Altered Mental Status

Published on 24/03/2015 by admin

Filed under Emergency Medicine

Last modified 22/04/2025

Print this page

This article have been viewed 1502 times

Chapter 6 Altered Mental Status

Douglas S. Nelson, MD, FAAP, FACEP

1 How can altered mental status present in an infant?

It may present as a combination of crying, irritability, poor feeding, or sleeping more or less than usual.

2 What clues can I use to determine whether altered mental status is due to a toxic ingestion?

Suspect a toxic ingestion when no history of trauma is present, abnormal consciousness was of sudden onset, the patient was unsupervised, the patient appears to have a chaotic home situation, or the patient has a history of previous ingestions.

Dobson JV, Webb SA: Life-threatening pediatric poisonings. J S C Med Assoc 100:327–332, 2004.

3 What scales are in use to quantify altered mental status? Why should I use them?

The level of consciousness of a neurologically impaired patient may initially be evaluated by using a simple AVPU scale, representing four major levels of alertness: alert, responsive to verbal stimuli, responsive to painful stimuli, and unresponsive.

A more widely used measurement of consciousness is the Glasgow Coma Scale (GCS). Patients are graded on three areas of neurologic function: eye opening, motor responses, and verbal responsiveness. These numeric scores are added to determine the GCS score. A GCS score of 3 is the minimum score possible and represents complete unresponsiveness, while a GCS score of 15 is assigned to fully alert patients. Details of the scale are listed below:

There are several good reasons to use a standard quantifiable mental status scale. It allows evaluation of a patient’s changing neurologic status over time and the recording of this information in the medical record. The effect of medical interventions may then be more easily assessed. The use of accepted scoring systems also facilitates communication with consultants, such as neurologists and neurosurgeons.

Nelson DS: Coma and altered level of consciousness. In Fleisher G, Ludwig S (eds): Textbook of Pediatric Emergency Medicine, 5th ed. Philadelphia, Lippincott Williams & Wilkins, 2006, pp 201–212.

KEY POINTS: CLUES TO TOXIC INGESTION IN A CHILD WITH ALTERED MENTAL STATUS

2 Sudden onset of symptoms

3 Lack of supervision of patient

5 Previous ingestions

4 Which toxins not detected on most drug screens can cause abnormal mental status?

The following toxins are associated with altered mental status and miosis: clonidine, chloral hydrate, organophosphates, and tetrahydrozoline. Mydriasis and altered mental status are found with other toxins: carbon monoxide, cyanide, methemoglobinemia, LSD, and γ-hydroxybutyrate.

5 What do the letters DPT, OPV, HIB, and MMR stand for?

Although these represent abbreviations for several childhood immunizations, the letters also comprise a mnemonic to recall common causes of abnormal mental status.

D = Dehydration	O = Occult trauma
P = Poisoning	P = Postictal or Postanoxia
T = Trauma	V = VP shunt problem
H = Hypoxia or Hyperthermia	M = Meningitis or encephalitis
I = Intussusception	M = Metabolic
B = Brain mass	R = Reye’s syndrome, other Rarities

Schunk JE: The pediatric patient with altered level of consciousness: Remember your “immunizations.” J Emerg Nurs 18:419–421, 1992.

6 When should I consider obtaining a computed tomographic scan on a child with abnormal mental status?

Consider computed tomography (CT) if there is any history of trauma, any focal or lateralizing signs on physical examination, or any suspicion of physical abuse.

7 A teenager is brought to the emergency department (ED) from a party by his friends. He is comatose and has profound respiratory and neurologic depression with no history of head trauma. You send a toxicologic screen, intubate his trachea, and arrange for admission to the intensive care unit (ICU). The ICU staff obtains a CT scan, which takes an hour to accomplish. The result of the scan is normal. Upon returning from the scanner, the patient sits up, rips the endotracheal tube out of his mouth, and says he wishes to leave. His toxicology screen is normal except for a clinically insignificant amount of ethanol. What was the most likely cause of his problem?

At the party he drank γ-hydroxybutyrate (GHB). It is an inhibitory neurotransmitter normally found in the brain, causing central nervous system (CNS) depressant effects, but some excitatory ones as well, such as seizures. The patient may have ingested it intentionally, or it may have been surreptitiously added to an alcoholic drink.

The CNS effects of GHB include drowsiness, ataxia, confusion, amnesia, incontinence, seizures, and coma. Behavioral manifestations can include euphoria, hallucinations, or delirium. Mydriasis and nystagmus may be present, accompanied by respiratory depression, bradycardia, and hypotension.

Recovery from GHB intoxication is usually rapid, within several hours after ingestion. Note that routine toxicologic screens miss the presence of this drug, which should now be considered in the differential diagnosis of all teens with abnormal mental status.

Suner S, Szlatenyi CS, Wang RY: Pediatric gamma hydroxybutyrate intoxication. Acad Emerg Med 4:1041–1045, 1997.

