Calgary Herald
Page C5
The first thing that pops into most people’s minds when they hear the word, “ultrasound,” is seeing their unborn child on a monochrome screen. But ultrasound is now much more.Thanks to companies like SonoSite Inc, General Electric, Philips and others, doctors can use a hand-held, portable, ultrasound device to take a quick look at a patient’s heart and other internal organs.
The devices, which weigh up to 4.5 kilograms, are gaining popularity around the world.
The main unit consists of a processor with a colour screen. Like conventional ultrasounds, each unit has a cord-like probe called a transducer. After applying a gel-like substance to a patient’s skin, the end of the transducer, which is like a ball, is rolled around the patient. The transducer sends signals to the unit, which then converts them into the image which appears on the screen. Most models have two modes: an image mode and colour doppler, a superimposition over organs that highlights the image so doctors can identify trouble spots.
“What we’re trying to do is give physicians a set of eyes to augment their ears,” said Patrick Martin, director of global cardiovascular medicine for SonoSite.
Foothills Hospital has one of SonoSite’s first models — called FAST — in its emergency room. It’s used on trauma patients to detect internal bleeding.
“We’re very early on in I think a major change in how we examine patients,” said Dr. Andy Kirkpatrick, who pioneered the usage of hand-held devices in trauma rooms while working at Vancouver General Hospital about two years ago.
He now works as a staff trauma surgeon at Foothills Hospital in Calgary’s northwest.
Kirkpatrick and Dr. John Kortbeek, director of trauma services for the Calgary Health Region, said the ultrasound is really handy for detecting internal bleeding in unstable patients because it’s less risky than the diagnostic peritoneal lavage (DPL). That test involves sticking a catheter — a needle, wire kit, and tube — into the abdomen. Fluid is pumped into it. If blood or other fluids and solids come out, doctors know if an organ or the bowel has been punctured.
Since internal bleeding appears 10 minutes after injury, sometimes doctors don’t get an accurate read from the test.
In contrast, the ultrasound is not invasive.
“We can repeat it if we’re not happy with the patient’s progress and it’s risk free,” said Kortbeek.
The device’s size is also a benefit. Since a trauma patient has as many as seven doctors and nurses around their bed, it’s too crowded to wheel in a regular-sized ultrasound machine.
“With this device, you can get in there at the same time and scan for internal bleeding,” said Kirkpatrick. “If somebody has large amounts of internal bleeding, you can detect it in seconds.”
Kirkpatrick emphasized that the best test for internal bleeding is a computed tomography imaging (CT/CAT scan). However, he said patients have to be wheeled down the hall to a different room and placed into the scanner. But patients who are bleeding internally suffer from shock and are difficult to move. It’s usually used for stable patients.
“If patients present shock because they’re bleeding to death, then we need to find out very quickly where they’re bleeding,” said Kortbeek.
He also said that it gives a better look at the heart in order to see if blood or fluid is collecting around it.
Dr. John Gorcsan at the University of Pittsburgh Medical Center’s Echocardiography Laboratories, once detected a similar problem with the SonoSite.
“A patient was not suspected to have fluid around a sack of the heart, and I did the ultrasound at the bedside and it was. . . crushing it in a life-threatening way,” the American expert in cardiac health and echocardiography said.
The patient was automatically wheeled to the operating room. He arrested in the elevator, but was resuscitated.
“To order an echocardiogram and send the patient to the lab, you were lucky if it would get done the same day, usually a few hours later,” Gorcsan explained. “(The patient) probably would have arrested on the floor if we had waited for the full tests.”
Gorcsan has been using the SonoSite machines in his rounds and clinics for two and a half years. He is currently doing a study on the effectiveness of the machines, and said so far he’s found the ultrasound changes his plans for the patient over 50 per cent of the time.
“I’d order a different test or I’d cancel a test,” said Gorcsan.
However, while Gorcsan said the device has a good imaging system, the colour doppler mode isn’t as good as the bigger machines.
“So, I think that there’s the ability to really miss some major problems with the doppler, so I don’t trust (the doppler) in other words,” he said.
Gorcsan also sends his patients for further testing if he finds any medical problems.
Kirkpatrick, who uses an older model than Gorcsan’s, is equally cautious.
“This machine doesn’t have good video capture, it doesn’t have strong batteries. It’s not a perfect machine, (but) it’s still incredibly useful.”
It’s so useful that it may become the stethoscope’s new friend.
Dr. Kwan Chan, director of the echocardiography lab at the University of Ottawa Heart Institute, has tested a few devices. They are now trying out a Philips model.
“Although it’s more handy, it’s also quite heavy. . . . At the end of the day, your shoulder (hurts),” he said. “It’s portable, but it’s not as small as the stethoscope.”
He said the main advantage of the ultrasound is doctors can see the heart and other organs to identify problems instead of only hearing evidence of them through a stethoscope.
But Kirkpatrick said the two instruments work in tandem.
“It has the potential to augment in a tremendous way, the stethoscope,” Kirkpatrick said. “The ultrasound is just another means of extending the physical senses.”
But a place where both the stethoscope and ultrasound fail is in the obese. Fat acts as an insulator and would muffle sounds through a stethoscope and make a blurry picture on an ultrasound screen, Kirkpatrick said.
But General Electric spokesman, Jeff Peiffer, said the stethoscope could become a museum piece.
“I think ultrasound will ultimately replace the stethoscope,” he said, explaining GE is trying to shrink its LOGIQ Book so it’s more convenient for doctors to carry.
“That’s something we’ve all had a passion to achieve for the past few decades. It could be a wearable device every physician will carry around,” he said.
Chan thinks the portable devices would work well in rural areas, where access to ultrasound and echocardiograms is limited.
But Gorcsan thinks the devices will also find a home in urban centres.
“I think there’s a definite future. One of the reasons that it hasn’t gained widespread acceptance is because it clearly does not replace the big machine,” he said.
But Patrick Jarvis, spokesman for General Electric, said in the end it all boils down to what benefits patient care.
“The reality is technology, when it has very practical applications — that is it helps a physician do his or her job better — it improves patient outcome. If it does some of those things, then it becomes embraced,” Jarvis said. “People were saying this new-fangled CD would never happen. It took a number of years to happen.”
As for the stethoscope, Dr. Bob Burns, registrar of the College of Physicians and Surgeons of Alberta said it’s up to fate.
“The stethoscope has stood the test of time. It’s been around for years,” said Burns. “Whether it’d be replaced by existing technology, who knows? I guess time will tell.”
Copyright 2002 CanWest Global
