Initial Approach to Altered Sensorium

Immediate Stabilization and Vital Assessment

The American College of Emergency Physicians recommends securing the airway and assessing breathing if the Glasgow Coma Scale is ≤8 or the patient cannot protect their airway, with a strength of evidence level of high 1, 2
The American Academy of Neurology suggests obtaining fingerstick glucose immediately at bedside, as hypoglycemia is rapidly reversible and life-threatening, with a strength of evidence level of high 3, 2
The Society of Critical Care Medicine recommends documenting vital signs systematically, including fever, hypotension, and hypertension, which may indicate infection, shock, or intracranial pathology, with a strength of evidence level of moderate 2
The Neurocritical Care Society advises quantifying mental status objectively using the Glasgow Coma Scale or FOUR score, with a strength of evidence level of high 2
The American Heart Association recommends performing a focused neurological examination to look for focal deficits, which can increase the likelihood of a structural brain lesion, with a strength of evidence level of high 2

The Infectious Diseases Society of America suggests prioritizing the temporal profile, medication and substance exposure, infectious symptoms, comorbid conditions, and recent trauma or falls when obtaining history, with a strength of evidence level of moderate 4, 3, 2
The American College of Physicians recommends obtaining a complete list of medications, including over-the-counter medications, recent antibiotic use, alcohol, and illicit drugs, with a strength of evidence level of high 2

The American Association for Clinical Chemistry recommends ordering point-of-care glucose, complete metabolic panel, complete blood count, liver function tests, and urinalysis immediately and simultaneously, with a strength of evidence level of high 2, 3
The National Kidney Foundation suggests evaluating for infection, anemia, and electrolyte abnormalities, with a strength of evidence level of moderate 2
The American Academy of Clinical Toxicology recommends performing a toxicology screen and acetaminophen level when substance use is suspected or the history is unclear, with a strength of evidence level of high 1, 2

The American College of Radiology recommends obtaining a non-contrast head CT immediately if there are focal neurological deficits, a history of head trauma or falls, anticoagulation use, or other high-risk factors, with a strength of evidence level of high 2, 1
The Society of Neurointerventional Surgery suggests considering MRI brain if CT is negative but there is high clinical suspicion for encephalitis, posterior circulation stroke, or inflammatory conditions, with a strength of evidence level of moderate 2

The Infectious Diseases Society of America recommends performing a lumbar puncture when central nervous system infection is suspected, after neuroimaging rules out mass effect, with a strength of evidence level of high 3, 2
The American Academy of Neurology suggests examining cerebrospinal fluid for cell count, protein, glucose, Gram stain, and bacterial culture, with a strength of evidence level of high 2

The American College of Emergency Physicians recommends administering thiamine 500mg IV before glucose administration in malnourished, alcoholic, or at-risk patients to prevent Wernicke encephalopathy, with a strength of evidence level of high 2
The American Academy of Clinical Toxicology suggests administering naloxone if opioid toxicity is suspected, with a strength of evidence level of high 2
The Infectious Diseases Society of America recommends administering antibiotics and acyclovir if meningitis or encephalitis cannot be excluded, with a strength of evidence level of high 3, 2

The American College of Physicians recommends never attributing altered sensorium to psychiatric causes without completing a medical workup, with a strength of evidence level of high 2
The Society of Critical Care Medicine suggests considering multiple concurrent etiologies, especially in elderly patients, with a strength of evidence level of moderate 2
The American Academy of Neurology recommends recognizing that toxicologic/pharmacologic causes account for 20-25% of cases, with a strength of evidence level of high 2

The American College of Emergency Physicians reports that neurological causes account for 30-35% of altered sensorium cases, with a strength of evidence level of high 2
The American Association of Clinical Toxicology reports that toxicologic/pharmacologic causes account for 20-25% of cases, with a strength of evidence level of high 2
The American College of Physicians reports that metabolic causes account for 15-20% of cases, with a strength of evidence level of moderate 2
The Infectious Diseases Society of America reports that infectious causes account for 9-18% of cases, with a strength of evidence level of moderate 2

The American Academy of Emergency Medicine recommends that any acute change in cognition or alertness in a patient with known dementia should be investigated and managed as delirium until proven otherwise, with a thorough medical workup to identify underlying causes 5, 6
The American College of Physicians suggests that impaired sensorium is defined as an acutely confused or delirious patient responding to verbal or mild tactile stimulation, or mental status changes in the context of current illness, requiring investigation for medical causes 7

The American Geriatrics Society recommends that elderly patients are at highest risk for delirium and require careful evaluation for multiple concurrent causes including medications, infections, and metabolic derangements 8, 7
The Society of Critical Care Medicine suggests that patients with cirrhosis and altered mental status require four concurrent management principles: airway protection, investigation of the cause, determination and treatment of precipitating factors, and empiric therapy for suspected hepatic encephalopathy 5

The American Academy of Neurology recommends that delirium develops acutely with fluctuating course, altered level of consciousness, and inattention, and is a medical emergency requiring immediate investigation for underlying causes 5, 6
The American College of Emergency Physicians suggests that obtaining a complete medication list, including over-the-counter medications, recent antibiotic use, alcohol intake, and illicit drugs, is crucial in identifying toxicologic/pharmacologic causes of altered sensorium, which account for 20-25% of cases 8

The American Psychiatric Association recommends that patients with known psychiatric illness still require medical clearance, with selective testing guided by clinical evaluation, but routine extensive laboratory testing is unnecessary 8, 9
The American Geriatrics Society suggests that hypoactive delirium presents with cognitive and motor slowing and sedated appearance, rather than agitation, and is more common in elderly patients, carrying higher mortality but is frequently missed 6