Emergency Medicine Altered Mental Status Case File

Emergency Medicine Altered Mental Status Case File

Eugene C. Toy, MD, Barry C. Simon, MD, Terrence H. Liu, MD, MHP, Katrin Y. Takenaka, MD, Adam J. Rosh, MD, MS

Case 32

A 76-year-old nursing home patient is transferred to the emergency department (ED) for reported altered mental status. The patient is confused and unable to provide any relevant information about his condition. According to EMS, the patient has been in the nursing home since he fractured his tibia 4 weeks prior. The patient has a past medical history of hypertension, diabetes, and chronic obstructive pulmonary disease (COPD).

His vital signs are BP 150/90 mm Hg, HR 110 beats per minute, RR 20 breaths per minute, T 36.7°C, and oxygen saturation of 92% on 4-L nasal cannula. On physical examination, the patient appears sleepy but is arousable. He has a difficult time following directions and appears confused. His pupils are 4 mm, equal and reactive. His mucous membranes appear dry. He is tachycardic and his lung sounds are clear and equal bilaterally. His abdomen is soft and nontender. There is a cast on his left lower extremity. The capillary refill on his toes is less then 2 seconds, he has strong femoral pulses. His skin reveals poor turgor and there is tenting. His motor and sensory examinations are normal.

Laboratory results reveal a WBC 12 cells/mm³ and hemoglobin 10 mg/dL. His sodium is 110 mEq/L, potassium 4.1 mEq/L, BUN 52 mg/dL, creatinine 1.0 mg/dL, magnesium 1.7 mEq/L, and glucose 125 mg/dL. His urine drug screen is positive for opiates and benzodiazepines. His urinalysis is negative for infection.

⯈ What is the most likely diagnosis?

⯈ What is the best management?

ANSWER TO CASE 32:

Altered Mental Status

Summary: This is a 76-year-old man from a nursing home with a history of hypertension, diabetes, and COPD. He presents to the ED with altered mental status (AMS). He has limited mobility due to a cast on his left lower leg secondary to a tibia fracture. His examination reveals dehydration and lab tests are consistent with significant hyponatremia and prerenal azotemia.

• Most likely diagnosis: Electrolyte abnormality (hyponatremia) secondary to deconditioning and dehydration.
• Next step in management: Intravenous fluid hydration and consider hypertonic saline.

ANALYSIS

Objectives

1. Recognize the diversity in presentation of patients with altered mental status and understand the diagnostic approach to the workup.
2. Be able to order the appropriate workup for patients and learn the initial management.

Considerations

This is a 76-year-old man who presents to the ED from a nursing home. The presentation of altered mental status in a nursing home patient should elicit concerns for underlying infection (eg, sepsis, meningitis, UTI), electrolyte and metabolic abnormalities (eg, hypo- or hyperglycemia, hyponatremia), delirium, and hypoxia. In the younger population, it is important to keep in mind other common causes of altered mental status such as intoxications and withdrawal syndromes.

Once the patient’s airway, breathing, and circulation (ABCs) are addressed, the first step in management is to obtain a capillary blood glucose to rule out hypoglycemia. The patient appears dehydrated and an electrolyte panel should immediately be sent to the lab and intravenous fluid started for resuscitation.

Approach To:

Altered Mental Status

DEFINITIONS

CONFUSION: Reversible disturbance of consciousness, attention, cognition, and perception that occurs within a short period of time

DELIRIUM: Global disturbance in consciousness and cognition, with an inability to relate to environment and process sensory input that is not better explained by preexisting or evolving dementia

DEMENTIA: Progressive, irreversible decline in mental function affecting judgment, memory, reasoning, comprehension

AGITATION: Excessive restlessness with increased mental and physical activity

COMA: Severe alteration of consciousness where one cannot be aroused

STUPOR: Level of decreased responsiveness where an individual requires aggressive or unpleasant stimulation

OBTUNDED: Level of diminished arousal or awareness frequently from extraneous causes (infection, intoxication, metabolic states)

CLINICAL APPROACH

The phrase “altered mental status” generally refers to a change from an individual’s “normal” mental state. This may reflect a change in behavior, speech, comprehension level, judgment, mood, or level of consciousness (awareness or arousal state). Changes in mental status should be thought of in terms of organic, functional or psychiatric, or as a mixed disorder. Organic causes have a pathological basis primarily with a systemic or metabolic root, however structural lesions must also be considered. Functional or psychiatric diseases do not have a clearly defined physiologic foundation.

