Medic word problems: Calculating drug dosages
What is your organization doing to enhance medics’ mathematical skills in the field?
Recently, one of my students presented a topic on vasopressors, specifically the use of push-dose epi versus the use of dopamine. An anecdote during his presentation struck a nerve. He said, “The old paramedics like the push-dose epi, and the newer paramedics like to use dopamine,” which made me question how he arrived at this conclusion. Is this true, and why would the veteran medics prefer push-dose pressors over infusions?
He succinctly responded that it is easier to calculate push-dose medications than to calculate infusions. Even though his analysis comes from a limited data set, his assumption is likely accurate.
In my experience, the old timers (and I fall into this category) are not enthusiastic about change and do not tend to be the progressive medicine type. However, is the lack of continuing education on medication calculations leading to skill degradation?
Calculating medication doses or drip rates is not a skill EMS professionals use every shift, and when the skill is required, it is often in high-stress situations – the patient’s condition is deteriorating rapidly, the family is yelling in the background, the new EMT is running around the room aimlessly (not that this would ever happen), and over at the patient’s side, the medic must work a medication word problem to get the correct dose or drip-rate quickly.
I don’t know about you, but word problems were my archenemy in school. Math in a controlled setting is complicated, even more so in an uncontrolled setting where excess noise or external stimulation will make it more challenging.
Without preparation, this is a recipe for disaster, more specifically, medication errors and poor patient outcomes. In many situations (if not most), we use premixed medications, which require little-to-no thought regarding a calculated dose. But what about the infrequently used medications we must mix and calculate?
In today’s world, many of us have come to rely heavily on phone apps and Google for the answer to our medication questions, and that is OK, but what if cell service is poor or your phone dies? Internet tools are an excellent source to access information regarding medications. Using these tools is suitable to confirm drug dose calculations or refresh our minds regarding an infrequently used medication. However, for our frequently used medications, we must commit to memory how the medications work (mechanism of action), proper dosing and formulas for quick recall when needed. One could argue we should know the infrequently used medications as well, and I would not disagree.
Another threat to knowledge degradation of old-school calculation methods is the introduction of intravenous infusion pump technology into the prehospital space. Infusing (pun intended) this technology into the prehospital setting is the right thing to do and it’s a valuable tool for paramedics. However, it should not supersede the paramedic’s responsibility to know how to manually calculate drip rates when needed. Technology can fail, and medics may be forced into using formulas they learned in paramedic school.
Paramedic students frequently come into the classroom with new shortcuts they’ve learned from preceptors during field internships or clinical rotations. These calculations may originate with dinosaur medics who were trained on shortcut methods like the clock for dopamine and lidocaine drips, or it may simply be laziness. What has the industry done to foster this lack of skill?
Ask yourself when was the last time your service offered continuing education focused on medications in your protocol or when you last worked through medication calculations on concentration, drip rate or dosage formulas? Have you regularly applied these tools in simulated high-stress situations? I suspect the answer is not frequently enough.
In 2000, there was a study performed in which paramedic participants reported that drug calculations were “infrequently performed in daily practice and were rarely a topic of continuing education programs” . Even though this study is more than 20 years old, not much has changed since. This study suggests that pharmacology and medication calculation training should occur more frequently. This skill – and yes, it is a skill – is vital to patient outcomes and patient safety.
In a retrospective literature review published in the “Western Journal of Emergency Medicine” in 2009, an extensive study of 523 paramedics found a significant mathematical gap between an unaided group of paramedics who answered 65% of the questions correctly, compared to an aided group who answered 95% correctly . The study suggested several factors contributed to the poor mathematical ability of paramedics – “varying pressures and extraneous variables unique to this discipline” – including time, environment, managing distressed individuals and managing critically ill patients, as well as skills decay and poor initial mathematical education . This should raise great concern and encourage administrators to prioritize training on this topic. Improving paramedic proficiency in calculating medications will improve confidence in using formulas and simple math.
How to build calculation skills
Spend time remediating drug calculation formulas, conversions and methods more frequently with your staff. Opportunities to use these skills in the field are infrequent. Implore your organizations to conduct more training on these topics. Studies have revealed that high-stress situations complicate medication dose calculations, and medication errors are likely to occur.
Frequent training and education in low and high-stress conditions, including simulation training, will help build lacking skills and significantly reduce degradation . Having students practice these skills in simulated critical care situations in which decisions and calculations must be made quickly will help prepare them for the real world when their sympathetic nervous system kicks into high gear.
Read more: 5 ways to eliminate dosing errors
1. Hubble MW, Paschal KR, Sanders TA. (2000). Medication calculation skills of practicing paramedics. Prehospital emergency care, 4(3), 253–260. https://doi.org/10.1080/10903120090941290
2. Eastwood KJ, Boyle MJ, Williams B. (2009). Paramedics’ ability to perform drug calculations. The western journal of emergency medicine, 10(4), 240–243.