8 A 6-month-old infant is brought in by her mother after being left alone with “the boyfriend.” She was well yesterday, but today will not feed and is sleepier than normal. She has no fever, congestion, vomiting, or diarrhea. The physical examination is normal except that the child seems more difficult to arouse than usual. What possible etiologies should be considered?

Child abuse is most likely. Also consider sepsis, intussusception, and inborn metabolic abnormalities. Pay particular attention to the fontanelle and fundi of the infant: bulging of the fontanelle or any abnormalities of the eye grounds is extremely significant. Child abuse in this scenario is most likely to take the form of a “shaken baby” injury, when the whipping motion of an infant’s head causes tearing of cortical bridging veins between the dura and arachnoid veins, leading to subdural hematoma formation. These can occur bilaterally and are five to 10 times more common than epidural bleeding. Subdural hematomas may occur on a chronic basis in young abused children, and are associated with skull fractures in 30% of cases. Retinal hemorrhages are found in 75% of patients with subdural hematomas. Neuroimaging classically reveals crescent-shaped lesions between the brain and skull. Skeletal survey performed on these children typically show orthopedic injuries in various stages of healing.

Belfer RA, Klein BL, Orr L: Use of the skeletal survey in the evaluation of child maltreatment. Am J Emerg Med 19:122–124, 2001.

9 Magnetic resonance imaging (MRI) provides a sharper, more detailed picture of the brain than does CT. Why, then, is CT usually performed first in a patient presenting with abnormal mental status?

MRI scans are more costly, take longer to obtain, and are generally more difficult to arrange than CT scans. CT images show most structural lesions that may present with altered mental status, such as tumors or hemorrhage. Young children may require sedation for MRI, but not for a quick head CT.

10 What are clues that a child may be “faking” an altered mental status?

Malingering should be suspected if the patient has a psychiatric history or falls down from “spells” without ever being injured. On physical examination, when you lift the patient’s hand to a position directly over his or her face and let go, the patient will not hit himself or herself in the face unless there has been an alteration in mental status. In very convincing cases, it may be necessary to perform electroencephalography to prove this suspicion.

11 A 3-year-old is brought for evaluation one winter day because he is groggy and has had a headache for a few days. The rest of the family members are all older and have had similar although less severe symptoms. No other signs of illness, such as fever, vomiting, diarrhea, rhinorrhea, or rash, are present. No history of ingestion or head trauma is present. Physical examination reveals a well-appearing but drowsy child with very mild tachypnea. He wants to sleep if you leave him alone and is cranky when you keep him up. The examination is otherwise normal; oxygen saturation is 100% in room air. Electrolytes, complete blood count, and blood gas are obtained. What test comes back with abnormal results?

The blood gas, which shows a carboxyhemoglobin level of 20%. This level indicates that the patient and presumably his or her family are being poisoned by carbon monoxide. This cause of abnormal mental status is seen most often in early winter, as families turn on their furnaces for the first time since the previous heating season. Treatment usually consists of administering 100% oxygen via a rebreather face mask. Severe cases, such as in children rescued from house fires, may require endotracheal intubation and hyperbaric oxygen. Pulse oximetry often reads 100% as carboxyhemoglobin is misread as oxygenated hemoglobin.

Chou KJ, Fisher JL, Silver EJ: Characteristics and outcome of children with carbon monoxide poisoning with and without smoke exposure referred for hyperbaric oxygen therapy. Pediatr Emerg Care 16:151–155, 2000.

12 If the physical examination of a patient with altered mental status does not reveal the source of neurologic disability, what laboratory tests should I consider?

Glucose is the most important laboratory test to check and one of the fastest and easiest. In many institutions, a rapid bedside test can be done to provide a value in minutes. Consider also a toxicologic screen, electrolytes, or head CT.

13 What subtle signs may represent seizure activity as the cause of altered mental status?

Suspect seizure if the patient is dazed or confused and exhibits staring, swallowing, eye blinking, lip quivering, nystagmus, and automatisms (motor actions performed without conscious intent). The degree of neurologic impairment can fluctuate over time.

Benson PJ, Klein EJ: New-onset absence status epilepsy presenting as altered mental status in a pediatric patient. Ann Emerg Med 37:402–405, 2001.

14 What causes of abnormal mental status are particularly life-threatening?

The list includes epidural hematoma, cerebral edema, brain neoplasms, cerebral infarctions, cerebrospinal fluid shunt malfunction, meningitis, encephalitis, toxic ingestions, carbon monoxide poisoning, hypotension, hypoxia, and sepsis.

Nelson DS: Coma and altered level of consciousness. In Fleisher G, Ludwig S (eds): Textbook of Pediatric Emergency Medicine, 5th ed. Philadelphia, Lippincott Williams & Wilkins, 2006, pp 201–212.

15 An obese African-American patient presents with abnormal mental status, a blood glucose level > 600 mg/dl, and mild changes of bicarbonate and ketone values. You suspect the presence of what endocrine disorder?

