Assessment and vital signs are some of the most basic but powerful ways EMS providers have to develop the clinical picture of their patients. While these techniques are relatively simple, there are possible pitfalls to each step which must be avoided to determine clearly what is going on with your patient.
Here are five patient assessment errors to avoid:
1. Avoid taking a pulse oximetry reading at face value
Pulse oximetry can be a helpful tool when assessing many patients, including those with an altered level of consciousness. Hypoxia is a potential explanation for confusion and decreased mental status but is by no means the only cause. It is important for EMS providers to remember what pulse oximetry is measuring – particularly when findings are abnormal.
Pulse oximetry ultimately measures the percentage of hemoglobin molecules in the blood which are saturated. While this reading often correlates well to the patient’s level of oxygenation, it may not in some instances.
For example, if a patient is anemic, the available hemoglobin may be fully saturated, but the tissues of the body could be oxygen deprived. Also, if a patient is cold, their extremities may experience vasoconstriction as the body shunts blood to the core. This reduction in blood flow to the finger with the probe may show abnormally low SpO2 readings. Finally, other gases like carbon monoxide may preferentially bind to hemoglobin, showing a high pulse oximetry reading with the patient still in a hypoxic state.
Providers should be sure to take a patient’s entire presentation into account when determining the accuracy of a pulse oximetry reading.
2. Check your thermometer’s temperature
Most of the equipment on your ambulance has a temperature range in which it is designed to operate. With a few exceptions, most of this equipment will function all around the world without difficulty.
One piece of equipment to be aware of, however, is your thermometer. A cold thermometer may not accurately read a patient’s temperature and could give an inaccurate low measurement.
Many EMS services are carrying temporal thermometers and at least one manufacturer recommends that the operating environment for the thermometer be between 60 and 104 F (15.5-40 C). In many places, it would not be unreasonable for the back of the ambulance to be below 60 F until the heat is turned on going to a call. In these cases, the thermometer, or the bag it is in, may be below the operating temperature when used to assess the patient.
Ensure all of your equipment, and particularly your thermometer, is kept within the storage temperature range and is used in the proper operating range. Consider storing the thermometer in the cab of your vehicle where the temperature is more likely to stay above the lower threshold.
3. Remember pain scale is subjective
While you weren’t able to obtain a pain scale from Mr. Stephenson, an elderly man who only groans in response to verbal stimulus, the pain assessment has a significant pitfall to be aware of. Medical providers often find themselves interpreting a patient’s pain scale based upon their own experiences.
In most cases, an EMS provider has seen an injury worse than the one affecting the patient she is treating. While that is the case, the pain assessment asks the patient to rate his pain and is a subjective measurement.
The pain assessment is not meant to compare one patient’s pain to another but merely to determine if treatment, time or movement makes a particular patient’s pain better or worse. Take the subjective measure of pain at face value and compare multiple ratings to determine a trend.
4. Take serial readings
Pain isn’t the only measurement during patient assessment which should contain multiple readings. A patient’s vital signs are a snapshot of his condition during a moment in time.
The only way to demonstrate changes in a patient’s status is to trend multiple readings over a period of time. To provide an accurate clinical picture of a patient’s status, it is important to obtain serial assessments and readings, and to use those findings to guide treatment.
5. Read the manual
While it seems obvious, medical equipment should only be used for its designed purpose. Take, for instance, the humble glucometer. Most patients who use a glucometer for home testing obtain their blood sample from the fingertip. As such, home glucometers (and those commonly used by EMS providers) are validated for use with capillary blood samples.
EMS providers, however, in an attempt to speed up assessment, may use other blood sources for glucose testing, like venous blood. While this may provide a reading, it is important to check that your glucometer is approved for these samples. Using a sample site that is not approved can lead to erroneous readings and incorrect treatment. When in doubt, ask your medical director or clinical leadership about using an alternate sample site.
Case resolution
After moving Mr. Stephenson to the ambulance and warming him up, you obtain an axillary temperature of 98.2 F (36.8 C). You also note his SpO2 is 98% on room air. A finger stick blood glucose reveals he is suffering from hypoglycemia.
Your partner gives him IV dextrose and his level of consciousness rapidly improves. When he is able to converse, Mr. Stephenson tells you he took his insulin while watching the news in the morning and when he got up to make breakfast he felt weak and slumped to the ground. He felt like his blood sugar was low but he wasn’t able to get up or reach the phone. Mr. Stephenson is transported to the ED for evaluation without incident.
