Atelectasis nursing: causes, assessment, and interventions

Atelectasis is the collapse or incomplete expansion of lung tissue, resulting in reduced or absent gas exchange in the affected area. It is among the most common pulmonary complications nursing students will encounter — particularly in postoperative patients, where general anesthesia causes some degree of dependent-zone collapse in virtually every case. Understanding atelectasis is essential for NCLEX and for clinical practice: nurses drive the primary prevention strategy (incentive spirometry and repositioning), recognize the early signs before patients deteriorate, and escalate appropriately when conservative measures fail.

This reference covers the types and mechanisms, postoperative context, assessment findings including breath sounds and CXR patterns, nursing interventions with rationale, medical management, complications, and 10 NCLEX tips — including several counterintuitive positioning and treatment rules that consistently appear on the exam.

Pathophysiology

The alveoli are designed to remain open due to surfactant — a phospholipid produced by type II pneumocytes that lines the alveolar surface and reduces surface tension. When the balance between alveolar opening forces and collapsing forces tips toward collapse, atelectasis results.

The key mechanisms:

• Airway obstruction: When a bronchus or bronchiole is blocked, the gas distal to the obstruction continues to be absorbed by the pulmonary capillary blood. Since no new gas can enter, the alveoli progressively deflate. This is obstructive or resorptive atelectasis — the most clinically common form in adults.
• Compression: External forces — a large pleural effusion, a pneumothorax, an elevated hemidiaphragm, or a large abdominal tumor pressing upward — physically compress adjacent lung tissue. The alveoli are squeezed shut from outside.
• Surfactant loss: Surfactant dysfunction (as in ARDS or neonatal RDS) allows surface tension to overwhelm the alveolar walls, causing collapse even when airways are patent. General anesthesia also transiently impairs surfactant function, contributing to the near-universal dependent-zone collapse seen under anesthesia.

Physiological consequences of atelectasis:

When alveoli collapse, they are no longer ventilated — but the pulmonary capillaries surrounding them remain perfused. This creates an intrapulmonary shunt (perfusion without ventilation, V/Q = 0). Deoxygenated blood passes through the collapsed region without picking up oxygen and returns to the systemic circulation, lowering the PaO2. The body attempts to compensate through hypoxic pulmonary vasoconstriction (HPV) — redirecting blood flow away from poorly ventilated zones — but this mechanism is incomplete, particularly in large areas of collapse. The result is hypoxemia that responds poorly to supplemental oxygen alone, because the oxygen cannot reach the alveoli to participate in gas exchange.

Types of atelectasis: clinical detail

Obstructive (resorptive) atelectasis

This is the type nurses most commonly intervene on. The obstruction can be:

• Mucus plug — the dominant cause postoperatively and in patients with cystic fibrosis, bronchiectasis, or COPD
• Foreign body aspiration — classic in pediatric patients; right mainstem bronchus is more susceptible due to its less acute angle
• Endobronchial tumor — consider in smokers with unexplained lobar collapse
• Right mainstem intubation — endotracheal tube advanced too far collapses the left lung; verify tube position on CXR at 2–3 cm above the carina

A large obstructive collapse produces ipsilateral mediastinal shift (trachea deviates toward the collapsed lung) as negative intrathoracic pressure draws structures toward the area of reduced volume.

Compressive (relaxation) atelectasis

Unlike obstructive atelectasis, compressive atelectasis involves an open airway — the lung is being physically compressed. The most common causes:

• Pleural effusion — the fluid pushes up against the lower lung zones (see pulmonary embolism nursing for the PE-effusion relationship)
• Pneumothorax — air in the pleural space collapses adjacent lung; tension pneumothorax is immediately life-threatening
• Elevated hemidiaphragm — abdominal distension, phrenic nerve paralysis, large ascites
• Postoperative diaphragmatic dysfunction — particularly after upper abdominal and thoracic surgeries

With large effusions, the mediastinum may shift away from the effusion side (opposite to obstructive atelectasis — this distinction appears on NCLEX).

