Podcast
Questions and Answers
Brain death is defined as the irreversible cessation of cerebellar function.
Brain death is defined as the irreversible cessation of cerebellar function.
False (B)
To diagnose brain death, drug effects, hypothermia and endocrine and metabolic disturbances, all of which may produce functional brain damage NEVER need to be excluded.
To diagnose brain death, drug effects, hypothermia and endocrine and metabolic disturbances, all of which may produce functional brain damage NEVER need to be excluded.
False (B)
Fixed pupils that do not react to light indicate impaired midbrain function.
Fixed pupils that do not react to light indicate impaired midbrain function.
True (A)
The corneal reflex tests pontine connections between the trigeminal and hypoglossal nerve nuclei.
The corneal reflex tests pontine connections between the trigeminal and hypoglossal nerve nuclei.
Signup and view all the answers
Intact vestibulo-ocular reflexes indicate normal connections between the vestibular nerve and eye-muscle nerves.
Intact vestibulo-ocular reflexes indicate normal connections between the vestibular nerve and eye-muscle nerves.
Signup and view all the answers
The gag reflex assesses vagal connections in the cerebrum.
The gag reflex assesses vagal connections in the cerebrum.
Signup and view all the answers
Absence of motor responses in any cranial nerves to nociceptive stimulation suggests impaired connections between cranial nerve nuclei.
Absence of motor responses in any cranial nerves to nociceptive stimulation suggests impaired connections between cranial nerve nuclei.
Signup and view all the answers
Facial grimacing from pressure on the supraorbital margins tests connections between the trigeminal and abducens nerve nuclei.
Facial grimacing from pressure on the supraorbital margins tests connections between the trigeminal and abducens nerve nuclei.
Signup and view all the answers
Respiratory movements should occur even after disconnection from the ventilator with $P_{CO_2}$ below 50 mm Hg to confirm absence of respiratory drive.
Respiratory movements should occur even after disconnection from the ventilator with $P_{CO_2}$ below 50 mm Hg to confirm absence of respiratory drive.
Signup and view all the answers
A $P_{CO_2}$ threshold of 6.7 kPa is adequate to stimulate respiration in brain death assessment.
A $P_{CO_2}$ threshold of 6.7 kPa is adequate to stimulate respiration in brain death assessment.
Signup and view all the answers
Flashcards
Brain Death
Brain Death
Irreversible cessation of all brainstem functions.
Comatose Patient
Comatose Patient
A patient in a prolonged state of unconsciousness.
Brainstem Reflexes
Brainstem Reflexes
Automatic responses mediated by the brainstem.
Fixed Pupils
Fixed Pupils
Signup and view all the flashcards
Corneal Reflex
Corneal Reflex
Signup and view all the flashcards
Vestibulo-Ocular Reflex
Vestibulo-Ocular Reflex
Signup and view all the flashcards
Gag Reflex
Gag Reflex
Signup and view all the flashcards
Nociceptive Stimulation
Nociceptive Stimulation
Signup and view all the flashcards
Respiratory Movements
Respiratory Movements
Signup and view all the flashcards
CO2 Threshold
CO2 Threshold
Signup and view all the flashcards
Study Notes
Brain Death Criteria
- Brain death is the irreversible cessation of brainstem function, crucial for defining when life support can be withdrawn.
- Criteria are used to diagnose brain death, particularly in comatose patients with irreversible structural brain damage (excluding drug, hypothermia, or endocrine/metabolic issues).
- Brainstem reflexes must be absent to confirm brain death.
Brainstem Reflexes
- Fixed Pupils, Non-Reactive to Light: Tests midbrain function. Fixed and non-reactive pupils indicate dysfunction.
- Absent Corneal Reflexes: Tests pontine connections between trigeminal and facial nerve nuclei. Absence indicates damage.
- Absent Vestibulo-ocular Reflexes: Tests connections between vestibular nerve and eye-muscle nerves; loss of these reflexes suggests brain damage.
- Absent Gag Reflex and Bronchial Stimulation: Tests vagal connections in the medulla. Absence implies problematic medulla function.
- Absent Motor Responses: Absence of responses to nociceptive stimulation (e.g., pressure on supraorbital margins, fingernails) across all cranial nerves indicates severe damage. Trigeminal and facial nerve nuclei, and cervical spinal cord, are examined.
- Absent Respiratory Movements: Absence of respiratory movements after disconnection from a ventilator, allowing arterial CO2 to rise above the threshold for respiratory stimulation (CO2 above 50 mm Hg, equivalent to 6.7 kPa, confirms lack of central breathing regulation).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the critical criteria used for diagnosing brain death, focusing on brainstem functions and reflexes. Understand the significance of absent reflexes in determining irreversible brain damage and the ethical implications of life support decisions.
