By: Christopher Matthews
Point of Care (POC) testing has been used by EMS for quite a long time. It allows the EMT and Paramedic to follow up on potential causes of a patient’s condition and rule out the things that could be a distraction to good care.
With POC testing, we can check the patient’s oxygen saturation, carbon dioxide levels, heart rhythm, blood sugar, carboxyhemoglobin, other blood gases, cardiac enzymes, and even the patient’s cholesterol.
POC testing used to take several minutes for each test, but with 21st century technology, multiple test results can be returned to us in less than five minutes. Some of the POC tests we can perform have nearly instant results. This can help guide us to provide more certain patient care. It can also help us avoid performing blanket treatments for several possible conditions, like the old fashioned “coma cocktail”.
We discuss some of the new POC options available for EMS field use in this article below.
I remember the days when having a glucometer was a luxury. We tested on a test strip by wiping the patient’s drops of blood across the strip, then you waited a minute for the color changes on the strip to show the value. It was cutting edge for its day. Now, faster and more accurate technology produces results in less than ten seconds, with microdrops of blood, using alternate testing sites, such as the forearm. A drop of venous blood retrieved from an angiocatheter is acceptable, as newer glucometers can tell the difference between capillary and venous samples. Some glucometers can take an arterial sample and deliver an accurate result.
Not so long ago, we added pulse oximetry (a.k.a., pulsox) into the POC toolbox. That allowed field EMS providers to more accurately detect hypoxia and ventilator effectiveness. It wasn’t the most accurate and even took up to three minutes to accurately reflect oxygenation status. When that technology was upgraded from analog to digital waveform, it became more accurate, even in the presence of motion artifact and poor peripheral perfusion status. With analog, you had to have good, pink, warm skin and have the patient remain motionless to get accurate readings.
Then the next POC advancement was capnometry. Formerly, it was done with colorimetric devices that were useful for about 2 minutes, then were wasted. Now the “luxury” of waveform capnography is considered a standard of care. With capnography, you not only get the most accurate diagnostic tool in our assessment toolkit, but careful observation of the shapes of the waveforms can tell you more than the numeric value it returns.
I’ve been able to prove my so-called seizure patient was drug seeking and faking their seizures with capnography. While the patient was doing the funky chicken, their respiratory rate was calm and even. If the patient were having a real seizure, the monitor would have displayed erratic waveforms and rates, but the monitor’s waveforms were smooth and regular. All of these POC tests we can perform are considered non-invasive and can be performed at the BLS level across the United States, with very rare exception. They’re also relatively inexpensive.
The newest comer to the POC test is the Masimo Rad-57 Carbon Monoxide (CO) detector, which also features pulsox. This is a boon to fire rehab for EMS. We no longer have to assess, transport and treat, and then get an Arterial Blood Gas (ABG) in hopes that readable levels of carboxyhemoglobin (COHgb) still show up. We can get nearly instant readings to see if we need to upload high concentration oxygen, assist with CPAP, or perhaps to warn our destination hospital of the need for a hyperbaric chamber.
One of our industry heroes, Randolph Mantooth a.k.a. Johnny Gage from the 60’s and 70’s TV show, Emergency!, has become an outspoken advocate for CO poisoning awareness in firefighters.
A 12-lead EKG is a POC test too. Properly conducted, these POC tests can prove or disprove certain conditions that can be treated in the prehospital environment. These POC tests can also trigger our well-trained minds to be aware that we need to place an ailing patient at a different emergency care facility, such as a trauma center. These tests may provide us the results we need to decide to bypass a rural facility that offers little more than an urgent care for the one that is another town or city away. The tests may help us choose a hospital that has an ICU, a surgery suite, or more comprehensive diagnostics at their disposal. We may need to alert a critical care unit or aircraft to rendezvous with us to upgrade the level of care during extended transport.
Some forward thinking EMS services are even boldly adding portable ultrasonography machines that can fit in one hand while the other hand manipulates the condenser across the patient’s chest or abdomen. We can use this technology to assess fetal viability, bowel and bladder disorders, cardiac contractility and circulatory volume, or just use a doppler reading to see if the patient even has a pulse that might not otherwise be palpable through the skin by hand or stethoscope.
All of this speaks to what we can already accomplish in the prehospital environment as of the day of this article’s writing, but what will be happening in the future?
Paramedicine is advancing, and we now expect our flight Paramedics to obtain their FP-C (Flight Paramedic–Certified) within a year of hire with a flight service. Many ground services are offering, or even expecting, CCEMT-P (Crtical Care EMT-Paramedic) certification to handle higher tier ALS and critical care transports. Ventilator and IV pump usage are becoming more common in EMS. The NREMT is following the EMS Agenda for the Future and is changing its EMS certification titles to include a more progressive scope of practice. Several EMS services in the US are now training Paramedics with a (further) advanced scope of practice.
You may hear these new levels of Paramedics referred to as Advanced Practice Paramedics (APP) or Community Paramedics (CP). In reality, all these new levels of Paramedic are still realistically equivalent to RN’s, but in practice, these medics are doing the jobs of case managers and social workers, and of mid-level practitioners like NP’s and PA’s. The only thing I have seen missing from the mid-level practitioner role is the prescribing of non-DEA Schedule medications. Hospitals and small labs have been using small platform rapid testing machines for a few years now.
I actually found one of these machines by happenstance back in 2004 and immediately saw a future for them in EMS critical care. Three manufacturers have machines that are adequately sized to fit into the patient compartment of an ambulance or into the back of an SUV for a CP response vehicle. These machines are all approved for use in the USA. I cannot speak to their use in other nations.
Each of these machines is rated to complete their main battery of tests in less than two minutes (cardiac tests excepted, as they typically take 10-15 minutes for results). Each of these machines is capable of producing results for basic electrolytes (Na, K, Ca, Cl), glucose, and hematocrit (Hct). Some are capable of testing blood gases, including some of the most important, COHgb and MetHgb (for Carbon Monoxide (CO) testing). Each of these machines performs its own calibrations automatically, which means it’s more or less a plug and play system. You shouldn’t expend time teaching EMS crews how to calibrate them.