The reticular activating system (RAS) is physiologically responsible for our level of arousal. Signals from the RAS run through the pons in the brainstem, through the thalami, then project to both cerebral hemispheres. Any disruption in this pathway will lead to a decreased level of arousal. Examples of this may be through chemical depression via endogenous or exogenous agents or via structural abnormalities such as decreased blood flow resulting in ischemia.

Altered mental status and confusion are estimated to occur in 2% of all ED patients, 10% of hospitalized patients, and 50% of elderly hospitalized patients.

The evaluation of a patient with altered mental status can be a diagnostic challenge and a complete history and physical examination (Table 32–1) is imperative to the workup. Because the patient often cannot provide a reliable history, it is important to obtain information from all available sources such as family, friends, bystanders, and nursing home staff. The severity of illness must be quickly assessed and any life-threatening issues must be rapidly addressed (See Table 32-2).

Assessing the patient’s ABCs, and quickly recognizing and managing reversible causes of AMS, such as hypoglycemia or hypoxia, are critical steps in

Data from Karas S. Behavioral emergencies: differentiating medical from psychiatric disease. Emerg Med Prac.2002;4(3):7-8.

early management. A systematic approach guided by your history and physical and gathering understanding as to how mentation is altered (see Definition list) should be undertaken. The mini-mental state examination (MMSE) or Quick Confusion Scale (QCS) can be used and these ask are 4 to 7 questions that can be used in reassessment to monitor change in mental status.

If altered patient is unable to provide a history, then gathering as much information as possible from EMS, nursing home staff, family or bystanders is critical. EMS may be able to provide clues by describing the scene from where they transported the patient. Was there an empty pill vial? Did the patient verbalize any recent complaints? When was the patient last seen normal? What is the baseline mental status? Was the change in mental status abrupt or gradual? Has the condition changed since first recognized?

Special consideration must be given to pediatric and geriatric populations. Seizures with prolonged postictal states, head injuries, and accidental ingestions are common causes for altered mental status in the pediatric population. In the geriatric population a change in mental status may occur concomitant with existing dementia. Electrolyte abnormalities and dehydration are common causes in addition to hypo and hyperglycemia and thyroid hormone abnormalities. The elderly are more prone to subdural hematomas due to age-related cerebral atrophy; increasing the vulnerability of the bridging veins to tearing. Polypharmacy and unintentional overdoses also commonly cause an alteration in mental status.

Many mnemonics are used to aid in the clinical workup for altered mental status. One popular pneumonic is AEIOU TIPS (see Table 32–3). In elderly patients who are confused and forgetful, understanding the differences between dementia and delirium is critical (Table 32–4).

Data from Smith J, Seirafi J. Delirium and dementia. In: Rosen P, Barkin R, eds. Emergency Medicine, Concepts and

Clinical Practice. 7th ed. Philadelphia, PA: Mosby; 2009: 1372.

Glasgow Coma Scale

The Glasgow coma scale (Table 32–5) was created as an assessment tool to quantify the degree of depression in the level of consciousness in patients with head trauma. Its purpose was to track the progress of patients’ neurologic status. Its use has widened to include patients with undifferentiated change in mental status. The scoring scale utilizes assessments of eye opening, and motor and verbal function to provide a rapid indication on any alteration of function. A higher score corresponds to a higher level of consciousness.

Management

Stabilization of Life Threats Always start by addressing the ABCs and treat any immediate threats to life. Opening the airway and providing a jaw thrust and

supplemental oxygen are the first steps in treating hypoxic causes of AMS. Subsequently begin bag-valve-mask ventilation. If the underlying cause of apnea or hypoventilation cannot immediately be corrected (eg, naloxone for opiate overdose), then the patient will require endotracheal or nasotracheal intubation and mechanical ventilation.

