Rosen & Barkin's 5-Minute Emergency Medicine Consult (44 page)

DIAGNOSIS

Confusion

• Difficulty in maintaining a coherent stream of thinking and mental performance:
  
  • Remember to consider level of education, language, and possible learning disabilities.
    
• Inattention
  
• Memory deficit:
  
  • Inability to recall any of the following:
    
    • The date, inclusive of month, day, year, and day of week
      
    • The precise place
      
    • Items of universally known information
      
    • Why the patient is in the hospital
      
    • Address, telephone number, or Social Security number
      
• Impaired mental performance:
  
  • Difficulty retaining 7 digits forward and 4 backward
    
  • Difficulty naming ordinary objects
    
  • Serial calculations: 3-from-30 subtraction test
    
• Disorganized and rambling language:
  
  • May be mistaken for aphasia
    
• Fever:
  
  • Infectious etiologies, drug toxicities, endocrine disorders, heat stroke
    
• Severe hypertension and bradycardia
  
  • Cushing reflex suggests intracranial lesion
    
• Hypotension:
  
  • Infectious, toxicologic etiologies, decreased cardiac output
    
• Eye movements:
  
  • Ocular bobbing:
    
    • Cyclical brisk conjugate caudal jerks of the globes followed by a slow return to midposition
      
    • Seen in bilateral pontine damage, metabolic derangement, and brainstem compression
      
• Ocular dipping:
  
  • Slow, cyclical, conjugate, downward movement of the eyes followed by a rapid return to midposition
    
  • Seen in diffuse cortical anoxic damage
    
• Pupil exam:
  
  • Nearly all toxic and metabolic causes of coma leave the pupillary reflexes sluggish but bilaterally intact.
    
• Focal findings (indicative of CNS process):
  
  • Hemiparesis
    
  • Hemianopsia
    
  • Aphasia
    
  • Myoclonus
    
  • Convulsions
    
  • Nuchal rigidity
    
• Asterixis:
  
  • Arrhythmic flapping tremor (almost always bilateral)
    
  • Seen in hepatic failure or severe renal failure
    

• Ask witnesses, family, pre-hospital personnel
  
• Baseline mental status
  
• Medical history (immunosuppressed, liver failure, depression, or chronic conditions)
  
• Recent events: Trauma, fever, illness
  
• Detailed medication list
  
• Substance abuse history
  

• Vital signs
  
• Head: Signs of trauma, pupils
  
• Fundoscopic exam: Hemorrhage, papilledema
  
• Neck: Rigidity, bruits, thyroid enlargement
  
• Heart and lungs
  
• Abdomen: Organomegaly, ascites
  
• Extremities: Cyanosis
  
• Skin: Diaphoretic/dry, rash, petechiae, ecchymoses, splinter hemorrhages, needle tracks
  
• Neurologic exam
  
• Mental status exam
  

• Dextrostix and glucose
  
• CBC
  
• Electrolytes (including Ca, Mg, P)
  
• BUN, creatinine
  
• Toxicologic screen (including toxic alcohols)
  
• ECG
  
• Urinalysis
  
• Blood and urine cultures (suspected infection)
  
• PT, PTT (anticoagulated, liver failure patients)
  
• Consider LFTs, thyroid function tests, ammonia, serum osmolarity, arterial blood gas
  
• Consider B
  ₁₂
  , folic acid, RPR, urine porphobilinogen, heavy metal screening
  

• Head CT scan:
  
  • Noncontrast only to rule out hemorrhage and mass effect
    
• Chest radiograph: To diagnose pneumonia
  
• MRI (if available):
  
  • Indicated when suspicious of ischemic stroke or other CNS abnormality
    
  • May be deferred when admitting the patient as part of the inpatient work-up
    

• Lumbar puncture (LP):
  
  • Indicated when the etiology remains unclear after lab and CT scan
    
  • Empiric antibiotics should be given before LP in patients with suspected meningitis.
    
