TEST #3 Stupor and Coma (Dr. Sachen) Flashcards
Definitions
1) CONSCIOUSNESS: total awareness of self and environment.
2) REQUIREMENTS:
• AROUSAL: level of alertness; ability to interact with environment
• AWARENESS (Content): sum of cognitive mental functions; “know what’s going on”
“Consciousness”
1) Depends on arousal of cerebral cortex by the brainstem Ascending Reticular Activating System (ARAS).
- Input from many sensory systems
- Projects to hypothalamus, thalamus, cortex
Impaired Consciousness therefore means:
- Diffuse or bilateral impairment of BOTH Cerebral Hemispheres or
- Failure of brainstem ARAS or
- Both
Confusion
- Attention deficit, orientation disturbed, stimuli misinterpreted
Delirium
- Disorientation, stimuli misinterpreted, hallucinations (visual)
Obtundation
- Mental blunting, increased sleep, arouses to mild stimuli (voice)
Stupor
- Arouses only to noxious stimuli and not environmental, only rudimentary awareness (e.g. purposeful motor responses)
Coma
- Unarousable, unresponsive, unaware
Persistent Vegetative State
Description:
- No reproducible response to stimuli; eyes may be open; roving eye movements; BP/pulse stable
- Arousal and Awareness are PRESENT!!!!
Akinetic Mutism
Description:
- No spontaneous motor activity
- Arousal APPEAR but NO Awareness
Locked in State (Monte Cristo Syndrome)
Description:
- Nl sensation/cognition but complete paralysis except for vertical eye movements
- Arousal and Awareness are PRESENT
Psychogenic
NOT Important
Description:
- Changing/inconsistent physical examination
- Arousal and Awareness are Present or Altered
Assessment of Comatose Patient
- History
- GeneralMedicalExamination
- NeurologicalExamination
- Laboratory Evaluation
- Diagnosis and Treatment
Assessment History
- From family, EMT’s, witnesses
- How and when was patient found
- Sudden or gradual onset
- Prior illnesses (esp. vascular) and medications
- Any recent symptoms (e.g. fever, confusion)
- History of substance abuse
Assessment: General Examination
- Vital signs (including respiratory rate and pattern*)
- Skin
- Breath odor
- Signs of trauma – racoon eyes, Battle’s sign, CSF leak (otorrhea, rhinorrhea)
- Neck stiffness – meningitis, SAH
* See Neurological Examination*
Assessment: General Medial- Vital Signs
HYPERTENSION
Consideration:
- Pheochromocytoma, drugs (amphetamine, cocaine, phencyclidine), increased ICP, PRES
Assessment: General Medial- Vital Signs
HYPOTENSION
Consideration:
- Addison’s, sepsis, drugs (β-blocker, Ca channel blocker, TCA’s, Li, sedatives, organophosphates, opioids, methanol), progression to brain death
Assessment: General Medial- Vital Signs
HYPERTHERMIA
Consideration:
- Infection, heat stroke, drugs (amphetamines, TCA’s, cocaine, salicylates, neuroleptics), SEROTONIN SYNDROME, central (Pontine Hemorrhage)
Assessment: General Medial- Vital Signs
HYPOTHERMIA
Consideration:
- Hypothyroid, hypoglycemia, exposure, drugs (opioids, sedatives, barbiturates, phenothiazine, Et-OH)
Assessment: General Medical- SKIN
1) Diaphoresis: Thyroid storm, ↓ BS, drugs (sympathomimetics, cholinergic)
2) Dry: Hypothyroid, drugs (anticholinergics, TCA’s)
3) Needle Marks: Drug OD
4) Rash: Meningitis, viral encephalitis, rickettsia
Assessment: General Medical- Breath Odor
1) Dirty Restroom: Uremia
2) Fruity: Ketoacidosis
3) Musty: Hepatic FAILURE!!!!
Assessment: Neurological Examination
The purpose is 2-Fold
1) Determine the LOCATION (Above or Below the Tentorium) and nature of the process that is causing the impaired consciousness with emphasis on the anatomic level of brain involvement (supratentorial, subtentorial, or diffuse).
