Natural preparation of Curare involves boiling it in water and then evaporating it to a paste. This implies that:
Curare is both heat stable and water soluble
These drugs bind competitively to the cholinergic receptors on the motor end-plate, and thus antagonize the action of ACh
depolarizing NMBA (succinylcholine)
True or False? NMBAs have no affect on pain or sensory perception
True!
Significant Adverse Effects of NMBAs
1. Hypotension due to autonomic ganglionic blockade & histamine release
2. Tachycardia due to vagal blockade (vagolysis)
This compound contains a benzenesulfonic acid and is a mixture of 10 isomers
Atracurium
The chirality of this bisbenzylisoquinoline-compound provides that the structure is a mixture of isomers
This compound has the shortest half-life of the bisbenzylisoquinolines and it also does not undergo hepatic degradation like the other two. However, it does cause moderate histamine release which the other two do not.
Mivacurium
This monoquaternary, monotertiary, semisynthetic bisaminosteroid contains two piperidine rings as side chains. Caution must be used when using this compound in patients with hepatic impairement.
Vecuronium
This monoquaternary, monotertiary, semisynthetic bisaminosteroid contains a pyrrolidine and morpholine ring as side chains. Caution must be used when using this compound in patients with hepatic impairment
Rocuronium
This bisquaternary, semisynthetic bisaminosteroid contains two piperidine rings as side chains. This compound has the longest duration of action and must be used cautiously in patients with renal failure.
Pancuronium
The objective of general anesthesia is:
reversible neronal blockade in CNS
This compound is the only incomplete anesthetic
Nitrous Oxide
This inhalation anestheic's ADVANTAGES include: good muscle relaxation, low incidence of arrhythmias, low
incidence of liver/kidney toxicity.
DISADVANTAGES are: hypotension, respiratory depression, seizures in at high concentrations
Enflurane
This inhalation anesthetic's ADVANTAGES include: good muscle relaxation, cardiac output maintained, no
arrhythmias, low incidence of liver/kidney toxicity, no seizures
DISADVANTAGES are: more pungent odor that enflurane, hypotension, respiratory depression
Isoflurane
This inhalation anesthetic has the same advantages as isoflurane; more rapid induction and easier control of anesthetic depth.
This inhalation anesthetic has the same advantages as desflurane; little odor
All halogens in this compound are fluorine.
DISADVANTAGES are: significant metabolism to inorganic fluoride → potential kidney toxicity, chemical instability when exposed to soda lime (CO2 removal), hypotension, respiratory depression
Sevoflurane
Barbiturates and benzodiazepines (and perhaps other agents) produce CNS depression by interacting with or mimicking ______________, a major inhibitory neurotransmitter at many levels of the neuroaxis from the spinal cord to the cerebral cortex.
GABA
These IV anesthetics have poor analgesic and muscle relaxant activity. May produce severe respiratory depression. Used primarily as induction anesthetics to promote rapid movement through Stage II.
Barbiturates
How long should aspirin or NSAIDS be held prior to surgery?
at least 10-14 days
How long should cardiovascular meds, opioids, BZDs, or antidepressants be held prior to surgery?
Do not hold these meds prior to surgery: risks > benefits
How long should warfarin be held prior to surgery?
at least 4-5 days
How long should Pradaxa be held prior to surgery?
1-2 days prior
How long should alternative meds be held prior to surgery?
At least two weeks
What are the three legs of Virchow's triad?
1. Venous Stasis
2. Injury
3. Hypercoagulable State
What are the three scenarios when Enoxaparin should be used over Heparin for DVT prophylaxis?
1. Hip replacement
2. Knee replacement
3. Trauma patients
What are the two consequences of ulceration in the GI tract?
1. Risk of bacteria translocating across the gut
2. Hemorrhage from erosion through surface vessels
What are the two independent risk factors for SRMD bleeding in ICU patients?
1. Respiratory failure requiring MV > 48 hours
2. Coagulopathy: platelet count < 50,000
What is the agent of choice for SRMD?
H2RA
**Use a PPI if patient has an acid problem --- example, blood in the gut**
What is the agent of choice for SSI prophylaxis?
If allergy to this drug?
1. Cefazolin 1 gram IV q8h
2. Vancomycin if PCN allergy
Who gets perioperative beta blocker prophylaxis?
Only patients who are on a beta blocker at home
Normal Range for MAP
65-90 mm Hg
Normal range for cardiac output (CO)
4-7 L/min
Normal range for cardiac index (CI)
2.8-3.6 L/min/m2
Normal range for central venous pressure (CVP)
[right ventricular preload]
8-12 mm Hg
Normal range for PCWP
[left ventricular preload]
6-12 mm Hg
normal range for systemic vascular resistance (SVR)
[left ventricle afterload]
800 - 1400 dyne/sec/cm-5
120-Normal range for pulmonary vascular resistance (PVR)
[right ventricle afterload]
120 - 250 dyne/sec/cm-5
Clinical indicators for hypovolemic shock:
CI = low
SVR = high
PCWP = low
Clinical indicators for cardiogenic shock:
CI = low
SVR = high
PCWP = high
Clinical indicators for septic shock:
CI = low
SVR = low
PCWP = low
Two examples of Crystalloids:
NSS and Lactated Ringer
Three examples of Colloids:
Albumin, Hetastarch, Blood
Which vasopressor is used for hypotensive patients that are tachycardic?
Phenylephrine
Two inotropic agents include:
Dobutamine and Milrinone
This inotrope is used in patients with Cardiogenic shock and Arrhythmias because it has no effect on beta cells
Milrinone
Vasopressor of choice for septic shock:
Norepinephrine
Vasopressor of choice for cardiogenic shock:
Dobutamine
Primary use of succinylcholine:
to facilitate intubation
Major side effect of succinylcholine:
Hyperkalemia --- need to be aware of renal patients (patient's who have a high serum K level)
Disadvantage to Panuronium:
1. Hepatic metabolism and renal excretion
2. Causes CV side effects: increased HR and BP (tachycardia)
**Do not use in patients with Tachycardia**
Vecuronium is not a vagolytic, meaning...
it could be used in patients with good kidney and renal fxn, and possibly those that are tachycardic