JACKSON HOLE, WYO. — Procedural ultrasound for use in placing central venous catheters and performing thoracentesis and arthrocentesis will make life easier, faster, and safer for emergency physicians, Luis Haro, M.D., said at a meeting on high-risk emergency medicine.
Procedural ultrasound for the emergency department is so new that even most professors in academic centers do not know how to do it, said Dr. Haro of the department of emergency medicine at the Mayo Clinic, Rochester, Minn.
But soon everyone will use it, he predicted. The advantages are clear, and, according to a survey, 60% of emergency departments have ultrasound capabilities, although they may not be doing procedures, Dr. Haro said at the meeting, sponsored by the Mayo Clinic.
At the clinic, the emergency department already has three ultrasound machines that can be used for procedural ultrasound, Dr. Haro said.
“This is cutting edge,” he added. “In our institution, we do a 6-hour ultrasound lecture for our physicians.”
Mastering the techniques is not difficult, since most emergency physicians know how to do these procedures blindly, Dr. Haro said.
The trick is mastering the concepts of ultrasound technology, and even that is basically simple, Dr. Haro said.
The concepts are these: First, for a procedure, one does not necessarily want the biggest ultrasound probe, but a probe that produces a linear field of view rather than a pie-shaped one. Second, procedures are generally about locating or evacuating fluid, and fluid is dark or black in an ultrasound picture. And third, lower-frequency waves penetrate deeper into tissue than higher-frequency waves.
The use of ultrasound for placing a central line can significantly reduce the likelihood of missing the jugular vein and hitting the carotid artery, he said. In one study, arterial puncture occurred 7% of the time when the procedure was done blindly. That rate was reduced to 1% with ultrasound. Minor complications also are reduced.
According to the literature, physicians correctly place a central line on the first try less than 40% of the time when they do it blindly. But with ultrasound, they succeed the first time about 80% of the time.
Studies also have shown that ultrasound-guided central vein catheterizations take an average of about 2 minutes less than blind catheterization, and they are revealing things about nuances of anatomy not previously appreciated, Dr. Haro said.
Similar advantages have been demonstrated for ultrasound-guided arthrocentesis and thoracentesis.
In arthrocentesis, ultrasound is used for evaluating the knee or other large joints before performing the procedure, rather than for guiding the needle, which is not that difficult.
Ultrasound clearly shows if puffiness represents fluid inside or outside the joint, Dr. Haro said.
In thoracentesis, the results of studies have clearly shown a reduced risk of pneumothorax, he added.
Given the simplicity and benefits of ultrasound, all emergency physicians who are able should give it a try, Dr. Haro suggested.
“You're doing these procedures all the time,” he said. “You do arthrocentesis. You do thoracentesis. You place central lines. You're already doing it blindly, so just take an extra look if you have a probe there.”