Preoperative pulmonary function in all comers for cardiac surgery predicts mortality†

Area of Science:

• Pulmonary Medicine
• Cardiovascular Surgery
• Critical Care Medicine

Background:

• Reduced lung function, including chronic obstructive pulmonary disease (COPD), is linked to increased mortality after cardiac surgery.
• Preoperative spirometry is not routinely performed, potentially leading to underestimation of surgical risk.

Purpose of the Study:

• To investigate the association between preoperative lung function and postoperative complications in all cardiac surgery patients.
• To determine if spirometry can improve risk stratification in this population.

Main Methods:

• Preoperative spirometry was conducted on elective adult cardiac surgery patients.
• Airflow obstruction was defined by forced expiratory volume in 1 second (FEV1)/forced vital capacity ratio below the lower limit of normal (LLN) and reduced FEV1 < LLN.

Main Results:

• 19% of patients reported a history of COPD, but only 56% had spirometry-verified obstruction. Conversely, 12% without a COPD history had verified obstruction.
• Patients with airflow obstruction (8.8% vs. 4.5%) and reduced FEV1 < LLN (8.7% vs. 3.7%) had significantly higher mortality.
• Independent predictors of increased mortality included age, prolonged cardiopulmonary bypass, reduced kidney function, and FEV1 < LLN.

Conclusions:

• Preoperative spirometry reclassified the risk for 18% of patients.
• A reduced FEV1 independently doubled the risk of death.
• Routine preoperative spirometry can enhance risk prediction and identify high-risk individuals for cardiac surgery.