Don't object unless you have all of the facts!
fast efast ultrasound ambulance prehospital ems ultrasound ems sonography emt emergency medical service sonogram sono echo echocardiogram poc point of care pocus point-of-care
Most paramedics are aware that in the United States, ED physicians have been using ultrasound machines for several years now. Specifically the physicians are doing a Focused Assessment Sonography in Trauma (FAST) or Enhanced FAST (E-FAST) exams. For critical medical patients the Rapid Ultrasound in SHock (RUSH) exam, or similar exam may be performed. This is different from calling in a sonographer or sending the patient to the radiology/ultrasound department for a comprehensive scan. This quick, limited use is known as point-of-care testing and has been extremely useful in quickly refining the correct diagnosis. When I first read an article in JEMS about Odessa Texas Paramedics using an ultrasound machine in an ambulance, I thought to myself this is a crazy idea and it would never fly.
The reasons I thought this would never catch on:
They are too expensive, the machines must cost hundreds of thousands dollars.
Training a paramedic to use the ultrasound machine might take hundreds of additional hours.
EMS agencies would not be reimbursed by insurance companies.
The machines are very complicated to run.
The images are too fuzzy, most paramedics will not be able to read them especially bouncing down the road in a moving ambulance.
All it will tell me is the patient is pregnant.
Scanning a patient will delay definitive care.
Physicians here will never go for this.
Paramedics are not licensed to use an ultrasound machine. It requires radiation technology and ultrasound training to be licensed to use them.
Ultrasound (US) energy is a form of non-ionizing radiation and could be harmful to patients.
Physical Exam can give me the same information.
How is this going to change the care we give?....probably not at all I thought.
Then I did my homework and found that none of these concerns were valid. I remember that when prehospital 12 lead ECG was in its infancy some of the same concerns were voiced by paramedics and physicians alike. I feel a little guilty about my knee-jerk reaction because now that I know more about the technology and what it can offer, I believe it can be of great value to the paramedic, physician and patient.
(1) The first thing I learned is that the prices have been plummeting over the last few years. The current price of some new, low-end devices is around 4 to 8 thousand dollars. They can top out at $70K for new, portable units that are really nice. Physiocontrol/Medtronic has announced a project with Sonosite to incorporate sales of ultrasound machines with future cardiac monitor/defibrillators. Your future heart monitor will probably have this technology built in. Are you going to continue to refuse to use it when it is sitting right in front of you or will you embrace the technology early?
(2) During my research I found that most ED physicians were trained "on the job" in the FAST exam and in only 6 to 24 hours. Most of the studies involving paramedics used a 6 hour training session. As with any other skill, practice and repetition are the keys to competence. Some paramedics will pick it right up and be great at it. Some will be average and some will be weak at the skill. Paramedic resistance to the idea may be due to a fear of not being able to master this skill.
(3) Like any other technology, if we can prove to the insurers that the patients can benefit, there may be reimbursement. It drives me crazy to hear paramedics say, "where are the studies that support its use in the field". You have to put it out there and use it in order to do the studies. At this point there are dozens of studies all very supportive of the idea. In fact, not a single study anywhere suggests that prehospital use had problems or a "downside".
(5) Ultrasound has come a long way. Back in 1980 my good friend Mary Beth, who was the head sonographer at Deaconess Hospital in Buffalo, NY, she showed me the state-of-the-art ultrasound machine she was using at the time. The US machine was as big as a refrigerator back then. She would show me images that I could barely understand. In the early 80s the images were hazy shadows that required a tremendous anatomical and patho-anatomical knowledge to interpret. I was impressed by her ability to read what basically looked like a snow storm on the screen. This is not true today. The images are very clear and most paramedics can immediately identify and understand the underlying anatomy and pathological findings that would be needed in the field. This study showed a 100% agreement between paramedic ultrasound assessments and physician diagnosis. The ultrasound can also be effectively performed in a moving ambulance (backed by a study) and movement artifact is more forgiving than ECG movement artifact. In my experience, this is the most asked question by EMSers.
