Impact of partial pressure of arterial oxygen and radiologic findings on postoperative acute exacerbation of idiopathic interstitial pneumonia in patients with lung cancer

Abstract

Purpose: To establish accurate diagnostic criteria and predictors of treatment response for postoperative acute exacerbation (AE) in patients with lung cancer and idiopathic interstitial pneumonia (IIP).

Methods: Among 93 patients with IIP who underwent surgery for lung cancer, suspected postoperative AE developed in 20 (21.5%). Patients were divided into a progressive AE group, comprising patients with bilateral alveolar opacities and decreasing PaO₂ ≥ 10 mmHg (n = 5); an incipient AE group, comprising patients with unilateral alveolar opacities and decreasing PaO₂ ≥ 10 mmHg (n = 10); and an indeterminate AE group, comprising patients with alveolar opacities but decreasing PaO₂ < 10 mmHg (n = 5).

Results: The progressive AE group had significantly higher 90-day mortality (80%) than the incipient AE group (10%, P = 0.017) or the indeterminate AE group (0%, P = 0.048). Bilateral opacities may indicate advanced AE and poor prognosis, whereas unilateral opacities may indicate an early stage of AE and a good prognosis. PaO₂ < 10 mmHg may indicate conditions other than AE.

Conclusions: In patients with lung cancer and IIP, decreasing PaO₂ and HRCT findings may allow for the initiation of rapid and accurate treatment strategies for postoperative AE.

Keywords: Idiopathic interstitial lung disease; Lung cancer; Postoperative acute exacerbation.

Fig. 1

Schema of diagnostic and classification criteria

Fig. 2

High-resolution computed tomography (HRCT) findings at the time of suspected onset of acute exacerbation (AE) and after treatment in representative cases from each group. A Progressive AE with new consolidation and bilateral ground glass opacities on postoperative day (POD) 3 in a patient who had undergone right middle and lower lobe lobectomy (left). Although the patient complained of mild shortness of breath on exertion, the decreasing PaO₂ was 10.2 mmHg. Despite the administration of pulse corticosteroid therapy, the opacity expanded further (right). The patient died 6 days after the onset of AE. B Incipient AE with new ground glass opacities in the right lung on POD 2 in a patient on home oxygen therapy after partial resection of the left lower lobe (left). Although the only reported symptom was mild shortness of breath at rest, the decreasing PaO2 was 15.9 mmHg. The abnormal opacities resolved after one round of pulse corticosteroid therapy and the patient was discharged (right). C Indeterminate AE with new peripheral ground glass opacities on POD 9 in a patient who had undergone left lower lobectomy (left). The patient complained of mild shortness of breath on exertion, and there was no decrease in PaO₂. Pneumonia was diagnosed and the opacity resolved after antibiotic therapy (right)

Fig. 3

90-day mortality in the progressive AE, incipient AE, and indeterminate AE groups

Fig. 4

Survival curves for the progressive AE, incipient AE, and indeterminate AE groups