Adhesive atelectasis

Surfactant dysfunction is central to two major clinical syndromes:

• Neonatal respiratory distress syndrome (nRDS) — premature infants lack mature surfactant; treatment is exogenous surfactant and CPAP
• ARDS — surfactant is destroyed by the inflammatory cascade; widespread alveolar collapse contributes to the severe hypoxemia. See the ARDS nursing reference for full management.

Under general anesthesia, the supine position and diaphragmatic relaxation cause dependent lung zones to collapse within minutes. This adhesive-type collapse affects 85–90% of patients under general anesthesia and is the reason incentive spirometry and early ambulation are standard postoperative orders.

Cicatricial atelectasis

Chronic scarring contracts lung tissue progressively, creating fixed areas of reduced volume. Causes include pulmonary fibrosis, sequelae of tuberculosis or histoplasmosis, and post-radiation fibrosis. Unlike the other types, cicatricial atelectasis is largely irreversible — management focuses on the underlying fibrotic process and preventing further deterioration.

Risk factors and causes

Postoperative (highest volume):

• Upper abdominal surgery (gastrectomy, hepatectomy, Whipple) — highest risk; diaphragmatic dysfunction, incisional splinting
• Thoracic/cardiac surgery — direct lung manipulation, pleurotomy
• General anesthesia duration >2 hours — cumulative surfactant suppression
• Inadequate pain control — patients breathe shallowly to avoid incisional pain

Patient-related:

• Immobility / prolonged bed rest — dependent zones collapse without position changes
• Obesity — elevated intra-abdominal pressure chronically loads the diaphragm
• Smoking — impaired mucociliary clearance, excess mucus production
• Neuromuscular disease (e.g., ALS, Guillain-Barré) — inability to generate sufficient inspiratory force
• Opioid analgesics — suppress respiratory drive, reduce tidal volume
• Underlying COPD or cystic fibrosis — impaired clearance and mucus plugging

Disease-related:

• Pleural effusion, hemothorax, empyema
• Pneumothorax
• Lung cancer (endobronchial obstruction)
• ARDS — see ARDS nursing reference

Clinical presentation and assessment

Early atelectasis is often asymptomatic — this is clinically important because it means nurses must not wait for symptoms before starting preventive interventions in at-risk patients.

Symptoms (when present):

• Dyspnea — ranges from mild with exertion to severe at rest depending on extent of collapse
• Cough — often nonproductive; productive cough with fever suggests secondary pneumonia
• Chest tightness or pleuritic chest pain (with large collapse or compressive effusion)

Signs on physical examination:

• Breath sounds: Diminished or absent over the affected area. This is the most specific finding. Distinguish from pneumonia, where breath sounds are typically bronchial (loud, harsh) over the consolidation.
• Percussion: Dullness over the collapsed area (fluid or solid tissue)
• Tracheal deviation: With large lobar collapse, the trachea deviates toward the collapsed side (mediastinal shift toward the area of volume loss)
• SpO2: May be normal in small atelectasis; drops in larger collapse or when patient is at baseline with limited reserve
• Tachypnea and tachycardia: Compensatory responses to hypoxemia
• Fever: Low-grade fever in the first 24–48 hours postoperatively is classically attributed to atelectasis, though this relationship is debated in current literature. Concurrent and later fever should prompt evaluation for pneumonia or other infectious sources.

Respiratory assessment approach:

Use a systematic head-to-toe assessment to evaluate respiratory status. Compare bilateral breath sounds in each zone, note effort (accessory muscle use, nasal flaring), document SpO2 trends, and assess the patient’s ability to perform a deep breath on command. Post-surgical patients in pain often take rapid, shallow breaths — a respiratory rate of 20–24 with very low tidal volumes is more concerning than a rate of 16 with adequate depth.

Diagnostic findings

Chest X-ray (CXR)

CXR is the most commonly used initial diagnostic tool.

