Factores predictores de defunción en pacientes con neumonía por influenza A H1N1

Background: Influenza is usually a self-limiting disease. In April 2009, a new type of influenza A H1N1 virus was discovered. There were a lot of cases with severe pneumonia associated to this virus, although the lethal cases were less than expected. However, we must be still alert for future severe cases of influenza AH1N1 pneumonia. Objective: to determine prognostic predictors of pneumonia mortality, due to influenza A H1N1 infection. Patients and methods: Adults treated at the National Institute of Respiratory Diseases (INER) during the period of April to June 2009. We included all those who required hospitalization for pneumonia. We analyzed the survival associated with the need of mechanical ventilation in intensive care and clinical conditions at admission (age, weight, history of chronic diseases, oxygen saturation, temperature, CPK level, LDH level and lymphocytopenia). Results: 38 patients met the inclusion criteria, 26 male (68.4%) and 12 women (31.6%). The mean age was 37 years old (1 to 85). 23 (60.5%) needed mechanical ventilation, of which 17 patients (44.7%) died. The most important mortality risk factors were: lymphocytopenia at admission ≤ 1,000 mm³ (OR: 3.2 95% CI 1.1 to 27.5) and LDH > 1.000 U / L (OR: 7.6 95% CI 1.2 to 47). This marker had a sensitivity and specificity predictor for death of 70.6% and 67% respectively. Conclusion: The mortality in this group was high, especially in those patients with lymphcytoopenia and elevated DHL.