The Ultrasound Advantage
At the University of Chicago Medical Center, cardiologist Kirk Spencer, MD, says ultrasound procedures still are performed mainly by sonographers and cardiologists. He hopes to change that with a slew of studies demonstrating the feasibility of putting portable ultrasound in the hands of internists.
In one study, hospitalized patients indicated for echocardiography received an echocardiogram, while all others were examined with ultrasound. “We found a significant number of cardio pathologies,” Dr. Spencer says. The findings, he says, were independent of specific medical complaints, such as endocrinology or orthopedic problems.2 “If you were sick enough to get in the hospital, there was a chance that you had a significant cardiac problem that needed to be addressed,” he says.
The study that most excites Dr. Spencer was presented at the 2007 IEEE International Ultrasonics Symposium in October.2 It looked at using ultrasound before releasing a cardiac patient. “One of the biggest problems, one of the most common diagnoses is congestive heart failure,” he says, with a six-month readmission rate of 30% to 40%. Giving ultrasound devices to internists allowed them to look at the amount of fluid around the heart of each cardiac patient.
“The patients who got readmitted all had more fluid detected by ultrasound,” Dr. Spencer says. “So we can do that and say, ‘Hey, you need to stay in the hospital two more days. But if that prevents you from coming back in six months, then that’s a good thing.’”
In patients diagnosed with congestive heart failure, he and his collaborators found, the mean fluid volume was higher for those who were later readmitted. Dr. Spencer plans to pick a reasonable cut-off value and prospectively test whether delaying the release of patients whose fluid levels exceed that value can cut readmission rates.
Most of the battery-operated units used by the medical center weigh between 6 to 10 pounds and cost between $12,000 and $20,000, he says. The devices, about twice the thickness of an iBook, can easily be carried on a shoulder strap. Echocardiogram machines, by contrast, weigh about 300 pounds, must be plugged in and retail for about $250,000.
