Chest x-rays may play vital role in diagnosis, treatment of H1N1 influenza

A new Israeli research suggests that chest X-rays can help predict which H1N1 patients are at greatest risk.

Lead author Galit Aviram, head of cardiothoracic imaging in the Department of Radiology at Tel Aviv Sourasky Medical Center in Tel Aviv, Israel, said: "Working in the emergency room is very stressful and physicians need information fast.

"Our study provides significant findings that will help clinicians triage patients presenting with clinically suspected H1N1 influenza."

Dr Aviram's and colleagues analysed the chest x-rays of 97 consecutive patients with flu-like symptoms and laboratory-confirmed diagnosis of H1N1, admitted to the emergency department of Tel Aviv Sourasky Medical Center between May and September 2009. The scientists then correlated the x-ray findings with adverse patient outcomes.

Dr Aviram said: "To our knowledge, this is the largest series describing the presentation of chest x-ray findings in patients diagnosed with H1N1 influenza."

The chest x-rays revealed abnormal findings for 39 of the patients, five (12.8%) of whom experienced adverse outcomes, including death or the need for mechanical ventilation. For the other 58 patients, chest x-ray findings were normal, while two (3.4%) of the patients experienced adverse outcomes. The mean age of patients in the study, which included 53 men and 44 women, was 40.4 years.

Dr Aviram said: "Abnormal findings in the periphery of both lungs and in multiple zones of the lungs were associated with poor clinical outcomes."

Though a normal chest x-ray did not exclude the possibility of an adverse outcome, Dr Aviram pointed out that the study's findings can help physicians better identify high-risk H1N1 patients who require close monitoring.

Dr Aviram noted: "In H1N1, as in various types of community-acquired pneumonia, initial chest x-rays may not show abnormalities that develop later in the course of the disease.

"Further x-rays should be performed according to the patient's clinical course."

The study has appeared in the April issue of Radiology.