Approach to altered mental status (pediatrics): Clinical sciences

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Introduction 0:00–0:26

Altered mental status refers to any change in brain function that significantly impacts behavior, mood, or consciousness.
Differential diagnosis for altered mental status includes metabolic disturbances, substance exposure, structural brain lesions, infection, hypoxemia, hypoventilation, shock, and seizures.
If a pediatric patient presents with altered mental status, first perform an ABCDE assessment to determine if they are stable or unstable.

Unstable 0:26–2:30

Because altered mental status is a manifestation of many life-threatening conditions, you should consider your patient unstable and start acute management.
First, stabilize the airway, breathing, and circulation. Then, assess their level of consciousness by checking the Glasgow Coma Scale or GCS, which measures eye-opening, verbal, and motor response to stimuli on a scale from 3 to 15.
For children less than 5 years of age, use the Pediatric Glasgow Coma Scale instead. A GCS score of 3 represents a comatose state, while a score of 15 indicates a normal level of consciousness.
In trauma patients, GCS of 8 or less might require intubation, however when dealing with a pediatric patient with altered mental status, you might want to intubate even with higher GCS to protect the airway!
Next, obtain IV access, check a bedside glucose, and administer naloxone if you suspect opioid intoxication. Finally, begin continuous vital sign monitoring; and if needed, provide supplemental oxygen.
Once you’ve stabilized your patient, obtain a focused history and physical exam. Since these patients are often unable to provide a history, you may need to gather information from family members or caregivers.
They typically report a significant change in the patient’s level of consciousness, with decreased alertness; confusion; altered mood; or altered behavior, like inconsolable crying.
These symptoms may fluctuate in severity. The exam reveals a decreased level of consciousness, with confusion, disorientation, or irritability.
In more severe cases, patients may exhibit lethargy, stupor, or coma. These findings indicate altered mental status.
To find out what’s causing it, you’ll need to use clinical findings to guide the diagnostic evaluation, but before you do, check the bedside glucose result.
If the glucose isbelow the reference range for age, your patient has hypoglycemia. This usually corresponds to glucose less than 55 mg/dL in newborns and less than 60 mg/dL in infants and children.

Hypoglycemia2:30–3:07

Hypoglycemia is a common cause of altered mental status and can result from various etiologies, including reduced oral intake, ethanol intoxication, excess insulin administration, or in rare cases, an inborn error of metabolism.
Regardless of its cause, hypoglycemia is a medical emergency that you can treat with intravenous dextrose. Alternatively, with a glucose level above 250 mg/dL, consider diabetic ketoacidosis.

Hyperglycemia 3:07–4:12

Next, order arterial blood gas, or ABG; BMP, serum beta-hydroxybutyrate level, and urinalysis. If arterial pH is less than 7.3 or serum bicarbonate level is less than 15, the serum beta-hydroxybutyrate is above 3 mmol/L, and urinalysis reveals moderate to severe ketonuria, your patient meets diagnostic criteria for diabetic ketoacidosis.
Here’s a clinical pearl! Hyperosmolar hyperglycemic syndrome, or HHS, is another important cause of altered mental status with hyperglycemia.
These patients have glucose levels above 600 mg/dL and serum osmolality above 320 mOsm/kg; without ketoacidosis. Keep in mind that HHS is typically seen in older patients, but it can occasionally occur in children with type 2 diabetes.
Moving on, if the bedside glucose is normal, you should look for medication or other substance exposures. Your patient might use recreational substances, like opioids, alcohol, or sympathomimetics; or take medications, such as salicylates, antihistamines, or tricyclic antidepressants.

Substance exposure4:12–4:50

Younger children might have ingested a household agent, such as antifreeze or an organophosphate pesticide. If there’s a confirmed or suspected substance exposure, or if your patient shows signs of improvement after naloxone administration, their altered mental status is probably medication- or substance-induced.
However, if there’s no confirmed or suspected substance exposure, be sure to rule out structural brain disease. Your patient may present after blunt head trauma, but even if there’s no reported injury, remember to think about non-accidental head trauma, especially when evaluating an infant.

Structural brain disease4:50–6:20

History may reveal a known CNS condition or a previous neurosurgical procedure, such as ventriculoperitoneal shunt placement.
In the case of trauma, the exam may show evidence of a basilar skull fracture, like raccoon eyes or periorbital bruising; Battle sign, which is bruising behind the ear; or hemotympanum, which is blood behind the tympanic membrane.
Focal neurological deficits, such as asymmetry in tone, movements, or reflexes, suggest intracranial pathology. If you see any of these findings, obtain a head CT.
It may reveal an intracranial hemorrhage, hydrocephalus, cerebral edema, a space-occupying lesion, or a vascular malformation.
Any one of these confirms structural brain disease, which is the likely cause of your patient’s altered mental status. Keep in mind that patients with concussion may have a normal CT scan, and some intrinsic CNS lesions resulting from vasculitis or multiple sclerosis might not show up on a CT scan, so you may need to consider other imaging modalities, such as MRI.
Now, if your patient has no indications for neuroimaging, proceed with an assessment for nonstructural causes of altered mental status, starting with infection.

