Basics
Description
- State of collapsed and airless alveoli
- May be subsegmental, segmental, or lobar or may involve the entire lung
- A radiographic sign of an underlying disease and not a diagnosis unto itself
Epidemiology
- Depends on the underlying disease causing atelectasis
- Resorption atelectasis is the most common form.
Risk Factors
Genetics
Depends on the underlying disease causing atelectasis (i.e., cystic fibrosis, primary ciliary dyskinesia)
General Prevention
- Maintaining adequate cough
- Good airway clearance techniques in patients at risk for atelectasis
Pathophysiology
- Reduced lung compliance
- Loss of alveoli (if extensive) may lead to hypoxia.
- Intrapulmonary shunting develops from hypoxia-induced pulmonary arterial vasoconstriction, which may lead to areas of ventilation-perfusion (V/Q) mismatch and further hypoxia.
- If atelectasis is extensive and long-term, pulmonary hypertension may develop.
- Atelectatic areas are prone to bacterial overgrowth and possible secondary infection.
Etiology
- Airway obstruction (resorption atelectasis)
- Most common cause of atelectasis in children
- Obstructed communication between alveoli and trachea
- Large airway obstruction
- Intrinsic
- Foreign body aspiration
- Mucous plug
- Tumor
- Plastic bronchitis
- Extrinsic
- Hilar adenopathy
- Mediastinal mass
- Congenital lung malformations
- Small airway obstruction
- Acute infection
- Bronchiolitis
- Pneumonia
- Respiratory infections are the most common cause of acute atelectasis
- Altered mucociliary clearance:
- CNS depression
- Smoke inhalation
- Pain
- Mechanical compression of the pulmonary parenchyma or pleural space (compressive atelectasis)
- Intrathoracic compression
- Pneumothorax
- Pleural effusion
- Lobar emphysema
- Intrathoracic tumors
- Cardiomegaly
- Diaphragmatic hernias
- Abdominal distention
- Large intra-abdominal tumors
- Hepatosplenomegaly
- Massive ascites
- Morbid obesity
- Decreased surface tension in the small airways and alveoli (adhesive atelectasis)
- Stems from surfactant deficiency
- Diffuse surfactant deficiency
- Hyaline membrane disease
- Acute respiratory distress syndrome
- Smoke inhalation
- Localized surfactant deficiency
- Acute radiation pneumonitis
- Pulmonary embolism
- Neuromuscular weakness (hypoventilation)
- Inherent weakness
- Duchenne muscular dystrophy
- Spinal muscular atrophy
- Paralysis
- Acquired weakness (e.g., postanesthesia hypoventilation)
Diagnosis
History
- Depends on the underlying disease process
- May be asymptomatic
- Cough and/or wheeze can be present.
- Dyspnea
- Chest pain
- Special questions:
- Is the atelectasis acute, recurrent, or chronic in terms of its duration?
- Is there a history of asthma, chronic lung disease, or exposure to smoke or toxic fumes that would increase the risk for atelectasis?
Physical Exam
- May be normal
- Tachypnea
- Rales or rhonchi
- The most specific sign is localized decrease or loss of breath sounds.
- Dullness to percussion if large area involved
- Tracheal deviation and shift of heart sounds toward atelectatic side
- Localized wheezes in cases of partial obstruction
- Cyanosis (seen when extensive atelectasis is present, causing impairment of oxygenation and areas of ventilation/perfusion mismatch)
Diagnostic Tests & Interpretation
Lab
Appropriate test depends on the underlying etiology:
- Asthma
- Spirometry
- Sweat test (if cystic fibrosis suspected)
- Infection
- Cultures (sputum, blood, bronchoalveolar lavage fluid)
- Nasal washing (especially for viruses)
- PPD (when tuberculosis is suspected)
- Foreign body aspiration
- Bronchoscopy (to remove the obstructing agent. Rigid bronchoscopy is indicated if the obstructing agent is a foreign body; flexible: can be used for mucous plugs, plastic bronchitis, or infectious etiology)
- Immunodeficiency
- CBC with differential
- Immunoglobulins (IgG, IgA, IgM)
- HIV testing
- Congenital malformations
- CT scan of the chest (for lung malformation)
- Bronchoscopy (for H-type tracheoesophageal fistula [TEF] or bronchial stenosis)
Imaging
- Chest radiograph
- Most important diagnostic tool
- Radiographic signs of atelectasis:
- Loss of lung volume from the affected lobe
- Compensatory hyperexpansion of the remaining lobes on the affected side
- Shift of interlobar fissures
- Elevation of diaphragm
- Mediastinal shift toward the affected side
- Approximation of ribs on the affected side
- CT of chest
- Confluence of bronchi and blood vessels converge toward the affected side.
