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Beyond the Basics: The Art of Critical Thinking Part 1


     The ability to think critically is desired by EMS providers at every level and may largely be a measure of success, yet the concept isn't easily defined, quantified or taught. This month's article will discuss the concepts of critical thinking and critical decision-making. Next month's case presentations will give readers an opportunity to apply the concepts presented here.

     Critical thinking isn't limited to medicine. It is used in many parts of our daily lives. Consider an everyday event that occurred recently:

     When I tried to start my car, it didn't want to catch. When it finally started, it bucked and sputtered. Then the check-engine light came on. I was about to go to a meeting two hours away and was hesitant to drive it.

     The car was relatively new and well-maintained. There were no odors, no unusual sounds and no stains on the floor indicating leaking fluids. The gas gauge was between 1/8 full and empty. It had been rainy for weeks.

     I questioned whether I should take the car on the trip or bring it to the shop and decided that driving it wouldn't cause damage. Bringing it to the shop would cost hundreds in diagnostics that I didn't want to pay if not necessary.

     I drove it to a gas station, put in some dry gas, then filled the tank. I drove it around town for a few minutes to see if the car ran better. It did. The check-engine light went off, and I drove to the meeting uneventfully.

     This real-life example demonstrates the components of a critical thinking process: identifying a problem (chief complaint), gathering facts (history and physical exam), identifying possibilities and narrowing them to probabilities (differential diagnosis), developing a plan, evaluating risks vs. benefits, and implementing the plan. This article will focus on the thinking process, i.e., how to get to the treatment choices, rather than the treatment itself.

     In Rosen's Emergency Medicine, Chapman, et al, describe the critical thinking process as having three parts: medical inquiry (history, physical exam and diagnostic testing), clinical decision-making (a cognitive process that evaluates information to diagnose or manage a patient's condition) and clinical reasoning, which involves both medical inquiry and clinical decision-making.

     In fact, proper decisions are made after evaluating necessary, accurate information. The relationship between decision-making and reasoning is a continuous process—a feedback loop rather than a straight line from assessment to care. New information is evaluated as it is obtained and applied to the body of knowledge about the patient's condition.

     The concept of critical thinking is more than a process; it is a mindset. This discussion is a good time to revisit the difference between a technician and a clinician. In the context of this article, the ability to apply clinical reasoning to a patient problem belongs exclusively to the clinician.

     A technician is not expected to use high levels of reasoning skills. Technicians are strictly protocol driven and respond in a specific way when a certain group of signs and symptoms appear.

     Clinicians gather pertinent information from many sources, carefully evaluate that information and develop a treatment plan from protocols or a series of protocols that will benefit the patient.

     There is a difference between a clinician and a technician in EMS (see sidebar at end of article). Part of the difference involves the provider's training and experience. The second, and perhaps the most important, is the clinician's mind-set.

     Clinicians aren't satisfied by observing superficial information or apparent patterns. They look at each patient as a challenge and seek out pertinent assessment information, even on the patients who appear to have an obvious presenting problem.

     Look at this from another perspective—you as a patient. Who would you want for your primary care provider? Would you want someone who came in, did a few perfunctory tests and made an assumption and a treatment decision based on this scant information? Or would you prefer the person who listens to you, looks at a variety of possibilities (differential diagnosis, discussed below) to find the most likely cause of your condition, and tests and treats accordingly? Like most, you would choose the latter—the clinician.

     Our training in initial assessment and the ABCs provides weak preparation for the wide range of life threats we see in the field. Opening the airway, checking for breathing and looking for and controlling bleeding are a small portion of this initial process.

     The initial assessment (or primary assessment, as it appears in the new education standards) is a foundation for the entire call and can't be completed without touching the patient—contrary to practical exam wisdom.

     During the process, you should also be able to identify breathing problems (requires exposing the patient, a stethoscope and, in some cases, palpation), including pneumothorax, open chest injury and inadequate breathing; identify shock (by a quick note of skin condition, pulse rate and quality); and decide if the patient is a load-and-go priority.

     Patient care is part of this early process, including oxygen and ventilation if necessary.

     There are many within and outside EMS who believe the forced mantra that EMS providers don't diagnose.

