Change In Mental Status

Definitions (nb. description of state better than imprecise use of terms)

• Confusion (encephalopathy): unable to maintain coherent thought process

• Delirium: waxing & waning confusional state w/ additional sympathetic signs

• Drowsiness:. level of consciousness, but rapid arousal to verbal or noxious stimuli

• Stupor, impaired arousal to noxious stimuli, but some preserved purposeful movements

• Coma: sleep-like state of unresponsiveness, with no purposeful response to stimuli

Etiologies

Primary Neurologic Systemic (especially in elderly)

Stroke

Seizure (postictal, status, nonconvulsive)

Infection: meningoencephalitis, abscess

Epidural subdural hematoma

Concussion

Hydrocephalus

Complicated migraine

Venous thrombosis

Cholesterol or fat emboli

CNS vasculitis

TTP

Cardiac: severe CHF. HTN encephalopathy Pulmonary: I P.Oj, T P.COj Gl: liver failure, constipation.Wilson s Renal: uremia, hypo- and hypernatremia Endocrine: i glc. DKA. HHNS, T Ca. hypo-or hyperthyroidism, Addisonian crisis ID: pneumonia, UTI. sepsis Hypo- and hyperthermia Medications (espec. opiates & sedatives) Alcohol & toxins

Initial evaluation

• History (typically from others): previous or recent illnesses, including underlying dementia or psychiatric disorders: head trauma; meds. drug or alcohol use

• General physical examination including signs of trauma, stigmata of liver disease.

embolic phenomena, signs of drug use. nuchal rigidity (may be present in meningitis or subarachnoid hemorrhage, but do not test if question of trauma cervical spine fracture)

• Neurologic examination

Observation for spontaneous movements, response to stimuli, papilledema Cranial nerves: eye position at rest, response to visual threat, corneal reflex, facial grimace to nasal tickle, cough gag (with ET tube manipulation if necessary) Pupil size & reactivity: pinpoint -» opiates; midposition & fixed -» midbrain lesion;

fix & dilated severe anoxic encephalopathy, herniation Intact oculocephalic ("doll's eyes." eyes move opposite head movement) or oculovestibular ("cold calorics." eyes move toward lavaged ear) imply brainstem intact Look for signs of * ICP: H A, vomiting. HTN. i HR. papilledema, unilateral dilated pupil Motor response in the extremities to noxious stimuli - noting purposeful vs. posturing Deep tendon reflexes. Babinski response

Glasgow Coma Scale

Eye opening

Best verbal response

Best motor response

Points

Follows commands

6

Oriented

Localizes pain

5

Spontaneous

Confused

Withdraws from pain

4

To voice

Inappropriate words

Flexor response

3

To painful stimuli

Unintelligible sounds

Extensor response

2

None

None

None

1

Sum points from each of the 3 categories to calculate the score

Initial treatment

• Control airway, monitor vital signs. IV access

• Immobilization of C-spine if concern for cervical trauma

• Thiamine (100 mg IV) prior to dextrose to prevent exacerb. of Wernicke encephalopathy

• Naloxone 0.01 mg kg if opiates suspected; flumazenil 0.2 mg IV if benzos suspected

• If concern for T ICP and herniation: t head of bed; osmotherapy with mannitol;

hyperventilation; dexamethasone; consider emergent surgical decompression

Diagnostic studies

• Head CT; radiographs to r o C-spine fracture; CXR to r o PNA (in elderly)

• Laboratory: electrolytes. BUN. Cr. ABG. LFTs. CBC. PT. PTT. tox screen.TSH. U A

• Lumbar puncture to r o meningitis

• EEG to r o nonconvulsive seizures

Anoxic Brain Injury

Prevalence

• Pts w at least 5 min of cerebral hypoxia at risk

• 1.5 million cardiac arrests per yr in U.S.; 30% survive, but only 10-20% return to independence Initial evaluation

• Neuro exam: focus on coma exam — cranial nerves, motor response to pain

• Imaging: usually not informative w in first day after arrest, but should be done prior to initiating hypothermia if patient found down or witnessed to hit head Induced hypothermia (NEJM 2002;346S49. S59)

• Indications: comatose w in 6 h following cardiac arrest (not isolated resp. arrest). Only fully studied in VT VF. but acceptable to perform after asystole or PEA arrest.

• Contraindications: active bleeding, including cerebral; known sepsis; recent surgery or trauma (relative); CV instability; clear improvement in neurological exam (purposeful movements, vocalizations)

• Method: target temperature 32-34°C x 24 h (from time of initiation of cooling)

cold saline infusions; ice packs to the head, neck and torso; cooling blankets may use cooling vest or endovascular catheter if available

• Complications cardiac dysrhythmias (bradycardia most common): if significant dysrhythmia or hemodynamic instability, d c cooling and actively rewarm patient (this is only circumstance in which active rewarming should be performed; o w rewarm at no faster than 0.5°C per h) coagulopathy: Pts can receive fibrinolytics. GP lib Ilia inhibitors, etc. and still undergo cooling. ✓ PT and PTT. infection: ✓ surveillance blood cultures during cooling hyperglycemia hypokalemia during cooling, hyperkalemia w rewarming; keep K 4-5 mEq L Ongoing evaluation

• Neuro exam: daily focus on coma exam, cranial nerves. GCS score. Pt needs to be off sedation for adequate time to evaluate (depends on doses used, duration of Rx. metabolic processes in the individual Pt)

• Imaging: noncontrast CT 24 h after arrest, if unrevealing. MRI around day 3-5

• EEG: should be performed in any Pt w seizures or myoclonus (to r o status epilepticus); 1 should be considered in all unresponsive Pts (to r o nonconvulsive seizures)

• Somatosensory evoked potentials (SSEP): helpful for prediction of poor outcome if absent | cortical responses bilaterally, should not be performed earlier than 48 h after arrest (72 | h if cooled)

Prognosis

• Uniformly poor prognosis can be predicted at 72 h only in Pts who have absent pupillary | and corneal reflexes, and no motor response to pain; also with absent SSEPs at 48 h

• Otherwise, requires multifactorial approach, considering neuro exam, age and comorbid diseases, and ancillary data (neuroimaging. EEG. SSEP)

• When in doubt, err on the side of giving more time (especially in younger Pts)

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