Characteristic findings by extent of collapse:

• Plate-like (discoid) atelectasis — linear bands of opacity, typically at the lung bases, running horizontally. This is the pattern seen in postoperative patients and those who are immobile. Often subtle and easily overlooked.
• Segmental atelectasis — wedge-shaped opacity corresponding to a bronchopulmonary segment
• Lobar atelectasis — entire lobe opacified; associated signs include elevation of the ipsilateral hemidiaphragm, deviation of the fissures, and mediastinal shift toward the affected side
• Total lung collapse — opacification of an entire hemithorax with marked ipsilateral mediastinal shift; emergency

Key CXR differentiators:

• Atelectasis: mediastinal/fissure shift toward the opacity (volume loss)
• Pneumonia: no volume loss; mediastinal shift uncommon
• Pleural effusion: blunting of costophrenic angle; fluid shifts with positioning (layering effusion vs. loculated)

CT chest

CT provides greater anatomical detail — identifies the level of obstruction, assesses for mucus plugs, endobronchial lesions, and distinguishes atelectasis from consolidation more reliably than plain film. Not required for routine postoperative atelectasis.

Arterial blood gas (ABG)

Review ABG interpretation for full context. In atelectasis:

• PaO2: reduced (hypoxemia from V/Q mismatch and shunting)
• PaCO2: often normal or slightly low initially (patients hyperventilate to compensate); may rise in severe or progressive collapse
• pH: respiratory alkalosis early (hyperventilation); respiratory acidosis if atelectasis worsens and hypoventilation occurs
• A-a gradient: elevated — this is the key ABG finding confirming a V/Q defect (not merely hypoventilation)

Pulse oximetry (SpO2)

A useful trend indicator but has limitations. SpO2 may remain normal until PaO2 falls below approximately 60 mmHg (the steep portion of the oxyhemoglobin dissociation curve). Postoperative SpO2 monitoring every 2–4 hours is standard — a downward trend is the first clue.

Nursing interventions

Nursing drives atelectasis prevention and early treatment. The interventions below are largely within nursing scope and should be initiated proactively in all high-risk patients — not only once collapse is diagnosed.

Medical management

When nursing interventions are insufficient or atelectasis is severe, medical management includes:

Bronchoscopy: The definitive intervention for mucus plug atelectasis that has not responded to suctioning, CPT, and nebulized therapy. Flexible bronchoscopy allows direct visualization, lavage, and removal of the obstructing plug. Indicated urgently for rapidly progressive lobar collapse, particularly in intubated or immunocompromised patients.

CPAP / BiPAP: Non-invasive positive pressure ventilation provides continuous positive airway pressure that splints open collapsed alveoli and prevents further collapse during expiration. BiPAP adds additional pressure support on inspiration to augment tidal volume. Both are used for postoperative hypoxemia, obesity hypoventilation, and as a bridge before intubation in deteriorating patients. See the ARDS nursing reference for the role of CPAP/PEEP in diffuse alveolar disease.

Mechanical ventilation with PEEP: For intubated patients, positive end-expiratory pressure (PEEP) maintains alveolar recruitment throughout the respiratory cycle. Recruitment maneuvers (brief periods of sustained high airway pressure) may be used to open collapsed regions before setting maintenance PEEP.

Bronchodilators (systemic/inhaled): Ipratropium and albuterol are first-line bronchodilators. Methylxanthines (aminophylline) are rarely used now but may be considered for refractory bronchospasm.

Antibiotics: Not indicated for atelectasis alone. Indicated when secondary pneumonia develops — differentiated by fever persisting beyond 48–72 hours, productive purulent cough, rising WBC, and new infiltrate on CXR that does not shift with positioning.

Treatment of the underlying compressive cause: For effusion: thoracentesis or chest tube drainage. For pneumothorax: needle decompression (tension) or chest tube. For phrenic nerve palsy: treat the underlying cause; NIV support may be required.

Postoperative atelectasis

Postoperative atelectasis deserves a dedicated section — it is the highest-volume clinical context and the one most directly driven by nursing interventions.