     While we may not be given the full spectrum of diagnostic modalities of in-hospital clinicians, we have an ever-expanding toolbox and quite an arsenal of treatments to employ based on our assessment findings. Sometimes called a presumptive or field diagnosis, it is an important responsibility, because the clinician makes treatment decisions based upon it.

     The differential diagnostic approach isn't limited to advanced level providers or based on license level, but is fueled by solid initial training, quality continuing education, field experience and clinical mentoring at any level of EMS certification or licensure.

     Consider the following case:

     You are called to a patient who complains of chest pain. The 55-year- old man has a history of angina and hypertension. He describes the pain as slightly to the left of center of his chest and radiating to his throat. It is different than any time he had angina in the past. He took one nitro without relief. You complete vitals and find his pulse is 104, blood pressure 130/84, respirations 20 and slightly labored. His skin is warm and slightly moist.

     An EMT following protocol would likely assist the patient with a second and third nitroglycerin. An advanced provider would have the option of administering a nitro from the drug box in the event the patient's meds were outdated and ineffective.

     But is this cardiac pain?

     The clinician listens to the patient and gets a thorough description of the pain. While it appears to be cardiac because of radiation to the throat, it is atypical for the patient and worthy of additional assessment.

     To be most effective, the provider—at any level—uses a differential diagnostic approach and develops a list of possible causes of the chest pain. This might include myocardial infarction, pneumonia, pneumothorax, pulmonary embolus, proximal aortic dissection and trauma (rib fracture, muscle pull).

     With the exception of diagnostic 12-lead monitoring, methods of evaluating and narrowing possibilities down to probabilities exist at all levels of EMS education for those who think like a clinician. Even if treatment options for each condition aren't available, the information obtained from the examination can promote more effective calls for ALS assist and alert the hospital of potentially serious conditions promptly.

     The goal of the differential diagnostic process is to narrow a wide range of possibilities down to probabilities. Consider Table 1 to either rule out or include any of the items in this patient's differential diagnosis.

     Upon development of the list of differentials, the actual exams and history items don't add significant initial time and are clinically very relevant.

     The patient denies trauma. The area is non-tender to palpation. He denies immobilization, fever, cough or other illness. Lung sounds are present, clear and equal bilaterally. The exam reveals a radial pulse deficit with a blood pressure in the left arm now at 130/90 while the right arm is 90/60.

     Suddenly, aspirin and a second nitroglycerin aren't looking as appealing as they did a few minutes ago.

     The process is not without pitfalls. The clinician must also know the pitfalls and balance risk versus benefits appropriately (the clinical reasoning process). For example, it has been reported that 10%–15% of patients with myocardial infarction report their pain as pleuritic or affected by movement. It would be unwise to rule out any condition or to advise against treatment and transport based on any single finding.

     An experienced provider realizes that the first planned assessments are rarely enough. Findings from the first assessments will bring up additional questions—or even take the provider in an entirely different direction. In fact, the assessment process is dynamic and directly linked to the differential diagnostic process described above. While it isn't within the scope of this article to discuss every possible history and assessment technique, we will provide some high-yield favorites.

  • In the SAMPLE history, look for key information—especially in "events." It is last in sequence but among the first in importance. Especially valuable in altered mental status cases, the events can be an important piece of the puzzle in building a clinical case for seizure vs. simple fainting vs. more serious pathologies. Specifically probe for prodromal signs and symptoms, such as dizziness, weakness, palpitations, changes in skin color, temperature and condition before the episode, and whether the patient was able to lower himself to the ground or if he dropped like a rock. Patients are often able to describe a feeling of their vision closing in—described as blackout or whiting out.
  • Listen to lung sounds properly and in a setting where it is possible to hear them. While we wish to make diagnostic decisions based on these sounds, the assessment is often inadequate. Many providers listen to lung sounds over only one or two locations (often only anteriorly). Lung sounds must be listened to for a full cycle and in multiple locations. In wheezes and other lung sounds, it is not enough to note they are present; it should be noted where in the respiratory cycle these sounds are heard. Due to the structure of the lungs, if you haven't auscultated posteriorly, you haven't heard the lower lobes.
  • Use orthostatic vital signs—safely. Orthostatic vital signs are somewhat misunderstood and often misapplied. The general concept is to take the vital signs after a patient has been supine for about 10 minutes prior to the exam. Have the patient stand and take the vitals immediately. Take them again in two minutes. Pulse elevation of 10–20 beats per minute or blood pressure decrease of 10–20 mmHg may indicate blood or other significant volume loss. Be sure to support the patient. If the patient feels dizzy or faint, stop the test and consider it positive. Rates indicating hypo-volemia may vary in the elderly and in those taking medications that slow the pulse (e.g., beta blockers).
  • Consider risk factors. This is a standard practice for in-hospital clinicians. It is used less in the field. Smoking, diabetes, obesity and hypertension are all significant risk factors for myocardial infarction. While these aren't the definite smoking gun we would like for diagnosis, when weighted properly, they may make the difference in some precautionary treatment and transport decisions.

