Abstract
Objective:To describe the epidemiological and clinical characteristics, treatment and clinical outcome of patients with severe pandemic influenza. Methods: This is a retrospective study of patients hospitalized on the ICU from August 1, 2009, to January 31, 2010, with influenza symptoms and Pandemic A (H1N1) 2009 virus infection confirmed by rtPCR or specific antibody detection. 16 patients fulfilled the inclusion criteria (9 men and 7 women, aged 21-65 years, median 40).
Median time from symptom onset to hospital admission was 5 days; from admission to transfer to the ICU 11 hours; from symptom onset to the start of antiviral therapy 5 days. Eight patients had a chronic underlying condition, 4 of them combined with obesity.
Seven patients were obese with BMI > 30. Fever, cough and dyspnoea were the most frequent influenza symptoms.
Median APACHE II score was 9.5. The reasons for ICU admission were bilateral pneumonia with acute respiratory failure (13 patients) and acute haemodynamic collapse (3 patients).
Conventional mechanical ventilation was required in 9 patients. Two patients with acute renal failure were treated with continuous renal replacement therapy.
The mean hospital stay was 25 days, median stay was 19 days. Twelve patients recovered and four died (25%).
Conclusion: The results confirmed the findings of previous studies: lower age of the patients with severe Pandemic A (H1N1) 2009 virus infection, common absence of comorbid conditions and a high rate of obesity. Primary influenza pneumonia was the prominent cause of the critical condition.
A rational choice of antibiotic and antiviral treatment is discussed. The authors conclude that daily dosage of oseltamivir in severe influenza pneumonia should be increased to 300-600 mg.