Anesthesia Machine Circuits
description
Transcript of Anesthesia Machine Circuits
![Page 1: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/1.jpg)
Anesthesia Machine Circuits
![Page 2: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/2.jpg)
Anesthesia Circuits
• Link machine to patient
• Eliminate carbon dioxide
• Mapleson classification– Many circuits in use– Modified Mapleson still in use– Know the current applications of modified
Mapleson circuits
![Page 3: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/3.jpg)
Types of Circuits
• Basic circle system
• Mapleson Classification
![Page 4: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/4.jpg)
Circle System
• Allows rebreathing of anesthetic gases– lower FGF rates– Less pollution
• Requires CO2 absorption
• Conserves heat and humidity
![Page 5: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/5.jpg)
Advantages of Circle System
• Highly efficient
• Minimal dead space
• Conserves heat and moisture
• Minimal pollution
• Disadvantage - many places to leak
![Page 6: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/6.jpg)
Components of the Circle System
• Fresh gas source
• Unidirectional valves
• Inspiratory & expiratory tubing
• Y-piece connector
![Page 7: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/7.jpg)
Circle System Components
• APL valve
• Reservoir bag
• CO2 absorber
![Page 8: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/8.jpg)
Rules for Circle System
• Unidirectional valve must be between patient & bag on both sides
• FGF cannot enter between patient & expiratory valve
![Page 9: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/9.jpg)
Rules for Circle System (Cont’d)
• APL cannot be located between patient &
inspiratory valve
![Page 10: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/10.jpg)
Four Basic Circuits
• Open
• Semi-open
• Semi-closed
• Closed
![Page 11: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/11.jpg)
Open Systems
• Insufflation– blow anesthetic gas over face– no direct contact– no rebreathing of gases– ventilation cannot be controlled– unknown amount delivered
![Page 12: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/12.jpg)
Open Systems
• Open drop anesthesia– gauze covered wire mask– anesthesia dripped– inhaled air passes through gauze & picks up
anesthetic
![Page 13: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/13.jpg)
Open Systems (Cont’d)
• Open drop anesthesia (cont’d)– concentration varies– re-breathing may occur– environmental pollution
![Page 14: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/14.jpg)
Semi-open Systems
• Breathing system which entrains room air
• Self inflating resuscitator system
![Page 15: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/15.jpg)
Semi-closed System
• Gas enters from machine– part leaves via scavenger
• Circle system
• Bain system
![Page 16: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/16.jpg)
Closed System
• Only enough gas enters to meet metabolic needs
• Scavenger is closed
• Closed circle system
• To-and-fro system
![Page 17: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/17.jpg)
Closed System Anesthesia
• Technique not commonly used
• APL is closed and only enough O2 is added to meet metabolic needs
• Anesthetic added based on square root of time
• Conserves anesthetic gas an eliminates pollution
![Page 18: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/18.jpg)
The Scavenger System
• Releases excess pressure from the system
• Prevents operating room pollution
• Gases leave through APL
• May put too much negative pressure on the system
![Page 19: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/19.jpg)
Open System
• No reservoir
• No rebreathing
![Page 20: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/20.jpg)
Semi-open System
• Has reservoir
• No rebreathing
![Page 21: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/21.jpg)
Semi-closed System
• Has reservoir
• partial rebreathing
![Page 22: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/22.jpg)
Closed System
• Has reservoir
• Complete rebreathing
![Page 23: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/23.jpg)
Mapleson Breathing Circuits
• Early pioneers developed their own delivery
systems
• Mapleson classified types of breathing
devices
![Page 24: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/24.jpg)
Mapleson Breathing Circuits (Cont’d)
• Mapleson circuits fall into which type of
system?
• See Morgan p. 26, Table 3-1
![Page 25: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/25.jpg)
Mapleson A
• FGI near bag
• Breathing tubing
• Expiratory valve near mask
• Volume of breathing tube should be as great as the tidal volume
![Page 26: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/26.jpg)
Mapleson A
• Spontaneous ventilation
• High FGF flushes tubing between breaths
![Page 27: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/27.jpg)
Mapleson A (Cont’d)
• Using “pop-off” enables controlled
ventilation but also causes CO2 rebreathing
• Current use?
![Page 28: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/28.jpg)
Mapleson B
• Similar to A with FGI near expiratory valve
• System fills with FGF
– inhaled by patient
![Page 29: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/29.jpg)
Mapleson B (Cont’d)
• Exhaled gas forced out through expiratory
valve
• Current use?
![Page 30: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/30.jpg)
Mapleson C
• Similar to Mapleson B
• Shorter breathing tubing– less dead space
• Current use?
![Page 31: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/31.jpg)
Mapleson D
• Long breathing tube
• FGI near mask
• Exhalation valve at distal end of breathing tubing
• Current use?
![Page 32: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/32.jpg)
Bain Breathing Circuit
• Modified Mapleson D
• Tube within a tube– FGF tube within larger tube
• Mounts on anesthesia machine
• APL valve
• Connects to scavenger
![Page 33: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/33.jpg)
Bain System• Advantages
– compact, easy to handle– warming of inspired gases– partial rebreathing improves humidification– APL controls system pressure– ability of scavenging
![Page 34: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/34.jpg)
Bain System Flow Rates
• Spontaneous ventilation– 200-300 ml/kg/min
• Controlled ventilation– infants <10kg 2 l/m– 10 - 50 kg 3.5 l/m– > 60 kg 70 ml/kg/min
![Page 35: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/35.jpg)
Bain System• Depends on fresh gas flow to flush out CO2
• Spontaneous ventilation200 - 300 ml / kg / min
• Controlled ventilation70 ml / kg / min
![Page 36: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/36.jpg)
Mapleson E
• Exhalation tube is reservoir– no bag
• FGI near mask
• Current use?
![Page 37: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/37.jpg)
Mapleson F
• FGI near mask
• Breathing tubing/bag
• Expiratory valve at end of bag
• Current use?
![Page 38: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/38.jpg)
CO2 Absorption
• Soda lime– 94% calcium hydroxide– 5% sodium hydroxide– 1% potassium hydroxide– silica to harden granules– ethyl violet as an indicator
![Page 39: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/39.jpg)
CO2 Absorption
• Baralime
– 80% calcium hydroxide
– 20% barium hydroxide
– ethyl violet as an indicator
![Page 40: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/40.jpg)
CO2 Absorption
• pH is extremely high
• Granule size
– 4 8 mesh
• Water is required for chemical reactions to
occur
![Page 41: Anesthesia Machine Circuits](https://reader035.fdocuments.net/reader035/viewer/2022062301/56813d5a550346895da722b1/html5/thumbnails/41.jpg)
CO2 Absorber Incompatibility
• Trichlorethylenedichloroacetylene
• neurotoxin
Phosgene• pulmonary irritant
• Sevoflurane• degrades in absorber