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Flashcards in The test JB's version Deck (117)
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3 processes by which a skin graft obtains nutrition

Plasmatic imbibition, inosculation and re-vascularization


Cat specifics when it comes to skin

Decreased vascularity vs dogs
Longer healing time - lower rates of granulation (2x's longer than dogs), epithelialization, contraction
Critical to preserve the Sub Q


Deploarizing neuromuscular blockade
Name 2 and how do they work "briefly"

Succinylcholine, decamethonium
These drugs mimic ACh
Binds acetylycholine receptors, result in persistent depolarization (Na channels left open = Na inactivation). And receptor burn out - reason uncertain


Non-depolarizing neuromuscular blockade
Name 2 and how do they work "briefly"

Atracurium, pancuronium, vecuronium
These drugs block ACh.
Block ACh post synaptic receptors so no ACh stimulation


Clinical highlights of depoloarizing NM blockade?

Deploarizing = Initially get muscle fasciculation. Paralysis due to prolonged depolarization of the motor end plate. Paralysis is not reversed by anti-cholinesterase drugs but rather metabolism by pseudocholinesterase


Clinical highlights of non-depoloarizing NM blockade?

Gradual relaxation (no mm fasiculations)
Can be partially reversed by anti cholinesterase drugs: Neo or Pyrido stigmine, edrophonium


Succinylcholine adverse effects

-Sore next day (fasciculation?)
-Hyperkalemia (K from skeletal mm)
-Malignant hyperpyrexia - Fast wicked high rise in temp +/- rigidity. Usually if give with halothane. Tx signs and use bicarb and dantrolene sodium (1-2mg/lb)
-Histamine release
-Tachycardia and hypertension (symp stim). but can sometimes get brady cardia


Decamethonium adverse effect

Same as succinylcholine except -
- no histamine release
-no metabolism (excreted by kidneys [so no usey if bad kidneys])
-longer duration of action (not metabolized by plasma cholinesterase)


Pancuronium (highlights)

non depolarizing
no histamine or catecholamine release
effects enhanced by inhalants
Major portion excreted unchanged in pee



-non depolarizing
-can give as infusion
-Hoffman elimination (chemical run) no liver or kidney involved



-non depolarizing
-short onset and duration
-potential choice for renal failure (40% eliminated in bile, 15% through kidney)


What affect, if any could temp have on blockade?

-prolongs depolarizing and antagonizes non-depolarizing
- prolongs non-depolarizing


What affect if any does respiratory acidosis have on blockade

Augments non-depolarizing blockade
Vicious cycle = inadequate reversal causes depressed ventilation which causes reap acidosis


Why would you give atropine with a neuromuscular blockade reversal

Reversals are anti cholinesterase drugs. By blocking AChesterase they increase the amt of ACh to compete with non-deploarizing blockers for the receptor.
Also get muscarinic stimulation (salivation, bradycardia, increased intestinal motility)
Atropine is an anticholinergic and will help decrease those side effects


Can you reverse succinylcholine

No. Paralysis is reversed by metabolism by pseudocholinesterase


How much trachea can be removed in

Adult - 25-50%
Puppy - 20-25%
tobias says experimentally 15-27 rings


What kind of muscle is the trachealis muscle?
Is it dorsal or ventral

Primarily composed of transversely oriented smooth muscle fibers


What is the blood supply to the trachea

Segmental - from the cranial and caudal thyroid attires. Except near the corona - here it shift primarily to the bronchoesophageal arteries.


How are AB's incorporated into PMMA beads released?

Bimodal manner (rapid phase then slow)


How much of the antibiotic used is released in the rapid phase and how long is this period

5% of total AB used is released in first 24 hours.


What affect does the addition of Metronidazole have on polymerization of PMMA? And what does that mean for you clinically?

The addition of metronidazole even at very low concentrations (100:1) significantly delays polymerization (hardening). Taking up to about 48 hours (apposed to the normal 5-10 minutes)


Local AB tissue concentrations have been reported to reach up to _______x's greater than when given systemically

200 (per Saygeh Compend 2003)
20 (per Ramos etal vet surg 2003)


It is estimated that the area receiving therapeutic levels of AB's may reach?



How long does elution of AB's persist from PMMA?

21 days in a uniform dose dependent manner is commonly reported (probably longer)


How much of the total ab incorporated into the PMMA elutes

2.3-11% has been reported for a variety of AB's tested


How much of the total cumulative elution occurs in first hour? First 24 hours?

1/3 in first hour, 2/3 in first 24 hours


What does the elution rates of AB's from PMMA beads depend on?

Bead associated factors
- Size of bead, pore size, permeability and type of cement used, exposed surface area
Antibiotic factors
-diffusion coefficient
-mixing of some AB's
Tissue factors
-circulation in the area
-amount of fluid surrounding bead


Requirements for AB to be used in PMMA beads

Should be bactericidal, effective against expected bact at MIC, and above all = HEAT STABLE


What is the most common concentration (recipe) of antibiotic to PMMA used

1g AB for every 20g of cement


What AB's cant you use in PMMA beads? And why?

Polymixin B, tetracyclines, chloramphenicol. Not heat stable enough