INDIAN PEDIATRICS VOLUME 35-MAY 1998

ATELECTASIS IN CHILDREN

T.S. Raghu Raman, Sunil Mathew, Ravikumar and P.S. Garcha

From the Departments of Pediatrics, Otorhinolaryngology and Anesthesia, Armed Forces Medical College, Punc-411 040.

Reprint requests: Wg. Cdr. T.S. Raghu Rarnan, Associate Professor, Department of Pediatrics, AFMC, Pune 411 040.

Manuscript received: July 1,1997; Initial review completed: August 27,1997; Revision accepted: November 27,1997.

Background: In children with lower respiratory tract symptoms, the elicited signs are not enough to distinguish common diagnosis like pneumonic consolidation, foreign body aspiration and . Radiology and bronchoscopy would identify the true nature of the etiology. Design: Prospective study. Subjects: Thirty five children with both acute and chronic lower respiratory tract symptomatology, were analyzed for clinical and radiological signs of atelectasis. Results: There were 23 cases in the acute group and 12 in chronic group. Acute group included cases of pneumonia, foreign body aspiration and mucus plug syndrome. Chronic group included cases of congenital heart disease, endobronchial tuberculosis and bronchial stenosis. Clinical recognition of atelectasis on the basis of localized loss of breath sounds and mediastinal shift was seen only in a minority of cases (8/35). The presence of atelectasis in children with pneumonia, missed clinically were diagnosed by the presence of tracheal shift, elevated hemidiaphragm and silhouette sign. In 21 cases, silhouette sign was positive making it an important radiological sign. Twenty one children underwent either diagnostic or/and therapeutic bronchoscopy. Findings included foreign bodies (n = 5), mucus plugs (n = 4), narrowing of main (n = 4) and inflammatory mucoid secretions and narrowing of lumen (n = 8). There were no major complications. Conclusion: The diagnosis of atelectasis in children may pose difficulties and there is a need to have a high index of suspicion to exclude atelectasis in children with either acute or chronic respiratory tract symptomatology.

Key words: Atelectasis, Bronchoscopy, Radiology.

A TELECTASIS is a collapsed and air- less developed, the functional significance of peripheral gas exchange region of the the collapsed , and the etiology lung. It is an abnormal condition associated responsible for its presence. Airway size with a variety of pulmonary disorders and constraints and physiologic considerations represents a manifestation of underlying have placed restrictions on the technique pulmonary pathology rather than a disease employed to derive information about the entity per se. Clinical identification of airways of pediatric patients. This presen- atelectasis in children remains difficult in tation highlights the clinical profile and view of non specific symptomatology. endoscopic experience in children with Hence many a time the presence of atelectasis at our center. atelectasis is missed. The clinician who Subjects and Methods identifies atelectasis in a child must deter- mine the mechanisms by which atelectasis This prospective study was based on

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children admitted with symptoms sugges- subjected to the procedure. The findings so tive of lower respiratory disorders. The pe- recorded were correlated with clinical find- riod of the study was from January 1991 to ings. All cases of atelectasis did not require May 1997. A detailed history in every child bronchoscopy. The selection of cases for including the onset of illness, symptoms bronchoscopy was determined by the need like sudden onset of dyspnea, choking epi- for diagnostic or therapeutic purpose. For sodes, fever, cough and retractions of chest endoscopic examination and intervention was recorded. Children with chronic symp- we utilized Karl Storz rigid ventilating toms of recurrent bouts of fever and cough bronchoscope with fibreoptic distal light- were also profiled in detail. In addition to ing, size 3, 4 and 5. The sizes represent detailed general examination, an effort was inner diameter of the bronchoscope in mm. made in each child to identify and locate General anesthesia was used in all cases. the region of atelectasis. An effort to classify Induction of anesthesia was done by in- the etiology of atelectasis clinically was also halation of oxygen and halothane or either included. Laboratory investigations through mask. After achieving a suitable included complete blood counts, blood cul- plane of anesthesia the rigid bronchoscope tures, radiological assessment, ultrasono- was passed beyond the glottis. Subsequent graphy (USG) chest, bronchoscopy and cul- maintenance of anesthesia was by inhala- ture studies of secretions from the airways. tional anesthesia given through the side Other investigations were done on specific arm (anesthetics channel) of the broncho- indications. Atelectasis was diagnosed scope. Bronchoscopic lavage was done in on clinical and radiological criteria. The those cases where mucopurulent secretions radiological signs looked for included were seen. The material was aspirated and opacification, shift of mediastinum, dis- sent for culture studies. Other treatment placement of interlobar fissure, elevated modalities included antibiotics, chest phys- diaphragm, shifting of interlobar fissure iotherapy, humidification and hydration. and silhouette sign. Silhouette sign refers to Follow up of those children who were on the finding that the borders of contiguous long term therapy, i.e., cases of tuber- structures of similar radiodensity are ob- culosis, congenital heart disease and scured by one another. Applying this con- bronchiectasis was done in the Outpatient cept to a disease process that produces a Clinic. water density when it is in contact with Results structures of similar density such as the heart, aortic arch, and superior surface of During the study period, a total of thirty the diaphragm, silhouette sign is present five children presented with features of when the contiguous borders of these struc- atelectasis. There were nineteen males and tures are lost. This sign is used most fre- sixteen females. For clinical simplicity, quently for localization of disease to the cases with duration of illness less than right middle lobe and lingula, in which the three weeks were classified as acute (Group right and left borders, respectively are ob- A) and cases with duration of illness longer scured. If disease is localized in the basilar than three weeks as chronic (Group B). The segments of the lower lobes, the adjacent distribution of cases in the two groups and diaphragmatic surfaces are obliterated. the mean age were: Group A- n = 23; age range : 6 months to 5 years; mean age : 3.5 Those requiring bronchoscopy either for years and Group - B n = 12; age range : 2 to diagnostic or therapeutic purposes were 8 years; mean age : 5.5 years. The historical

