Quiz 2 Review Flashcards
What do Upper Motor Neuron Injuries cause?
Spastic Paralysis & Hyperreflexia
No Muscle Atrophy til Later
What do Lower Motor Neuron injuries cause?
Flaccid Paralysis & Hyporeflexia w/ Muscle Atrophy
What do injuries above T6 cause?
Autonomic Dysreflexia
&
Neurogenic Shock
What happens with T1-T4 damage?
Paralysis below level of Injury
What is a main sign of Autonomic Hyperreflexia?
Dangerously High BP precipitated by Noxious Stimuli below the Injury Level
Which patients are infamous for Autonomic Hyperreflexia?
Cysto Patients
What does C3-C5 Innervate?
Phrenic Nerve - Diaphragm
What do C1-C4 injuries cause?
Quadriplegia requiring Mechanical Ventilation
Injuries at what level would cause Difficulty Clearing Secretions?
C5 & Above Injuries - Indicates Intubation
What is the Neurotransmitter of the Parasympathetic Nervous System?
Acetylcholine
Where does the Parasympathetic Nervous System orginate from?
Cranial & Sacral Areas of Spinal Cord & Brainstem
What does the Sympathetic Nervous System do?
Increase HR & Contractility
+
Relax Airway Smooth Muscles
Which adrenergic receptors are stimulated by the Sympathetic Nervous System?
Alpha & Beta Receptors
How do Alpha & Beta receptors affect the Airway?
Alpha: Minor - Contraction & Bronchconstriction
Beta: Major - Bronchodilation
What is not included in regards to Sympathetic Nervous System receptors?
Glands
Viscera
Adrenal Medulla
What are the receptors of the Parasympathetic Nervous System?
Cholinergic / Muscarinic Receptors
What are the effects of Alpha-1 Receptors?
Vasoconstriction & Bronchoconstriction
What happens when Alpha-2 Receptors are activated?
Inhibition of Norepi Release
What are examples of Alpha-2 Agonists?
Clonidine & Precedex
Where are Beta-1 Receptors located and what do they do?
Increase HR, Contractility, & AV Node Conduction in the Heart
What does Beta-2 Stimulation do?
Vasodilation, Bronchodilation, & Uterus Relaxation
What happens when Muscarinic receptors are activated?
Decrease HR & Contractility
Bronchoconstriction
Vasodilation
What controls the Autonomic Nervous System?
Hypothalamus - Captain of the ANS
What does the Brainstem control?
CV & Pulmonary Function
How do Autonomic Reflexes affect the SNS & PNS?
Activates one while supressing the other
What does Neurogenic Shock cause?
Loss of Vasomotor Tone
Diminished SNS
Hypotension
Bradycardia
What is the normal ICP?
5-15 mmHg
When should the ICP be treated?
20 mmHg or Higher
What can affect ICP?
Anesthetic Meds & Techniques
How much of the Intracranial volume is CSF?
10-15 %
How much CSF does the Choroid Plexus produce a day?
~500 mL/day
How much total CSF is there at any one time?
150 mL
What can cause Cerebral Edema?
Ishemic Stroke
Meningitis
BBB Disruption
How much Cardiac Output goes to Cerebral Blood Flow?
~14 %
Cerebral Blood Flow is tightly coupled to _______
Cerebral Blood Flow is tightly coupled to CMRO2
At what MAP is Cerebral Blood Flow autoregulated?
MAP of 60-160 mmHg
What can cause of loss of Cerebral Blood Flow autoregulation?
Acidosis
Hypoxia
Volatile Anesthetics
What is a potent Cerebral Vasodilator & has a linear relationship to CBF?
PaCO2
What level of PaO2 will cause an increase in Cerebral Blood Flow, even with Hypocapnia?
PaO2 < 50 mmHg
PaO2 of 50 mmHg = ? SaO2
PaO2 of 50 mmHg = ~80% SaO2
How should O2 Saturation be managed for patients w/ Increased ICP?
Dont let O2 Saturation go below 80%
What are the Neuro Effects of Volatile Anesthetics?
↑CBF
↓CMRO2
Profoundly affects Motor EPs
What are the Neuro Effects of Propofol & Etomidate?
↓CBF
&
↓CMRO2
What are the Neuro Effects of Ketamine?
↑CBF
&
↑CMRO2
How do Opioids affect Cerebral Blood Flow?
No Direct Effect, but respiratory depression can ↑CO2 & ↑ICP
How do Benzos affect Cerebral Blood Flow?
Minimal Effect
How does Succinylcholine affect Cerebral Blood Flow?
No Significant Increase
What is required to be able to monitor Motor Evoked Potentials (MEPs)?
Patient CANNOT be paralyzed for entire case, only the beginning of case is OK
How do Ketamine & Etomidate affect Evoked Potentials?
Enhances SSEP
How do Propofol & Thiopental affect Evoked Potentials?
Attenuates Amplitude without Obliteration
How do Opioids, Benzos, and Precedex affect Evoked Potentials?
Negligible Effects
How do N2O & Inhalation agents compare to IV Agents regarding Evoked Potentials?
N2O & Inhalation Agents have more Depressant Effects
How do Volatile Agents affect Evoked Potentials?
Profound influence on Amplitude & Latency - Sensory & Motor
How should Inhalation Agents be managed in order to obtain Evoked Potential signals?
Keep below full MAC
When should Cerebral Oximetry be used?
Any case where Vascular Compromise to Brain d/t from blood flow restriction is possible
A decrease of Cerebral Blood Flow of ______ is considered Significant
A decrease of Cerebral Blood Flow of 20% is considered Significant
True/False: Acute Burns is a contraindication for Succinylcholine?
False - only contraindicated if it has been 2-3 days since burn
What meds will NOT work for patients who have had a Heart Transplant?
Vagolytics & Sympathomimetics such as Atropine or Ephedrine
Which meds should be used to for patients who have had a Heart Transplant?
Direct Acting Agents - Epinephrine
What is the antidote for Seron, an Aerosolized Neostigmine?
Atropine - Antimuscarinic