The EMS Detective

Using critical thinking with a prioritization, situation and analysis formula can help you avoid serious errors in judgment when assessing and treating patients. EMS providers must act as detectives, especially when basing judgment on information obtained from other personnel or bystanders at a scene. That information may be useful, but you must do your own assessments and evaluations if you want to do your job well.

First, prioritize. While doing your ABCs, think about the situation in general. Next, collect data: vital signs, history of present illness and past medical history, then analyze the data and make connections. Finally, take action, if you haven't already, and gather more data or reassess, reanalyze and evaluate the outcome of the actions already taken while en route to the ED. The following case review illustrates all these points.

Case Review

A skilled nursing facility calls dispatch to request an ambulance for a 61-year-old woman complaining of severe knee pain. Upon your arrival at the facility, the nurse sitting behind the desk nonchalantly informs you that the patient had a portable/mobile x-ray of her right knee and it was negative. No fracture, no trauma was involved, and she seems sorry about having to call. She continues to chat with your partner from behind the desk, as if nothing is wrong.

Upon entering the room, you find the patient supine in bed, alert and oriented, skin warm and dry, complaining of severe pain in her right knee. As she tells you what's wrong, you can see there is edema just above her knee and deformity at the patellar area. You check vital signs, which are: BP 140/80, HR 68, respirations 20 and pulse ox on room air is 92%. After you administer oxygen, her pulse ox improves to 99%. Pedal pulses are present but unequal, with the right bounding and the left barely palpable. She says she has no other symptoms and no trauma has occurred. When questioned further, she tells you she may have injured herself three days earlier when getting in and out of her daughter's car ":about three times." You can see from the paperwork that she has a history of recent tumor surgery and osteoporosis, and she tells you she had carpal tunnel surgery in the past. She is obese, with no cardiac history. The monitor shows an irregular rhythm from 68 to 108, and is in bigeminy. Having already placed her on oxygen, you decide to transport with full leg immobilization, request med control for an order of morphine for pain (which was 10 on a 1--10 pain scale) and hope the ED takes your patient's obvious fracture and what you suspect is a pulmonary embolus a little more seriously than the nurse back at the nursing home. Even though the patient had no chest pain and her lung sounds were clear, these were the diagnoses upon her admission to the hospital.

Let's analyze what might have happened in this case. If you are going to be a good detective, you must be continually thinking and analyzing. Use all of the information at your disposal. Don't take things at face value, and don't stop thinking just because the nurse or doc is unimpressed. Don't automatically think, "The x-ray showed no fracture, so there must not be one," or "Maybe there's something to this knee pain, but there can't be anything else wrong." In fact, there can be more than one thing at a time going on, and many times there will be. Just because the patient is not complaining of chest pain does not necessarily mean no cardiac problem exists. She says she is only slightly short of breath and she is sure it's due to the pain, but is it? Assess the patient. Does she have shallow, irregular respirations, or is she breathing normally? Does her story fit what you see? Use other people's clues in your analysis and decision-making if they work, but don't automatically use those clues as the basis for what you are going to do when you treat your patients.

Sometimes, we run into people who are overexcited about a patient. In that instance, it seems we should take a step back or timeout to look at the situation, data, analysis, connections and action at a slightly slower pace. Surely, if an overexcited person is trying to convince you that a loved one is near death and the patient is sitting up, breathing, talking coherently and in no distress, you can take that little timeout. In the reverse case, if a patient is telling you he is fine and "nothing's wrong," but you can hear him wheezing from across the room, you are going to continue trying to treat.

In the above-mentioned case, think, "Just because the nurse was not impressed doesn't mean I don't have to be. Our patient has been complaining of severe pain. Something has to be wrong." Start looking for answers. The patient reports that no trauma was involved, but something happened. Try asking the same question in another way. "You say you didn't fall or hurt your knee, so have you any idea how this might have happened?" The patient may still not have any idea what happened to her, but she might be able to tell you when the pain started and the type of pain she is feeling. Visually, our patient's right knee looked deformed and there was edema above the patella. Palpation can also help. Is it cooler than the other leg? Is it warmer? Is there crepitus? In this situation, the pedal pulses were very unequal, which could be caused by AAA (abdominal aortic aneurysm), diabetes, PVD (peripheral vascular disease), septicemia or shock. In this case, it's most likely that the bounding pulse on the side of the break was the result of pain and possibly infection.

