In a 60-year-old man with GOLD stage III chronic obstructive pulmonary disease undergoing a 90‑minute sternotomy for mediastinal mass excision, which ARISCAT risk factor—surgical incision site (thoracic), age, surgery duration, or anemia—carries the greatest risk for postoperative pulmonary complications?

Surgical Incision Site Confers the Greatest Risk

In this patient undergoing sternotomy for mediastinal mass excision, the surgical incision site (thoracic surgery) carries the greatest risk for postoperative pulmonary complications according to the ARISCAT scoring system and established evidence.

Risk Factor Analysis Using ARISCAT Components

The ARISCAT score assigns different point values to various risk factors. Based on the American College of Physicians guidelines and the structure of validated risk prediction tools, here's how this patient's factors compare:

Surgical Incision Site: Highest Risk

• Thoracic surgery (sternotomy) is consistently identified as one of the highest-risk surgical sites for postoperative pulmonary complications 1
• The ACP guidelines explicitly list thoracic surgery among procedures requiring heightened vigilance and pre/postoperative interventions 1
• Thoracic procedures carry inherently elevated risk due to direct chest wall manipulation, altered respiratory mechanics, and pain-related splinting

Age (60 years): Moderate Risk

• While age >60 years is a significant risk factor (OR 2.09 for ages 60-69), this patient is at the lower end of this risk category 1
• The risk escalates more substantially at age 70-79 (OR 3.04) 1

Surgery Duration (90 minutes): Minimal Risk

• Prolonged surgery is defined as >3 hours in the ACP guidelines 1
• At 90 minutes, this procedure falls well below the threshold for increased risk from duration alone
• The pooled odds ratio for prolonged surgery (3-4 hours) is 2.14, which doesn't apply here 1

Anemia (Hemoglobin 11 g/dL): Variable Risk

• While anemia can contribute to postoperative complications, the ACP guidelines do not identify anemia as a primary independent risk factor for pulmonary complications specifically 1
• Low serum albumin (<35 g/L) is emphasized as a more powerful marker than hemoglobin alone 1
• The patient's mild anemia is less impactful than the surgical site in ARISCAT scoring

Clinical Context and COPD Consideration

This patient's GOLD stage III COPD is already a major risk factor (OR 1.79), making him inherently high-risk 1. The COPD was identified as the most commonly recognized risk factor in multivariable analyses 1. However, among the four factors specifically asked about, the thoracic surgical approach dominates the risk profile.

Practical Implications

This patient requires aggressive perioperative pulmonary risk reduction strategies:

• Mandatory interventions include deep breathing exercises or incentive spirometry postoperatively 1
• Consider preoperative pulmonary function testing given his COPD diagnosis 1
• Optimize pain control to prevent splinting and atelectasis
• Early mobilization protocols
• Selective nasogastric tube use only if clinically indicated 1

Common Pitfall to Avoid

Don't be misled by the relatively short surgical duration or the patient's age being "only" 60 years. The combination of thoracic surgery via sternotomy in a patient with severe COPD creates substantial cumulative risk 2, 3. The surgical site alone would place him in an intermediate-to-high ARISCAT risk category, and the underlying lung disease amplifies this further.

The evidence consistently demonstrates that procedure-related factors (particularly surgical site) are as important as patient-related factors in determining pulmonary complication risk 1. In this specific case, the thoracic approach through sternotomy represents the single greatest modifiable and quantifiable risk element among the four options presented.