Changes in arterial oxygenation and self-reported oxygen use after lung volume reduction surgery

Abstract

Rationale: Lung volume reduction surgery (LVRS) is inconsistently reported to improve arterial oxygenation in patients with chronic obstructive pulmonary disease.

Objectives: We studied the effects of surgery on oxygenation in a large cohort and identified predictors of postoperative oxygenation improvement.

Methods: We evaluated oxygenation in 1,078 subjects with chronic obstructive pulmonary disease enrolled in the National Emphysema Treatment Trial after LVRS compared with medical control subjects, including arterial blood gases, use of supplemental oxygen during treadmill walking, and self-reported use of oxygen during rest, exertion, and sleep.

Measurements and main results: Pa(O(2)) breathing room air was equal in medical and surgical subjects at baseline (64.8 vs. 65.0 mm Hg, P = not significant), but lower in medical subjects at 6 months (63.6 vs. 70.0 mm Hg, P < 0.001), 12 months (63.9 vs. 68.7 mm Hg, P < 0.001), and 24 months (62.4 vs. 68.0 mm Hg, P < 0.001). Fewer medical subjects required oxygen for treadmill walking at baseline compared with surgical subjects (46 vs. 53%, P = 0.02). However, more medical subjects required oxygen for this activity at 6 months (49 vs. 33%, P < 0.001), 12 months (50 vs. 36%, P < 0.001), and 24 months (52 vs. 42%, P = 0.02). Self-reported oxygen use was greater in medical than in surgical subjects at 6, 12, and 24 months. Multivariate modeling of preoperative characteristics showed baseline oxygenation status was the best predictor of postoperative oxygenation.

Conclusions: LVRS increases Pa(O(2)), and decreases treadmill and self-reported use of oxygen for up to 24 months post-procedure. Clinical trial registered with www.clinicaltrials.gov (NCT 00000606).

Trial registration: ClinicalTrials.gov NCT00000606.

Figures

Figure 1.

(A) PaO2 values and (B) PaCO2 values while breathing room air at baseline and 6, 12, and 24 months after randomization. Error bars are 95% confidence intervals. *P < 0.0001.

Figure 2.

Percentage of patients with resting PaO2 ≤ 55 mm Hg at baseline and 6, 12, and 24 months after randomization. Dark cross-hatched bars, medical; light cross-hatched bars, surgical. *P < 0.05.

Figure 3.

Percentage of patients requiring supplemental oxygen during treadmill titration at baseline and 6, 12, and 24 months after randomization. Dark shaded bars, medical; light shaded bars, surgical. *P < 0.05.

Figure 4.

Percentage of patients self-reporting supplemental oxygen use during rest, activity, and while sleeping at baseline and 6, 12, and 24 months after randomization. Dark shaded bars, medical; light shaded bars, surgical. *P < 0.05.