Infection6:20–8:53

Let’s start with CNS infections. These patients typically have fever, headache, photophobia, and occasionally neck stiffness; while the exam may demonstrate nuchal rigidity and a positive Kernig or Brudzinski sign.
With these findings, consider CNS infection. Then, perform a lumbar puncture, and send cerebrospinal fluid, or CSF, for analysis and culture.
Remember, as soon as you suspect a CNS infection, administer intravenous antibiotics, and don’t wait for lab results! If the CSF analysis reveals elevated white blood cells, possibly with a positive Gram stain or culture, your patient has a CNS infection, which can be caused by viral or bacterial meningitis, as well as viral encephalitis.
Now let’s move on to sepsis. These patients often have fever or hypothermia, and some have localizing symptoms, like cough or dysuria, that suggest a primary source of infection.
The physical exam typically reveals temperature instability, tachycardia, and in some cases, low blood pressure. Here, consider sepsis and obtain labs, including a CBC, blood culture, and inflammatory markers such as CRP and PCT.
If you suspect a primary infection, order appropriate studies to identify the source. For example, get a urinalysis and urine culture if you suspect a urinary tract infection, or a chest X-ray if you suspect pneumonia.
Remember, once you suspect sepsis, administer intravenous antibiotics, and don’t wait for lab results! The white blood cells and inflammatory markers are typically elevated, and the blood culture might be positive.
If you ordered additional testing, results may reveal a source of infection. For example, a urinalysis might show white blood cells and a urine culture might be positive, or a chest X-ray could demonstrate an infiltrate or consolidation.
With these findings, diagnose sepsis. Here’s a clinical pearl to keep in mind!
Altered mental status can also be caused by extremes of temperature that are unrelated to infection, like hyperthermia from heat stroke; or hypothermia from environmental exposure.
After you’ve looked for infection, you should rule out hypoxemia and hypoventilation. History might reveal either shortness of breath or apnea, while the exam may demonstrate tachypnea and signs indicating increased work of breathing; or it may reveal shallow, slow, or absent breaths; decreased breath sounds; and possibly cyanosis.

Hypoxia and hypoventilation 8:53–10:16

With these findings, consider hypoxemia, hypoventilation, or a combination of both; and obtain ABG. An arterial partial pressure of oxygen less than 60 millimeters of mercury indicates respiratory failure due to hypoxemia.
In this case, your patient might have experienced an acute hypoxic event, like neonatal asphyxia; or they may have survived a drowning event.
Patients with shock due to hypovolemia, hemorrhage, heart failure, or carbon monoxide poisoning often experience altered mental status as a result of hypoxemia and impaired organ perfusion.
On the other hand, an arterial partial pressure of carbon dioxide above 50 millimeters of mercury indicates respiratory failure due to hypoventilation.
This can occur in conditions characterized by neuromuscular weakness or decreased respiratory drive, where hypoventilation leads to carbon dioxide retention and altered mental status.
Now, if the ABG doesn’t reveal hypoxemia or hyperventilation, you’ll need to assess for seizure activity. Caregivers typically report focal or generalized motor activity, possibly with a preceding aura.

Unprovoked Seizure10:16–11:14

As for the exam, you may see ongoing tonic-clonic motor activity; or if the seizure has resolved, the patient might demonstrate a postictal state; or Todd paresis, which is temporary postictal paralysis.
These signs and symptoms are highly suggestive of an unprovoked seizure, which can cause altered mental status during both the seizure and the postictal period.
Remember that additional workup is needed to find the cause of the seizure including EEG and in some cases MRI of the brain.
Time for a clinical pearl! Seizures causing altered mental status might also be provoked seizures, in which case you will find some clues to the provoking factor like fever or hypoglycemia.
Lastly, you’ll need to assess for metabolic disturbances. In addition to glucose disturbances, these include disorders of electrolytes such as sodium and calcium, as well as uremia and hyperammonemia.

Metabolic Disturbances11:14–13:13

Your patient may have known liver or kidney disease, a chronic condition like sarcoidosis, or an inborn error of metabolism.
Otherwise healthy patients might report an acute gastrointestinal illness with dehydration. The exam may reveal diffuse neurologic deficits and manifestations depending on the specific electrolyte disturbance.
For example, hyponatremia might result in cerebral edema and seizures; while hypernatremia can cause irritability and a high-pitched cry; and hypocalcemia is associated with muscle spasms and seizures.
Regardless of your patient’s signs and symptoms, remember to order a CMP and ammonia level. Results may demonstrate elevated or decreased sodium levels, elevated or decreased calcium levels, or elevated BUN or ammonia levels.
Any of these findings confirms a metabolic abnormality, which could be contributing to your patient’s altered mental status.
Some possible underlying causes include kidney failure, which can lead to uremia; inborn errors of metabolism or liver failure, both of which can cause hyperammonemia; and chronic kidney disease or sarcoidosis, which can cause hypercalcemia.
Here’s your last clinical pearl! Remember to consider intussusception in young children with altered mental status.
This medical emergency typically presents with intervals of vomiting and colicky abdominal pain, followed by lethargy. If you’ve completed your diagnostic workup and still can’t find a clear cause for your patient’s altered mental status, be sure to consider the possibility of delirium or psychiatric disorders, such as psychosis or conversion disorder.
Alright, as a quick recap…. When a child presents with altered mental status, provide acute management, determine a GCS score, and obtain a history and physical exam.

Review13:13–13:38

Check a bedside glucose to assess for hypo- and hyperglycemia, and then assess for medication and substance exposure; structural brain disease; infection; hypoxia and hypoventilation; seizure; and metabolic disturbances.
Approach to altered mental status (pediatrics) | Osmosis