Why surgery causes atelectasis:

1. General anesthesia: Within minutes of induction, the combination of supine positioning, diaphragmatic paralysis (from neuromuscular blockade), and reduced chest wall compliance causes dependent lung zones to collapse. This occurs in 85–90% of patients and can persist for hours postoperatively.

2. Diaphragmatic dysfunction: Upper abdominal and thoracic surgeries cause phrenic nerve irritation and reflex inhibition of diaphragmatic movement, reducing tidal volumes for 24–72 hours postoperatively.

3. Incisional pain: Thoracic and upper abdominal incisions intersect the respiratory muscles. Pain causes patients to breathe shallowly and suppresses cough — the two behaviors that most rapidly lead to mucus plugging and collapse.

4. Retained secretions: Intubation and anesthesia dry secretions, impair mucociliary transport, and suppress cough reflex. Secretions accumulate and can form plugs that obstruct segmental bronchi.

Risk stratification:

• Highest risk: Open upper abdominal surgery (relative risk ~40%), thoracic/cardiac surgery, prolonged anesthesia (>3 hours), morbid obesity (BMI >40), pre-existing pulmonary disease (COPD, cystic fibrosis), current smokers
• Moderate risk: Lower abdominal surgery, laparoscopic procedures, duration 2–3 hours
• Lower risk: Peripheral procedures, spinal anesthesia without general anesthesia, duration <1 hour

Postoperative fever and atelectasis: Low-grade fever within the first 24–48 hours after surgery is often attributed to atelectasis — this teaching has been widely disseminated. However, current literature increasingly questions this relationship, noting that atelectasis itself does not reliably cause fever and that early postoperative fever often reflects the systemic inflammatory response to surgical trauma. The clinical implication: atelectasis should always be addressed promptly, but fever workup should not stop at “atelectasis” without considering other causes (urinary tract infection, wound infection, thrombophlebitis).

Preoperative optimization: Nurses in preoperative and surgical settings should teach IS technique before surgery, not after. Preoperative IS instruction significantly improves postoperative compliance and reduces pulmonary complications.

Atelectasis vs. pneumonia: differentiation

This comparison is one of the most frequent NCLEX traps in the respiratory category. The two conditions can coexist (atelectasis predisposes to pneumonia), but the initial nursing interventions differ substantially.

Complications

Pneumonia: Collapsed lung segments are poorly cleared, retain secretions, and provide an ideal environment for bacterial growth. Atelectasis is one of the most common precursors to hospital-acquired pneumonia. The transition from atelectasis to pneumonia is monitored through fever trend, sputum character, WBC, and CXR progression.

Hypoxemic respiratory failure: Large or rapidly progressive atelectasis can cause severe enough intrapulmonary shunting to produce respiratory failure requiring mechanical ventilation. Patients with limited reserve (COPD, heart failure, obesity) decompensate faster.

ARDS: Widespread alveolar injury from diffuse atelectasis, sepsis, or trauma can trigger the inflammatory cascade leading to ARDS. ARDS involves bilateral lung involvement, refractory hypoxemia, and diffuse alveolar damage beyond simple collapse.

Chronic atelectasis and bronchiectasis: Recurrent or prolonged atelectasis — particularly from recurrent mucus plugging in cystic fibrosis or other chronic conditions — can permanently damage the bronchial walls and lead to bronchiectasis. The airway dilation and impaired clearance of bronchiectasis then perpetuates the cycle of recurrent collapse and infection.

Sepsis: Secondary pneumonia from atelectasis that is not recognized and treated can progress to sepsis. See the sepsis nursing reference for recognition and management of systemic infection.

NCLEX tips

1. Incentive spirometry is prophylaxis and early treatment — not a treatment for established pneumonia. IS works by expanding collapsed alveoli. It has no mechanism for treating bacterial infection. If a question presents a patient with purulent sputum, fever, and a new infiltrate, the answer is not IS — it is antibiotics or notifying the provider.

