Bedside scanning provides easy way to monitor lungs

October 1, 2008



Bedside ultrasound can be a valuable diagnostic tool for monitoring pulmonary congestion in patients with acute decompensated heart failure. As the heart weakens, fluid backs up into the lungs, and critical patients could benefit greatly by being monitored for their condition without having to be moved for radiographs or other diagnostic tests.

Roughly a quarter of a million people die each year of heart failure, the leading cause of hospitalization in adults over 65. The estimated direct cost for heart failure in 2006 in the U.S. was $29.6 billion, according to the Centers for Disease Control and Prevention.

Dr. Giovanni Volpicelli and colleagues at San Luigi Gonzaga Hospital in Torino, Italy, studied 70 patients with acute decompensated heart failure. They examined these patients with transthoracic ultrasound first upon admission to the hospital and again 4.2 (±1.7) days later, after they had received treatment.

The researchers used bedside ultrasound to look for multiple B lines, a proposed sign of pulmonary congestion, on five anterolateral thoracic ultrasound exams conducted on each patient's left side and six on the right side. Standard diagnostic tests are chest x-rays and CT scans.

Multiple B lines showed up on the first scans for all patients. The patient with the lowest number of subsequent scans showing B lines had three of 11 total scans turn out positive, while the patient with the most scans positive for B lines had nine. Across all patients, a median of eight scans per patient turned out positive for multiple B lines.

When the exams were repeated after several days of treatment, the median number of scans per patient dropped to zero, with a range of zero to seven.

Every scan was scored according to the presence and number of B lines. These scores had a positive linear correlation with scores given to radiologic exams showing extravascular lung water, plasma brain natriuretic peptide improvement, and clinical improvement. The changes in the sonographic score also correlated with changes in the clinical and radiologic scores.

The researchers concluded that bedside ultrasound is a reliable diagnostic tool for monitoring the treatment of pulmonary congestion in patients with acute decompensated heart failure. They published their findings in June 3 online issue of the American Journal of Emergency Medicine.

-By Wendy Despain