ANS Flashcards
What function is lost if the artery of Adamkiewicz has disrupted blood flow? Upper? Lower? Motor? Proprioception?
Lower Motor
Pain
Temperature
ED
Urinary and fecal
What tracts are the lower motor?
Corticospinal tract and anterior horns?
What part of the spinal cord does the artery of Adamkiewicz supply? What level ?
Anterior 2/3 of the spinal cord, T9-T12
What is preserved when the artery of Adamkiewicz is blocked?
Proprioception, fine touch, vibrations because they are perfused by the posterior spinal cord
What is the best anesthetic for a patient with autonomic hyperreflexia?
Neuraxial with local or general
Which drug class does not work with autonomic hyperreflexia?
Intrathecal opioids
When does autonomic hyperreflexia occur?
Cutaneous or visceral stimulation below the spinal cord injury
Bowel or bladder stimulation
Cystoscopy
Uterine contraction
Lower extremity burns
Vasoconstriction vs vasodilation what occurs above and below the injury of the spinal cord in AH?
Vasoconstriction below the level of injury
Vasodilation above the level of injury
S&S of Autonomic hyperreflexia?
Acute HTN
Reflex bradycardia
MI
Headaches
Retinal hemorrhages
Pallor and coolness in LE
Sweating in uppers
How is AH treated?
**Stopping the triggering agent
Avoid beta blockers
Fast acting vasodilators
When does AH susceptibility begin ?
2 weeks to 6 months
What is Horner syndrome?
Stellate ganglion blockade
Mad as a hornet
Miosis on ipsilateral side
Ptosis
Anhidrosis
Pseudoenophthalmos
Hyperemia
When producing a stellate ganglion block, what complication may produce a seizure?
Vertebral artery injection
Sings of a successful stellate ganglion block?
Flushing of the face
Horner syndrome
Nasal congestion
Temperature increase in the ipsilateral arm
In the elderly do they have an increase or decrease in SNS? What about PNS?
Increased resting SNS tone
Decreased resting PNS tone
In the elderly, what happens to their arteries?
Decreased compliance due to stiff arteries thug increasing systolic BP
However no change in systolic function
How does the HR of the elderly respond to catecholamines?
Decreased response to catecholamines
CO and circulation time in the elderly?
Decreased CO
Increased circulation time (takes longer to circulate)
Do the elderly have a decreased ability to respond to hypotension, hypovolemia, and hypoxia?
Yes they have a decreased response
Elderly response to beta stimulation and baroreceptors?
Decreased
Filling pressures in the elderly?
Increased due to less compliant heart
Elderly ischemic preconditioning response?
Decreased
Does the ejection fraction change in a healthy elderly person?
No
Which substances increase during surgical stress?
Antidiuretic
Renin
Cortisol
Ang 2
Aldosterone
Which substances are decreased during surgical stress?
Secretion of insulin
Gonadotropin releasing hormone
When may thyroid storm be triggered?
Surgical stress in patients with hyperthyroidism
What happens with gastric section when acetylcholine binds to muscarinic receptor?
Increases
Is ephedrine effective in a heart transplant?
No
Is dobutamine effective in a denervated heart?
Yes
What does 2 P waves on a EKG indicate?
Heart transplant (residual atrial tissue)
Where do first order neurons synapse?
Dorsal Root Ganglion
Where do second order neurons synapse?
Dorsal horn
Where do third order neurons synapse?
Thalamus
Where is the primary control center for the descending pain pathway?
Periaqueductal gray area
What is the heart rate of most Heart transplant patients?
90-110
Will the Valsalva maneuver affect the transplanted heart?
NO
HR and BP for autonomic hyperreflexia?
HTN and bradycardia
Will smaller children have more or less heat loss?
Less because of a increased surface area-to-body ratio and small amount of subq fat
What type of fat in infants helps achieve Non shivering thermogenesis?
Brown fat
What is MAC BAR? What does it blunt?
1.5 - blunts autonomic responses
What is MAC-Awake?
50% of patients will not respond to a command
Usually 0.15-.5 MAC
What is MAC?
50% of patients will not move at surgical incision
What is the earliest feature that can be seen in diabetic autonomic neuropathy?
Tachycardia
What a major risk of diabetic autonomic neuropathy?
Silent MI because the heart can become denervated
What level for a sensory blockade is most at risk for bradycardia?
T4 - because of the cardioaccelerator fibers
What type of fibers are blocked first?
B fibers - preganglionic autonomonic
Which type of fibers are blocked second?
C fibers - dorsal root
Postganglionic autonomic + slow pain, temperature and touch
Which type of fibers are blocked last?
A Beta - touch and pressure
Which two diseases have a high risk of gastroparesis?
DM
Opioids
How does Tetanus affect neurons?
-Inhibit the release of inhibitory neurotransmitters
Which organ is blocked during a celiac plexus block?
Adrenal
