Clinical Perspectives of Reticular system, Brain Death, & Coma Flashcards
What is the Lazarus sign?
Movement of the foot in response to pain due to intact spinal reflex. A patient may be brain dead and still exhibit the Lazarus sign
What diagnostic tests are considered standard when a patient presents with altered mental status?
Finger stick glucose, CBC, CMP, urinalysis, toxicology screen, liver enzymes, blood gas, EEG
Brain death can be diagnosed at the bedside, except in what patient populations?
Children, hypothermic patients
A patient should blink in response to the cornea being touched. This is called the corneal reflex. What CN are tested?
CN V (afferent) & CN VII (efferent)
How do delirium and dementia differ?
Delirium has a sudden onset, abnormal vital signs, and non-pathologic etiology. Dementia has a progressive onset, normal vitals, and pathologic etiology
What are the two dimensions of consciousness?
Arousal & Cognition
What are the four steps of determining brain death?
- Clinical evaluation
- Neurological evaluation
- Ancillary tests (if applicable)
- Documentation
A patient with a negative gag reflex is typically intubated. What CN are tested?
CN IX (afferent) & CN X (efferent)
What is the predominant function of the ascending reticular activating system?
Arousal
Arousal is a vegetative function maintained by what structure in the body?
Brainstem, hypothalamus, thalamus
For how long must the apnea test be performed?
10 minutes
In order for a diagnosis of coma, what structures must be involved?
Both cerebral hemispheres, Reticular Activating System, or both
A patient who is not oriented, does not follow commands, and requires excessive stimuli for alertness is said to have…?
Altered Level of Consciousness
What questions are important in the history of a patient presenting with altered mental status?
What is different? How are they different? When did this start? What do you think may have caused this?
What are the three classifications of altered mental status?
Delirium, dementia, psychosis
True/False. Brain death is the death of the patient.
True. The brainstem is responsible for regulating involuntary actions, such as respiration, blood pressure, etc.
A patient presents with a mild reduction in alertness. How would you describe this patient?
Lethargic
Light is shined into both eyes of a comatose patient. Neither eye responds to the light and there is no constriction of either pupil. Does this patient have a positive or negative pupillary reflex?
Negative reflex since there was no reaction. CN II, CN III, and the Edinger-Westphal Nucleus were tested
True/False. Delirium is a form of dementia.
False. Delirium is not related to dementia. While presentation may be similar, delirium does not have a pathological cause.
What is the ice water calorics test?
The head is tilted to 30 degrees and the tympanic membrane is washed with ice cold water. In a typical patient, the eyes should shift in the direction of the tympanic membrane that was washed
A patient cannot be determined as brain dead if what class of drugs is present in their system?
Barbituates
What requirements must be meant for a diagnosis of brain death?
- Absent brainstem reflexes
- Absent motor reflexes
- Absent respiratory drive
- Normothermic
- Non-drugged
- Comatose
- Irreversible brain lesion
- No metabolic derangements
How will a patient in a state of obtundation present?
Mild reduction in alertness, with increased response time to stimuli
What brainstem reflexes are tested to make a determination of brain death?
Pupillary reflex, corneal reflex, gag reflex, doll’s eye maneuver, ice water calorics, motor reflex, apnea test
What is the appearance of a positive doll’s eye maneuver?
There is no eye movement. The eyes spontaneously move in the direction the head was turned
A patient appears to be in a state of deep sleep. They are aroused with continuous and vigorous stimuli, but returns to sleep when stimuli is stopped. How would you describe this patient?
In a state of stupor
