chapter 11. quiz 7. pathology and Considerations for Complete Global Ischemia (Cardiac Arrest)
56 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What happens to neuronal function when cerebral blood flow (CBF) decreases below normal levels?

  • It deteriorates progressively rather than abruptly. (correct)
  • It remains unaffected.
  • It stops completely.
  • It deteriorates abruptly.
  • At what level of CBF does the brain show indications of potentially irreversible membrane failure?

  • 6-10 mL/100 g/min (correct)
  • 1-5 mL/100 g/min
  • 30-40 mL/100 g/min
  • 15-20 mL/100 g/min
  • What is the term used for brain regions where neuronal dysfunction is temporarily reversible but neuronal death will occur if blood flow is not restored?

  • Penumbra (correct)
  • Cerebral infarction
  • Hypoperfusion zone
  • Ischemic core
  • At what CBF level does the brain show isoelectric cortical EEG?

    <p>15 mL/100 g/min</p> Signup and view all the answers

    What are the consequences of decreased CBF to approximately 10-15 mL/100 g/min?

    <p>Progressive deterioration in energy supply leading to membrane failure.</p> Signup and view all the answers

    What level of CBF marks a time course of slow neuronal death over hours rather than minutes?

    <p>10-15 mL/100 g/min</p> Signup and view all the answers

    What is the key difference between complete cerebral ischemia and incomplete cerebral ischemia?

    <p>The rate of failure of the energy supply</p> Signup and view all the answers

    Why does incomplete cerebral ischemia show greater tolerance compared to complete global ischemia?

    <p>Residual blood flow can deliver enough oxygen for ATP generation</p> Signup and view all the answers

    During normothermic complete cerebral ischemia, what occurs within minutes that is catastrophic?

    <p>Irreversible membrane failure</p> Signup and view all the answers

    What factor contributes to the apparent tolerance for focal or incomplete ischemia?

    <p>Rate of energy supply failure</p> Signup and view all the answers

    What is the central event that occurs during cerebral ischemia?

    <p>Energy failure</p> Signup and view all the answers

    What ion gains entry into the cytosol ?

    <p>Ca2+</p> Signup and view all the answers

    Which enzyme system requires Ca2+ as a cofactor for activation?

    <p>Proteases</p> Signup and view all the answers

    What initiates the activation of various cellular processes contributing to injury during excitotoxicity?

    <p>Uncontrolled increase in cytosolic Ca2+ levels</p> Signup and view all the answers

    Which neurotransmitter is released in massive quantities into the synaptic cleft during ischemia?

    <p>Glutamate</p> Signup and view all the answers

    What type of injury is initiated by excessive glutamatergic activity?

    <p>Excitotoxicity</p> Signup and view all the answers

    What can lead to lipid peroxidation and membrane injury during the metabolism of arachidonic acid to prostaglandins and leukotrienes?

    <p>Generation of superoxide free radicals</p> Signup and view all the answers

    Which enzyme participates in DNA repair but can lead to energy failure when its activity is excessive due to DNA injury?

    <p>Poly–adenosine diphosphate [ADP]–ribose polymerase (PARP)</p> Signup and view all the answers

    In response to mitochondrial injury, what type of radicals can be generated along with superoxide free radicals?

    <p>peroxynitrite</p> Signup and view all the answers

    What effect does an increased preischemic serum glucose level have on the process of anaerobic glycolysis during ischemia?

    <p>Acceleration of anaerobic glycolysis</p> Signup and view all the answers

    What is the killer substance used by macrophages that can contribute to neuronal damage?

    <p>Peroxynitrite</p> Signup and view all the answers

    Which molecule, important for energy metabolism, becomes depleted as a result of excessive PARP activity during DNA repair?

    <p>[NAD+]</p> Signup and view all the answers

    What is a characteristic feature of necrotic neuronal death?

    <p>Presence of acidophilic cytoplasm</p> Signup and view all the answers

    Which molecule is released into the cytoplasm from injured mitochondria ?

    <p>Cytochrome c</p> Signup and view all the answers

    What limits injury to surrounding neurons in apoptotic neuronal death?

    <p>lack of a substantial inflammatory response to apoptotic death</p> Signup and view all the answers

    What is the key difference between necrotic neuronal death and apoptotic neuronal death?

    <p>Formation of apoptotic bodies</p> Signup and view all the answers

    During apoptosis, what is the role of activated caspase-3?

    <p>Cleaves essential protein substrates for DNA repair</p> Signup and view all the answers

    What initiates the formation of an apoptosome during apoptosis?

    <p>Interaction of APAF with procaspase-9</p> Signup and view all the answers

    What new understanding about postischemic neuronal injury has more recent data revealed?

    <p>Postischemic neuronal injury is a dynamic process where neurons continue to die for an extended period.</p> Signup and view all the answers

    What contributes to the gradual expansion of cerebral infarction after focal ischemia?

    <p>Delayed neuronal death after the initial insult</p> Signup and view all the answers

    Why does the occurrence of delayed neuronal death have important implications for studies on neuroprotective strategies?

    <p>It shows that neuroprotective efficacy may not be sustained over time.</p> Signup and view all the answers

    What is indicated by evidence of cerebral inflammation even 6 to 8 months after primary ischemia in experimental studies?

    <p>A potential for further neuronal injury.</p> Signup and view all the answers

    What happens to neurons that survive the initial insult with more moderate ischemic insults?

    <p>They undergo delayed death.</p> Signup and view all the answers

    How does the severity of the ischemic insult affect delayed neuronal death?