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INDIAN PEDIATRICS VOLUME 35-MAY 1998 and clinical data is reflected in Table I. A presented with acute respiratory distress, few important observations drawn from fever, cough and non specific clinical signs the data are: (a) Cough and fever were uni- (opacification, elevation of hemidiaphragm versally present; (b) History of choking epi- and silhoute sign in all; air bronchogram in sode and foreign body aspiration was elic- 2; emphysema in 1) which were non con- ited only in 5 (20%) and 9 (38%) cases in tributory in confirming the diagnosis. In Group A, respectively; (c) Clinical recogni- Group B there were a total of 12 children tion of atelectasis on the basis of localized with atelectasis. The three cardiac cases loss of breath sounds and mediastinal shift were congenital acyanotic heart disease was seen only in a minority of cases (8/35); with ventricular septal defect in two and (d) Universally all children with atelectasis patent ductus arteriosus in the third with presented with cough, fever, retractions, pulmonary hypertension. All three cases crepitations and rhonchi. The radiological presented with recurrent pneumonia and findings in the present study are high- atelectasis of left lower lobe. The eight lighted in Table II. The presence of cases of tuberculosis presented with recur- atelectasis in children with pneumonia, rent episodes of lower respiratory tract missed clinically was diagnosed by the infection, failure to thrive, chronic cough, presence of tracheal shift, elevated hemi- and signs of collapse consolidation clini- diaphragm and silhouette sign. Children cally. In addition to radiological findings with mucus plug syndrome (four cases) of atelectasis, hilar and paratracheal adenopathy was also seen. Bronchoscopy with rigid bronchoscope was done in 21 cases with atelectasis. In addition to re- moval of foreign bodies and mucus plug, bronchial lavage and culture studies were done. On bronchoscopy in Group A, the five foreign bodies removed were bits of groundnuts, custard apple seed, multiple stones (twice bronchoscopied) and an uni- dentified foreign body. Four children had presence of mucus plug obstructing the left main bronchus.

In Group B, three cases of congenital heart disease had narrowing of left main bronchus with visible pulsation, six chil- dren with chronic respiratory symptoms had narrowing of right middle bronchus with mucoid to muco - purulent secretions, two had similar findings on left main bron- chus and one case had extreme narrowing of the left main bronchus. Culture results of the secretions removed during broncho- scopy were not of significant value except in three cases in whom acid fast bacilli (AFB) was isolated. No major complica-