Bones break due to trauma, simply because they are weak, or when there is a tumor or infection. These are called pathological fractures. The most common femur (or hip) fractures are femoral neck fractures or intertrochanteric femur fractures. These are fractures that occur up high near the hip and are the ones we are used to seeing with dramatic rotation and shortening of the affected leg. But there is an unusual fracture called a supracondylar femur fracture, which is a break just above the knee joint. There are several reasons why this patient's x-ray may not have shown her fracture: The x-ray was not clear; portable x-rays may not be as easy to read as the standard in-hospital type; or, the fracture was simply missed. In this patient, the x-ray may not have been taken at the actual site of the break. In any case, it was missed.

Let's look at the patient's second condition, pulmonary embolism, in the same way. She wasn't complaining of chest pain, but she had a broken bone in her leg, a low pulse ox, a history of recent surgery, slight shortness of breath and sudden-onset irregular cardiac rhythm. When blood clots form, they can travel from one part of the body to another. This is called an embolus. Sometimes other substances, like pieces of a tumor, fat from fractured bones or air, can enter the blood and create a blockage. These clots can travel through the bloodstream and into the lungs, where they become a true life-threatening emergency.

Causes of pulmonary embolism include: inherited tendencies, surgery, long periods of bed rest or inactivity (pulmonary embolus is the third leading cause of death in hospitals), certain types of cancer, birth control pills, stroke, myocardial infarct, amniotic fluid embolus in pregnancy and injury to the veins. Pulmonary embolus is third on the list of most common causes of death in the United States. The symptoms of a PE can include chest, back, shoulder or abdominal pain; syncope; hemoptysis; shortness of breath; new-onset wheezing; cyanosis; and new cardiac arrhythmias. However, these symptoms may or not be present, which can make diagnosis in the field elusive.

EMS providers must think like detectives. Listen to the story, then decide whether it makes sense. Don't take things at face value. Put the pieces together, get the real picture and treat appropriately. Using the prioritization, situation and analysis formula can aid in your lifesaving capabilities. Although PE is often fatal, prompt diagnosis and treatment can reduce the mortality rate dramatically. The classic triad of PE signs and symptoms (hemoptysis, dyspnea, chest pain) are neither sensitive nor specific and occur in fewer than 20% of patients in whom the diagnosis is made. Of patients who die from massive PE, only 60% have dyspnea, 17% have chest pain and 3% have hemoptysis. This patient survived her injuries due to the paramedics' vigilance, and competent care in the ED and her subsequent hospital stay.

Differential Diagnoses: Pulmonary Embolism

• Acute coronary syndrome
• Acute respiratory distress
• Altitude illness
• Acute anemia
• Aortic stenosis
• Asthma
• Atrial fibrillation
• Cardiomyopathy
• COPD
• Mitral stenosis
• Myocardial infarction
• Myocarditis
• Pericarditis and cardiac tamponade
• Pulmonary edema
• Pneumonia
• Pneumothorax
• Pulmonary embolism
• Pulmonic valvular stenosis
• Respiratory distress
• Shock, cardiogenic
• Syncope
• Toxic shock syndrome

According to emedicine.com, a small number of often-repeated mistakes in diagnosis and treatment are responsible for a large proportion of the bad outcomes with serious legal repercussions. The most common and most serious of these errors are:

• Dismissing complaints of unexplained shortness of breath as anxiety or hyperventilation without an adequate workup.
• Dismissing complaints of unexplained chest pain as musculoskeletal pain without an adequate workup.
• Failure to properly diagnose and treat symptomatic DVT.
• Failure to recognize that DVT just below the knee is just as serious as more proximal DVT.
• Failure to order a V/Q scan when a patient has symptoms consistent with PE. (A V/Q scan is a ventilation and perfusion scan that uses inhaled and injected material to measure breathing and circulation in all areas of the lung.)
• Failure to pursue the diagnosis after a V/Q scan that is not perfectly normal.
• Failure to start full-dose heparin at the first real suspicion of PE, before the V/Q scan.
• Failure to give fibrinolytic therapy immediately when a patient with PE becomes hemodynamically unstable.

Special concerns: DVT and PE are common during all trimesters of pregnancy and 6--12 weeks after delivery. PE is increasingly common with age.

Bibliography

• www.mayoclinic.com
• http://emedicine.medscape.com

Judy Torres, BFA, JD, EMT-P, is a paramedic with Tri County Ambulance in Mentor, OH, and also works for Saint Vincent Charity Hospital in Cleveland.