How is atelectasis prevented and managed in post-operative patients?

Prevention and Management of Postoperative Atelectasis

Postoperative multimodal physiotherapy combining early mobilization, breathing exercises, and coughing techniques is strongly recommended to prevent and manage atelectasis in post-operative patients. 1

Causes of Postoperative Atelectasis

• Atelectasis occurs due to alveolar instability from surface tension and regional differences in alveolar size, leading to lung collapse 2
• Surgery, anesthesia, and postoperative pain have deleterious effects on the respiratory system, causing hypoxemia, decreased lung volume, and atelectasis due to diaphragm dysfunction 1
• Diaphragm dysfunction may persist for up to 7 days after surgery, leading to significant deterioration in arterial oxygenation 1
• Risk factors include low lung volume, high closing volume, oxygen therapy, rapid shallow breathing, chronic lung disease, smoking, obesity, postoperative pain, narcotic-induced ventilatory depression, and mechanical impairment of respiratory function 2

Prevention Strategies

Intraoperative Measures

• Apply protective ventilation during surgery with tidal volumes of 6 mL/kg, PEEP, and alveolar recruitment maneuvers 1
• Avoid zero end-expiratory pressure (ZEEP) during induction and emergence from anesthesia 1
• Maintain head elevation at 30 degrees during emergence 1
• Avoid routine suctioning of the tracheal tube before extubation as it reduces lung volume 1
• If clinically appropriate, use FiO₂ <0.4 during emergence to reduce atelectasis formation 1
• Prevent coughing and bucking on the tracheal tube during emergence 1

Immediate Postoperative Measures

• Position patients in a head-elevated, semi-seated position to prevent further development of atelectasis and improve oxygenation 1
• Remove chest tubes, urinary catheters, and arterial/venous catheters as early as possible to facilitate early mobilization 1
• Provide adequate pain control to enable effective breathing exercises and coughing 1
• Consider regional analgesia techniques to reduce opioid requirements and their respiratory depressant effects 1

Management Approaches

Multimodal Physiotherapy

• Implement a postoperative multimodal physiotherapy program combining at least three components 1:

  1. Early mobilization and walking
  2. Breathing exercises
  3. Bronchial drainage and coughing techniques

• Start physiotherapy interventions as early as the first postoperative day 1

• Provide pain management education as part of this management 1

Respiratory Support

• Consider CPAP or non-invasive positive pressure ventilation (NIPPV) for patients with postoperative desaturation (SpO₂ <90%) despite supplemental oxygen 1
• Continue CPAP/BiPAP treatment in patients who were using these modalities before surgery 1
• Use CPAP with caution in patients with hypoxemia, as it may increase the duration and time to detection of apnea/hypopnea 1

Additional Interventions

• Consider incentive spirometry on a case-by-case basis, but do not use it as the sole intervention 1
• Vibratory expiratory pressure techniques may be considered as an adjunct but should not be used alone 1
• For patients with relapsing atelectasis or swallowing disorders, consider bronchoscopy to remove mucous plugs 3

Special Considerations

• High-risk patients (COPD GOLD 3, patients >75 years) may benefit from preoperative prehabilitation programs 1
• Obese patients are at higher risk for perioperative atelectasis that persists longer compared to normal-weight patients 1
• Patients undergoing upper abdominal or thoracic surgery are at increased risk due to diaphragmatic dysfunction 1

Evidence of Effectiveness

• Postoperative rehabilitation interventions that include breathing exercises significantly decrease the incidence of atelectasis (OR = 0.35; 95% CI, 0.18 to 0.67) 4
• These interventions improve lung function by increasing forced vital capacity, forced expiratory volume in one second, and FEV1/FVC ratio 4
• CPAP of 10 cm H₂O after thoracoabdominal surgery reduces postoperative pulmonary complications and decreases ICU and hospital stay 1

By implementing these evidence-based strategies, healthcare providers can effectively prevent and manage postoperative atelectasis, thereby reducing associated morbidity and improving patient outcomes.