     If every patient came with a diagnosis, EMS would be boring. Even a run-of-the-mill nursing home transfer contains a wealth of clinical challenges by providing patients with multiple conditions.

     Patients often throw us curves—and only the clinicians among us are there to catch them. Remain open to the fact that patients may have co-existing conditions. Pneumonia and urinary tract infections are common causes of sepsis. Medications mask the reactions to illness and injury. Geriatric patients present differently in many disease states. Occasionally, the patient's complaint isn't even the most serious problem you uncover.

     It is up to the clinician to determine what findings are important and in what proportion.

     To many providers, especially those new to their level of certification, care is about performing modalities. Experienced providers know that care is a carefully balanced event. It is balanced between need and risk, standing order and online consult, and present need at the scene vs. consideration of hospital care down the line. In some cases, oxygen and calming are prudent, powerful treatments.

     Care plans fit into the continuum of clinical reasoning in that constant monitoring for therapeutic benefit or adverse reaction is necessary, and the patient's response to a particular modality may be diagnostic.

     Remember that each patient contact is a clinical mystery waiting to be solved and an educational experience that builds the foundation of a true clinician.

SIDEBAR: Technician vs. Clinician
     EMS is summoned by a 73-year-old female who is having difficulty breathing. When the crew arrives, the woman is sitting in the tripod position with her feet dangling over the side of her bed. She says she suddenly developed difficulty breathing.

     While obtaining a pertinent history and administering oxygen, EMS finds Dura-Vent and Nasonex. The patient says that her doctor gave her the medications for allergies when she went in for wheezing about 10 days ago. Her only history is hypertension, for which she hasn't refilled her prescription in some time.

     She does, in fact, have some scattered wheezes, and her blood pressure is on the high side.

     From this point on, the technician and clinician take different approaches.

     The technician hears wheezes, notes that there is a treatment for recently diagnosed wheezes present and either assists with the inhaler or provides albuterol by small volume nebulizer.

     The clinician uses a differential diagnostic process to identify causes for the patient's condition. Through this process and the accompanying respiratory and cardiac work-up, it is determined that the patient has had a recent weight gain, complained about abdominal ascites, had difficulty breathing when walking up stairs at home and began sleeping in her chair due to orthopnea. She quit smoking many years ago and denies occupational or other exposure to respiratory toxins.

     This information combined with the history of hypertension—a risk factor for heart failure—led the clinician to correctly determine the patient was experiencing congestive heart failure and begin appropriate therapy.

     It is important to note that the technician versus clinician discussion is not an attack on any specific level of provider. In fact, within each level of provider there are technicians and clinicians.

     An EMT who is a thinking clinician is able to identify patients who are stable or unstable and require prompt transport. The EMT clinician also makes decisions such as when to call for advanced life support or air-medical evacuation, when to perform a rapid extrication and when to immobilize the patient before removing him from the vehicle.

     In most cases, clinicians aren't created in class—they are developed on the street through experience, continuing education and clinical mentoring.

     Regardless of your level of training, strive to be a clinician.

Daniel Limmer, AS, EMT-P, has been involved in EMS for 31 years. A passionate educator, Dan teaches basic, advanced and continuing education EMS courses throughout the country.

Joseph J. Mistovich, Med, NREMT-P, is a professor and chair of the Department of Health Professions at Youngstown (OH) State University, author of several EMS textbooks and a nationally recognized lecturer.

William S. Krost, MBA, NREMT-P, is an adjunct assistant professor of emergency medicine at The George Washington University.

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