Abstract
Introduction:- H1N1 Influenza A virus spreads globally causing pneumonia and high mortality.
Aim:- We studied clinical characteristics of patients admitted with influenza pneumonia in a tertiary care hospital of northern India over one year.
Method:- We analyzed 77 patients with H1N1 influenza,confirmed with RT-PCR assay.
Results:-Out of 77 patients,33(43%)were female. Mean age was 41+/-13 years.Thirty eight patients (50%) had at least one comorbidity,Diabetes Mellitus was most frequent. Presenting symptoms were fever in 75 (97%),cough in 67(87%)and dyspnoea in 59 (76%) patients. Mean duration of dyspnoea at presentation was higher in expired group 6 +/-3 Vs 4+/-3 days(P=0.02). Bilateral opacities on chest radiograph seen in 49 (55%) patients. Mean PaO2/FiO2 ratio on admission was 213+/-133 and 175+/- 101 at 24 hours in discharge patients while expired patients it was 141+/-92 and 122+/- 65 respectively. Mean PaCo2 was higher in expired group 55+/-27 Vs 37 +/- 11 (P=0.002). Forty five patients (59 %) had one or more organ failure. Respiratory Failure was commonest (n=43, 56 %) requiring Invasive ventilation in 13(17%) patients and Non invasive ventilator in 23(30%) patients. Overall mortality was 13% (n=10). PaCo2 on admission (odds ratio,1.093; confidence interval, 1.133 to 1.193; P=0.044)and number of organ failure(odds ratio,8.089; confidence interval,1.133 to 57.77;P=0.037)were identified as independent risk factors for in hospital mortality.
Conclusion:-Factors associated with poor outcome in acute viral pneumonia are long duration of dyspnoea, bilateral pneumonia, low PaO2/FiO2 ratio on admission and 24 hours later, high PaCo2 & number of organ failure.
- © 2012 ERS
