Altered mental status (AMS) is not a diagnosis, but rather a clinical presentation that may result from neurologic, metabolic, toxicologic, infectious, traumatic, respiratory, circulatory or psychiatric etiologies. For paramedics, recognizing AMS is insufficient to guide treatment, narrow the prehospital differential diagnosis or establish the primary clinical concern.
The main challenge for providers managing patients with altered mental status is appropriately utilizing the initial assessment: interpreting findings, determining subsequent steps and modifying interventions based on the patient’s response to initial treatment. This article examines how to translate assessment into informed clinical decision-making in cases of altered mental status.
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A patient’s mental status matters
Mental status assessment is among the initial skills taught in EMS training programs. Early instruction emphasizes observation and descriptive terminology (e.g., “normal,” “sleepy,” “lethargic” or “combative”). As obtaining a detailed history from an altered patient is often challenging, mental status assessment assumes heightened importance in these cases.
However, mental status assessment goes beyond simply recognizing that a patient is altered. Providers must quantify the degree of alteration (example.g., using the AVPU scale: alert, verbal, pain, unresponsive), and utilize this information to narrow potential etiologies and initiate appropriate treatment.
Start with the threats that can kill your patient right now
Prehospital assessment is not a strictly linear process. Information obtained from the patient’s appearance; input from staff, family members, bystanders; and environmental elements continue to inform the assessment as it progresses. Begin with a primary assessment, including general impression, scene safety, airway, breathing and circulation. Identify any immediate life-threatening conditions through focused history-taking, medication verification or medical-alert identification and initial physical examination.
Obtain vital signs, pulse oximetry and blood glucose; assess level of consciousness; and determine if obvious causes are present. Prioritize identification and management of the most immediately reversible life-threatening cause. Early intervention for hypoglycemia is critical; however, do not delay oxygen administration in cases such as near-drowning while awaiting blood glucose results. Similarly, aggressive fluid resuscitation should not be postponed while considering psychiatric etiologies for altered mental status.
Completing a mental status assessment checklist does not always identify the underlying cause. Treating hypoglycemia based solely on a blood glucose of 60 may not address other potential etiologies. Clinical judgment must guide the assessment process.
Use AEIOU-TIPS to develop your prehospital differential
Before initiating treatment, carefully consider the assessment findings. Multiple frameworks exist for organizing potential causes of altered mental status. Basic knowledge, both didactic and practical, will inform the differential diagnosis. Avoid anchoring on the first plausible explanation identified.
AEIOU-TIPS does not replace comprehensive patient assessment, nor is it a rigid algorithm that must be followed sequentially. Structured assessment should guide clinical reasoning; once initial information regarding current threats and baseline status is obtained, systematically consider the AEIOU-TIPS categories.
- A: Alcohol/other intoxication: Consider odor on the patient or scene, containers, alcohol withdrawal findings, medication interactions, trauma related to intoxication, and bystander or family information.
- E: Epilepsy/Electrolytes/Endocrine/Encephalopathy: Consider seizure history or witnessed seizure-like activity, postictal tremor or confusion, history of dialysis or renal disease, diabetes, other endocrine problems, and medications. Did the change in mental status follow a possible seizure, or does this presentation suggest another cause?
- I: Insulin/glucose abnormality: Check blood glucose early. Both hypoglycemia and hyperglycemia are common causes of AMS, but non-extreme blood sugar alone rarely defines your assessment or treatment. Treat as appropriate.
- O: Overdose/Opiates/Oxygenation problems: Consider respiratory rate, respiration quality, oxygen saturation, pupil size, overall medication history, drug paraphernalia, containers and possible environmental exposures. Remember that hypoxia, hypercapnia, prescription medications, illicit drugs, and combined ingestions/opioids can all cause altered mentation.
- U: Uremia/metabolic causes: Consider renal disease or history of dialysis; missed treatment, medications or other prescription medicines that may accumulate if dialysis is missed; dehydration; or other clues that point toward a metabolic cause of AMS.
