Mortality prediction to hospitalized patients with influenza pneumonia: PO₂/FiO₂ combined lymphocyte count is the answer

Abstract

Introduction Community‐acquired pneumonia (CAP) severity scores perform well in predicting mortality of CAP patients, but their applicability in influenza pneumonia is powerless. Objectives The aim of our research was to test the efficiency of PO2/FiO2 and CAP severity scores in predicting mortality and intensive care unit (ICU) admission with influenza pneumonia patients. Methods We reviewed all patients with positive influenza virus RNA detection in Beijing Chao‐Yang Hospital during the 2009–2014 influenza seasons. Outpatients, inpatients with no pneumonia and incomplete data were excluded. We used receiver operating characteristic curves (ROCs) to verify the accuracy of severity scores or indices as mortality predictors in the study patients. Results Among 170 hospitalized patients with influenza pneumonia, 30 (17.6%) died. Among those who were classified as low‐risk (predicted mortality 0.1%–2.1%) by pneumonia severity index (PSI) or confusion, urea, respiratory rate, blood pressure, age ≥65 year (CURB‐65), the actual mortality ranged from 5.9 to 22.1%. Multivariate logistic regression indicated that hypoxia (PO2/FiO2 ≤ 250) and lymphopenia (peripheral blood lymphocyte count <0.8 × 109/L) were independent risk factors for mortality, with OR value of 22.483 (95% confidence interval 4.927–102.598) and 5.853 (95% confidence interval 1.887–18.152), respectively. PO2/FiO2 combined lymphocyte count performed well for mortality prediction with area under the curve (AUC) of 0.945, which was significantly better than current CAP severity scores of PSI, CURB‐65 and confusion, respiratory rate, blood pressure, age ≥65 years for mortality prediction (P < 0.001). The scores or indices for ICU admission prediction to hospitalized patients with influenza pneumonia confirmed a similar pattern and PO2/FiO2 combined lymphocyte count was also the best predictor for predicting ICU admission. Conclusion In conclusion, we found that PO2/FiO2 combined lymphocyte count is simple and reliable predictor of hospitalized patients with influenza pneumonia in predicting mortality and ICU admission. When PO2/FiO2 ≤ 250 or peripheral blood lymphocyte count <0.8 × 109/L, the clinician should pay great attention to the possibility of severe influenza pneumonia.

Effect of low‐to‐moderate‐dose corticosteroids on mortality of hospitalized adolescents and adults with influenza A(H1N1)pdm09 viral pneumonia

“…To further explore whether corticosteroid therapy at a certain dose range is effective for a certain group of influenza pneumonia patients or not, we performed stratified analysis of patients with different disease severity, based on PaO 2 /FiO 2 on admission. This stratification is of great importance, because PaO 2 /FiO 2 is a key factor predicting mortality and may respond to corticosteroid use . In the present study, based on the largest dataset to date, we found that corticosteroids have a tendency to reduce mortality of patients with severe influenza A(H1N1)pdm09 viral pneumonia who have PaO 2 /FiO 2 <300 mm Hg.…”

“…This stratification is of great importance, because PaO 2 /FiO 2 is a key factor predicting mortality and may respond to corticosteroid use. 30,37 In the present study, based on the largest dataset to date, we found that corticosteroids have a tendency to reduce mortality of patients with severe influenza A(H1N1) Despite being an important factor related to the efficacy of corticosteroids, dosage was mentioned in few studies published to date. 17,21 In the current study, we further performed stratified analysis based on the doses of corticosteroids and found that only lowto-moderate dose of corticosteroids could lower the mortality rate in severe influenza A(H1N1)pdm09 viral pneumonia patients with PaO 2 / FiO 2 <300 mm Hg.…”

FluA-p score: a novel prediction rule for mortality in influenza A-related pneumonia patients

“…During the H1N1 influenza A pandemic in 2009, a large proportion of severe cases were young patients who experienced acute respiratory failure [25,26]. Another issue to consider is that the current severity tool that relies on PSI and CURB-65 scores was possibly derived from patients diagnosed primarily with bacterial and atypical bacterial pneumonia rather than influenza pneumonia [20,27]. In fact, Guo et al reported that CURB-65 scores were not powerful predictors of mortality in the context of viral pneumonia [28].…”

Invasive pulmonary aspergillosis in patients with influenza infection: A retrospective study and review of the literature

“…3 Influenza may represent a novel host risk factor for this invasive fungal infection. Meanwhile, the mortality rate among co-infected patients has been found to be approximately 50%-60%, 4 which is approximately 5 times that of hospitalized patients with influenza alone.…”