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Altered Mental Status: A Review
By Jim Brasiel, MD
Those of us new and old in the business of providing emergency medical care on the streets and in homes across America have always followed certain precepts when it comes to caring for the patient with an altered mental status. The Altered Mental Status (AMS) patient is one of the most challenging patients to deal with. Early on in my EMS career I always felt as though we should have one syringe with naloxone and dextrose fifty percent in it. I felt this way because it seemed as though it was the only treatment we had for the AMS patient. As technology has brought us to a point now where we know exactly what the patient’s sugar and oxygen status is the blanket treatments of yesterday have fallen to the wayside. It is now our responsibility as caregivers to the sick to use our examination skills to tell us more about what is going on with our patient and treat them with accurate and correct modalities for their condition.
A-E-I-O-U-T-I-P-S (Table 1) was the first mnemonic most of us learned when we were faced with learning about the AMS patient. I am going to highlight this exam tool and explore some of the common patient presentations with each item as well as some examination results that should determine the ultimate patient care.A - Alcohol E - Epilepsy - All seizure disorders I - Insulin O - Overdose U - Underdose/Uremia T - Trauma/Temperature I - Infection P - Psychosis S - Stroke Table 1: AMS helper mnemonic
Alcohol is responsible for close to 4% of fatalities world wide. It is a well known substance that will cause AMS in most people in relatively small quantities. Care providers from every level have had to examine a patient suffering the effects of alcohol. The human body’s primary inhibitory neurotransmitter is GABA, and alcohol has a direct interaction with GABA A receptors. This makes the effects of alcohol as we know them very medically significant. EMS educators emphasize the need to always examine and treat the “drunken” patient as the effects of alcohol will mask many injuries. Over consumption is but one reason alcohol can affect a patient’s mental status. Medically unsupervised alcohol cessation can result in withdrawal in a chronic user and can cause seizures and thus create the AMS of a postictal phase. Tactile formications and other signs and symptoms of Delirium Tremens can present with an “AMS” as well. Alcohol is a drug that has prolific consequences for the user.
Epilepsy is a diagnostic term used to identify a multitude of seizure disorders, close to 125 thousand new cases of “epilepsy” are diagnosed each year in the United States. The dramatic “Grand Mal” full body, “tonic/clonic” seizure is the origin of most EMS calls to treat a seizure patient. Seizures for a lack of a better description are a synaptic electrical storm that results in aberrant or atypical muscle actions and responses by the patient. The relationship of AMS and epilepsy is typically one that follows the seizure event known as a postictal phase. The majority of the time when EMS caregivers are called to the scene of a seizure they arrive to find an AMS patient that is done seizing; treating an active seizure is another topic entirely. Treating the postictal phase is done simply by protecting the airway, providing oxygen and allowing some time to pass for normal mentation to return.
Insulin is one of two hormones that play a major role in carbohydrate metabolism and the maintenance of normal brain activity. The usage of insulin by patients diagnosed with Diabetes Mellitus is common. When a patient is dependent upon an exogenous injected hormone to maintain metabolism that patient must follow a schedule of regular meals and activities. If the patient exceeds the right amount of hormone or does more activity or eats less, a low sugar event is the likely outcome. Recall that the low sugar event is a rapid onset with tachycardia, diaphoresis and AMS. In today’s EMS environment the usage of glucometers is commonplace and the treatment of a low sugar is simply giving the appropriate sugar replacement based on your level of training.
What does one do if the AMS patient presents with a prolonged onset of illness with an irregular breathing pattern and associated nausea, vomiting and weight loss? The prolonged onset is the key clue in this scenario to lead you in the direction of not enough insulin leading to the AMS event. After your examination and testing with the glucometer reveals a blood sugar reading that is inordinately high, prompt treatment that is within your scope of practice should follow. Making sure that the treatment includes airway protection, supplemental oxygen, fluid replacement and appropriate pharmacologic care.
Overdose on any number of different compounds can cause an AMS. The most likely EMS scenario for an overdose that results in AMS is that of an opiate or opiate-like substance. The prevalence of heroin use has been the source of many debates; suffice it to say that there is close to 800,000 users of this illegal drug in the United States yearly. In addition to heroin there many abusers and addicts to prescription opiates in America. The fact that there is such widespread use makes recognition of this source of AMS a necessity. Interestingly, a user of opiates can become sensitized to the drugs effect on the body and thus require more and more drug for the high that they experience by using the drug. However, there is one drug effect the user cannot ever change and that is the effect on the pupil; opiates cause a miosis by the parasympathetic stimulation of cranial nerve three, commonly called “pinpoint” pupils. In most instances of overdose on opiate type drugs there will be a slowing of the patient’s respiratory drive. The respiratory drive being slowed is a true emergent concern. If your AMS patient presents with small pupils and slowed respiratory drive then prompt treatment that is within your scope of practice should follow. Making sure that the treatment includes airway protection, supplemental oxygen and appropriate pharmacologic care.
