Lung ultrasound imaging in avian influenza A (H7N9) respiratory failure.

BACKGROUND: Lung ultrasound has been shown to identify in real-time, various pathologies of the lung such as pneumonia, viral pneumonia, and acute respiratory distress syndrome (ARDS). Lung ultrasound maybe a first-line alternative to chest X-ray and CT scan in critically ill patients with respiratory failure. We describe the use of lung ultrasound imaging and findings in two cases of severe respiratory failure from avian influenza A (H7N9) infection. METHODS: Serial lung ultrasound images and video from two cases of H7N9 respiratory failure requiring mechanical ventilation and extracorporeal membrane oxygenation in a tertiary care intensive care unit were analyzed for characteristic lung ultrasound findings described previously for respiratory failure and infection. These findings were followed serially, correlated with clinical course and chest X-ray. RESULTS: IN BOTH PATIENTS, CHARACTERISTIC LUNG ULTRASOUND FINDINGS HAVE BEEN OBSERVED AS PREVIOUSLY DESCRIBED IN VIRAL PULMONARY INFECTIONS: subpleural consolidations associated or not with local pleural effusion. In addition, numerous, confluent, or coalescing B-lines leading to 'white lung' with corresponding pleural line thickening are associated with ARDS. Extension or reduction of lesions observed with ultrasound was also correlated respectively with clinical worsening or improvement. Coexisting consolidated pneumonia with sonographic air bronchograms was noted in one patient who did not survive. CONCLUSIONS: Clinicians with access to point-of-care ultrasonography may use these findings as an alternative to chest X-ray or CT scan. Lung ultrasound imaging may assist in the efficient allocation of intensive care for patients with respiratory failure from viral pulmonary infections, especially in resource scarce settings or situations such as future respiratory virus outbreaks or pandemics.

Metformin-associated lactic acidosis in Chinese patients with type II diabetes.

Metformin is a widely used antidiabetic agent that is generally considered safe. However, metformin-associated lactic acidosis (MALA), though not common, occurs from time to time and results in significantly high mortality. A series of 23 MALA cases in a local major hospital in Hong Kong is reported in this article to demonstrate the epidemiological data, risk factors, clinical features as well as the clinical outcomes for better understanding of this disease entity. It is the first MALA case series in which plasma metformin levels were assessed. However, the results show that plasma metformin levels in MALA bear no diagnostic and prognostic values. Risk factors of mortality were identified as shock and high plasma lactate levels. The majority of patients were found to have significantly raised creatinine versus a normal baseline value before the acute illness. Concomitant illnesses taking place alongside MALA were common. With a high utility rate of renal replacement therapy (82.6%) in the study group, the mortality rate was 30.4%.