What are the most common postoperative complications?

Most Common Postoperative Complications

The most common postoperative complications include pulmonary complications (atelectasis, pneumonia, respiratory failure), cardiovascular complications, surgical site infections, postoperative atrial fibrillation, acute kidney injury, gastrointestinal complications, and delirium. These complications significantly contribute to postoperative morbidity, mortality, and increased length of hospital stay 1, 2.

Pulmonary Complications

Pulmonary complications are among the most prevalent and serious postoperative issues:

• Atelectasis: Most common early pulmonary complication
• Pneumonia: Peaks at 4-7 days postoperatively 3
• Respiratory failure: Highest incidence 1-3 days after surgery 3
• Exacerbation of underlying lung disease

Risk factors for pulmonary complications include:

• Chronic obstructive pulmonary disease
• Age >60 years
• ASA class II or greater
• Functional dependence
• Congestive heart failure
• Prolonged surgery (>3 hours)
• Abdominal, thoracic, neurosurgery, head and neck, or vascular surgery
• Emergency surgery
• General anesthesia 1

Cardiovascular Complications

Cardiovascular complications occur frequently and significantly impact mortality:

• Atrial fibrillation: Particularly common after cardiac surgery, with symptoms including palpitations, chest pain, fatigue, and shortness of breath 1
• Hypotension: Highest risk within first 24 hours (43%) 3
• Myocardial infarction: Most common within first 24 hours (47%) 3
• Congestive heart failure: Peaks at 1-3 days postoperatively (46%) 3
• Arrhythmias: Occur throughout the postoperative period 3

Patients with postoperative atrial fibrillation have a nearly 3.5-fold higher risk for perioperative stroke 1.

Infectious Complications

• Surgical site infections: Common and potentially serious
• Sepsis: Predominantly occurs 8-30 days after surgery (71%) 3
• Pneumonia: As noted above, peaks at 4-7 days postoperatively

Renal Complications

• Acute kidney injury: Shows a bimodal distribution with peaks at 1-3 days (31%) and 8-30 days (56%) 3
• Predicts increased mortality in emergency laparotomy patients 1

Gastrointestinal Complications

• Nausea and vomiting
• Ileus
• Gastrointestinal bleeding: Risk remains similar throughout all postoperative intervals 3

Neurological Complications

• Delirium: Common, especially in elderly patients 2
• Cerebrovascular accidents: Occur predominantly 8-30 days after surgery (53%) 3

Thromboembolic Complications

• Pulmonary embolism: Highest incidence at 1-3 days postoperatively (50%) 3
• Deep vein thrombosis

Temporal Patterns of Complications

Understanding when specific complications typically occur can aid in early detection and management:

• Within 24 hours: Hypotension, myocardial infarction, respiratory depression
• 1-3 days: Congestive heart failure, pulmonary embolism, respiratory failure
• 4-7 days: Pneumonia
• 8-30 days: Cerebrovascular accidents, sepsis 3

Prevention and Early Detection

Early detection of complications is crucial for preventing "failure to rescue" scenarios:

• Track and trigger systems: Early warning scores can predict complications up to 3 days before clinical diagnosis 1
• Regular monitoring: Particularly important on day 3 when complication rates peak 1
• Preventive measures: Deep breathing exercises or incentive spirometry for patients at high risk of pulmonary complications 1

High-Risk Patients

Certain patients require heightened vigilance:

• Elderly patients (≥75 years) have higher failure-to-rescue rates, especially after pulmonary or infectious complications 1
• Patients with low serum albumin (<35 g/L) are at increased risk for pulmonary complications 1
• Frail patients have higher complication rates and mortality 1

Clinical Implications

The highest incidence of major complications occurs 1-3 days after surgery, but vigilance must be maintained throughout the postoperative period, as complications like sepsis and cerebrovascular accidents tend to occur later (8-30 days) 3. Mortality from complications can be reduced through early detection systems, appropriate staffing ratios, and rapid response teams that include intensivists experienced in managing postoperative surgical patients 1.