2. For unilateral atelectasis, position the good lung DOWN. This is the most common positioning trap in NCLEX respiratory questions. The unintuitive answer: when one lung is atelectatic, lay the patient on the side of the healthy lung. This places the good lung in the dependent (lower) position, where pulmonary blood flow is greatest (gravity pulls perfusion downward). Blood is directed to the well-ventilated lung, improving V/Q matching and oxygenation. The atelectatic lung, now non-dependent, has reduced perfusion, limiting the shunt effect.

3. With pleural effusion, the mediastinum shifts AWAY from the effusion. With atelectasis (volume loss), the mediastinum shifts TOWARD the affected side. These opposite directions are a common multiple-choice differentiator.

4. Incentive spirometry: teach preoperatively, not only postoperatively. Preoperative teaching significantly improves postoperative compliance. NCLEX questions about preoperative teaching for surgical patients should include IS technique as a standard nursing action.

5. Postoperative fever in the first 24–48 hours — think atelectasis first, but do not anchor there. Early postoperative fever is associated with atelectasis (and the surgical inflammatory response). Later postoperative fever (days 3–5) is more likely infectious: wound infection, UTI from catheter, DVT, or pneumonia. The pneumonia mnemonic “Wind, Water, Wound, Walk, Wonder drugs” is a classic NCLEX teaching tool for postoperative fever differential by post-op day.

6. Absent breath sounds ≠ always pneumothorax. Absent breath sounds with no tracheal deviation in a postoperative patient most likely represent atelectasis. Pneumothorax is accompanied by sudden-onset pleuritic pain, tracheal deviation (tension), and often a precipitating event (central line insertion, mechanical ventilation). Always correlate with the full clinical picture.

7. General anesthesia causes near-universal dependent-zone collapse. Any question asking why IS, early ambulation, and repositioning are standard postoperative orders is testing this concept. Anesthesia-related surfactant suppression and diaphragmatic paralysis make collapse nearly inevitable — prevention is the goal, not reaction.

8. The priority nursing action for a postoperative patient with decreased breath sounds and SpO2 89% is: deep breathing / IS first, then escalate if no improvement. Before calling the provider, confirm IS has been performed, reposition the patient to optimize ventilation (semi-Fowler’s, turn), and apply supplemental oxygen. Reassess SpO2 within 15–30 minutes. If SpO2 does not improve or clinical status worsens, escalate. NCLEX expects nurses to try the least-invasive nursing intervention first.

9. Mucus plug → bronchoscopy when nursing measures fail. If IS, suctioning, CPT, repositioning, and nebulized bronchodilators have not resolved an obstructive atelectasis, the intervention is bronchoscopy — direct removal of the plug. This is a medical procedure that requires escalation, but nurses should recognize when conservative measures have been exhausted.

10. Absorption atelectasis can be caused by high-FiO2 administration. When nitrogen (which normally splints alveoli open) is washed out by breathing 100% oxygen, alveoli can collapse — this is absorption atelectasis. It is clinically relevant during high-flow preoxygenation and in intubated patients on high FiO2. The prevention is using the lowest FiO2 that achieves the SpO2 target.

Summary

Atelectasis is a preventable and reversible condition in most clinical contexts, and nursing interventions — incentive spirometry, repositioning, early ambulation, pain management, and suctioning — are the first and most effective line of management. The postoperative patient is the highest-priority target: anesthesia causes nearly universal dependent-zone collapse, and every hour of the first 24–48 postoperative hours matters.

For NCLEX preparation, the critical concepts are: IS as prevention not infection treatment, the counterintuitive positioning rule for unilateral disease, mediastinal shift direction to differentiate atelectasis from effusion, and the clinical and CXR features that distinguish atelectasis from pneumonia. Competence in recognizing early collapse and escalating appropriately when conservative measures fail is a core nursing skill in every clinical setting from PACU to the medical-surgical floor to the ICU.

For related respiratory topics, review the pneumonia nursing reference, ARDS nursing reference, pulmonary embolism nursing reference, and the ABG interpretation guide.