(6) I was astonished by the number and depth of prehospital uses. In addition to the obvious OB uses, there are as many medical indications as there are trauma indications. My first endeavor into US was to learn about pneumothorax identification. US can be used in 60 seconds to immediately identify a likely pneumothorax. The negative predictive value for pneumothorax using ultrasound is 100%. Pneumos that are even too small to be detected by physical exam or chest x-ray can be easily identified with US. This can quickly be done in a moving ambulance with very little issue of movement artifact. When we breathe, the visceral lung pleura slides against the chest wall if it is intact. By looking for the lung sliding sign in B-Mode or, at the click of a button, M-mode, a paramedic can quickly identify a potential collapsed lung by discriminating between two specific images. The "seashore sign" is the normal lung and the "barcode sign" is the potential pneumothorax. By marching the probe down the chest, looking for "lung point", one can determine how big the collapse is. I am sure paramedics can quickly master this easy task. You can also use color power Doppler to look for lung sliding. This technique is called "Power Slide". There is no question in my mind that the E-FAST would be very useful in EMS. Additional uses include identifying early pregnancy, number of fetuses, fetal heart rate, second trimester issues, delivery position and placental location, the ultrasound can also tell us about cardiac capture during pacing, normal abdomen vs. abdominal bleeding, thoracic bleeding, normal vs. aortic aneurysm, cardiac tamponade, cardiac strength, hydration/volume status, psuedo-EMD vs. true EMD and occult Vf. Yes that's right, in some rare instances Vf exists while asystole is observed on the ECG. Ultrasonography has correctly identified this and allowed for proper defibrillation. A quick ultrasound of the neck can identify if the ET tube is in the esophagus rather than the trachea or allow us to clearly see the distension of the IJ in heart failure assessments (Remember you can't use the EJ for this! The IJ is typically difficult to assess in the field). It takes a little more skill but US guided IVs can be useful in large patients and patients with poor veins. More exotic uses include differentiating CHF/Pulmonary Edema from exacerbated COPD by looking at the number of B-lines in the lungs (see fig. above), detecting pulmonary embolus and identifying skull and long bone fractures. Ocular ultrasound is quick, easy and can detect retinal detachment, papilledema and increased ICP by indirect methods. Graves disease/Hyperthyroidism/thyroid storm has a sensitive and specific finding on ultrasound. There are even high end units that can scan the middle cerebral artery to look for stroke or midline shift indicating swelling. This is by no means a complete list of techniques that could be used in EMS.
(7) All EMS trauma protocols to date indicate that the device will be used on the way to the hospital in a moving ambulance. I believe this may actually shorten scene time because medics will want to get into the ambulance to use this technology. Most authorities say that the average scan time both in the ED and field averages 3 minutes. The ambulance can be moving while the ultrasound machine is in use. For cardiac arrest, where transport is not the priority, ultrasound units are small, battery operated, boot-up in seconds and can be taken to the patient side for immediate detection of the H's and T's. You can easily scan the heart and IVC without interrupting CPR or ventilations. If you think you can accurately and reliably identify the H's and T's without the aid of ultrasound in the arrested patient, you are deluding yourself.
(8) Like anything else, some physicians will love the idea, some will hate it and some will be unsure. I recall many physicians hating the idea of 12 lead machines in the ambulance. They would frown and warn don't waste any time doing them. Back then we never dreamed of bypassing the ED and going directly to the cath lab but this has become commonplace in many cities. Today those same doctors would probably insist that you should have done one at the scene and then several serial ECGs on the way in.
(9) As it turns out, physicians and paramedics are allowed to possess and operate ultrasound machines in every state. A very important point to remember is that our goal is not to become certified ultrasonographers. We only need introductory training to look for a few emergency conditions. This abbreviated style of use goes by many names: limited exam, Point of Care use (POC) , focused examination, goal directed or goal oriented exams. Basically a question is asked i.e. "does the patient have a cardiac effusion?". The clinician would answer yes or no based on the exam. These cursory exams would not take the place of the more formal comprehensive ultrasound study if needed. Credentialing to use ultrasound can come from the hospital, similar to how ED physicians are credentialed or even the EMS educational system can do this. While at a WINFOCUS conference in South Carolina last year I heard a physician lecturer during his plenary presentation say "I object to over regulation of this device! No one credentialed me to use my stethoscope and no one credentialed me to use a 12 lead machine. Just as a nurse or respiratory therapist uses a stethoscope in their own unique way to get answers, I believe the ultrasound machine will be used in a very similar way with each specialty." I absolutely agree with him in that we should not create obstacles that will slow the propagation of this technology out to the patients.
(10) We have more than 50 years of experience with clinical ultrasound. It is true that ultrasound is a form of non-ionizing radiation which can induce some free radicals in tissue, at very high levels it can translocate genetic material. Most notably it can heat, mechanically vibrate and cavitate the tissues. Scientists have known that when very high doses are given over a long time period there are damaging biological effects on tissues. While this is true in the laboratory it has not been observed in the human clinical setting. The technology has a long history of safety and effectiveness. It may even reduce the need for CT and radiographs which expose the patient to ionizing radiation. The amount of US energy we would use in EMS is very small in comparison to a standard full ultrasound study. Currently, there has never been any conclusive link to injury, disease or any other problem with appropriate medical use and supervision.
