What is Postoperative Pulmonary Complication (POPC)?
Postoperative pulmonary complications (POPCs) are unexpected respiratory disorders occurring within 30 days after surgery that affect the patient's clinical status and require therapeutic intervention, with the most important and morbid complications being atelectasis, pneumonia, respiratory failure, and exacerbation of underlying chronic lung disease. 1
Clinical Significance and Impact
POPCs are as prevalent as cardiac complications and contribute equally to morbidity, mortality, and length of stay. 1 The clinical impact is substantial:
- Even mild POPCs are associated with increased early postoperative mortality, ICU admission, and prolonged hospital/ICU length of stay 2
- Pulmonary complications may be more likely than cardiac complications to predict long-term mortality after surgery, particularly among older patients 1
- The incidence in high-risk surgical populations (ASA class 3) is approximately 33.4%, with the most common complications being prolonged oxygen therapy requirement (19.6%) and atelectasis (17.1%) 2
Major Patient-Related Risk Factors
The American College of Physicians identifies these significant risk factors requiring pre- and postoperative interventions: 1
- Chronic obstructive pulmonary disease (most commonly identified risk factor; OR 1.79,95% CI 1.44-2.22) 1
- Age >60 years (second most common risk factor; OR 2.09 for ages 60-69, OR 3.04 for ages 70-79) 1
- ASA class II or greater (OR 4.87 when comparing ASA ≥II vs <II) 1
- Functional dependence (OR 2.51 for total dependence, OR 1.65 for partial dependence) 1
- Congestive heart failure (OR 2.93) 1
- Low serum albumin <35 g/L (one of the most powerful predictors) 1, 3
- Current smoking (OR 1.26) 1
Important: Obesity and mild-to-moderate asthma are NOT significant risk factors for POPCs. 1
High-Risk Surgical Procedures
Patients undergoing these procedures require evaluation for concomitant risk factors and pre/postoperative interventions: 1
- Prolonged surgery (>3 hours; OR 2.14) 1, 3, 2
- Abdominal surgery 1
- Thoracic surgery 1
- Neurosurgery 1
- Head and neck surgery 1
- Vascular surgery 1
- Aortic aneurysm repair 1
- Emergency surgery (OR 4.47) 1, 2
- General anesthesia 1
Prevention Strategies
Preoperative Risk Assessment
Measure serum albumin in all patients clinically suspected of hypoalbuminemia or those with ≥1 risk factor for POPCs. 1
Do NOT routinely use preoperative spirometry or chest radiography for risk prediction. 1 However, pulmonary function testing or chest radiography may be appropriate in patients with previously diagnosed COPD or asthma 1, and abnormal chest radiograph is independently associated with PPC development (OR 8.26) 3.
Preoperative Interventions for High-Risk Patients
The European Respiratory Society recommends inspiratory muscle training as part of multimodal prehabilitation to decrease POPCs, particularly for patients with COPD undergoing high-risk procedures like aortic aneurysm repair 4.
Postoperative Interventions (MANDATORY for High-Risk Patients)
All high-risk patients MUST receive: 1
- Deep breathing exercises or incentive spirometry (hourly while awake, 30 deep breaths per hour) 1, 5
- Selective use of nasogastric tube (only for postoperative nausea/vomiting, inability to tolerate oral intake, or symptomatic abdominal distention—NOT routine placement) 1, 5
Additional effective interventions include: 5
- Early mobilization (begin as soon as medically indicated, progressing from bed mobility to ambulation) 5
- Supported coughing with incision splinting 5
- Neuraxial blockade when appropriate (reduces pneumonia risk; OR 0.61) 5
Interventions That Should NOT Be Used
Do NOT use these solely for reducing POPC risk: 1
- Right-heart catheterization 1
- Total parenteral or enteral nutrition for malnourished patients or those with low albumin 1
Common Pitfalls to Avoid
- Relying on incentive spirometry alone without deep breathing exercises and mobilization—no single technique outperforms others, and multimodal approach is essential 5
- Routine nasogastric tube placement increases pulmonary complications 5
- Inadequate pain control prevents effective deep breathing 5
- Delaying mobilization 5
- Using preoperative spirometry for individual risk prediction (does not translate to effective risk assessment) 5
- Ignoring mild PPCs (even mild complications like atelectasis and prolonged oxygen requirement deserve intervention as they increase mortality and length of stay) 2
Potentially Modifiable Risk Factors
Target these factors preoperatively to reduce POPC risk: 6