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Altered Level of Consciousness
Aka: Altered Level of Consciousness, Decreased Level of Consciousness, ALOC, Altered Mental Status, Altered Mental State, Altered State of Consciousness, Depressed Level of Consciousness, DONT Mnemonic
- See also
- Altered Level of Consciousness Causes
- Altered Mental Status in Febrile Returning Traveler
- Unknown Ingestion
- Level of Consciousness
- Coma
- Delirium
- Psychosis
- Dementia
- Coma Exam
- FOUR Score Coma Exam (Full Outline of Unresponsiveness)
- Glasgow Coma Scale (GCS)
- History
- See AMPLE History
- See Unknown Ingestion
- Recent Trauma or Head Injury
- Symptoms or exposure to infectious disease including recent travel
- New or changed medications
- History of Substance Abuse or mental illness
- Exam: General
- Vital Signs and general findings
- Obtain Blood Pressure, Heart Rate, Temperature, Respiratory Rate and Oxygen Saturation
- Obtain bedside Glucose and treat Hypoglycemia (see below)
- Initiate telemetry
- Initiate End-Tidal CO2 (if available)
- See Toxin Induced Vital Sign Changes
- See Toxin Induced Odors
- Blood Pressure is a sensitive indicator of Brain Lesions
- Systolic Blood Pressure <90: Brain Lesion unlikely
- Systolic Blood Pressure >170: Brain Lesion likely
- Ikeda (2002) BMJ 325:800-2 [PubMed]
- Level of Consciousness
- See Level of Consciousness
- AVPU Scale
- Glasgow Coma Scale (GCS)
- FOUR Score Coma Exam (Full Outline of Unresponsiveness)
- Trauma exam allows for a complete survey (regardless of etiology)
- See Primary Survey (includes ABC Assessment)
- See Secondary Survey
- Evaluate for loss of Gag Reflex, GCS 8 or less, and other indications for Endotracheal Intubation
- Fully expose the patient for an optimal exam
- Eye Exam
- Pupil changes (Miosis, Mydriasis, and Pupil Reactivity)
- See Eye Examination Signs of Chemical Dependency
- Pupil Constriction (Miosis) and a slowed Respiratory Rate (Bradypnea) suggests Opioid Overdose
- See Naloxone as below
- Examine for unilateral Pupil Dilation without pupil response (blown pupil) suggestive of Uncal Herniation
- Complete Neurologic Exam
- See Emergency Neurologic Exam
- See Delirium
- See Toxin Induced Neurologic Changes
- Skin Exam
- See Rash in the Febrile Patient
- See Toxin Induced Skin Changes
- Differential Diagnosis
- See Altered Level of Consciousness Causes
- Includes mnemonics "AEIOU TIPS" and "I WATCH DEATH"
- Includes pitfalls of critical diagnoses that are easily missed
- See Altered Mental Status in Febrile Returning Traveler
- See Unknown Ingestion
- See Coma
- See Delirium and Dementia
- See Psychosis and Agitated Delirium
- Toxic or metabolic condition?
- Structural CNS disease?
- Encephalitis or Meningitis?
- Labs
- Immediate
- Bedside Glucose (Dextrostick or Glucometer)
- First-line
- Complete Blood Count (CBC)
- Comprehensive Metabolic Panel (electrolytes, Renal Function tests, Liver Function Tests)
- Serum Osmolality (if available)
- Serum Calcium
- Serum Magnesium
- Urinalysis
- Urine Pregnancy Test (all women of child bearing age)
- Thyroid Stimulating Hormone (TSH)
- Toxicology Screening (most cases)
- Urine Tox Screen
- Venous Blood Gas
- Consider Arterial Blood Gas instead if concerned for hypercarbia
- Blood Alcohol level
- Acetaminophen level
- Salicylate level
- Other drug levels (as indicated)
- Infection screening (fever, infection suspected or unknown cause)
- Blood Culture
- Urine Culture
- Lumbar Puncture
- Serum Lactic Acid
- Procalcitonin level
- Other labs to consider
- Ammonia
- Carboxyhemoglobin level
- HIV Test
- If unable to obtain, consider a surrogate: Absolute Lymphocyte Count Estimation of CD4 Count
- Rapid Plasma Reagin (RPR)
- Heavy metal screen
- Vitamin B12 Level
- Serum Cortisol
- Diagnostics: Electrocardiogram (EKG) and cardiac monitor
- Findings suggestive serious cardiotoxicity (and risk of Ventricular Tachycardia or Torsades)
- Prolonged QT interval
- Wide QRS
- Tall R Wave (or Terminal R Wave) in AVR
- Interventions to consider for EKG changes
- Sodium Bicarbonate for wide QRS Complex
