we studied lambs with respiratory distress syndrome and spontaneous atelectasis or atelectasis caused by bronchial obstruction with a balloon catheter. Pulmonary blood flow distributions were measured by quantifying 15-mu, microsphere-associated radioactivity within multiple pieces of lung. Lambs with well aerated or very atelectatic lungs had relatively uniform blood flow/gram lung in all pieces of lung. Blood flow was much less uniform in lungs with both aerated and atelectatic regions. In 9 lambs with spontaneous atelectasis that included 25 +/- 5% (mean +/- SE) of the lungs by weight, blood flow was 29 +/- 4% less to atelectatic than to aerated lung volumes (p less than 0.01). In 5 lambs with well-aerated lungs, 18 +/- 3% of the lung by weight was made atelectatic by balloon occlusion of a major lower lobe bronchus. There was a 44 +/- 11% decrease in blood flow to the atelectatic lung segments. These studies document the ability of the lung of the premature, ventilated lamb to shunt pulmonary blood flow away from atelectatic lung volumes.

Animals↗

PubMed1985

Pediatric flexible bronchoscopy and its application in infantile atelectasis.

Forty-six pediatric flexible fiberoptic bronchoscopies were done on 29 infants under 1 year of age, including a 2.3-kg 1-week-old infant girl, and 17 small children between 1 and 2 years of age with persistent unilobar or multilobar atelectasis and declining PaO2 or rising PaCO2. Atelectasis resolved in all 29 infants (100%) and 10 of 17 (59%) small children after direct visualization, bronchial washing, and removal of mucous plugs and/or secretions using a flexible fiberoptic bronchoscope (FFB). The procedure was not associated with any mortality or significant morbidity. Only one infant experienced minor epistaxis and another had transient minimal stridor. None of the 17 small children developed complications. The procedure resulted in resolution of respiratory distress and cough within 24 hours, as well as early hospital discharge in all patients regardless of complete or partial radiographic expansion. Arterial blood gases were improved or normalized in 16 patients. When utilized for selective aspiration of mucous plugs or bronchial secretions, pediatric flexible bronchoscopy is particularly helpful in children with segmental or lobar atelectasis.

Bronchoscopy↗

PubMed1998

The effect of intraoperative ventilation strategies on perioperative atelectasis.

Several methods of ventilation have previously been shown to reduce intraoperative atelectasis and alveolar to arterial oxygen gradient (A-a DO2) in healthy patients. This study was designed to show firstly the relative intra-operative benefit and secondly if any method had an effect on atelectasis postoperatively. Using a factorial design we randomized 24 patients to each of the four ventilatory interventions (manual inflations, large tidal volumes, PEEP, and pressure control inverse ratio ventilation (IRV)). The A-a DO2 was used as the measure of atelectasis and data collected intra- and postoperatively for 24 hours. The mean pre-induction A-a DO2 was 80 mmHg. This study demonstrated that PEEP and IRV were most effective in reducing intraoperative A-a DO2 (P < 0.05 ANCOVA). Using more than one intervention did not improve the A-a DO2. No method had any effect on postoperative A-a DO2.

Aged↗

PubMed1985

National survey of the usage of lung expansion modalities for the prevention and treatment of postoperative atelectasis following abdominal and thoracic surgery.

A national survey of hospitals was conducted to evaluate the usage of lung expansion maneuvers in the prevention and management of postoperative atelectasis associated with abdominal and thoracic surgery. Equal numbers of hospitals were randomly selected from the nine American Hospital Association regions and from bed-size groups of 50 to 200 beds, 201 to 400 beds, and greater than 400 beds. Preoperative and postoperative prophylactic therapy was found to be similar in all groups except for a lower usage of intermittent positive-pressure breathing (IPPB) in the western third of the United States compared with the central third. In the treatment of postoperative atelectasis there are significant differences in the use of chest physical therapy, IPPB, and intermittent continuous positive airway pressure based on hospital size. Objective measurements of tidal volume or inspiratory capacity as a guide to therapeutic decisions are performed more frequently in the western regions. Surgical statistics relative to the number of abdominal and surgical procedures done and the incidence of postoperative atelectasis are also presented.

Abdomen↗

PubMed1985

Etiology and prevention of topical cardiac hypothermia-induced phrenic nerve injury and left lower lobe atelectasis during cardiac surgery.

Left hemidiaphragm elevation is frequently noted following cardiac surgery employing topical hypothermia. We speculate that contact of the left phrenic nerve with ice causes nerve injury, resulting in left hemidiaphragm paresis or paralysis and left lower lobe atelectasis. Left diaphragm elevation was noted on postoperative chest x-ray examination of 36 of 60 (60 percent) consecutive patients in whom topical cooling of the heart with a cold slush solution was administered prior to use of a cardiac insulation pad (CIP, Shiley Laboratories, Irvine, California). Following the use of the CIP in a similar group of 60 consecutive patients, only five (8 percent) showed evidence of diaphragmatic elevation. The difference in the incidence of diaphragmatic elevation between these two groups is statistically significant (p less than 0.001). A comparison of postoperative left lower lobe atelectasis prior to the use of the CIP was also statistically significant (p less than 0.001). There was no significant difference in the aortic cross-clamp time or the volume of intraaortic cardioplegia used in these two groups. The use of topical cardiac hypothermia has been shown to protect the myocardium. Phrenic nerve injury secondary to the use of ice in this method has been documented. The use of a cold solution without ice chips or slush, or the insertion of a CIP prior to the use of topical cardiac hypothermia (when ice chips or slush are used) decreases the exposure of the phrenic nerve to cold injury and decreases the incidence of paresis of the left diaphragm and resultant atelectasis.

Cardiac Surgical Procedures↗