Exam 2 Review Flashcards
___ (upper/lower) motor neuron injuries can cause spastic paralysis
Upper motor neuron injuries
___ (upper/lower) motor neuron injuries are typically not associated with muscle atrophy (until later on in the disease)
Upper motor neuron injuries
___ (upper/lower) motor neuron injuries cause hyperreflexia
Upper motor neuron injuries
___ (upper/lower) motor neuron injuries cause flaccid paralysis
Lower motor neuron injuries
Lower motor neuron injuries ___ (are/are not) associated with muscle atrophy; cause ___reflexia (hypo/hyper)
Lower motor neuron injuries are NOT associated with muscle atrophy; cause hyporeflexia
Injuries above T___ will cause autonomic dysreflexia, neurogenic shock, and paralysis below the level of injury
Above T6
Autonomic dysreflexia and autonomic hyperreflexia are two terms that can be used interchangeably—T/F?
True… dysreflexia = hyperreflexia
Injuries above T6 can cause neurogenic shock, especially when the T___-T___ levels are damaged
T1-T4 levels—cardiac accelerators
Autonomic hyperreflexia = dangerously high ___; can be caused by T___ and above spinal cord injuries; can be precipitated by noxious stimuli ___ (above/below) the level of injury
Dangerously high BP; can be caused by T6 and above spinal cord injuries; can be precipitated by noxious stimuli below the level of injury
Cysto patients with spinal cord injuries are infamous for autonomic hyperreflexia—T/F?
True
Spinal cord transections above T6 will very frequently have autonomic hyperreflexia—T/F?
True
What nerves innervate the diaphragm?
C3-C5
C___-C___ injuries cause quadriplegia and need for mechanical ventilation
C1-C4 injuries
C___ and above injuries = difficulty clearing secretions
C5 and above injuries
Patients with C5 and above injuries will have difficulty clearing secretions, which indicates a need for mechanical ventilation—T/F?
True
___ (parasympathetic/sympathetic) nervous system = rest and digest
Parasympathetic nervous system
PNS originates in ___ and ___ areas of spinal cord and brainstem; uses ___ as the neurotransmitter
Cranial and sacral areas of spinal cord and brainstem; uses ACH as the neurotransmitter
___ (parasympathetic/sympathetic) nervous system = fight or flight
Sympathetic nervous system
SNS ___ (increases/decreases) HR and contractility; ___ (contracts/relaxes) the muscles of the airways, broncho___ (constricts/dilates)
Increases HR and contractility; relaxes the muscles of the airways, bronchodilates
Even though there are both alpha and beta receptors on the bronchioles, the bronchioles are dominated by ___ (alpha/beta) receptors, which cause smooth muscle ___ (contraction/relaxation)/broncho___ (constriction/dilation)
The bronchioles are dominated by beta receptors, which cause smooth muscle relaxation/bronchodilation
Alpha and beta receptors are both adrenergic receptors that are stimulated by the SNS—T/F?
True
The alpha receptors on the bronchioles play a major role in smooth muscle contraction and bronchoconstriction—T/F?
False—alpha receptors on the bronchioles play a very very MINOR role in smooth muscle contraction/bronchoconstriction
The bronchioles are dominated by beta receptors—T/F?
True
Except for glands, viscera, and the adrenal medulla, the receptors of the SNS are ___ and ___ receptors and are referred to as ___ receptors
The receptors of the SNS are alpha and beta receptors and are referred to as adrenergic receptors
Receptors of the PNS are ___, referred to as ___ receptors, and use ___ as a neurotransmitter
Receptors of the PNS are muscarinic, referred to as cholinergic receptors, and use ACH as a neurotransmitter
Alpha 1 = vaso___ and broncho___
Vasoconstriction and bronchoconstriction
Alpha 2 activation inhibits the release of ___
Norepi
What two medications are alpha 2 agonists?
Clonidine and precedex
Beta 1 receptors are present on the ___ (what organ?); ___ (increase/decrease) HR and contractility; ___ (increase/decrease) AV node conduction
Beta 1 receptors are present on the heart; increase HR and contractility; increase AV node conduction
Beta 2 receptors = vaso___ (constriction/dilation); broncho___ (constriction/dilation)
Vasodilation; bronchoconstriction
What receptors dominate when it comes to increasing BP?
Alpha 1 receptors
What receptors relax the smooth muscles, specifically the uterus?
Beta 2 receptors
So a beta 2 agonist will relax the uterus
Activation of muscarinic receptors ___ (increases/decreases) HR and contractility; causes broncho___ (constriction/dilation); vaso___ (constriction/dilation)
Activation of muscarinic receptors decreases HR and contractility; causes bronchoconstriction; vasodilation
What is the captain of the autonomic nervous system?
Hypothalamus—controls autonomic NS
The brainstem has control over ___ and ___ function
CV and pulmonary function
Autonomic reflexes will suppress one branch of the ANS while activating the other branch—i.e.: when SNS is activated, PNS is inactivated and vice versa—T/F?
