Anesthesia Gas Laws Flashcards
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Poiseuille’s Law
- Gas through flowmeters
2. Selection of ETT/IV catheter sizes
Henry’s Law anesthesia
- Over-pressurizing anesthetic gases
- Increasing deliver of O2 by increasing concentration
- Hyperbaric O2 chamber
Boyle’s Law
- Squeezing bag to ventilate a patient
- Diaphragm contracts and inspiration begins, diaphragm relaxes and exhalation begins
- Hyperbaric O2 therapy
- Bellows
Bernoulli’s principle
- Ventrain/jet ventilation
- Venturi mask
- Scavenge system
Avogadro’s hpothesis
How much gas in E-cylinder
Charle’s law
ETT cuff pressure
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Regulation of anesthetic gas through metal strip
3rd gas law/Gay-Lussac’s Law
- steel tanks will explode when heated
- Regulation of anesthetic gas through metal strip
- Medical gas cylinders, ETTs, hydrogen thermometers
Univers gas law or ideal gas law
- amount of inhalation agent delivered to patient would increase/decrease depending on temperature compensative valves
- Emptying of an E-clinder
Graham’s Law
- Flow meters must be calibrated with correct gas or they would be inaccurate
- How anesthetic gases diffuse and effusion
Law of Laplace
- Ventilation and pressure
- AS and preload
- Collapsing pressure of alveoli and ability to keep open
- Surface tension, alvoli radius, lung compliance
Fick’s law anesthesia
- Pt with COPD will have reduced area for gas exchange to transpire & decreased speed of onset of anesthetic agents
Dalton’s law
- Total pressure of mixture of gases is equal to each gases individual partial pressure
Avogadrado’s hypothesis
- Equal volumes of gasses at a constant temperature and pressure have equal amounts of atoms and molecules
- 1 mole = 6.023 x 10^23
- Lead to discovery of universal gas law
Bernoulli’s principle
- velocity and pressure are INVERSE (velocity increases, pressure decreases)
- Applies ONLY to liquids and gases
- As velocity increases through a constant area, pressure on the lumen wall decreases, resulting in a tendency to collapse
Charles Law
- Temp and vol are proportional
- V1T2 = V2T1
- Published by Gay-Lussac
Universal Gas law or ideal gas law
- combo of Gay-lussac’s/boyle’s law, and charles law
2. PV=nRT (pressure x volume = moles x constant x temperature
Standard molar volume in STP
22.71 L
Gay-Lussac Law
- Temp and pressure are proportional
Graham’s Law
- Deals with diffusion and effusion of gases
2. Rate of effusion INVERSE to square root of MW
Poiseuille’s Law
- Describes relationship of the amount of fluid flowing through tube
- Viscosity INVERS flow; radius directly proportional to flow
- Q = πPr^4 / 8nL: Q=flow, pressure, radius, n=viscosity, Length
Gay-Lussac’s Law (3rd)
- Draws from Charles Law and Boyle’s Law
- P1T2=P2T1
- Pressure is proportional to temperature
What cuff pressure, if exceeded, causes tracheal granulation, ulceration of stenosis
30 mmHg
Boyle’s Law
- Pressure INVERSE volume
2. P1V1 = P2V2
Fick’s Law
- Rate of transfer DIRECTLY proportional to driving force (diffusion coefficient), surface area, and INVERSE proportional to thickness of membrane barrier
- Driving force is partial pressure difference NOT concentration difference
Law of LaPlace
- Smaller radius the greater collapsing pressure
2. Greater radius LESSER collapsing pressure
Treatment of ARDS
- PEEP to keep lungs open
- Supportive care
- Volume 6 mL/kg
Henry’s Law
- Partial pressure of a gas above a liquid is DIRECTLY proportional to the concentration of the gas in that liquid
3 Main factorsthat affect anesthetic uptake
- Solubility in blood
- Alveolar blood flow
- Difference in PP between alveolar gas and venous return
Over pressurizing is a method to partially compensate for
- V/Q deficits
- Increased C.O
- High elevation
