Altered level of awareness/altered level of consciousness is a call that really should get your heart rate up. Unlike the other symptoms in this series, ALOC only has serious causes. There are no stable patients with acute onset alterations in neurological status; its not a thing. These patients all come with the very real potential to go south and go south fast, so we need to be vigilant when treating them. Unfortunately, like the other symptoms in this series, there are a lot of potential causes of ALOC, so we really need to take clues from our patients, bystanders, medications, and environmental factors. The accepted mneumonic for altered patients, AEIOUHOTTIPS, provides us with a number of potential causes of change in cognition. For those unfamiliar, it stands for:
Alcohol
Epilepsy
Insulin
Overdose
Uremia/Underdose
Hypoxia
Obstetrics
Trauma
Thermal
Infection
Psychiatric
Syncope
This provides a good framework for looking at potential causes for our patient's condition. I would offer a differential of significant causes that should be looked for first. The acronym SITES, stands for Stroke, Infection, Toxicological, Endocrine, and Seizure. Of all the potential causes of ALOC, these 5 are the ones I feel to be critical not to miss.
Assessment of the altered patient:
As with all patient's we begin with our primary assessment, correcting life threats to the ABCs before moving on. With altered patients, there is risk of aspiration, and obstruction of the airway, so give that area special attention. If we cannot get information from our patient, we should attempt to gain it from family or bystanders who know the patient. We need to know:
-Has this ever happened before? If so, was a cause determined?
-When did the symptoms begin, or when was the patient last seen acting normal?
-If the onset was witnessed, what was the patient doing immediately prior to symptom onset?
-Has the patient had any recent infections, fevers, or other complaints?
-What is the patient's medical history?
-Is the patient on medications?
Physical should involve examination:
-Pupils for symmetry, size, and reactivity.
-Facial symmetry, and any signs of head trauma.
-The presence of drooling, or cyanosis.
-Speech deficits or slurring.
-Assessment of grips, pronator drift, pedal strength.
-Assessment for vertigo, nausea, headache, or ringing in the ears.
-Lungs for adventitious sounds.
Vitals should include:
-Temperature
-Pulse
-ECG, 3 lead and 12-lead
-Blood pressure
-Blood glucose
-SPO2
-ETCO2
We need to begin at the head and work down. Pupil inequality suggests potential for a stroke. Dilated pupils are seen in sympathomimetic drug use, and in brain death. Pupil constriction occurs in overdose on opioids or sedative/hypnotics. Nystagmus is present in alcohol intoxication, and cerebellar ischemia. Facial asymmetry can indicate a stroke (or Bell's Palsy, but we need to assume stroke unless it is already a diagnosed condition). Speech abnormalities are also indicative of potential stroke if they have an acute onset. Unilateral motor responses of also classic signifiers of cerebral ischemia. Assessment of lung sounds in the altered patient serves 2 purposes: 1) it allows us to assess for aspiration of secretions, and 2) we can look for pneumonia as a potential cause of ALOC.
A lot of the time the history, patient presentation, and our vitals are going to tell a story. Patients with stroke will typically present with sudden onset of one sided motor deficits; often accompanied by alterations in speech and cognition. Patients who have systemic infections or sepsis will have a more gradual decline, and can present with hyperthermia or hypothermia, delirium, and signs of SIRS. Toxicological exposure may require clues from the environment itself. If drug use is the cause, we may find evidence on scene. Opioid users are typically apneic, but pulsatile, with constricted pupils. Hypoglycemic patients present with altered LOA, seizures, confusion or agitation, cool pale clammy skin, and a low BGL. Hyperglycemic patients are not usually altered with the exception of DKA or HHK, which present with nausea, rapid deep respirations, and warm dry skin. Seizure is typically a witnessed event, and we need to ask about the patient's apparent state prior to seizure, history of past seizures, medications and recent changes, type of seizure, and length of seizure. Clues in a patient with unwitnessed seizure include lateral tongue lesions, incontinence, and secondary injuries. '
Other clues such as a hot environment, and a temperature >39-40 degrees celsius may lead us to consider heat stroke. Conversely, altered LOC in a cold environment should direct us to consider hypothermic causes. Low SPO2 should identify hypoxic causes, but we also need to be aware of potential exposure to CO or cyanide gases which will lead to hypoxia with an apparently normal SPO2.
12-lead ECG needs to be performed on unresponsive patients to look for potential cardiac causes. If an identified cause, such as hypoglycemia is found, the 12-lead would not be required.
The point is, we need to be thorough with these patients. NONE of them are “stable”, and there needs to be a high index of suspicion for critical causes until ruled out. A good history, when available is key to diagnosis, however this may not always be possible. This is why we need to use our environment and vitals to direct our assessments. There may be times you cannot identify a clear cause, in which case you need to treat the threats you find or anticipate, and transport them rapidly.
Comments