Assess circulation by feeling for pulses, placing the patient on a cardiac monitor, assess skin perfusion, and check blood pressure. The only way to fix a hypoperfused brain is to restore circulation. Begin CPR if the patient is pulseless or a nonperfusing rhythm (v-fib, pulseless v-tach) is seen on the monitor and prepare for defibrillation or cardioversion. If there is a pulse, but signs of shock are present (mottled skin, cool extremities), you need to assure adequate volume (IV fluids), hemoglobin (transfusion), and peripheral vascular resistance (pressors).

As soon as adequate airway, breathing and circulatory support has been established then make a global assessment of neurologic functioning. Assess the GCS scale. Check for pupil size and reactivity. Look for any spontaneous movement, especially noting seizure-like activity or lack of movement on one side suggesting a stroke or below a certain level (spinal cord injury). Any suspicion of cord injury requires placement of a cervical collar and immobilization. Undress the patient and onto his or her side to look for any signs of trauma, drug patches or infection sources.

Infectious Fever, recent history of infection, or any signs of infection on physical examination need to be addressed immediately. Any patient who is altered with a fever should always raise the suspicion for meningitis. It is prudent to empirically treat (ceftriaxone and vancomycin and pretreat with steroids) these patients while you proceed with the diagnostic workup (lumbar puncture). If the history and physical suggests any other sources of infection (pneumonia, UTI), appropriate antibiotics and cultures should be started right away. Indwelling lines need to be removed or changed and any fluid collections must be drained.

Metabolic Hypoglycemia is a common cause of altered mental status. If you cannot quickly determine blood glucose go ahead and give an amp of D50 (25 g of dextrose). In addition to unconsciousness, hypoglycemia can cause seizures and the patient may have a prolonged postictal phase. If the patient is unconscious and intravenous access is difficult, you can consider administering intramuscular glucagon, which acts as a counterregulatory hormone to increase serum glucose levels.

Hypo- and hypernatremia are primarily problems of water metabolism and are frequently associated with volume overload or dehydration states. Hyponatremia can cause altered mental status, focal neurologic abnormalities, and seizures. This should be treated with hypertonic (3%) saline. Hypernatremia should respond to appropriate rehydration. These patients typically require admission to the intensive care unit.

Hypo- and hypercalcemia can result from several metabolic abnormalities or paraneoplastic syndromes. Hypocalcemia should be treated with calcium, whereas the initial treatment for hypercalcemia is intravenous fluid hydration.

Primary CNS Seizure is a common cause for AMS. Always rule out hypoglycemia first. Benzodiazepines are the first-line therapy. Send blood for levels if the patient is on anticonvulsants with measurable levels or metabolites. Load subtheraputic patients where appropriate.

Tumors can present as altered mental status. Any previous cancer history, focal neurologic findings, headache, or papilledema should prompt a head CT scan. IV contrast enhances the ability of plain CT to identify tumors. If there is evidence of edema or mass-effect, then consider administering steroids to help reduce vasogenic edema. Obtain an emergent neurosurgic consultation. These patients typically require admission to the intensive care unit.

Brain abscesses can be identified with a contrast-enhanced head CT scan. These patients should immediately be placed on antibiotics and be seen by a neurosurgeon.

Drugs and Toxins Many overdoses can lead to altered mental status. Look for signs of a toxidrome (sedative/hypnotic, sympathomimetic, anticholinergic, cholinergic, and opiate/opioid). Most toxidromes can be treated with supportive measures, however specific antidotes exist for each (see Case 40).

Ethanol intoxication is a common ingestion for ED patients. These patients need to be thoroughly evaluated to exclude other causes of their change in mental status (stroke, hypoglycemia, Wernicke encephalopathy, intracranial bleed, toxic alcohol). Once serious causes are ruled out, these patients require supportive care until they can be discharged.

Withdrawal states can lead to altered mental status. Patients with ethanol and benzodiazepine withdrawal are typically hyperadrenergic, agitated, and confused. These patients require administration of benzodiazepines, supportive care, and inpatient admission.

Trauma A CT scan should be performed immediately in patients with evidence of head trauma and altered mental status. It is important to rule out an intracranial injury such as acute bleeding, skull fracture, and evidence of increased intracranial pressure. The trauma or neurosurgical service should be contacted for any positive findings.

Disposition Unless the patient with altered mental status presents to the ED with an identifiable reversible cause for his or her change in mental status (heroin overdose), the majority of patients who present to the ED with altered mental status will require admission for further inpatient workup.

