Think ahead: Wouldn’t you like to open the back doors of your just-delivered 2019 ambulance and find it equipped with one of Star Trek’s wireless “medical tri-corders,” allowing you to assess and diagnose patients simply by waving a handheld sensor?
We’re not there yet, but today we’re on the leading edge of a complete revolution in EMS biometric technologies. We’re about to see data collected and presented to responders in new ways, data from new sources such as consumer technologies on smartphones, and data shared wirelessly across the care continuum.
But first, let’s hit the rewind button and look at some of the early monitor defibrillators such as the Physio-Control LifePak 5, the ZOLL 1600 and others that us “old guys” lugged around. They were pretty basic: a screen, a single-lead ECG strip recorder and a synchable defibrillator. Over time, every new generation of monitor bolted on one biometric sensor after another—SpO2, EtCO2, 12- and 15-lead ECG, noninvasive blood pressure, temperature, invasive inputs and now carboxyhemoglobin, all crammed into new bump-outs on the defibrillator’s bulging housing, driving up weight, footprint and battery demands.
But for all its simplicity, the LifePak 5 had a feature we predict will make a comeback: the ability to detach the monitor module from the defibrillator module. Lots of us would routinely slide off the LifePak 5’s defibrillator side when heading into a trauma center or other situations where the ECG module alone was safe and most useful.
Since we only shock about 0.5% of patients, and defibrillators are getting smaller and lighter, splitting these two functions makes a lot of sense. Two manufacturers are showing us the way on this, and others are likely to follow.
The Bavaria-based GS Elektromed corpuls3 device—now gaining popularity in Europe, Asia and Australia—features a 2-lb. compact wireless biometrics package (containing all leads, ECG and sensor features, and a backup screen) sits with the patient, but can be re-docked with the defibrillator and large display screen when needed. Full wireless connectivity between the modules (and back to hospitals and host data networks) is coming, a feature that will revolutionize its flexibility.
The Tempus Pro from English manufacturer RDT sheds the defibrillator entirely, but provides a dense package of all the regular sensors and ECG features, along with encrypted communications capabilities, including live video, voice and still transmission, as well as onboard ultrasound and video laryngoscopy devices. Designed to link a remote consulting physician directly to the scene of the emergency, it also has embedded full-feature electronic patient care record (ePCR) software, allowing bedside documentation and immediate integration of biometric trend data for both the medic and the consulting physician.
As our understanding of resuscitation grows, a compact defibrillator makes a lot of sense. Do you really need batteries that deliver 200 shocks in a row? And moving shock data around on data cards or flash drives—really? Direct wireless transmission of defibrillator data to ePCRs isn’t far off.
Beyond changes in packaging, new on-scene diagnostic and biometric capabilities are emerging. Before we look at these, it’s worth asking some important clinical questions:
- What scientific evidence supports a new sensor’s ability to enhance patient outcomes or decisively alter prehospital care in our system?
- Does this device promote situational awareness or contribute to information overload, particularly for less experienced providers?
- Does this device help us understand a patient’s progression over time, or simply bombard us with snapshot values that providers have to integrate in their heads?
- Is this the best way to spend EMS dollars?
As in all of medicine, there are lots of things we could do on-scene, but only a limited number of things we should do. Knowing the difference is key. Above all, new medical devices shouldn’t be bought for bragging rights.
So let’s look a bit of what’s out there.
Novel noninvasive blood pressure (BP) monitoring: BP derived from pulse oximetry sensors or from pressure transducers may give us continuous BP measurement and reduce errors arising from conventional cuff-based devices. This is potentially very useful (think post-arrest patients), particularly if more accurate than episodic manual monitoring using a classic cuff.
Carboxyhemoglobin monitoring: This technique is being heavily marketed in EMS and may be useful in detecting occult carbon monoxide poisoning in the asymptomatic patient. It remains unclear whether it will substantially alter the prehospital care of symptomatic patients, particularly as hyperbaric oxygen treatment remains controversial.
Blood alcohol content (BAC) measurement: Many EMS systems are using handheld “breathalyzer” BAC measurement as part of screening patients for diversion to detoxification centers and behavioral health facilities instead of EDs.
Point-of-care blood lab testing: Potentially useful for lactate in suspected shock, particularly sepsis, as well as other “panels” such as cardiac enzymes. It’s also potentially useful in mobile integrated healthcare and remote primary care programs, but may be subject to substantial regulatory controls, including the need for a mobile health lab license in some jurisdictions, as well as mandated calibration and other quality controls.
Tissue perfusion monitoring: This technology, which identifies hypooxygenation and/or rising CO2 in peripheral tissue in shock patients, is very promising. The European Society of Intensive Care Medicine’s November 2014 consensus on shock management indicates large-scale trials of these technologies are still needed and recommends they should remain used in research only at this time.
