Handheld office-based spirometry versus laboratory spirometry in low-risk patients undergoing lung resection.

OBJECTIVE: To compare handheld office spirometry with laboratory spirometry in evaluation of low-risk patients undergoing pulmonary resection.
METHODS: Low-risk patients evaluated for lung resection were enrolled in a prospective study and underwent office and laboratory spirometry. Standard laboratory spirometry values were considered the gold standard. Values of forced expiratory volume in 1 second (FEV1) <1.5 L or FEV1% <60% were determined in advance to signal high risk.
RESULTS: Thirty patients with mean age 64 ± 12 years and median Karnofsky performance status 100 (80-100) were evaluated. The mean FEV1-office spirometry and mean FEV1-laboratory spirometry were comparable (2.14 L vs 2.36 L) as were the mean FEV1%-office spirometry and FEV1%-laboratory spirometry (78% vs 85%). The differences were within limits established a priori. Laboratory spirometry identified 3 of 30 (10%) patients as high risk and office spirometry identified 5 of 30 (16%) patients as high risk, including the 3 patients identified by laboratory spirometry. The sensitivity of office spirometry for detecting high risk was 100% (3/3) and specificity was 93% (25/27). The negative predictive value of office spirometry was 100% (25/25). Office spirometry added a median of 1 minute to the office visit, whereas laboratory spirometry added 42 minutes. Eventually, 25 of 30 (83%) patients underwent lung resection. There were 12 lobar and 13 sublobar resections. One patient developed postoperative respiratory morbidity. This patient was high risk by office spirometry but not by laboratory spirometry. This patient was discharged on home oxygen.
CONCLUSIONS: Office spirometry FEV1 and FEV1% are clinically comparable to formal laboratory spirometry values. Office Spirometry saves time and possibly expense in the preoperative workup of patients evaluated for lung resection.