H1N1 influenza A virus Related Pneumonia and Respiratory Failure

Abstract

Influenza viruses are common respiratory pathogens in humans and can cause serious infection that leads to the development of pneumonia. In this study, the clinical and laboratory features of 36 patients from Turkey who are hospitalized in intensive care unit due to pandemic influenza A (H1N1) associated pneumonia and respiratory failure were retrospectively evaluated. The most common symptoms were cough and fever. Consolidation (36.1 %) and interstitial changes (30.6 %) were the most frequently identified findings on chest radiographs at the time of admission. Six of the patients (16.7 %) died. Mortality occurred in 3 of 13 patients (23.1 %) with underlying disease, whilst it occurred in only 3 of 23 patients (13 %) who were previously healthy. Mortality was found to be significantly associated only with an elevated lactate dehydrogenase level. A significant relationship was determined only between the presence of lymphopenia and acute respiratory distress syndrome and the need for intensive care treatment. The average time elapsed from the onset of the symptoms until admission was 8.67 ± 2.87 days for the patients died, and 6.0 ± 3.8 days for the patients survived.

Keywords: H1N1; Pneumonia; Respiratory failure; Swine influenza virus.

Fig. 1

The symptoms and chest X-ray findings in patients with H1N1 related pneumonia and respiratory failure. The most frequent symptoms were cough and fever. Approximately two-thirds of the patients had dyspnea and sputum. Consolidation and interstitial changes were detected in one-thirds of the patients. Fewer patients had a ground-glass appearance. The lesions were often bilateral. Usually, it was influenced by the lower zone of the lungs. Additionally, one patient had pleural effusion, and one patient had atelectasis, and another patient had pneumothorax. GGO ground-glass opacities, ARDS ARDS