Neurointensive & Perioperative care Flashcards
Which one of the following statements regarding cerebral blood flow is LEAST accurate?
a. Cerebral blood flow to white matter is approximately 25 ml/100 g/min
b. Total cerebral blood flow is approximately 750 ml/min in adults
c. Regional cerebral blood flow tends to track cerebral metabolic rate of oxygen consumption rather than cerebral metabolic rate of glucose consumption
d. Cerebral blood flow to gray matter is approximately 80 ml/100 g/min
e. Brain tissue accounts for 20% of basal oxygen consumption and 25% of basal glucose consumption
c. Regional cerebral blood flow tends to track cerebral metabolic rate of oxygen consumption rather than cerebral metabolic rate of glucose consumption
Which one of the following statements regarding intracranial compliance is LEAST accurate?
a. Increase in the volume of one intracranial
compartment will lead to a rise in ICP
unless it is matched by an equal reduction
in the volume of another compartment
b. Cerebral compliance is equal to intracranial volume displaced divided by the resultant change in intracranial pressure
c. CSF and CBV compartments normally represent a volume of approximately 1400 ml
d. Additional intracranial volume is initially
accommodated with little or no change
in ICP
e. Once craniospinal buffering capacity is
exhausted further small increases in intracranial volume lead to substantial rises
in ICP
c. CSF and CBV compartments normally represent a volume of approximately 1400 ml
Which one of the following statements regarding the intracranial pressure pulse waveform is most accurate?
a. Percussion wave, which reflects the ejection of blood from the heart transmitted
through the choroid plexus in the
ventricles
b. Third arterial wave is the percussion wave
c. First wave is the tidal wave which reflects
brain compliance
d. Second wave is the dicrotic wave that
reflects aortic valve closure
e. Intracranial hypertension increase in the
peak of the tidal and dicrotic waves
e. Intracranial hypertension increase in the
peak of the tidal and dicrotic waves
Regarding cerebral autoregulation in adults,
which one of the following statements is
LEAST accurate?
a. Increasing hypoxia results in increasing
cerebral blood flow
b. Cerebral blood flow is relatively constant
over a range of cerebral perfusion pressures from 50 to 150 mmHg
c. Cerebral blood flow is directly proportional to cerebral perfusion pressure
(CPP) when CPP is greater than
150 mmHg or less than 50 mmHg
d. A pCO2 of 4.0 kPa (30 mmHg) is associated with an average cerebral blood flow of approximately 50 ml/100 g/min
e. Cerebral blood flow¼cerebral perfusion
pressure/cerebral vascular resistance
d. A pCO2 of 4.0 kPa (30 mmHg) is associated with an average cerebral blood flow of approximately 50 ml/100 g/min
Which one of the following statements regarding control of cerebral vascular tone is LEAST accurate?
a. CO2 causes vasoconstriction at low tensions in the blood, and vasodilatation at higher tensions
b. Alpha2 and beta-1 adrenergic stimulation cause vasodilatation
c. Prostaglandins PGE2 and PGI2 are vasodilators
d. Increase in perivascular K+ causes vasodilatation
e. Thromboxane A2 is a potent vasoconstrictor
b. Alpha2 and beta-1 adrenergic stimulation cause vasodilatation
Maintenance of which one of the following
requires the highest proportion of energy
expenditure in the brain?
a. Transmembrane electrical and ionic
gradients
b. Membrane structure and integrity
c. Synthesis and release of neurotransmitters
d. Neurogenesis
e. Axonal transport
a. Transmembrane electrical and ionic gradients
Immediately below which one of the following regional cerebral blood flow values does
the onset of infarction occur if sustained for
more than 2-3 h?
a. Less than 50 ml/100 g/min
b. Less than 23 ml/100 g/min
c. Less than 17 ml/100 g/min
d. Less than 10 ml/100 g/min
e. Less than 5 ml/100 g/min
c. Less than 17 ml/100 g/min
Which one of the following statements
regarding neuroprotection during anesthesia
is LEAST accurate?
a. Burst suppression must be achieved
before any neuroprotective effects are
seen with barbiturates
b. Hyperglycemia exacerbates ischemic
injury
c. Mild hypothermia for low-grade aneurysm clipping and for head injury may
not be of benefit
d. Hyperthermia should be treated
e. Volatile anesthetics reduce the vulnerability of the brain to ischemic injury
a. Burst suppression must be achieved
before any neuroprotective effects are
seen with barbiturates
Which one of the following statements
regarding successful strategies for cerebral protection during cerebrovascular surgery is LEAST accurate?