COMPREHENSION QUESTIONS

32.1 A 77-year-old women is brought to the ED by her daughter. The daughter provides the history that her mother is usually alert and oriented and performs all of her activities of daily life (ADLs) by herself. Over the past week, the patient has been eating and drinking less and tells her daughter that she is not hungry. Yesterday she had an episode of incontinence and this morning she woke up confused, unable to follow commands and kept asking where her husband was (he’s been deceased for over 5 years). The patient is tachycardic with a HR in the 130s, appears dehydrated, has a low-grade fever, and smells of urine. The most likely cause of her altered mental status is?

A. Alzheimer dementia

B. Alcohol Intoxication

C. Overmedication

D. Urinary tract infection

32.2 A 45-year-old man who runs his own business has been struggling with his finances since undergoing three surgeries to fix his right shoulder. He has been visiting multiple doctors to help control his pain. EMS was called to his office after an employee found the patient on his office floor with a bottle of vodka and a prescription medication bottle lying next to him. Which of the following should be the first course of action in the ED?

A. Administer naloxone as he likely overdosed on pain medications.

B. Give thiamine to prevent Wernicke-Korsakoff syndrome.

C. Obtain a capillary blood glucose check.

D. Disrobe the patient, place on a monitor, and obtain vital signs.

32.3 A 68-year-old woman was brought to the ED after her friends noticed that during lunch the patient began slurring her speech and started acting confused. They were about to take her home when she developed jerking movements of the extremities and become unresponsive. When EMS arrived she was conscious, hypertensive at 160/90 mm Hg, with otherwise normal vital signs. She was not talking or following commands. After addressing the ABCs, what is the most appropriate next step in the management of this patient?

A. Administer lorazepam as she likely had a seizure.

B. Administer glucose as she likely is having a hypoglycemic episode.

C. Obtain a head CT scan as she may be having a stroke or intracranial hemorrhage.

D. Treat her blood pressure emergently as she is having a hypertensive emergency.

ANSWERS

32.1 D. Infection is a common cause of altered mental status especially in the elderly population. The history suggests a urinary tract infection concomitant with dehydration. This is the most likely cause of this patient’s altered mental status. Alzheimer’s does not develop rapidly, but rather gradually over time. The history is not suggestive of alcohol abuse and additional history and physical examination signs should be present to suggest a medication overuse.

32.2 D. In all patients the ABCs take priority. The patient should be assessed and the physical examination performed before administering any medications. In this patient with altered mental status of unknown etiology, the “coma cocktail” will likely be administered, but should be guided by the physical examination and history.

32.3 C. This presentation is concerning for a stroke. The history obtained from friends in this case is critical to making a diagnosis for this patient. She did have a seizure and may be in a postictal state. However, the history of slurred speech and confusion raise suspicion for stroke and as soon as the patient is stable, she should undergo a CT scan. It is important to first establish the type of stroke before altering the blood pressure as it can be detrimental if the blood pressure is lowered too much and too rapidly in patients with ischemic stroke.

CLINICAL PEARLS

⯈ Be sure to talk with family, EMS, nursing home care providers and review medical records for important pieces of historical information, new medications, and baseline behavior and functional status.

⯈ Check vitals signs frequently, making sure to get accurate readings on pulse oximetry, temperature, and blood pressure.

⯈ A glucose level should be checked immediately in all patients with altered mental status.

⯈ Be careful not to classify a confused elderly patient as demented without first ruling out organic causes of their confusion.

References

Cooke JL. Depressed consciousness and coma. In: Rosen P, Barkin R, eds. Emergency Medicine, Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Mosby; 2009:106-112. 

Huff, JS. Confusion. In: Rosen P, Barkin R, eds. Emergency Medicine, Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Mosby; 2009:101-105. 

Karas, S. Behavioral emergencies: differentiating medical from psychiatric disease. Emerg Med Prac. 2002;4(3):1-20. 

Nassisi D, Okuda Y. ED management of delirium and agitation. Emerg Med Prac.2007;9(1):1-20. 

Smith J, Seirafi J. Delirium and dementia. In: Rosen P, Barkin R, eds. Emergency Medicine, Concepts and Clinical Practice. 7th ed. Philadelphia, PA: Mosby; 2009:1365-1378.

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