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tions were noted with the bronchoscopy and radiological resolution during immedi- procedures. One patient had delayed ate postoperative period; (Hi) Out of the recovery from anesthesia (ether). Patients three cases of congenital acyanotic heart given ether had excessive salivation, nau- disease, one child died of infective endo- sea and vomiting for 6 to 12 hours. They carditis, other two due to want of surgical are controlled with metoclopramide. The 8 correction continued to have persistent cases of endobronchial tuberculosis were atelectasis of the left lower lobe; (iv) the confirmed on the basis of narrowing of case of congenital bronchial stenosis is lumen and presence of mucoid secretions, awaiting specific therapy; and (v) Out of positive AFB (3 cases), positive Mantoux the eight cases of endobronchial tuberculo- test (3/8) and BCG diagnostic test (5/8). sis, resolution was seen only in four cases USG chest was useful in identifying mini- despite adequate antitubercular treatment mal synpneumonic not with steroids. The other four during follow apparent in routine X-ray chest PA view in up developed signs of bronchiectasis, i.e., both Group A (pneumonia) and Group B persistent and localized crepitations and (tuberculosis). Complete blood count and radiological signs localized to lower lobe culture studies were not of significant help segments. Bronchography was not done in in establishing the etiology. any of them. All four are on regular physio- The final outcome of cases were: (i) therapy and follow up. Atelectasis associated with pneumonia was Discussion transient and complete resolution was seen in all 14 cases within three weeks on follow Atelectasis occurs in three ways: (a) in- up X-rays; (ii) Cases with mucus plugs and creased surface tesion in small airways and foreign bodies showed dramatic clinical alveoli; (b) compression of pulmonary

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parenchyma by intrathoracic chest wall, only clinical means of accurately docu- and extrathoracic processes; and (c) obs- menting the presence, extent, and distri- truction of airways. Diseases producing bution of atelectasis. The most direct and airway obstruction account for most of the reliable sign is the displacement of an atelectasis encountered in children. Pro- interlobar fissure. Other signs of volume cesses that produce obstruction involve the loss, such as elevation of hemidiaphragm airway lumen directly, the airway wall, or and mediastinal shift, are maximal nearest the tissue surrounding the airway. The inci- to point of volume loss and accompanied dence of atelectasis accompanying several by an increase in focal density(3). How- respiratory disorders in childhood is re- ever, in the present study, shifting of ported to range as: meconium aspiration 40 interlobar fissure could be demonstrated to 55%, post extubation collapse in infants - only in 4/35 cases. 35%, bronchopulmonary dysplasia - 46 to In the lower lobes and middle lobe 50%, bronchiolitis -12 to 24%, pneumonia - collapse, silhouetting of diaphragm and left 23 to 25%, asthma - 4 to 19%, foreign body and right cardiac border was an important aspiration - 10 to 20% and tuberculosis - sign in recognizing volume loss apart from 8%(1). the presence of elevated hemidiapgragm and density increase (31/35). The impor- History and clinical examination are in- tant contributing sign was elevation of sensitive means of detecting the presence of hemidiaphragm (26/35) in atelectasis of atelectasis. The clinical manifestations of lower lobes. Crowding of ribs and media- atelectasis depend on the underlying cause stinal shift was seen in chronic cases and as well as the degree of volume loss within wherein more than one lobe was involved. the lung. When the atelectasis is relatively Generally the distribution of atelectasis small and associated with little physiologi- does not help identify a specific underlying cal impairment, there may be no signs or etiology in an individual patient. However, symptoms. The most specific sign on physi- observations from some studies indicate cal examination is a localized loss of breath that atelectasis in the right lung occurs in sounds. When unilateral atelectasis is mas- more than 70% children with asthma, cystic sive, tracheal deviation and shift of heart fibrosis, and tuberculosis. In contrast, the sounds towards the atelectic side may left lower lobe is the most common location occur. However, the majority of children for atelectasis associated with acute upper with atelectasis will present with cough, or lower respiratory tract infection(4). Our tachypnea, rales, rhonchi, a history of chest observations were similar. When all causes pain, or fever and less often dyspnea or for obstruction of the airway are consid- cyanosis. Further, atelectasis that occurs ered, the right lower and left lower lobes during the course of tuberculosis, asthma, are most frequently collapsed. Further dif- or infections such as bronchiolitis, bronchi- ferentiation based on bronchial anatomical tis, and pneumonia produces no change in considerations is possible by the fact that clinical picture unless the obstructed area is mucus plugs cause more often left lower large(2). In the present study also, children lobe collapse and foreign bodies more often in Group A with acute atelectasis due to right lower lobe collapse(5). In the present pneumonia, foreign body aspiration and study, there were five children with foreign mucus plugs, did not clinically demon- body aspiration and atelectasis of right strate specific signs of atelectasis. lower lobe and four with atelectasis of left In contrast, the chest radiograph is the lower lobe as a result of mucus plugs. Right

