|
|
Ultrasound intensity
|
Logged in as: Guest
|
|
Users viewing this topic:
none
|
|
Login  | |
|
Ultrasound intensity - May 19, 2005 12:01:00 PM
|
|
|
PTnl
Posts: 4
Joined: May 18, 2005
Status: offline
|
Hello,
First time poster here with a question about ultrasound intensity. I am a PT with 20 yrs experience, graduated from a good school in U.S. I have always done continuous ultrasound at a 1.0-1.5 W/cm2 intensity, never higher, sometimes lower.
I am filling in at a clinic I used to work at and know all the aides very well. They have mentioned to me a PT in the office (was not there when I was there) who requests that they perform continuous ultraound at 2.0 W/cm2 and sometimes patients complain of pain at this intensity. The aides are concerned and stop treatment when this happens. They tell the PT of the problem. He says they should stop the ultrasound but does not advise a change in parameters.
The aides are not sure how to approach the PT without being insubordinate (they feel 2.0 is too high. No other PT has requested this high of a setting). They stop the treatment but think the PT should change the parameters himself without suggestions from the aide. One patient was receiving ultrasound to the medial knee joint at 2.0 (as directed by the PT) and was feeling pain during the treatment so the aide stopped.
I plan to talk to the owner when he returns but was wondering if the higher settings are ever indicated? I just don't recall any other clinicians in my experience using the high settings. I have always lowered the intensity, switched to pulsed, or stopped ultrasound when patients had any symptoms with it. It seems to me the high setting is contraindicated in some of the current situations.
Thanks for your input.
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 12:32:00 PM
|
|
|
FLAOrthoPT
Posts: 1011
Joined: May 8, 2004
From: West Palm Beach
Status: offline
|
what is the Mhz what is the duty cycle and what is the size of the sound head? I never use US anymore, but when i did, I'd use 2 on the plantar fascia, on some bigger muscualr lumbar areas and occasionally thigh. why is an aid doing US is the REAL question???
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 3:24:00 PM
|
|
|
PTnl
Posts: 4
Joined: May 18, 2005
Status: offline
|
Hi FLAOrthoPT,
Thanks for your response. The machine has 1MHz and 3.3MHz settings. The MHz setting is determined by the PT depending on the structure that is being treated/depth needed. The duty cycle is pulsed (10, 20, 50) or continuous. The sound head is 5 cm. The problem has been with continuous ultrasound at intensity of 2.0 W/cm2.
With the exception of Medicare patients, it is legal in our state for an aide to administer ultrasound as long as the therapist has assessed the patient prior to the aide giving ultrasound. In addition the PT must be in immediate proximity to the location where the aide is performing patient related tasks, and is readily available at all times to provide advice or instruction to the aide.
I think your question about the aide doing ultrasound is a good one. Since there is a problem then it would make sense for the PT to do the ultrasound. I will mention this to the owner. It has not been an issue before because the other PTs use a lower intensity.
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 4:22:00 PM
|
|
|
jma
Posts: 2415
Joined: August 24, 2000
From: NY
Status: offline
|
I see no reason why the aide cannot tell the PT that the patient cannot tolerate the US because of discomfort. If the primary PT is not aware of the current situation, then the parameters cannot be adjusted, if that is necessary.
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 4:44:00 PM
|
|
|
srcase
Posts: 551
Joined: November 30, 2004
From: Michigan
Status: offline
|
Two thoughts: 1) Check the beam nonuniformity ratio (BNR) of the machine...hopefully the machines are regularly serviced, but even so, I believe a high BNR can make higher intensities very uncomfortable.
2) Maybe the therapist has a good rationale for wanting to proceed in that way. I suggest you speak to the PT in question first before snitching to his/her boss. Tell the PT that the aides have come to you to ask questions and you are concerned. Heck, worst case scenario, the PT might WANT the patients to have a bad reaction so he/she doesn't have to use a useless modality on the patients anymore (seems quite unethical, but still possible). At least then you would have something to form an opinion on....don't make assumptions based on second or third party information...go to the source.
Sarah
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 4:51:00 PM
|
|
|
Bournephysio
Posts: 585
Joined: April 25, 2002
From: Calgary
Status: offline
|
As far as I know the only good studies that show benefit for ultrasound are at 2.5 W/cm2 I know of at least a couple of therapists who don't turn the settings down or stop if the patient experiences some aching. ECSWT is a very similar modality. No one seems concerned if it hurts. Going to the owner about this seems underhanded to me.
