Flashcards in Maintenence* Deck (43):
what's included in a "balanced anesthetic?"
what are two ways to calculate the O2 maintenance requirement?
VO2 = 10*kg^0.75 = ml/min or
VO2 = 2.5*kg+67.5 = ml/min
numeric values for dead space
Anatomic Dead space = 2 ml/kg
= 140 ml/B *10 = 1400 ml/min
Alveolar Oxygen Equation
PAO2 = [(PB-PH2O)(FiO2)]-(PaCO2/R)
What is the initial treatment for a patient whose sats begin to drop?
why does a low BP lead to VQ mismatch?
PEEP can be simplified to mean what?
resistance to expiration
therapeautic range for PEEP
What is the physiological value for PEEP?
advantages of inhalational agents
Rapid appearance of drug in arterial blood
Efficient to distribute
Easy to deliver - Unique route
High safety profile
drawbacks of inhalational agents?
No analgesia (N20 exception)
MACBAR = 1.5
MACawake = 0.3-0.5 (10% of MAC)
MACamnestic = 0.25
what effects do age, accute intoxication and pregnancy have on MAC?
age = increase/decrease
EtOH = decrease
Pregnancy = decrease
rate of rise for the Fa/Fi curves depends on what?
The more _____ the anesthetic agent, the quicker the pt will go to "sleep"
Factors affecting inspiratory concentration (Fi)
Fresh gas flow (increase)
Circuit Volume (decrease)
Any machine/circuit absorption (decrease)
In terms of time constants, what percent must change in order for the change to be therapeautic?
What pathway does the agent take once in the body?
lung -> blood -> brain
Describes relative affinity of anesthetic gas for blood
Blood/gas partition coefficient
Increased partition coeff -> _______ solubility -> ________ agent uptake
Increased agent uptake -> ______ induction
Blood/Gas values for Iso, Des, Sevo
Iso = 1.4
Des = 0.42
Sevo = 0.65
Muscle/Blood values for Iso, Des, Sevo.
& why are they important?
Iso = 4.0
Des = 2.0
Sevo = 3.1
Determines speed of wake up
What is Cardiac Output?
CO = HR x SV
Which agents are most effected by CO?
Highly soluble agents are most effected by CO
What are some factors affecting arterial concentration (Fa)?
Alveolar dead space
Nonuniform alveolar gas distribution
What effect does N2O have on MAC?
cuts MAC requirement by 50%
Powerful analgesic properties
Decreases MAC of other inhal. Agents
Safe in MH patients
Decreases myocardial contractility
Increase risk PONV
Increase ICP by inc CBF
Pneumothorax (75% 2-3x 10 min)
Acute intestinal obstruction
Intracranial air (tension pneumocephalus)
Pulmonary air cyst
Intraoccular air bubbles
Tympanic membrane grafting
What does Sevo smell like?
juicy fruit (according to Sam)
If you sniff enough, you won't remember it though
What is a potential risk with Sevo and when is it seen?
Compound A (fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether
Low gas flows
Non-irritant sweet odor
Does not sensitize myocardium to catecholamine
No CO production with Na lime
Compound A production (2L/min)
Contraindicated with Baralyme
Post op agitation in children*
Which agent is a gas at room temp?
Which gas is Capable of increasing HR, documented myocardial ischemia?
Stable with CO2 absorbers
Requires special vaporizer
Pungency (not good for asthma)
Rapid increase >1.25 MAC SNS stimulation
which agent can you not use in pt's with renal or hepatic dysfunction?
Min CV effects
Low blood solubility
Low potency (MAC – 70%)
Not readily available
Sam's 10 commandments
1. never turn down a break
2. You can always give more
3. Go ahead it is not my MAMA
4.Tank ‘em till they froth, then back off
5.Give them what they need add it up later
6.Straighten out your lines , keep them that way
7. There is always an exception to what you think you know
8. Learn how to disagree without being disagreeable
9.Never say it has not happened to me
10. Never Never use the drugs you give to your patients