Type 2 diabetes is increasingly common among pediatric patients. Children with this disorder may present with a nonketotic hyperglycemic (serum glucose > 600 mg/dL) and hyperosmolar (osmolality > 330 mOsm/L) state. In Fourtner and colleagues’ series, the mean time to the return of a normal mental state was 3 days (range, 1–7 days).

Bhowmick SK, Levens KL, Rettig KR: Hyperosmolar hyperglycemic crisis: An acute life-threatening event in children and adolescents with type 2 diabetes mellitus. Endocr Pract 11:23–29, 2005.

Fourtner SH, Weinzimer SA, Levitt Katz LE: Hyperglycemic hyperosmolar non-ketotic syndrome in children with type 2 diabetes. Pediatr Diabetes 6:129–135, 2005.

16 An 11-year-old boy is brought to the ED after awakening from sleep with headache and vomiting. He is disoriented and does not recognize his parents. Head CT, blood and cerebrospinal fluid chemistries, and toxicologic screens are normal. His mental status cleared shortly after admission. What diagnosis did the consulting neurologist make?

Acute confusional migraine. This is an atypical type of migraine headache characterized by the sudden onset of mental status changes. These may include confusion, disorientation, dysarthria, and diminished level of consciousness. It is thought to be more common in males. Treatment consists of standard migraine medical management.

Bechtel K: Acute mental status change due to acute confusional migraine. Pediatr Emerg Care 20:238–241, 2004.

17 A 6-year-old girl presented to the ED with diminished loss of consciousness (LOC). The prior evening, the patient had reported shortness of breath and chest pain on inspiration. In the morning, the patient was noted to be very weak and progressively less responsive to external stimuli. On physical examination, heart rate was 155 beats per minute (BPM), respiratory rate was 48 per minute, and blood pressure (BP) was 60/25 mmHg. No fever was present, nor was there any focus of infection on examination. Complete blood count and blood chemistries were normal, and room-air oxygen saturation was 98%. Mucous membranes were moist and skin turgor was normal. Lungs were clear to auscultation, and the heart had a tachycardic but regular rhythm. CT scan was normal. What problem did the patient have?

This patient’s altered mental status was due to hypotension. The cause of this abnormality was not sepsis or dehydration. This tachycardic and hypotensive patient had pericardial tamponade, despite her lack of distended neck veins or muffled heart tones. The hypotension associated with this disorder will not respond to administration of IV fluids. Pericardiocentesis is the appropriate treatment, which was performed on this patient and resulted in prompt restoration of normal mental status.

Milner D, Losek JD, Schiff J, Sicoli R: Pediatric pericardial tamponade presenting as altered mental status. Pediatr Emerg Care 19:35–37, 2003.

18 A 4-year-old boy was brought to the ED because of sleepiness and “not acting right.” He had been born prematurely and had spent several weeks in a neonatal ICU after birth. Since then, he had been doing well. He had no recent history of head trauma, fever, toxic ingestion, or illness. Review of symptoms was positive for vomiting and decreased responsiveness. Patient was afebrile, with a heart rate of 120 BPM, BP of 140/80 mmHg, and a respiratory rate of 36 per minute. The patient was difficult to arouse and cried when awake. Cerebral spinal fluid was not obtained because of concerns of increased intracranial pressure. A CT scan was ordered because of concerns of child abuse. It was read as normal, but MRI revealed subtle occipital abnormalities. After treatment, the patient’s repeat MRI scan was normal. What problem caused the patient’s abnormal mental status?

The patient had hypertensive encephalopathy due to renal artery stenosis caused by an umbilical artery catheter used during their postnatal neonatal intensive care unit stay. The MRI findings were consistent with posterior leukoencephalopathy syndrome. Clinical findings may include altered mental status, seizures, headache, and blindness. Appropriate treatment of hypertension results in resolution of neurologic and MRI abnormalities.

Singhi P, Subramanian C, Jain V, et al: Reversible brain lesions in childhood hypertension. Acta Paediatr 91:1005–1007, 2002.

19 A 12-year-old boy is brought to the ED by his parents, who are concerned by his diminished responsiveness. He has a history of sinus and ear infections. The previous evening, he had reported a headache and seemed to have a tactile fever. On the day of presentation, he is noted to be somnolent and difficult to arouse, with slower than normal reaction times. He has no focal neurologic findings, and physical examination is unremarkable. Why is he ill?

The patient has a subdural abscess from long-standing sinusitis. Intracranial complications of sinusitis are rare but possible in childhood. When pus-filled sinuses decompress into the cranial vault, minimal facial tenderness may be present. A high index of suspicion is needed to order brain and sinus CT scans that reveal the etiology of the patient’s mental status.

Giannoni C, Sulek M, Friedman EM: Intracranial complications of sinusitis: A pediatric series. Am J Rhinol 12:173–178, 1998.

^* Preverbal children should receive full verbal score for crying with stimulation.

Related

Pediatric Emergency Medicine Secrets