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 6:23:00 PM
|
|
|
pwrandall
Posts: 66
Joined: May 14, 2004
From: Elk Grove, CA
Status: offline
|
Cameron's (1999)Physical Agents in Rehabilitation states that for Continuous US at 1Mhz an intensity of 1.5 to 2.0 W/cm2 is needed for thermal effects, no more. At 3Mhz 0.5 W/cm2 can yield thermal effects. In either case, the authors clearly state that the patient "should not feel increased discomfort at any time during the treatment. In Prentice's (2002) it is suggested that 100%, 1 Mhz, 2 w/cm2 can help /c scar mobility and stretching.
In my limited experience, I use a trial of US with many patients, but have never found it to be useful, especially when treating patients /c spinal related symptoms.
PETE
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 8:09:00 PM
|
|
|
PTnl
Posts: 4
Joined: May 18, 2005
Status: offline
|
Thanks everyone for your responses and for citing references. The machines are serviced annually but I will ask the company who services them about the beam nonuniformity ratio. I will approach the PT directly. Please post any additional comments you may have.
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 8:34:00 PM
|
|
|
steve
Posts: 470
Joined: May 14, 2003
From: Canada
Status: offline
|
Doug,
Didn't the good ultrasound use high intensities but at a pulsed 1/5 ratio? Or is there evidence that continuous ultrasound can be used at that intensity - as is the case in this scenario?
Steve
|
|
|
|
|
Re: Ultrasound intensity - May 19, 2005 9:34:00 PM
|
|
|
nari
Posts: 1568
Joined: November 14, 2003
From: Australia
Status: offline
|
US seeems to be marginally useful where there is acute inflammation very early on in an injury, but it has been shown to be remarkably useless for anything else.
Even with mastitis it has been shown that placebo is as effective - a study done in the UK, if I recall correctly.
nari
|
|
|
|
|
Re: Ultrasound intensity - May 20, 2005 4:13:00 AM
|
|
|
Shill
Posts: 1098
Joined: February 13, 2003
From: Madison WI USA
Status: offline
|
The intensity often chosen for US is based on what we are taught in school, not what has been shown to provide some benefit. For calcific tendinitis the higher intensities are warranted (2.5w/cm2, pulsed however, at 20%, for 15 minutes, according to Ebenbichier et al in New England Journal of Medicine 1999). 1.5 w/cm2 inhibited bone healing, while 0.5 increased healing rate (Tsai et al, Chinese (yes, Chinese) Journal of Physiology 1992). Most other studies, whether good or not study 0.5 w/cm2, yet we are still arbitrarily assigning 1.5 w/cm2. Why? Beats me. I used to do it too.
Here are a few more that looked and found results at 0.5 - 1.0 w/cm2w/cm2. Keep in mind that most of these used pulsed US.
Ebenbichler et all in British Medical Journal 1998 for Carpal Tunnel syndrome 1 MHz, 1.0w/cm2 pulsed.
Young and Dyson in Ultrasound in Med and Biol, 1990 - 0.5 w/cm2,
The Treating PT needs to be clear on the INTENT of the US. Then parameters can be based on what evidence is there, and if the parameters chosen dont mesh, then they need to talk. Its easy for me to say, as I am not in this situation, but the PT needs to listen, as pain during US is NOT appropriate.
_____________________________
Steve Hill PT
|
|
|
|
|
Re: Ultrasound intensity - May 21, 2005 12:38:00 AM
|
|
|
Randy Dixon
Posts: 744
Joined: August 6, 2004
Status: offline
|
I hate to throw in a simple possibilty but the aide may just be moving the head too slowly or not enough.
Still the PT should check out what is going on.
|
|
|
|
|
Re: Ultrasound intensity - May 21, 2005 3:39:00 AM
|
|
|
avalon
Posts: 181
Joined: March 18, 2005
Status: offline
|
[QUOTE]The sound head is 5 cm. The problem has been with continuous ultrasound at intensity of 2.0 W/cm2.[/QUOTE]Thus you are applying 5*2= 10 W!!!
And continuous US is rarely used since it increases heat in tissues. Inflammation will occur with pain.