- Especially consider if Terminal R Wave in aVR, Anticholinergic findings, suspected Overdose
- Magnesium for QT Prolongation (especially if QTc > 600 msec)
- Diagnostics: Lumbar Puncture
- Indications
- Altered Level of Consciousness without obvious non-infectious cause identified in first hour
- Fever or other signs of infection without an identified source and Altered Level of Consciousness
- Precautions
- Do not delay antibiotics (e.g. Ceftriaxone 2 g) for the Lumbar Puncture if Meningitis or Encephalitis suspected
- Lumbar Puncture may be safely performed in the ALOC patient (after CT Head negative)
- Perform in left lateral decubitus position
- Perform an opening pressure in addition to standard CSF Exam
- Observe for markedly increased CSF Opening Pressure or cloudy CSF Color
- Early findings at the time of Lumbar Puncture may prompt reflexive start of antibiotics prior to lab results
- Imaging
- Head CT
- Cervical Spine CT
- Strongly consider at the time of Head CT if any risk of Trauma
- Examples: Found down or fall from height or even from standing height in the elderly
- Chest XRay
- Management: Initial
- ABC Management
- Assess Level of Consciousness
- Endotracheal Intubation for GCS 8 or less (or other Advanced Airway Indications)
- Trauma-related management for Closed Head Injury
- See Management of Severe Head Injury
- See Status Epilepticus
- C-Spine Immobilization
- Protect patient and staff from injury
- Consider Physical or Chemical Restraints
- See Violent Behavior
- IV-O2-Monitor
- Intravenous Access (or IO access if delays and patient unstable)
- Oxygen Delivery
- Cardiac Monitor
- Empiric reversal agents
- See agent protocols below
- Consider DONT Mnemonic empiric management (Dextrose, Oxygen, Naloxone, Thiamine)
- Empiric infection management
- Consider for fever, signs infection or if no obvious non-infectious ALOC cause identified in first hour
- See Sepsis for antibiotic selection
- If no obvious source, cover for Meningitis and Encephalitis
- See Bacterial Meningitis Management
- Includes Vancomycin, Ceftriaxone, Acyclovir (and in some cases Ampicillin)
- Consider Dexamethasone prior to antibiotics if Bacterial Meningitis is strongly suspected
- Management: Empiric reversal agents
- Dextrose
- Indicated for Hypoglycemia on bedside Glucometer
- May be given empirically
- Do not give empirically to a brain injured patient (check Glucometer first)
- Give Thiamine 100 mg before Dextrose in suspected Wernicke's Encephalopathy
- Dosing
- Adult or child >25 kg: 50 ml of D50 IV
- Child 5 to 25 kg: 2-4 ml/kg (0.5-1.0 g/kg) D25 IV
- Neonate: 5 ml/kg D10 (0.5 g/kg) IV
- Naloxone (Narcan)
- Indicated for signs of Opioid Overdose such as Pupil Constriction and respiratory depression (but may be given empirically)
- Precaution: Naloxone can act as Sympathomimetic and my theoretically exacerbate myocardial irritability
- Child: 0.01 mg/kg IV
- May repeat with 0.1 mg/kg IV (up to 2 mg) if inadequate response to the first dose
- Adult
- Respiratory depression: 0.4 mg IV (up to 1-2 mg IV every 2-3 minutes)
- Cardiac Arrest: 2 mg IV (if possible Overdose induced Cardiac Arrest)
- Concern for Opioid Withdrawal (slow titration method)
- Draw up Naloxone 1 ml (0.4 mg/ml) and 9 ml Normal Saline
- Inject at 1-2 ml/dose (0.04 mg/ml) titrating and observe for increased responsiveness
- Management: Other empiric reversal agents less commonly indicated
- Flumazenil (rarely used in acute Altered Mental Status)
- Indications
- Not typically used due to the risk of withdrawal Seizures in chronic Benzodiazepine use
- Consider if Altered Level of Consciousness follows a single dose of Benzodiazepine
- Dosing
- Flumazenil 0.2 - 1.0 mg IV
- Precautions
- Tricyclic Antidepressant Overdose
- Benzodiazepine Abuse
- Thiamine
- Dosing
- Adult: 100 mg IV
- Child: 10-25 mg IV
- Indications
- Suspected Wernicke's Encephalopathy
- References
- Orman and Chang in Herbert (2017) EM:Rap 17(4): 8-9
- (2016) CALS, 14th ed, 1:52-3
- Herbert et al. in Herbert (2014) EM:Rap 14(10): 11-2
- Herbert et al. in Herbert (2014) EM:Rap 14(11): 10-12