Abstract
BACKGROUND: Early identification of treatment failure for nosocomial pneumonia remains a major challenge. The goal of this study was to test whether procalcitonin kinetics can be used to assess the clinical efficacy in older critically ill patients with nosocomial pneumonia.
METHODS: A prospective observational study was conducted with 60 subjects (≥ 65 y old) admitted to the ICU with severe nosocomial pneumonia. Serum procalcitonin was measured on days 0, 3, and 7 and at the end of treatment. The procalcitonin time course was analyzed according to the therapeutic efficacy.
RESULTS: Procalcitonin levels were elevated in all subjects (n = 60) on day 0, and the median level (range) was 2.5 (0.85–42.7) μg/L. There were no differences in procalcitonin between the improved subjects (n = 41) and those without improvement (n = 19) on day 0 (P > .05). However, lower procalcitonin levels on days 3 and 7 and at the end of treatment (all P < .05) and greater rates of procalcitonin decline between days 0 and 3 (ΔPCTd3%; 29.5 ± 10.8% vs 15.1 ± 5.9%, P = .009) were observed in the improved subjects compared with those with no improvement. ΔPCTd3% was the best single predictor of efficacy (area under the curve of 0.79, P < .001) and had a sensitivity of 75.7% and a specificity of 72.0% with a threshold of 26.2%. By comparison, traditional parameters and absolute procalcitonin failed to predict treatment response (P > .05). Indeed, the combination of ΔPCTd3% > 26.2% and a modified Clinical Pulmonary Infection Score of < 6 points improved the predictive value (area under the curve of 0.89, sensitivity of 81.3%, specificity of 86.5%).
CONCLUSIONS: Procalcitonin levels were not influenced by aging, and procalcitonin kinetics might help to identify treatment failure. ΔPCTd3% in combination with the Clinical Pulmonary Infection Score has been shown to be a marker of clinical efficacy at an earlier stage.
- nosocomial pneumonia
- procalcitonin
- procalcitonin kinetics
- therapeutic efficacy
- modified Clinical Pulmonary Infection Score (mCPIS)
- older critically ill patients
Footnotes
- Correspondence: Yan Shi MD, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, 1 Shuai Fu Yuan Wang Fujing Street, Dongcheng District, Beijing 100730, China. E-mail: pumchshi{at}sina.com.
The authors have disclosed no conflicts of interest.
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