a. For a given total vessel occlusion time,
brief-repetitive occlusions rather than a
longer-single occlusion where possible
should be the goal
b. Collateral blood flow can be increased by
inducing hypertension (e.g. target MAP
150 mmHg)
c. Preoperative perfusion imaging to help
identify patients who have low cerebrovascular reserve and may be at higher risk
for iatrogenic ischemia
d. Intraoperatively, vessel or graft patency
can be confirmed by
e. IHAST2 trial showed improvement in
outcome for clipped ruptured aneurysms
(WFNS1 and 2) given mild hypothermia
compared to normothermia
e. IHAST2 trial showed improvement in
outcome for clipped ruptured aneurysms
(WFNS1 and 2) given mild hypothermia
compared to normothermia
Which one of the following statements
regarding the role of hypothermia in the
management of traumatic brain injury is
LEAST accurate?
a. Eurotherm trial showed a significant
increase in odds of unfavorable outcome
but not death at 6 months in the mild
hypothermia group
b. Two trials of hypothermia therapy in children with TBI have shown no improvement in neurologic or other outcomes
one pediatric trial showed a nonsignificant
increase in mortality
c. Eurotherm trial RCT included patients
with TBI last 10 days and hypothermia
was induced if the ICP climbed above
20 mmHg for 5 min refractory to tier 1
management
d. Statistically significant increase in the odds
of an unfavorable outcome in the group
allocated to therapeutic hypothermia
e. Statistically significant increase in the odds
of death at 6 months (HR 1.45 (1.01-2.10))
hence discontinued due to futility
a. Eurotherm trial showed a significant
increase in odds of unfavorable outcome
but not death at 6 months in the mild
hypothermia group
A 27-year-old man undergoes general anesthesia for a hernia repair. As the anesthesia begins, his jaw muscles tense and he becomes generally rigid. He becomes febrile, tachycardic, and tachypneic. Which one of the following treatments is most appropriate?
a. Atropine
b. Procyclidine
c. Succinylcholine
d. Dantrolene
e. Thiopental
d. Dantrolene
Which one of the following is LEAST likely to
be associated with massive blood transfusion?
a. Iron overload
b. Hyperkalemia
c. Hypocalcemia
d. Hypothermia
e. Coagulopathy
a. Iron overload
Which one of the following statements
regarding intraoperative blood loss management techniques applied in patients refusing blood product transfusion is LEAST accurate?
a. Meticulous attention to hemostasis and
technical blood losses during surgery are
not usually important
b. Phlebotomy should be rationalized
c. Jehovah’s witnesses generally accept prothrombin complex concentrate
d. Intraoperative cell saver use should be
considered if appropriate
e. DDAVP (vasopressin) can be used as a
procoagulant
c. Jehovah’s witnesses generally accept prothrombin complex concentrate
Which one of the following statements
regarding the oxygen-dissociation curve is
LEAST accurate?
a. It is sigmoidal due to cooperative binding
of oxygen to hemoglobin
b. The Bohr effect is a shift of the dissociation curve to the left
c. Reducing pH shifts the oxygendissociation curve to the left
d. The fetal oxygen-dissociation curve is
shifted to the left reflecting the increased
oxygen affinity of fetal hemoglobin caused
by the presence of the gamma subunit of
hemoglobin
e. Increased temperature shifts the oxygendissociation curve to the left
b. The Bohr effect is a shift of the dissociation curve to the left
Which one of the following statements
regarding mechanical ventilation is LEAST
accurate?
a. PEEP and CPAP aim to keep alveoli open
during inspiration
b. Delivery of machine breaths may be triggered by time or start of a patients spontaneous breath
c. SIMV allows patients to breath spontaneously between machine breaths
d. Patients with sufficient spontaneous
respiratory drive can be managed with
pressure support ventilation alone
e. Tidal volume is usually calculated as
6-8 ml/kg of ideal body weight
a. PEEP and CPAP aim to keep alveoli open during inspiration
A 44-year-old male sustains a major trauma and is found with vomitus in his airway at scene with a GCS on E2V2M4. Primary survey suggests isolated head injury and is admitted to intensive care for medical management of intracranial pressure. ICP is 19 mmHg therefore he is kept sedated and ventilated. On day 2 he starts to desaturate and CXR is performed. PaO2/FiO2 ratio is 113 mmHg
(15 kPa). TTE is normal and there is no evidence of peripheral edema. Which one of the following is the most likely diagnosis?
a. Lower respiratory tract infection
b. ARDS
c. ALI
d. Congestive cardiac failure
e. Hemopneumothorax
b. ARDS