2. Narrow the differential possibilities.
Broad Category of Lesion that produce Coma
- Large, pressure producing SUPRATENTORIAL mass lesions
- cause dysfunction in the upper ARAS
- cause downward herniation of the brain to compress the ARAS - INFRATENTORIAL mass lesions that involve the brainstem
- DIFFUSE or MULTIFOCAL brain disease (Inoxic Brain Damage)
Supratentorial Causes
UNILATERAL HEMISPHERE (Mass Effect!!!!!!):
- Intracerebral hemorrhage
- Large MCA infarct
- Subdural hematoma
- Epidural hematoma
- Brain abscess
- Neoplasm
BILATERAL HEMISPHERE:
- Subarachnoid hemorrhage
- Multiple infarcts
- Venous thrombosis
- Cerebral edema
- Acute hydrocephalus
- Multiple metastases
Subtentorial Causes
- Pontine hemorrhage
- Basilar artery occlusion
- Central pontine myelinolysis
- Cerebellar hemorrhage/infarct - Cerebellar/brainstem neoplasm
- Cerebellar abscess
Diffuse Causes
- HYPOXIA
- Hypercapnia
- MENINGITIS/ ENCEPHALITIS
- HYPOGLYCEMIA
- HYPERGLYCEMIA (non ketotic)
- HYPONATREMIA
- Hepatic failure Uremia
- Acute hypothyroidism
- Hypercalcemia
- Malignant hypertension
- Hypo/hyperthermia Toxins
- Drug withdrawal
- Malignant neuroleptic syndrome
Elements of Neurological Examnation
ESSENIAL:
- Pupillary responses
- Corneal reflex
- Extraocular movements
- Cough/gag reflex
- Motor responses
- Respiratory pattern
(Nearly) ESSENTIAL:
- Neck stiffness
- Carotid auscultation
- Funduscopic examination
Neurological Examination: Pupillary Responses
- SYMPATHETIC/ PARASYMPATHETIC balance determines size.
a) SYMPATHETIC path:
- HYPOTHALAMUS → lower cervical cord → sympathetic chain → superior cervical ganglion → up carotid a. to CN V(I), long ciliary nerve (dilator), Mueller’s muscle
b) PARASYMPATHETIC path:
- Upper midbrain (Edinger Westfall nuc) → CN III → ciliary ganglion → short ciliary nerve (constrictor)
- NUCLEI/ TRACTS controlling pupils are anatomically adjacent
to ARAS; therefore… Absent or Unequal responses imply brainstem lesion.
Pupillary Light Responsses
***** ANISCORIA – which is the abnormal pupil?
RULE OF THUMB:
a) If it’s the LARGE pupil – it should fail to constrict to light
b) If it’s the SMALL pupil – it should fail to dilate in dark
Rules of thumb for Pupillary Responses
- Enlarged on one side: parasympathetic dysfunction (usually CN III)
- Enlarged bilaterally: bilateral CN III lesion, post ictal, barbiturate intox
- Constricted: sympathetic dysfunction (hypothalamus, carotid)
- Pinpoint: pontine lesion, opiates, pilocarpine
- Midposition and unreactive: sympathetic + parasympathetic (midbrain)
Interpretation of Pupillary Signs may be confused by:
a) Atropine/scopalomine – dilated, fixed
b) Opiates – pinpoint, +/- reactive
c) Pilocarpine – pinpoint
d) Glutethimide – dilated, fixed, unequal
c) Hypothermia, anoxia, ischemia – possibly dilated, fixed, unequal
Neurological Exam: Extraocular Movements
- Conjugate gaze depends on intact cranial nerves III, IV, and VI, their nuclei and interconnections
- FRONTAL gaze centers deviate eyes to OPPOSITE SIDE
- PONTINE gaze centers deviate eyes to SAME SIDE
Neurological Exam: Extraocular Movements
Spontaneous
1) ROVING:
a) Conjugate – implies brainstem intact
b) Dysconjugate – implies a brainstem lesion
2) CONJUGATE DEVIATION AT REST: (also see oculocephalic reflex)
a) Hemispheric lesion:
- Destructive - toward lesion
- Irritative – away from lesion
b) Brainstem lesion
- Destructive – away from lesion
Neurological Exam: Extraocular Movements
Nystagmus
Type—> Location
1) Ping-pong (right-left deviation every few seconds)
- Bihemispehric, Midbrain
2) Convergence (slow abduction with rapid jerk back)
- Mesencephalon
3) Retractory (retraction orbit)
- Mesencephalon
4) Bobbing (rapid down, slow up)
- Pons
5) Dipping (slow down, rapid up)
- Bihemispheric
Neurological Exam: Extraocular Movements
Reflexive: DOLL’S EYES MANEUVER
OCULOCEPHALIC MANEUVER (Doll’s Eyes) - Mid pons
(Used to assess cranial nerves III, IV, and VI)
A) PASSIVE Horizontal head ROTATION – eyes move Horizontally opposite
B) PASSIVE Vertical head ROTATION – eyes move Vertically opposite
- **Notes:
1) Be sure neck is stable
2) Overridden in alert patient
Neurological Exam: Extraocular Movements
Reflexive: CALORIC Reflex
CALORIC (OCULOVESTIBULAR) REFLEX – Lower Pons!!!!!