- T: Trauma/Temperature: Get the patient appropriately exposed and examined. Look for head injury or blunt trauma, positional weakness that might suggest a fall, other evidence of occult trauma, anticoagulant use, and hypothermia/hyperthermia/environmental causes (we were caught by surprise once because of a mother who forgot her child was sleeping in a running car).
- I: Infection: Obtain temperature, if possible; look for possible sources of sepsis or meningitis; consider pneumonia (hypoxia, crackles); urinary sources; wounds, pressure ulcers, decubitus ulcers or other obvious areas where infection could occur. Don’t forget that non-localizing fever in elderly patients can suggest infection. Remember immunocompromised patients may have atypical presentations.
- P: Poisoning/Psychiatric: Medications, medication errors, environmental exposures, intentional ingestions, overdose and psychiatric history should all be considered. Always rule out treatable medical causes of altered mental status before assuming a primary psychiatric cause.
- S: Stroke/Shock/Subarachnoid hemorrhage/Sepsis: Look for focal neurologic deficits, slurred speech, odd gaze as you examine the patient, sudden severe headache onset, signs of poor perfusion or shock, hypotension (especially after fluids if your patient has trauma), occult bleeding, severe non-traumatic abdominal pain or signs that could suggest systemic infection.
Look beyond your first answer
“The drunk driver who hit her head” may explain part or most of your patient’s presentation, but not always. Remember your reversible causes and avoid becoming tunnel-visioned based on the first expected cause you identify. Is there anything about your patient’s exam or history that doesn’t match up with your initial impression?
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AEIOU-TIPS serves as a tool to guarantee consideration of differential diagnoses across multiple categories. Apply it comprehensively and maintain critical thinking beyond the first apparent cause. TMAO may be prioritized if cardiac monitoring is available but should not be omitted based on initial impressions.
Altered mental status case study
You respond to a 67-year-old patient who is “acting strange.” The patient is awake but unable to consistently answer simple questions correctly and seems confused. She keeps stating the wrong month when asked what month it is. A family member states patient was fine about an hour ago.
Subsequent obvious follow-up steps include managing any life-threatening issues identified during the initial assessment before proceeding.
Treat hypoglycemia according to local protocols if blood glucose is low. Ongoing assessment findings should guide additional evaluation and interventions.
Assess (AVPU scale; responsiveness to pain if unresponsive), obtain vital signs, measure oxygen saturation, obtain blood glucose and document physical exam findings. Document exactly what you mean when you say the patient is altered.
Look through the patient’s medications, assess the scene for trauma, evidence of alcohol use or drug ingestion/presence, missing wheelchair pointing to possible dehydration/seizure/diabetic crisis in an elderly patient, or environmental causes (freezing temperatures with decreased responsiveness can be hypothermia).
Finally, try to establish when the patient was last known well if stroke is a possibility based on examination and history.
Utilize AEIOU-TIPS as a cognitive checklist to ensure that no obvious etiologies are overlooked. Consider whether the patient exhibited confusion as well as agitation following a seizure, and evaluate for trauma, temperature abnormalities, infection or stroke as potential causes of the symptoms.
Summary: Altered mental status
Approach patients with altered mental status systematically: begin with identification and management of immediate life threats, evaluate vital signs and oxygenation, review medications and prioritize oxygen administration if hypoxia is present, check blood glucose, assess mental status, and obtain a directed history with attention to last-known-well if stroke is suspected. Document baseline vital signs and examination findings, review the patient’s medications, consider environmental and situational factors, and utilize AEIOU-TIPS as a final check to avoid premature diagnostic closure.
Allocate additional time for clinical reasoning regarding the patient. Use assessment findings to identify abnormalities, potential etiologies, and immediate treatment priorities. As treatment progresses or new information emerges, continually reassess the patient to determine whether abnormal findings resolved, improved, or deteriorated. If the patient’s condition worsens despite normal glucose levels, hypoglycemia should be reconsidered as a potential cause.
ABOUT THE AUTHOR
Michael K. Anderson is a nationally recognized fire and EMS legal expert, instructor and published author with 40 years of operational, command, training and leadership experience. He provides nationwide litigation support and expert analysis in fire operations, EMS standard of care, emergency vehicle operations, and incident command.
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