_____________________________
http://www.somasimple.com
|
|
|
|
|
Re: Ultrasound intensity - May 21, 2005 3:32:00 PM
|
|
|
PTupdate.com
Posts: 1478
Joined: October 8, 2001
From: Pittsburgh, PA USA
Status: offline
|
I had once read the US waves are longitudinal, but when they enter the bone periosteum, they become transverse waves, and ping back and forth, releasing energy between the bone cortex and the periosteum, causing pain. Probably not a good thing, so I have always turned the unit down. Besides, I never use continuous US anyway....just pulsed over focal lesions.
John Duffy, PT OCS
[URL=http://www.PTupdate.com]www.PTupdate.com[/URL]
_____________________________
John M. Duffy, PT
Board Certified Orthopaedic Clinical Specialist
www.PTupdate.com
|
|
|
|
|
Re: Ultrasound intensity - May 23, 2005 6:36:00 AM
|
|
|
NorthernPT
Posts: 21
Joined: January 30, 2005
From: MN
Status: offline
|
I once had a copy of an article that states ultrasound enhances the inflammatory effect, but I cannot find it. Does anyone have this article?
|
|
|
|
|
Re: Ultrasound intensity - May 23, 2005 11:45:00 AM
|
|
|
Yogi
Posts: 403
Joined: April 5, 2004
From: San Antonio, Tx., USA
Status: offline
|
The idea, as I recall, for continuous US, was for the thermal effects, which, in theory, would increase the metabolic cell processes and speed healing. Aching was a precursor to the sharp painful periosteal pain, meaning the bone tissue interface was heating and tissue damage from burns was possible if not alleviated. If there was little soft tissue over the bone, such as fingers, or knees, then pulsed US is safer as the thermal effects are less. Underwater could be done to heat parts such as fingers that maintaining head contact would be difficult on. It would be difficult to prevent periosteal pain at 2 W/cm2, (20 W/cm), unless the head was moved rapidly and or the treated area size was increased, or lots of tissue depth was present over the bone. Dosage units are specifically calibrated on the machines for the size head used on the machine, the head size only has to do with the ease of maintaining contact with the body surface, with underwater, as mentioned making feasible treatment of surfaces not otherwise possible to maintain good head contact, even with lots of gel. As Shill says, US shouldn't be painful, and the aching is a sign, I suppose the intensity could be maintained with aching as Bourne suggests, but that seems aggressive, perhaps risky, to me. Aides performing treatments, esp. modalities, is common with on premises supervision, in the states I've been in. This may be changing if PT is moving away from the modality cash cow, as most here seem to advocate. PTnl, maybe you could print and post or discuss somehow the site on dosage calculatione David so kindly posted.
|
|
|
|
|
Re: Ultrasound intensity - May 23, 2005 5:02:00 PM
|
|
|
jma
Posts: 2415
Joined: August 24, 2000
From: NY
Status: offline
|
Nice link. Very informative
|
|
|
|
|
Re: Ultrasound intensity - May 23, 2005 8:29:00 PM
|
|
|
PTnl
Posts: 4
Joined: May 18, 2005
Status: offline
|
Thanks for so many responses. David, great links, I liked the ultrasound dose calculation page, good suggestion Yogi. I'm going to gather info. from this topic and other research articles to bring in to work to share. I will check into the beam nonuniformity ratio with the service people.
Today the PT I work with came to me with a question about taping. The conversation led into a discussion about Cont. Ed. courses and I asked questions about his PT education in general. I am seeing a patient that had been seen by him at the beginning of her treatment. I saw the high intensity documented in her file which allowed me to ask about our differences in use of ultrasound, and what we were taught in our respective programs, in the course of conversation. He was open to talking about periosteal pain and I said I could bring in some info. which he seemed interested in. Anyway, long story short, we had a good talk and I think we can talk comfortably about it. This site has been a good source of info. Please post other links or suggesions you think might be helpful.
|
|
|
|
 New Messages |
 No New Messages |
 Hot Topic w/ New Messages |
 Hot Topic w/o New Messages |
 Locked w/ New Messages |
 Locked w/o New Messages |
|
 Post New Thread
Reply to Message
Post New Poll
Submit Vote
Delete My Own Post
Delete My Own Thread
Rate Posts |
|
0.109
|
Printable Version
