Delirium

Delirium (aka altered mental status, encephalopathy) is an impairment of a patient's level of consciousness (arousal, attention, alertness) and/or cognition (orientation, memory, judgement, thinking). It is is a waxing/waning condition marked with delusions, the potential for illusions and formed hallucinations, and abnormal thought processes. It is a reversible condition. The fluctuating nature of the syndrome makes it incredibly challenging for care-teams and family. Red flag features that a patient may not suffering from delirium but rather an underlying neurological condition include (amongst other things) focal or lateralized neurological findings (eg, hemibody weakness or paralysis, cranial neuropathies) and symptoms of seizure-like activity (stereotyped behaviors). Patients can be verbally abusive to family, which can be fairly traumatizing for the family members. Family should be warned not to contextualize comments from their loved one. The patients are almost always amnestic to the events and what has been said during the time of the delirium. What follows is a best-attempt to consolidate notable causes of delirium. 5 Broad Categories Neurologic Hypoperfusion & Hypoxia Metabolic & Endocrine oxicologic Psychiatric (diagnosis of exclusion) D: Dextrose O: Oxygen N: Naloxone T: Thiamine A: Alcohol, Acidosis, Arrythmia E: Endocrine, Electrolyte, Encephalopathy I: Infection, Ischemia O: Opiates, Overdose, Oxygen U: Uremia T: Trauma I: Insulin P: Poisoning, Psychosis S: Stroke, Seizure, Syncope, Shock

• Altered mental status exists on a spectrum, with coma being the most critical state (unresponsiveness to verbal or painful stimuli)
• Glasgow Coma Scale (GCS) and AVPU Scale are clinical tools used to describe level of consciousness
• It is important to identify the patient's baseline using ancillary sources (family, caregivers, previous records, if available)
• Other history and physical exam findings will differentiate depending on the etiology.

Immediate stabilization

• Place patient on cardiac monitor and continuous pulse oximetry, secure IV access, obtain point of care glucose, and consider EKG
• Assess patient's airway, breathing, circulation, disability, and exposure
• Address abnormal vitals and provide life-saving interventions including intubation, oxygen, IV fluids, and glucose as needed

• Differential diagnosis and workup are tailored towards history and physical exam
• Labs: glucose, CBC, CMP, EKG, CT head, urinalysis, CXR
• Additional tests to consider based on clinical presentation: ABG, CSF studies, urine pregnancy, urine tox, salicylate and acetaminophen levels, EtOH level, TSH, CTA head/neck, ammonia, CO level

• Glucose: hypoglycemia, DKA, HHS
• CBC: leukocytosis, leukopenia, severe anemia, thrombocytopenia
• BMP: electrolyte abnormalities, uremia, anion gap
• ABG: hypoxemia, hypercarbia
• Urinalysis: UTI, ketonuria
• Urine tox: drug overdose
• Salicylate and acetaminophen level: toxic ingestion
• Ammonia: hepatic encephalopathy
• TSH: thyrotoxicosis, myxedema coma
• CSF studies: meningitis, encephalitis
• Urine pregnancy: eclampsia

• EKG: arrhythmia, ischemia, electrolyte abnormalities
• CT head: ICH, intracranial mass
• CTA head/neck: stroke, aneurysm, AVM, venous sinus thrombosis
• CXR: pneumonia, pneumothorax, pulmonary edema

• Ultimate interventions and treatment are specific to the underlying disease
• Most patients require admission, unless presentation is chronic and of known etiology

60 year-old-female with acute encephalopathy.