A) Otoscopic exam – be sure canal clear and TM intact
B) Irrigate TM with cold (usually) or warm water
C) Cold water irrigation with intact brainstem causes:
- Eyes to deviate to IRRIGATED SIDE if UNILATERAL irrigation
- Eyes to deviate DOWNWARD if BILATERAL irrigation
Neurological Examination: Motor Responses
1) PURPOSEFUL – follows commands, localizes pain
2) REFLEXES:
a) DECORTICATE – arms flexed, legs extended (hemispheric)
b) DECEREBRATE – all extremities extended (brainstem)
c) Flaccid – pontomedullary or metabolic
Neurological Examination: Respiratory Patterns
1) CHEYNES- STOKE: Hyperpnia regularly alternating with apnea (bilateral hemispheres or diencephalon). Seen in many disorders ranging from metabolic to structural.
2) CENTRAL NEUROGENIC HYPERVENTILATION: – Midbrain.
3) APNEUSTIC BREATHING: long inspiration followed by apnea (mid/low pons). Seen in structural lesions and anoxia, hypogycemia, meningitis.
4) ATAXIC: completely irregular (medullary respiratory centers)
Four Broad Categories based on History and PE
1) Supratentorial
2) Subtentorial
3) Diffuse/Metabolic
4) Psychiatric unresponsiveness
Supratentorial Mass Lesions
- INITIAL signs usually FOCAL
- Neurological signs at any given time point to one anatomic location
- Progression of signs is rostral to caudal
- Motor signs are often ASYMMETRIC
Herniation Syndromes
- Caused by expanding supratentorial mass lesions.
- Effect is to DISPLACE brain tissue into adjacent intracranial compartments (so called rostral to caudal progression of herniation).
Uncle Herniation
- Herniation of uncus under edge of the tentorium
compressing CN III (ipsilateral dilated pupil, poor EOM, ptosis), then contralateral brainstem (ipsilateral hemiparesis), then respiratory abnormalities, posturing, fixed pupils and death.
Central Transtentorial
- Herniation into foramen magnum leads to early coma, small pupils, normal EOM’s, posturing and later bilateral fixed pupils, RESPIRATORY ARREST and death.
Cingulate Gyrus
- Herniates under the FALX
Subtentorial Mass Lesions
- History - preceding brainstem dysfunction usual (e.g. dysequilibrium, dysarthria, dysphagia, diplopia, vertigo) but there may be sudden onset of coma.
- Localizing brainstem signs precede or accompany onset of coma and almost always include a form of oculovestibular abnormality.
- Cranial nerve palsies usually present.
- “Bizarre” respiratory patterns common
Stupor and Coma
DIFFUSE/ METABOLIC
- Confusion and stupor commonly precede motor signs.
- Motor signs are usually SYMMETRICAL.
- Pupillary reactions are usually preserved.
- ASTERIXIS!!!!!!, Myoclonus, tremor, seizures common.
- Acid-base imbalance with hyper or hypoventilation frequently seen.
- Level of CONSCIOUSNESS may FLUCTUATE
Stupor and Coma
DIFFUSE/ METABOLIC
Some Causes
- HEPATIC/ RENAL FAILURE!!!!!!
- Hyper/hypoglycemia
- Hypoxia
- Endocrine disorders – thyroid, adrenal, parathyroid
- Electrolyte imbalance – hyper/hyponatremia, calcium disorders
- Sepsis
- Infections
- Drugs and toxins
Psychiatric Unresponsiveness
- Pupils reactive or dilated (cycloplegics).
- Lids ACTIVELY CLOSE.
- Oculocephalic reflexes unpredictable
- Oculovestibular reflexes physiologic
- Motor tone is INCONSISTENT or NORMAL.
- Eupnea (nl) or hyperventilation is usually seen.
- No pathologic reflexes.
- NORMAL EEG.
Global Cerebral Ischemia
- Occurs whenever blood flow is INADEQUATE to meet the metabolic requirements (oxygen and glucose) of the brain, as in CARDIAC or PULMONARY ARREST.
- The result is a SPECTRUM of disorders, ranging from reversible encephalopathies to brain death.
- *** BRIEF (≤ about 6 minutes) ISCHEMIC EPISODES!!!!!!!!!!:
- Are commonly REVERSIBLE Encephalopathies, generally after 12 hours or less of stupor or coma.
- ANTEROGRADE and/or RETROGRADE amnesia can occur.
- Recovery often occurs within 7-10 days, but may be delayed by 1 month or longer.
Global Cerebral Ischemia Cont
1) PROLONGED ISCHEMIC EPISODES:
- Focal cerebral dysfunction. Patients are usually COMATOSE for at least 12 hours and may have lasting focal or multifocal motor, sensory, and cognitive deficits.
