The effect of continuous renal replacement therapy on the outcome of severe pneumonia in patients receiving long-term immunosuppressants

Abstract

To investigate the effect of continuous renal replacement therapy (CRRT) on the outcome of severe pneumonia in patients receiving long-term immunosuppressants. Thirty-four patients, who had been treated with long-term immunosuppressants, were admitted for severe pneumonia. After admission, the dose of immunosuppressants including glucocorticoids was decreased, and the patients were divided into 2 groups: antibiotic treatment group (n = 16) and antibiotic + CRRT treatment group (n = 18). Before and after treatment, the changes of the patients' condition, chest CT and blood gas analysis were monitored. Biomarkers including C-reactive protein (CRP), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8(IL-8), white blood cell and neutrophil counts were determined. After treatment, the levels of CRP[(109 ± 24) vs (40 ± 13) mg/L], IFN-γ [(151 ± 28) vs (42 ± 12) ng/L], TNF-α [(301 ± 45) vs (118 ± 28) pg/L], IL-6 [(214 ± 45) vs (76 ± 23) pg/L], IL-8[(590 ± 121) vs (159 ± 60) pg/L], white blood cell count [(14.3 ± 5.7)×10⁹/L vs (8.5 ± 2.7)×10⁹/L], and neutrophil percentage [(91.3 ± 3.1)% vs (75.3 ± 2.6)%] decreased significantly in the antibiotic + CRRT group (P < 0.05) as compared to the antibiotic treatment group. In the antibiotic + CRRT group, blood gas showed significant improvement in pH [(7.30 ± 0.12) to (7.37 ± 0.18)], SaO₂ [(80.6 ± 7.6)% to (91.9 ± 7.3)%] and PaO₂ (41 ± 6) mm Hg (1 mm Hg = 0.133 kPa) to (71 ± 9) mm Hg. The patients' condition and chest CT abnormalities also improved more rapidly in the antibiotic + CRRT group. The 6-month survival was increased by 12.9% in the antibiotic + CRRT group as compared to the antibiotic group (P < 0.05). CRRT is effective in clearance of inflammatory mediators and may increase survival of severe pneumonia patients receiving long-term treatment of immunosuppressants.