Ultrasound: EMS-based devices able to provide on-scene ultrasound imaging may eventually prove useful in austere or remote environments where studies such as an early focused assessment with sonography for trauma exam might be useful, to assess cardiac wall motion in pulseless electrical activity, or to assist in placement of certain IV lines. While there’s some evidence medics can be trained to perform these exams, it remains unclear whether this is a transformative technology for most prehospital decision-making.
Telepresence: We can’t always bring a doctor to the scene, but we can bring the scene to our physicians through telepresence audio-video links. Although initially proposed to “let the trauma doc see his patient before arrival,” in most EMS systems, telepresence is likely to find its niche in cases when paramedics are considering not transporting a patient or referring them to other health resources, or when patient appearance or symptoms perplex on-scene providers.
Voice-activated interfaces: Wouldn’t it be great to dictate your assessment findings at the patient’s bedside right to your ePCR without touching a keypad? Consistently reliable voice-activated ePCR recording or device operation remains a future prospect in the noisy and stressful environment of EMS. However, today’s sensor-packed and data-rich “big-box” monitors currently do have a downside. Fast-changing technologies such as wireless data transmission can mean your new monitor may be obsolete in some way even before the check clears. At this point, the complexity of FDA device recertification and the business model surrounding defibrillator sales discourage vendors from offering fully modular designs allowing stepwise upgrades that would keep devices continuously current.
Consumer-Supplied Data & Data Integration
Perhaps we’re on the edge of something even bigger—new ways to really know what’s going on with a patient before the ambulance is even dispatched. EMS providers pride themselves in “starting care when the phone rings” through EMD pre-arrival instructions and carefully designed caller interview questions. But wouldn’t real patient vitals, even an ECG, be helpful too? In a world of hypervigilant obsessive people, consumer-level biometric monitoring is a reality on smartphones today and therefore instantly transmissible worldwide. Let’s start to use it!
Consider the following case: A 58-year-old man calls 9-1-1 and says he’s “feeling faint.” Without other symptoms or specific history, EMS call priority algorithms might classify this as low priority, eligible for an extended response time. What if this patient could place his thumb on an iPhone sensor and send us a basic ECG?
That’s not the future, that’s today! A $75 iPhone clip-on allows patients to record and transmit a usable Lead I ECG. It’s not a home 12-lead, but a tracing that looks like v tach or perhaps bradycardia at 30 beats per minute would change this call interview from guesswork to a real emergency. Once in the dispatch center, this data should appear on the responding crew’s mobile data terminal and move right into their ePCR record like CAD times do today.
With home Wi-Fi and contemporary consumer technologies, we can now receive a wide range of patient biometrics, including blood pressure, pulse rate, SpO2 and blood sugar. So many of our dispatch questions are geared to inferring alterations in these vital signs—a guess at best—that real data would at least alert us to possible alterations that deserve a rapid response.
When really bad things happen, getting EMS real-time data really counts. Wouldn’t be it incredibly helpful if every AED called 9-1-1 the moment it was powered up, sending dispatchers and all responders the exact GPS coordinates of the cardiac arrest, and ECG segments on arrival and after every analysis or shock? How about opening a twoway voice link directly to the device so that EMDs can ensure CPR is started and assist in managing the arrest before 9-1-1 responders can arrive?
When airbags deploy, many cars report the crash to highly sophisticated call centers operated by OnStar or ATX. The automatic crash notification (ACN) data flow sent from onboard sensors can tell us a lot about crash dynamics and severity, but few EMS systems actually use this data to decide an appropriate response, and transmission of this data to responders is nearly unheard of. Ironically, the on-scene picture could be even clearer. There remains great reluctance to transmit some key data via ACN because some vehicle owners and litigation attorneys may not want 9-1-1 to receive an indisputable record of certain parameters at the moment of the crash.
As technology advances, we’re seeing the lines between traditional devices and traditional uses of the 9-1-1 system blurred through convergence of consumer data, defibrillator data, biometrics, EMS ePCR systems and the patient’s ongoing master electronic medical record (EMR). Do we really need a full-function laptop running standalone ePCR software, or should that live on the monitor, or maybe on a smartphone? Since we see many patients more than once, we should have full access to all previous EMS and ED encounters, including 12-leads and other key data.
Internet-based data systems will increasingly free us from owning and maintaining our own data hardware and software, and will be key to knitting together the patient’s full medical story, both to better inform on-scene decisions, and to ensure our findings and care are available to everyone else who sees the patient. We’re seeing fledgling products emerge to test all of these possibilities, but, like in-hospital EMR systems, we’re a long way from seamless data.
As we put away the EMS crystal ball, a final reality check: We treat patients, not monitors. Lots of patient data is great, but it must be presented in a timely and useful manner. It’s our cumulative clinical experience and training that lets us interpret that data and decide what a patient actually needs during EMS care. These devices will never be a substitute for being astute clinicians, nor for the kindness and gentle touch of a person who cares.