2) PERSISTENT VEGETATIVE STATE:
- Awake but functionally decorticate and unaware of surroundings
- Eye opening, eye movements, sleep-wake cycles, and brainstem and spinal reflexes may remain intact
Brain Death
Definition:
• IRREVERSIBILITY
- Complete CESSATION of BRAIN FUNCTION (including respirations but not heartbeat)
- PERSISTENCE
Brain Death: Irreversible
- Cause of coma should be known, it must be adequate to explain the clinical picture, and it MUST BE IRREVERSIBLE.
- Sedative intoxication, hypothermia (≤ 90F), neuromuscular blockade, and shock must be ruled out, since these conditions can produce a clinical picture that resembles brain death but ARE potentially Reversible.
Brian Death: Cessation of Brain Function
– UNRESPONSIVENESS: The patient must be unresponsive to all sensory input, INCLUDING Pain and Speech.
– ABSENT BRIAN REFLEXES: including pupillary, corneal, oculocephalic, and oculovestibular reflexes. Respiratory responses are absent at 8 to 10 minutes after the patient’s pC02 is allowed to rise to 60mmHg, while oxygenation is maintained with 100% O2 (apnea test).
Brain Death: Persistence
Criteria for brain death must persist for an appropriate length of time
- SIX HOURS with a confirmatory isoelectric (flat) EEG, performed according to the technical standards of the AEES.!!!!!!
- TWELVE HOURS WITHOUT a confirmatory isoelectric EEG.
- TWENTY FOUR HOURS for anoxic brain injury WITHOUT a confirmatory isoelectric EEG.
Brain Death: Precautionary Notes
• State law may impose additional requirements such as:
- The qualification of the examiner
- Confirmation by a second examiner
• ANCILLARY TESTS (EEG, angiography, nuc med scan) are not required unless there is uncertainty about the diagnosis or the apnea test cannot be performed. However, some countries do require them.
Management of Comatose Patient
INITIAL STEPS
A) Insure patent AIRWAYS (spontaneous, mouth piece, ETT…etc)
B) Insure BREATHING and adequate oxygenation (pulse oxy., O2, ABG)
C) Insure adequate CIRCULATION and control any active bleeding (BP, P)- IV line, arterial line, ECG…etc)
(Stabilize neck, get C – spine films if trauma suspected)*
Management of Comatose Patient
INITIAL STEPS Cont!!!
– Quick history (seizure, medications, drug use, trauma)
– Quick exam
– EKG to monitor for arrhythmia
– Give Glucose (1 amp = 25 gms), thiamine (100 mg IM) – Give specific antidote (e.g. Narcan)
– Adjust body temperature
– Control agitation
– Stop seizures if present
Management of Comatose Patient
Laboratory Evaluation
– VENOUS BLOOD: glucose, electrolytes (including calcium, phosphorus, magnesium), BUN/creatinine, osmolality, drug screen, liver functions, ammonia, coagulation studies, thyroid function, blood cultures
– ARTERIAL BLOOD: pH, pO2, pCO2, HCO3, HbCO
– URINE: UA, culture, drug screen
– IF FEBRILE: Blood cultures
– IF STIFF NECK: LP (AFTER CT) with CSF for cell count, glucose, protein, gram stain, cultures (bacterial, viral, and fungal)
Management of Comatose Patient
Diagnostic Testing
• Non contrast head CT
– Acute blood
– Space occupying lesion
• LP
– Xanothochromia (SAH)
– Infection
• +/- MRI
– Posterior fossa
– Early infarct
• +/- EEG!!!!!!!!!
Management of the Comatose Patient
Specific Interventions
• Reduce elevated intracranial pressure:
- Elevate head of bed
- Intubate and hyperventilate to PCO2 of 20 mm
- Use mannitol for ischemic lesions
- Use decadron for tumor, abscess, and perhaps cerebral hemorrhage
- Lasix 20 – 40 mg IV possibly
• Treat seizures
- LORAZEPAM 2 mg IV q 10-15 minutes up to 10 mg
- PHENYTOIN 18 mg/kg load (about 1000 mgs) then 300 mg/day
Glasgow Coma Scale 3 - 15
EYE OPENING:
- Never: 1
- To Pain: 2
- To Verbal: 3
- Spontaneous: 4
BEST VERBAL RESPONSE:
- None: 1
- Sounds: 2
- Inapp Words: 3
- Disorientated: 4
- Orientated: 5
BEST MOTOR RESPONSE:
- None: 1
- Extensor: 2
- Flexor: 3
- Withdrawal: 4
- Localizes: 5
- Obeys: 6
** Sum and individual elements are important:
Localizes 5 Obeys 6
e.g. GCS=9, E2, V3, M5 ***
Key to ACCURACY in Diagnosis and Management lies in TWO STEPS
1) INTEGRATION of PHYSICAL SIGNS to determine the anatomic level of brain involvement.
2) Determine whether the pathophysiology that BEST EXPLAINS the pattern and evolution of these signs is supratentorial, subtentorial, or metabolic.