Underdose is another concern in the United States, the US Department of Health and Human Services reports that half of the population of the US takes at least one prescription medication. They further report that ten out of twelve people over 65 years of age take three or more medications. It is of these many people that use prescription medications that concern us. If a person presents with an AMS and is found to be on a medication it could be that they forgot to take the medication and that resulted in the AMS event. This is vague category in the mnemonic as it could be postulated that anything could have caused the AMS in this scenario. It is up to you the caregiver to do a complete but rapid physical exam to rule out obvious causes immediately while you stabilize the patient. Once the patient is stabilized you can do a very focused and detailed examination and you will figure out just what happened. The patient’s medications become the starting point for an in depth history of possibilities of the resultant AMS.
Uremia is a condition in renal failure in which the blood retains toxins. In the situation of emergency medicine and prehospital care patients can present several days after missing their necessary dialysis appointment. This is a significant issue as dialysis is normally done three times a week. The kidney buffers the blood and maintains the bloods health by filtering it and removing waste products. The patient that misses dialysis can be metabolically unstable to the point of AMS. The uremic patient might have other issues involving the airway and cardiac instability as well. It is safe to say this patient will be very sick and in need of absolute emergency care and stabilization.
Trauma is quite possibly one of the most dramatic reasons to have an AMS. Most typically related to head trauma, although in the elderly population we can see an AMS related to a ground level fall in which the patient is unable to summon help and is left on the floor of their home for several days. Again in either scenario of trauma the caregiver is left with doing a complete physical exam to rule out the obvious and find clues for the ultimate and definitive cause of the AMS.
Temperature is another “T”; environmental heat and cold injuries are causes of AMS. These are not always injuries that the caregiver will readily recognize. It is one thing to be an outdoorsman and to be in an austere environment in which an incident where hypo or hyperthermia become an issue. If one considers the simple environment of the inner-city where elderly live it might be that as a cost savings the heat is turned off for a period of time during the day or night and the patient may become very cold and ill as a result. That same scenario may repeat itself in summer when it is hot and the cost savings comes from no air conditioning. It is not uncommon in seasonal transition months for the elderly to overdress and become very hot. Patients have had documented heat stroke simply by walking to the grocery store on a sunny day while wearing too many warm layers of clothing. When examining the AMS patient consider all possibilities and causes, if your patient feels too hot or too cold it may be that you have your answer.
Infection; this can be an obvious source of AMS and it can be a hidden source too. Considering the common population of users of EMS it should not be surprising that the elderly population that we treat is impacted by AMS with infectious associations. In the clinical world it is widely known that approximately 25% of admissions for AMS over the age of 70 will have a urinary tract infection. In most of these patients treatment of the UTI alone will relieve the AMS. In other age groups AMS associated with infection can be relieved by simply replenishing fluids lost and increasing oxygen saturation with supplemental oxygen. For the prehospital provider it is not necessary to diagnose the exact infectious agent but rather to recognize there is some kind of infectious process and to begin fluid resuscitation for volume loss secondary to the infectious state.
Psychosis; this particular topic can range from the delirium of dementia to a psychotic break with violent tendencies. The caregiver must recognize that the patient needs to be protected not only from harming him/herself but harming others both intentionally and unintentionally. Many prehospital systems across the US are now employing sedation protocols for people that are wildly psychotic. The norm clinically for years has been to chemically restrain enough to examine and refer. It is this standard of care that is the best tact to take when you recognize there is a potential for patient self harm. It never hurts to remind the caregiver to manage the airway after sedation and to do a detailed physical exam for injuries.
Stroke; clearly there is a great deal to know here, however considering the clues that will lead the caregiver to a diagnosis there are very few things that will need to be examined before a decision of care is made. The AMS patient for the most part is assumed to have any one of these nine letter associations but CVA/TIA is always at the top of the list. I firmly believe this to be the case that is why it is the last item we typically rule out. All other examinations lead here in my opinion. If the patient is at all lucid in their AMS we can get them to participate in the three-step prehospital stroke exam. The exam as we all know looks for facial drooping, word slurring and arm drift. If your AMS patient can participate in this exam and fails part of it then CVA/TIA is a likely field diagnosis. Keep in mind that many other things on this list can mimic this field diagnosis as well and a complete physical examination with the use of all of your monitoring and testing devices is essential to accurate field diagnosis and care prior to delivery to the definitive setting.
This mnemonic gives the caregiver a solid pattern to follow when dealing with the AMS patient. Creating that index of suspicion to find the next thing wrong that will lead to the resolution of the AMS event. The goal with the use of this tool is not so much finding out the answer to what is wrong but helping the patient to begin their recovery from the onset of diagnosis. Make no mistake one should not stop ruling-out issues until the whole mnemonic is exhausted as it is not uncommon for a patient to fit into more than one category of this short list of potential reasons for AMS.