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middle lobe atelectasis is relatively com- studies(10-13). Our study has reinforced mon in children and has been the source of the point that correct diagnosis of airway considerable interest in the literature. It is obstruction in infants and young children is most vulnerable when there is enlargement limited by the mimicking nature of symp- of hilar lymph node and is often referred toms and signs and difficult to demonstrate to as right middle lobe syndrome and radiological signs. Equally important is the usual causes are tuberculosis and early recognition of atelectasis, determin- asthma(6,7). Out of nine cases with middle ing the etiology and instituting appropriate lobe atelectasis, six were due to tuberculo- therapy to ensure a better prognosis. sis presenting with chronic recurrent pneu- REFERENCES monia and hilar and parateracheal lymph nodes in the present study. Pneumonic con- 1. Redding GJ. Atelectasis in childhood. solidation and atelectasis is frequently Pediatr Clin North Am 1984; 31: 891-905. associated with loss of volume. The subtle 2. Hazinski TA. Atelectasis. In: Disorders of signs of elevated hemidiaphragm, fissure the Respiratory Tract in Children, 5th position and silhouette sign are important edn. Ed. Cherniv V. Philadelphia, W.B. to recognize in this setting(l). However, Saunders Company, 1990; pp 509-516. atelectasis of pulmonary segments occurs 3. Proto AV, Tocino I. Radiographic mani- less often because collapse is prevented by festations of lobar collapse. Semin collateral air drift(8). CT scan and high Roentgenol 1980; 15:117-173. resolution computerized tomography 4. Gillies LD, Reed MH, Simons FER. Radio- (HRCT) are other modes of identifying graphic findings in acute childhood structural lesions of parenchyma of lung. asthma. J Assoc Can Radiol 1978; 29: 28- HRCT is a valuable method of studying the 33. lung parenchyma which combines very 5. Holinger LD. Foreign bodies of the lar thin slices with mathematical filtering of ynx, and bronchi. In: Pediatric the computer data to produce increased Otolaryngology, 2nd edn. Ed. Philadel- edge definition in the final image. HRCT phia, W.B. Saunders Company, 1990; pp images closely resemble macroscopic 1206-1214. appearances of pathological specimens of 6. Livingston GL, Holinger LD, Luck SR. inflated lung and this has led to attempts to Right middle lobe syndrome in children. describe HRCT patterns of disease in ana- Int J Pediatr Otorhinolaryngol 1987; 13: tomical terms rather than the sometimes 11-23. vague terminology used for the description 7. Miller FJW. Intrathoracic tuberculosis and of diffuse shadowing on chest radiography. miliary spread. In: Tuberculosis in Chil- There is no doubt that the fine morphologi- dren, 1st edn. Edinburgh, Churchill cal detail available from HRCT images is Livingstone, 1982; p 105-136. responsible for the increased confidence 8. Miller TW. Radiographic evaluation of with which specific histopathological diag- the chest. In: Pulmonary Diseases and nosis can be made(9). Disorders 2nd end. Ed. Fishman AP. New The experience of bronchoscopy in this York, Mcgraw - Hill, 1988; pp 479-528. study has been very rewarding both as a 9. Sostman HD, Matthay RA. Chest imag- diagnostic tool and has a therapeutic value. ing. In: Chest Medicine; 3rd edn. Eds. The beneficial aspect of an early and if re- George RB, Light RW, Matthay MA, quired repeated bronchoscopic examina- Matthay RA. Philadelphia, Williams and tion has been well illustrated by many Wilkins, 1995; pp 110-131.

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10. Casasnovas BA, Martinez EE, Sanchez 12. Wong KS, Lin TY, Lan RS. Evaluation of BR, Perez RE, Gancedo CR, Cives VR. Pe- chronic atelectasis in children using chest diatric fibre bronchoscopy. Ann Esp computed tomography and flexible Pediatr 1993; 39: 313-316. bronchoscopy. Acta Pediatr - Sin 1996; 37: 193-196. 11. Ledesma - Albarran JM, Perez - Ruiz E, Fernandex V, Martinez GB. Endoscopic 13. Burton EM, Brick WG, Hall JD, Riggs W, evaluation of endobronchial tuberculosis Houston CS. Tracheobronchial foreign in children. Arch Broncopneumol 1996; body aspiration in children. South Med J 32:183-186. 1996; 82:195-198.

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