The pathways underlying chronic obstructive pulmonary disease exacerbations (ECOPD) remain unclear. This study describes the clinical, functional and biochemical changes during recovery from ECOPD.

Thirty hospitalized patients with Anthonisen's type-I ECOPD were evaluated on days 0 (admission), 3, 10 and 40. A five-symptom score (TSS), performance status and quality of life were evaluated. Post-bronchodilator spirometry, blood gases, oxidative stress, C-reactive protein (CRP), serum amyloid-A (SAA), tumor necrosis factor-⍺ (TNF-⍺), interleukin-6 (IL-6) and fibrinogen were also measured. Patients were classified as early- or late-recoverers, based on whether dyspnea had returned to pre-exacerbation level by day 10.

Most clinical, functional and biochemical parameters improved during follow-up. CRP and IL-6 levels reduced on Day 3 (p<0.05), whereas SAA on Day 10 (p<0.01). TNF-⍺ was reduced on Days 3 and 10, but on Day 40 its levels returned to baseline. Fibrinogen and WBC reduced only by day 40. TSS and dyspnea were correlated inversely with FEV₁ on days 3, 10 and 40. Although late-recoverers had lower FEV₁ on admission, none of the reported measurements on admission and day 3 predicted early recovery.

During recovery from ECOPD, symptomatic improvement correlates only with post-bronchodilator FEV₁ whereas systemic inflammatory burden subsidence does not correlate with clinical and functional changes. Although late-recoverers have lower FEV₁ on admission, none of the measured parameters is able to predict early symptomatic recovery.