A PROSPECTIVE STUDY OF PREDICTORS OF MORTALITY IN ACUTE RESPIRATORY FAILURE IN H1N1 INFLUENZA.

Dr. Mahendra M., Dr. Chaya S. K., Dr. Lokesh K. S., Dr. Jayaraj B. S., Dr. Anirudh Kumar and Dr. Mahesh P. A.*

ABSTRACT

Aim: H1N1 pneumonia with respiratory failure is associated with significant mortality and morbidity. There is a need to evaluate independent predictors of mortality. Methodology: Patients with suspected H1N1 pneumonia presenting to emergency at JSS Hospital, Mysuru during February-June 2015 were screened for H1N1. Patients with H1N1 were evaluated for independent predictors of mortality. Survivors were followed up at 3rd month and 1 year for long-term sequelae and activity limitation. Results: 175 patients were screened for H1N1 and 71 were confirmed, of which 52 needed ICU admission and 24 needed mechanical ventilation. Nine subjects were given a trial of NIV before mechanical ventilation. Twenty eight subjects could be managed with NIV alone. A very high mortality 24/71 (33.8%) was observed inspite of anti-viral treatment. Cox regression analysis identified APACHE II score (>10), comorbidities and rise in platelet counts (<15% from baseline) were independently associated with mortality. No long term sequelae or activity limitation was observed in survivors. Conclusion: H1N1 pneumonia with respiratory failure is associated with very high mortality. Each of the above 3 variables APACHE II score (> 10), comorbidities and rise in platelet counts (<15%from baseline) were associated with a greater than 3 times the hazard for mortality.

Keywords: APACHE II, H1N1, Influenza, long-term sequelae, mortality.