    <p>Most neurons undergo rapid death with severe ischemia.</p> Signup and view all the answers

    Why is long-term evaluation of a therapeutic intervention important in the context of cerebral infarction?

    <p>To determine the efficacy of the intervention beyond the acute phase of injury</p> Signup and view all the answers

    What is the mainstay in the reduction of brain injury in the setting of acute ischemic stroke?

    <p>Thrombolysis</p> Signup and view all the answers

    What is recommended for patients with acute ischemic stroke when the time from symptom onset to treatment is less than 3 hours?

    <p>Thrombolysis with iv alteplase</p> Signup and view all the answers

    In selected patients, up to how many hours can the window for thrombolysis be extended from the onset of symptoms?

    <p>4.5 hours</p> Signup and view all the answers

    What is a key contraindication to thrombolysis in patients with acute ischemic stroke?

    <p>Recent intracranial or spinal surgery</p> Signup and view all the answers

    Which factor has considerably expanded the window for potential benefit from clot removal in patients with acute ischemic stroke?

    <p>Mechanical thrombectomy</p> Signup and view all the answers

    What has limited the number of patients who may benefit from clot removal in the context of acute ischemic stroke?

    <p>Narrow window for thrombolysis</p> Signup and view all the answers

    What characteristic defines tissue that is amenable to salvage in the context of thrombectomy for acute ischemic stroke?

    <p>Mismatch between ischemic and infarcted tissue indicating salvageability</p> Signup and view all the answers

    What is the primary outcome observed in patients who met the enrollment criteria for the DAWN and DEFUSE 3 trials?

    <p>Improved neurologic outcome following thrombectomy</p> Signup and view all the answers

    What is one of the important therapeutic objectives in patients who sustain a cardiac arrest?

    <p>Normalization of systemic pH</p> Signup and view all the answers

    What is an effective strategy in reducing mortality and morbidity in patients with altered mental status following cardiac arrest?

    <p>Induction of mild hypothermia</p> Signup and view all the answers

    What was the outcome of induction of whole-body hypothermia in neonates with hypoxic-ischemic encephalopathy?

    <p>Reduced incidence of mortality</p> Signup and view all the answers

    How was passive rewarming achieved after inducing mild hypothermia in patients?

    <p>Over a period of 8 hours</p> Signup and view all the answers

    What does the text suggest about the incidence of complications in patients undergoing induced hypothermia?

    <p>Similar to the control group</p> Signup and view all the answers

    What is one of the benefits observed in patients undergoing induced hypothermia post-cardiac arrest?

    <p>Improved neurologic outcome and survival 6 months after cardiac arrest</p> Signup and view all the answers

    Why is maintaining adequate perfusion pressure after cardiac arrest considered important?

    <p>To prevent hypotension from developing which may aggravate the microcirculatory and vasospastic processes</p> Signup and view all the answers

    What is a late phase complication that may occur after cardiac arrest?

    <p>Excessive cerebral edema</p> Signup and view all the answers

    what is considered effective to control intracranial hypertension ?

    <p>osmotherapy</p> Signup and view all the answers

    which of the following is considered ineffective treatment after cardiac arrest ?

    <p>barbiturates</p> Signup and view all the answers

    In a small cohort study, what effect did nimodipine show in patients after cardiac arrest?

    <p>improve CBF but not neurologic outcome</p> Signup and view all the answers

    What was the outcome of the multicenter lidoflazine cardiac arrest study regarding nimodipine administration?

    <p>Indicated no overall benefit in neurologic outcome</p> Signup and view all the answers

    important therapeutic objectives after Complete Global Ischemia (Cardiac Arrest) ?

    <p>prevention and treatment of seizures</p> Signup and view all the answers

    Study Notes

    • Pharmacologic agents to protect the brain from ischemic injury have not been identified.
    • Thrombolysis is the main treatment for reducing brain injury in acute ischemic stroke.
    • Thrombolysis with IV alteplase is recommended within 3 hours of symptom onset.
    • Mechanical thrombectomy has expanded the window for clot removal in acute ischemic stroke.
    • Trials showed improved outcomes in patients undergoing thrombectomy with substantial ischemic tissue.
    • Endovascular treatment eligibility in acute ischemic stroke patients has increased due to recent trials.
    • Anesthesiologist involvement in caring for these patients will significantly increase.
    • The brain is highly vulnerable to energy failure during cerebral ischemia.
    • Neuronal function deteriorates progressively with declining cerebral blood flow.
    • Ischemic penumbra refers to brain tissue with reversible dysfunction but potential for irreversible damage.
    • Energy failure during cerebral ischemia leads to membrane depolarization and excitotoxicity.
    • Excessive glutamatergic activity initiates excitotoxicity and neuronal swelling.
    • Glutamatergic receptors activation leads to calcium influx and cellular injury processes.
    • Free radicals generated during cerebral ischemia contribute to oxidative injury and inflammation.
    • Neuronal death in ischemia can occur through necrosis or apoptosis pathways.
    • Apoptosis in neurons is initiated by the release of cytochrome c from injured mitochondria.
    • Therapeutic goals in ischemic brain injury include maintaining normocapnia and normotension.
    • Induced mild hypothermia has shown effectiveness in reducing mortality and morbidity after cardiac arrest.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Learn about the relevant considerations for complete global ischemia (cardiac arrest), including the importance of maintaining adequate perfusion pressure and the development of intracranial hypertension and cerebral edema post-resuscitation.

    More Like This

    Global Perspectives IGCSE Flashcards
    27 questions
    Global Wind Patterns Quiz
    4 questions
    Use Quizgecko on...
    Browser
    Browser