breathing systems and the anaesthetic machine zsolt molnár szte, aiti
TRANSCRIPT
Breathing systems and the anaesthetic machine
Zsolt Molnár
SZTE, AITI
• Irish anaesthetist (1888-1986)– Endotracheal tube, anaesthesia (The Magill endotracheal tube, oral & nasal
designs)– An anaesthetic breathing system (Magill circuit and expiratory valve)– Intubating Forceps– Laryngoscope a straight bladed version– Catheter mount (endotracheal tube-to-circuit connector)– Endotracheal tube connectors, oral & nasal versions– Magill tracheal spray (glottis anaesthetic)– Single-lung anaesthesia– Endobronchial tubes and bronchial blockers– Bobbin flowmeters
Sir Ivan Whiteside Magill
• British anaesthetist
• Cardiff 1952– Mapleson WW. The elimination of rebreathing in various semi-closed
anaesthetic systems. Br J Anaesth 1954; 26: 323–32
– Mapleson WW, Mushin WW. Relaxant action in man: an experimental study. Anaesthesia 1955; 10: 265–78, 379–90
Mapleson WW. Br J Anaesth 2004; 93: 319-321.
WW Mapleson
• „Auld” definitions• Open-, semi open-• Semi-closed, closed-systems
• „New”: Mapleson systems 1954• Rebreathing• Non-rebreathing
Introduction
• VT• 4-7 ml/kg
• VD• 2-3 ml/kg
• Peak inspiratory flow (PIF)• At rest: 20-30 l/min
• Breathing cycle• Inspiration – expiration – expiratory pause
Physiolgy refreshment course
• Parts• FG inlet• Rezervoire balloon• Pop-off valve
• Efficacy• FGF – to prevent CO2 rebreathing
Mapleson systems
• Parts• Disc• Sharp edge • Spring
• Safety opening P• 60-70 cmH2O
Pressure relieving valve
• „Magill attachment”• >110 cm• FGF = 1 x VA (70ml/kg/m)• VA = ?• PIF = ?• Monitoring: capnograph
Mapleson A – spont. breathing
• A: normal
• B: rebreathing
• C: diaphragm movements
• D: cardiac oscillation
• E: sampling error
• F: bronchospasm
Molnár ‘99
A B
C D
E F
pCO2
Capnography
History
• Birth of: intensive therapy, blood gas machine, and the use of Mapleson C
• 1952 Coppenhagen: polio-epidemic
• 31 patients – 21 dead within 72 hrs
• Bjorn Ibsen (1915-2007)• Waters: To-and-fro
Lassen HCA. 1956. Management of poliomyelitis. In HCA Lassen Management of life threatening poliomyelitis. Copenhagen, 1952-1956; E.S. Livingstone Ltd, London
SZEGEDI INTENZÍVES TALÁLKOZÓ 2010
SZINT
Water’s circuit
Molnár ‘99
Mask, ET-tube
O2
Valve
Rezervoire baloon
• E: Ayre’s T-piece• Spont: FGF = 1.5 x VA
• IPPV: FGF = 3 x VA
• F: Jackson-Rees• Monitoring• PEEP
Mapleson E and F
T-piece
Molnár ‘99
T-piece
Inlet
Outlet
A happy chapy on T-piece
Molnár ‘99
The anaesthetic machine
• Cylinders (O2, N2O, Air)• Rotameters• Vaporizers• Breathing circuit• CO2 absorber• Safety:
• FiO2 + alarm• O2 bypass• Pressure relieving valve
Rebreathing system (circuit)
CO2 absorber
• CaOH2, NaOH, sylicate
• CO2 + 2NaOH Na2CO3 + H2O + heat• Na2CO3 + CaOH2 2NaOH + CaCO3
Rotameters
Rotameters
10
4
8
πpp
l
RI
• Gas specific• Safety features:
• Min FiO2 = 0.3• FiO2 alarm
Vaporisers ages ago…
• Inside the circuit• Small vaporizing surface• Quick cooling
…and today
• Outside the circiut• Well insulated containers
…and today
• Outside the circiut• Well insulated containers• Agent safe
…and today
• Outside the circiut• Well insulated containers• Agent safe• Heat compensation
• Mapleson systems: advantages• Simple, cheap, safe• Low resistance• Good for practice
• Mapleson systems: disadvantages• Non-economic• Not environment friendly• High heat and humid loss
Summary
Get to know your equipment!