M5 Flashcards
Why does a patient desaturates 5 min after retrobulbar block
Local anesthetic in CSF causing high spinal
What is ecothiophate and what anesthetic drug should be avoided?
Irreversible cholinesterase inhibitor used for chronic glaucoma. Avoid using succinylcholine and other drugs metabolized by plasma cholinesterases including pseudocholinesterase.
Next best step in treatment of patient with likely corneal abrasion
Topical antibiotics
Protopathic sensation
Noxious (painful)
Epicritic sensation
Non-noxious (touch, pressure, temperature, proprioception)
Nociceptive pain is caused by activation of what type of receptors
High threshold peripheral nociceptive receptors
Nociceptive pain is transmitted via what types of nerves
A-delta and C nerve fibers
Pain fibers enter spinal cord via which nerve roots?
Mostly dorsal nerve root but some enter via ventral nerve root
Primary area of pain pathway that opioids act upon
Dorsal horn where 1st order neurons synapse with 2nd order neurons
How is resistance to flow related to length and radius?
Resistance proportional to 8 times length
Resistance inversely proportional to radius to 4th power
What’s an intrinsic property of a transplanted lung that is kept intact?
Hypoxia pulmonary vasoconstriction
Which procedure is hypotension most likely, insertion of venous cannulation or insertion of aortic cannulation?
Venous cannulation can significantly reduce preload
What are advantages to off pump cabg?
Decreased incidence of respiratory infection and afib postop, less inotrope use, fewer blood transfusions
Mechanism of heparin
Binds to anti-thrombin 3, which accelerates inhibition of thrombin and factors 9 and 10
Next best step if heparin causes no change in ACT prior to CPB
Give 2 units of ffp then give heparin. Pt likely has anti-thrombin 3 deficiency
Functions of thromboxane
1) Platelet aggregator, facilitating clot formation. 2) Vasoconstrictor that reduces blood flow to site of clot
Pulmonary artery pressure rise after protamine administration for heparin reversal
Heparin protamine complexes can cause thromboxane release from macrophages
Hypotension after protamine administration for heparin reversal
Dose dependent histamine release from mast cells
Best way to decrease time to rewarm patient
nitroglycerin infusion
Fast pain is carried by what type of nerve fibers?
A delta fibers (myelinated)
Delayed slow secondary pain is carried by what type of nerve fibers?
C fibers
Induction agents except for ketamine work on which type of GABA receptor?
GABA-A receptor
Propofol should be discarded after being drawn into a syringe after how many hours?
12 hrs, it used be 6 hrs before EDTA preservative was added.
What part of egg is used in propofol?
Egg lecithin from the egg yolk. People allergic to eggs are allergic to egg albumin which is in egg white.
Pretreatment with what drug can decrease etomidate associated myoclonus?
Opioids
Reason why etomidate causes burning pain
Propylene glycol solvent that etomidate is in
Etomidate causes increase in ICU mortality because of?
Prolonged infusions causing adrenal suppression
In what percent of patients does a single induction dose of etomidate cause adrenal suppression?
All patients
Hydrophilic or lipophilic drug has smaller volume of distribution
Hydrophilic
Induction agent that is completely metabolized by liver on a single pass
Propofol
2 pathways signaled by G protein coupled receptors
1) cAMP -> PKA
2) phospholipase C -> IP3
Where is propofol metabolized?
Liver and lung
How is fospropofol different than propofol?
Water soluble, prodrug that has to be metabolized by liver to release propofol and formaldehyde
How does barbiturates affect tolerance to pain?
Decrease tolerance to pain
Barbiturate injected in artery causes?
Limb gangrene due to arterial spasm and vasoconstriction, treatment is stellate ganglion block
Morphine metabolite
Morphine-6-gluconoride, major contributor to mu receptor mediated respiratory depression
Oversized BP cuff affects BP measurement how
BP will be underestimated
Correlation between central venous pressure and left ventricular end diastolic volume
None at all
Betadine or chlorhexadine use has lesser catheter related bloodstream infection
Chlorhexadine
How does insulin affect glycogen and protein synthesis?
Increases
Hypernatremia or hyponatremia is associated with hypothyroidism?
Hyponatremia: hypothyroid patients retain free water
Classic diuretic of choice to treat Cushing’s syndrome
Spironolactone
Anesthetic considerations with Cushing’s syndrome
Increased sensitivity to muscle relaxants, hypokalemic arrhythmias, difficult intubation for obesity and swelling
Healthy person can produce up to how much cortisol in a day when maximally stressed
300 mg of cortisol
Historically why is succinylcholine contraindicated with pheochromocytoma pts?
Supposedly fasciculations cause catecholamine release secondary to abdominal pressure
Historically why is pancuronium contraindicated with pheochromocytoma pts?
Pancuronium is vagolytic
Pheochromocytoma is associated with which syndromes?
MEN2A, NF1, Von Hippel-Landau
How are anaphylactoid reactions different from anaphylaxis?
Anaphylactoid reactions are NOT IgE mediated
MC type of vWD
Type I
Type of vWD that responds to DDAVP
Type I