(11) It's time to come to grips with the truth! Most of our physical exam tests have poor sensitivity and specificity even if they are done properly by experienced providers. Simply put - physical exam and vital sign assessment doesn't work well enough to allow us to make accurate decisions for our patients in a reliable way. Patients with life threatening bleeds can have relatively normal vital signs until it's too late due to vasoconstriction. A patient with a failing heart or severe cardiomyopathy can have perfectly normal 12 Lead EKGs, normal vital signs or even hypertension but if you were to look at the heart you would see a very different clinical picture. An abdomen full of blood can be soft, non-tender with normal vital signs. EMS educators have brain washed you to think that history and physical exam is very accurate. It's not their fault, they were taught that as well. Physical exam is not always accurate or reliable. Some estimates are that it is only 30% in emergency scenarios. That's why docs use more technology to get the answers. History, physical exams AND imaging with ultrasound would give us the best chance at being accurate with our clinical impressions and therefore more accurate with treatment and triage.
(12) How will this change our care? I see real value with looking for pneumothorax, cardiac tamponade and AAA. I believe the E-FAST exam would definitely help trauma patients. Visualizing the IVC volume could be very useful in guiding IV therapy. Looking at heart action in cases of shock could guide more appropriate use of inotropes. Procedurally it can aid with external pacing, help you start a difficult IV and even tell if a tube is in the esophagus. The real value of Paramedic US may be similar to what we, as paramedics, do with the 12 lead ECG. The 12 lead does not drastically change our field care but it sure does dramatically help the patient by ramping up the response at the hospital. The positive ultrasound exam may do the same thing by speeding the patient to the most appropriate location like ED/CT/OR or treatment such as having O- packed cells hanging upon arrival. Only time will tell. I feel with close physician medical control we may be able to help pioneer this technology to better care for our patients. The paramedics and physicians we work with are very clever people. I am sure good things can come from our efforts. You have to try something to succeed at it!
Good links to get started with your education in EMS Ultrasound:
Cross section anatomy Spend some time looking at Plates 5.5, 5.7 and 6.8. The liver, spleen, and full urinary bladder are your "acoustic windows" into the body. When you study these plates try to think about the anatomy in 3D and tomographically.
Great US Intro by Dave Spear, MD. Dr. Spear is one of the pioneers of field US in the USA
Society of Ultrasound in Medical Education Learning Modules (these are very well done)
Vanderbilt has very good POC Ultrasound Training Videos
A very good online slide show by Bassel Ericsoussi, MD
Additional interesting reading and links:
SonoSpot: Topics in Bedside Ultrasound [make sure you read the last line]
US in the field A review
TeleUltrasound another favorable study supporting the idea
Ultrasound Application in EMS JEMS article by Jason Bowman, CCEMT-P, NREMT-P
Mediccast Podcast Host: Jamie Davis RN, NREMT-P with guests Eric Brader, MD and Brian Dunnigan, EMT-P
Mitigation Journal's YouTube video Host: Rick Russotti, FF, EMT-P, CI/C
Mitigation Journal podcast about field ultrasoundHennepin County Medical Center, Minneapolis, MN. Trauma center uses US extensively.
Kidney in health and in disease
Scandinavian Journal 2009 article
GE's Vscan - Cool device but in my opinion not a good choice for EMS. These are fairly delicate devices. No live composite video out connector is a problem. Unfortunately the first model of Vscan can't do lung slide or m-modes. In addition to that it can't do superficial things like look at veins for IV starts. Recently the second generation Vscan has added a dual transducer on the same probe! This does increase the utility of the device. See the new Vscan . If you are into hearts it does directional color flow, records cine loops and can measure Aorta / IVC. It's nice for OB as well. The same is true of the Seimens Acuson P-10 but it has no color flow.
Ok there are some problems to consider
Feeling confident after all of this? Try the ACEP US Exam. It's not easy but you will learn from it.
Ultrasound Podcast . com Great site for ED doc's and paramedics who want to excel at this skill.
The Soundwave of the future. 2006 article
Contact me if you would like me to come out and present a promotional PowerPoint and demo some devices at your location. There is no charge for any location in NYS. I will present to any size group or audience. EMS dinosaurs, hecklers and nonbelievers are not only welcome but encouraged to come. I'll bet I can change their minds. Just invite me and put on the coffee. Some example PPT Slides (12.3 Megs) Contact: Peter@ParamedicUltrasound.com
Originally published to the web: 10/05/2010 Last update: 10/08/2014 21:00:00
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