[Eleven fatal cases with A H1N1 influenza in Tianjin]

To describe the clinical characteristics of fatal cases with confirmed A H1N1 influenza so as to improve the diagnosis and treatment of this severe disease.

We retrospectively analyzed the medical records of 11 fatal cases with A H1N1 influenza in Tianjin between September 1 and November 4 2009.

There were 6 males and 5 females with a median age of 25 (21 - 36) years old. Two cases were pregnant women and 3 patients suffered such concurrent disorders as dilated cardiomyopathy, multiple myeloma or atrophic gastritis. Over 3 lung fields were involved on chest imaging studies and the oxygenation index was less than 300 mm Hg at admission. The therapies of oseltamivir and methylprednisolone were administered and mechanical ventilation was initiated within 24 hours. Refractory hypoxemia and a higher level of lactate dehydrogenase were present during treatment. Pneumothorax or mediastinal emphysema occurred in 4 patients, acute renal failure in 1 and pneumopyothorax in 1. The culture of airway secretion at 3 - 7 days after mechanical ventilation showed Staphylococcus aureus in 4 patients and Aspergillus in 2. The progress of disease was so quick that the duration from onset of clinical symptoms to hospitalization was a median of 4 (3 - 6) days and the duration from onset of clinical symptoms to death a median of 12 days.

The fatal cases with A H1N1 influenza in Tianjin occurred mostly in young individuals and pregnant women. This severe disease had a rapid progression. And bacterial co-infections were quite common. Refractory hypoxemia resulting in respiratory failure was the main mortality reason.