Performance of new spirometry reference values in preoperative assessment of lung function

Area of Science:

• Pulmonology
• Preoperative Assessment
• Spirometry

Background:

• Pulmonary function is often unassessed preoperatively in asymptomatic patients, including smokers.
• Current spirometric reference values may not accurately reflect lung health in all patient groups.

Purpose of the Study:

• To evaluate the impact of new Global Lung Initiative (GLI) spirometric reference values on preoperative lung function assessment.
• To compare GLI z-scores with older predicted values in allegedly healthy individuals.

Main Methods:

• Spirometry was performed on 219 non-smokers, past smokers, and current smokers before surgery.
• Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratios were analyzed using GLI z-scores.
• FEV1 was used to grade airway obstruction, comparing new and old reference values.

Main Results:

• GLI z-scores identified a higher proportion of asymptomatic smokers with reduced lung function compared to old values (24% vs. 14%).
• In smokers over 60, airway obstruction was detected in 50% using GLI z-scores versus 30% with old values.
• Old FEV1 values underestimated airway obstruction, particularly in middle-aged smokers.

Conclusions:

• Allegedly healthy current smokers exhibit a greater prevalence of reduced preoperative lung function when assessed with GLI z-scores.
• The GLI guidelines appear more sensitive in detecting lung function abnormalities, especially in elderly smokers.