True
Neurogenic shock causes loss of ___ tone
Neurogenic shock causes loss of vasomotor tone
Loss of vasomotor tone = ___tension; causes diminished ___ (SNS/PNS) innervation of the heart which results in ___cardia
Hypotension; causes diminished SNS innervation of the heart which results in bradycardia
Normal ICP = ___-___ mm Hg
5-15 mm Hg
ICP is usually treated above ___ mm Hg
Above 20 mm Hg
ICP can be affected by anesthetic meds and techniques—T/F?
True
CSF accounts for ___-___% of intracranial volume
10-15%
Choroid plexus produces ~___ ml of CSF per day
~500 ml of CSF per day
Total volume of CSF at any one time = ___ ml
150 ml
Cerebral edema can be caused by ischemic stroke, meningitis, or disruption of blood brain barrier—T/F?
True
Cerebral blood flow accounts for ~___% of cardiac output and is tightly coupled to ___
Cerebral blood flow accounts for ~14% of cardiac output and is tightly coupled to CMRO2
Cerebral blood flow is autoregulated between MAP of ___-___ mm Hg
60-160 mm Hg
Autoregulation of CBF can be lost with ___osis, ___ia, and ___ anesthetics
Acidosis, hypoxia, and volatile anesthetics
PaCO2 is a potent cerebral vaso___, has an approximately linear relationship to ___, and is a potent determinant of ___
Potent cerebral vasodilator, has an approximately linear relationship to CBF, and is a potent determinant of CBF
Regarding PaO2–once PaO2 drops below ___ mm Hg, there is an increase in cerebral blood flow, even in the presence of ___capnia
Once PaO2 drops below 50 mm Hg, there is an increase in cerebral blood flow, even in the presence of hypocapnia
So, even if you are blowing off CO2 and keeping CBF/ICP down, if you allow the PaO2 to drop below 50, it doesn’t make a difference how much CO2 you are blowing off
PaO2 of 50 mm Hg approximately equates to SaO2 of ___
SaO2 of low to mid 80s
Don’t let patients with increased ICP O2 sat drop below ___
Mid 80s
Volatile anesthetic agents ___ (increase/decrease) CBF; ___ (increase/decrease) CMRO2; and have a profound effect on ___ (motor/sensory) evoked potentials
Volatile anesthetic agents increase CBF; decrease CMRO2; and have a profound effect on motor evoked potentials
Propofol and etomidate ___ (increase/decrease) CBF; ___ (increase/decrease) CMRO2
Decrease CBF; decrease CMRO2
Ketamine ___ (increases/decreases) CBF; ___ (increases/decreases) CMRO2
Increases CBF; increases CMRO2
Opioids alone have no direct effect on CBF—T/F?
True
However—if you give patients opioids any time BEFORE securing the airway (i.e.: during induction), they can suppress the respiratory drive, patient will become hypercarbic/hypoxic, which will then cause an increase in ICP…but opioids alone have no direct effect on CBF
Benzos have minimal effect on CBF—T/F?
True
Studies have shown that there is no clinically significant increase in CBF with the administration of succinylcholine—T/F?
True
___ (somatosensory/motor) evoked potentials are exquisitely sensitive to inhalational agents
Motor evoked potentials
Monitoring of MEPs requires the patient to NOT be paralyzed throughout the entire case—T/F?
True
If MEPs are going to be monitored during a case, it is typically okay to paralyze the patient during induction—T/F?
True—just make sure you communicate with neurophysiology to know when they are going to want twitches back/begin monitoring MEPs so you don’t re-dose your paralytic
Regarding evoked potentials—what (2) medications enhance the quality of SSEP signals?
Ketamine and etomidate
What (2) medications attenuate (AKA reduce) the amplitude of all evoked potentials?
Propofol and thiopental
Propofol and thiopental attenuate the amplitude of evoked potentials but do not obliterate them—T/F?
True
Opioids, benzos, and precedex have negligible effects on the recording of evoked potentials—T/F?
True
Inhalation agents, including nitrous oxide, generally have more depressant effects on evoked potential monitoring than do IV agents—T/F?
True
Volatile agents can have profound influence on amplitude and latency of evoked potentials, both sensory and motor—T/F?
True
Evoked potential signals are not obtainable under inhalation agents—T/F?
False—signals ARE obtainable under inhalation agents, but the anesthetic is typically kept at sub MAC doses to avoid degradations in the quality of signals
Cerebral oximetry can be used in any procedure where there may be vascular compromise to the ___ from restriction of blood flow
Vascular compromise to the brain from restriction of blood flow
___% decrease in cerebral oximetry is significant
20% decrease
Cerebral oximetry can be used in any procedure where there may be vascular compromise to the brain from patient positioning—T/F?
True