- Provides information regarding precise location and extent of any obstructing process
Differential Diagnosis
- Pneumonia
- Viral pneumonia versus subsegmental atelectasis
- Bacterial pneumonia versus segmental or lobar atelectasis
- Thymus (may often be mistaken for atelectasis in an upper lobe)
- Congenital malformations (e.g., sequestration, bronchogenic cyst)
- Pleural effusion
- Asthma (acute exacerbation or poorly controlled)
Treatment
General Measures
- Treat underlying disease (i.e., removal of aspirated foreign body, clearance of mucous plugs, treatment of any underlying infection)
- Chest physical therapy with bronchodilators (usually for at least 1 month)
- If no improvement with conservative therapy, a bronchoscopy with lavage to remove possible mucous plug is indicated (lavage may be with saline or, in select cases, with recombinant human DNase, N-acetylcysteine, or hypertonic saline).
- Consider surgery to remove the affected region:
- Chronic or recurrent atelectasis
- Unresponsive to therapy
- Focal bronchiectasis has developed.
- Significant morbidity is seen.
- Prevention of recurrent or future atelectasis: directed toward underlying cause, when applicable
- Airway clearance is important in clearing areas of atelectasis.
- Various techniques are available including the following:
- Manuel chest physiotherapy
- Mechanical chest physiotherapy (ThAIRapy vest)
- Incentive spirometry
- Acapella or Flutter devices
- Intermittent positive pressure breathing (IPPB) or intrapulmonary percussive ventilator (IPV)
- Mechanical insufflator-exsufflator (Cough Assist):
- For patients with weakened cough (i.e., neuromuscular weakness)
Ongoing Care
Follow-up Recommendations
Patient Monitoring
Expect improvement: 1-3 months in typical, uncomplicated cases
Prognosis
- Depends on the underlying disease process
- In otherwise healthy individuals: excellent
Complications
- Recurrent infections
- Bronchiectasis
- Hemoptysis
- Abscess formation
- Fibrosis of the pulmonary parenchyma
Additional Reading
- Altunhan H, Annag ¼r A, Pekcan S, et al. Comparing the efficacy of nebulizer recombinant human DNase and hypertonic saline as monotherapy and combined treatment in the treatment of persistent atelectasis in mechanically ventilated newborns. Pediatr Int. 2011;54(1):131-136.
- Birnkrant DJ, Pope JF, Eiben RM. Management of the respiratory complications of neuromuscular diseases in the pediatric intensive care unit. J Child Neurol. 1999;14(3):139-143. [View Abstract]
- Hough JL, Flenady V, Johnston L, et al. Chest physiotherapy for reducing respiratory morbidity in infants requiring ventilator support. Cochrane Database Syst Rev. 2008;(3):CD006445. [View Abstract]
- McCool FD, Rosen MJ. Nonpharmacologic airway clearance therapies: ACCP evidence-based clinical practical guidelines. Chest. 2006;129(1)(Suppl):250S-259S. [View Abstract]
- Oermann CM, Moore RH. Foolers: things that look like pneumonia in children. Semin Respir Infect. 1996;11(3):204-213. [View Abstract]
- Redding GJ. Atelectasis in childhood. Pediatr Clin North Am. 1984;31(4):891-905. [View Abstract]
- Riethmueller J, Kumpf M, Borth-Bruhns T, et al. Clinical and in vitro effect of dornase alfa in mechanically ventilated pediatric non-cystic fibrosis patients with atelectasis. Cell Physiol Biochem. 2009;23(1-3):205-210. [View Abstract]
- Slattery DM, Waltz DA, Denham B, et al. Bronchoscopically administered recombinant human DNase for lobar atelectasis in cystic fibrosis. Pediatr Pulmonol. 2001;31(5):383-388. [View Abstract]
Codes
ICD09
- 518.0 Pulmonary collapse
- 770.5 Other and unspecified atelectasis
- 770.4 Primary atelectasis
- 769 Respiratory distress syndrome in newborn
ICD10
- J98.11 Atelectasis
- P28.10 Unspecified atelectasis of newborn
- P28.0 Primary atelectasis of newborn
- P28.19 Other atelectasis of newborn
- P22.0 Respiratory distress syndrome of newborn
SNOMED
- 46621007 Atelectasis (disorder)
- 54959009 perinatal atelectasis (disorder)
- 42908004 Primary atelectasis, in perinatal period (disorder)
- 59113005 Perinatal secondary atelectasis (disorder)
- 702438005 Surfactant dysfunction (disorder)
FAQ
- Q: What should be considered if atelectasis is recurrent in nature but in different segments?
- A: Asthma should always be considered if atelectasis is recurrent and in varying segments.
- Q: When is the optimal time for bronchoscopy?
- A: There are no established criteria for when a bronchoscopy should be performed. A bronchoscopy should be done early in the course of illness when:
- There is a high suspicion of a foreign body
- Significant respiratory distress is present
- Cases of acute chest syndrome in patients with sickle cell disease
- The atelectasis is extensive and conservative treatment is ineffective
- Bronchoscopy is infrequently performed in patients with cystic fibrosis secondary to its recurrent nature.