• EEG (inpatient): For suspected seizure, nonconvulsive status epilepticus
  
• Caloric stimulation of the vestibular apparatus to assess unresponsive patients:
  

• Locked-in syndrome:
  
  • Rare disorder caused by damage to the corticospinal, corticopontine, and corticobulbar tracts resulting in quadriplegia and mutism with preservation of consciousness.
    
  • Communication may be established through eye movements (maintain vertical eye movements).
    
• Psychogenic unresponsiveness:
  
  • Conversion reactions
    
  • Catatonia
    
  • Malingering
    
  • Akinetic mutism (abulic state)
    
• Dementia:
  
  • Multiple progressive cognitive deficits
    
  • Attention is preserved in the early stages.
    

TREATMENT

• Airway management if loss of airway patency
  
• IV access, supplemental oxygen, cardiac monitor
  
• Spine immobilization if possibility of trauma
  
• “Coma cocktail”:
  
  • Dextrose
    
  • Naloxone
    
  • Thiamine
    
• Look for signs of an underlying cause:
  
  • Medications, medic alert bracelets
    
  • Document a basic neurologic exam, GCS, pupils, extremity movements
    
  • Gross signs of trauma
    
• CONTROVERSIES
  
  • Empirical dextrose should not be withheld or delayed if Dextrostix is not available
    
    • Glucose can be safely administered before thiamine.
      

• IV D
  ₅₀
  
• Naloxone
  
• Thiamine
  

• Consider empiric use of antibiotics for altered mental status of undetermined etiology:
  
  • Broad spectrum with good CSF fluid penetration such as ceftriaxone and vancomycin
    
• Empiric treatment if a toxic ingestion is suspected:
  
• Correct body temperature:
  
• Specific therapy directed at underlying cause
  

• Ceftriaxone: 2 g (peds: 50–75 mg/kg/d q12–24h) IV q12–24h
  
• Dextrose: 1–2 mL/kg of D
  ₅₀
  W (peds: 2–4 mL/kg D
  ₂₅
  W) IV
  
• Diazepam: 0.1–0.3 mg/kg slow IV (max 10 mg/dose) q10–q15min × 3 doses
  
• Lorazepam: 0.05–0.1 mg/kg IV (max. 4 mg/dose q10–q15min)
  
• Mannitol: 0.5–1 g/kg IV
  
• Naloxone: 0.01–0.1 mg/kg IV/IM/SC/ET
  
• Thiamine: 100 mg IM or 100 mg thiamine in 1,000 mL of IV fluid wide open
  
• Vancomycin: 1 g (peds: 10 mg/kg q8–12h) IV q12h
  

FOLLOW-UP

All patients with acute and persistent changes in mental status require admission.

• Treated hypoglycemia related to insulin therapy with resolved symptoms
  
• Chronic altered mental status (e.g., dementia) without change from baseline
  
• Acute drug intoxication with return of patient’s mental status to baseline with observation and drug has no potential for delayed toxicity
  

Primary care follow-up to manage etiology which led to altered mental status (i.e., adjust medication dosing, drug abuse treatment referral)

• Consider reversible causes
  
  • Hypoglycemia (check glucose, give dextrose)
    
  • Opiate overdose (trial of naloxone)
    
  • Thiamine deficiency (trial of thiamine)
    
• Consider head CT for any patient with unclear etiology or neurologic abnormality
  
• Consider empiric antibiotics in patients with fever or unclear etiology
  

• Kanich W, Brady WJ, Huff JS, et al. Altered mental status: evaluation and etiology in the ED.
  Am J Emerg Med
  . 2002;20:613–617.
  
• Sporer K, Solares M, Durant E, et al. Accuracy of the initial diagnosis among patients with an acutely altered mental status.
  Emerg Med J.
  2013;30(3):243--246.
  
• Young GB. Disorders of consciousness: Coma.
  Ann NY Acad Sci.
  2009;1157:32–47.
  
• Zehtabchi S, Abdel Baki SG, Malhotra S, et al. Nonconvulsive seizures in patients presenting with altered mental status: An evidence-based review.
  Epilepsy Behav.
  2011;22(2):139–143.
  

CODES