Acute Undifferentiated Altered Mental Status (< 18 years)

75% 100% Zoom 125%

Export to PDF
Contribute Edits
Acute Undifferentiated Altered Mental Status (< 18 years)

Emergent neurosurgical evaluation, elevate HOB to 30 degrees, rapid sequence intubation, maintain normal blood oxygeniation, blood pressure, temperature, normocarbia (maintain PaCO2 35-40 mmHg)

3% NS bolus

Treat appropriately

Concern for infectious cause (sepsis or meningitis)?

CT Head WO Contrast
Complete Blood Count, Serum
Complete Metabolic Panel, Serum
Blood Culture (Aerobic and Anaerobic), Serum
Glucose by Meter, POC
ISTAT Venous Blood Gas and Lactate, Serum
Ammonia, Serum
Alcohol Volatile Screen, Serum
Urine Toxicology, Urine
Acetaminophen, Serum
Salicylate Level, Serum

Consider additional CSF studies depending on the clinical situation

Culture & Gram Stain, CSF
Glucose, CSF
Protein Total, CSF
Cell Count and Differential, CSF
Inclusion Criteria
  • Clinical concern for a pathologic change in the patient's state of awareness
Exclusion Criteria
  • Obvious clinical cause of the change in awareness

Rapid detailed history and physical to identify potential causes of AMS

Signs of impending herniation?

Work-up cause appropriately

Differential Diagnosis of Undifferentiated Altered Level of Consciousness


Alcohol, Abuse of Substances


Epilepsy, Encephalopathy, Electrolyte Abnormalities, Endocrine Disorders


Insulin, Intussusception


Overdose, Oxygen Deficiency




Trauma, Temperature Abnormality, Tumor




Poisoning, Psychiatric Conditions


Shock, Stroke, Space-occupying Lesion (intracranial)

Structural Causes

  • Cerebral vascular accident
  • Cerebral vein thrombosis
  • Hydrocephalus
  • Intracerebral tumor
  • Subdural empyema
  • Trauma (intracranial hemorrhage, diffuse cerebral swelling, non-accidental trauma)

Medical Causes (Toxic-Infectious-Metabolic)

  • Anoxia
  • Diabetic ketoacidosis
  • Electrolyte abnormality
  • Encephalopathy
  • Hypoglycemia
  • Hypothermia or hyperthermia
  • Infection (sepsis)
  • Inborn errors of metabolism
  • Intussusception
  • Meningitis and encephalitis
  • Psychogenic
  • Postictal state
  • Toxins
  • Uremia (hemolytic-uremic syndrome)

Consider additional testing depending on clinical differential diagnosis

  • Subclinical status epilepticus -> consider EEG, neurology consult
  • Acute psychosis -> consider psych consult
  • Stroke non-visualized on CT -> consider MRI
  • Inborn errors of metabolism -> consider additional metabolic workup and consult
  • 6mo-6yo with or without abdominal pain -> consider intussusception
  • Unidentified poisoning agent -> consider observation and further toxin workup

If the diagnostic workup is exhausted, consider neurology, pediatric consultation and admission for further evaluation.

Key historical questions

  • Onset (rapid vs. gradual)
  • History of trauma (even minor)
  • Early morning headaches, dizziness, and somnolence - concern for increased ICP
  • Proximity to a poorly ventilated combustible gas source - concern for CO poisoning
  • Drug or alcohol use or availability of prescription or nonprescription drugs
  • Dizziness and lethargy
  • Fevers

Key physical exam findings

  • Vital sign changes
  • Respiratory pattern - Cheyne-Stokes respiration
  • Cushing triad (systemic hypertension, bradycardia, abnormal respiration)
  • Anterior fontanelle in infants
  • Level of consciousness
  • Pupillary size and reactivity
  • Extraocular movements
  • Motor responses and reflexes
  • Funduscopic examination (however, changes in this exam are a late finding of increased intracranial pressure because it usually requires more than 12 hours to develop)
  • Neck examination for meningeal irritation
  • Exam for signs of coagulopathy (petechiae, bruising, easy bleeding)
  • Exam for signs of hepatomegally (metabolic, toxic or heart failure causes)

Signs of impending herniation

  • Headache
  • Vomiting
  • Altered level of consciousness
  • Papilledema (may be absent in acute elevation ICP as it takes several days to become apparent)
  • Pupillary changes (anisocoria)
  • Combination of systemic hypertension, bradycardia, and respiratory depression (Cushing's triad)
  • Abnormal breathing patterns (Cheyne Stokes respirations)
  • Hemiplegia
  • Decorticate or decerebrate posturing

Consider neurology consultation

Immediate antibiotics, do not wait for cultures

Ceftriaxone injection
Vancomycin injection