Anesthesia Delivery Systems Flashcards

Question

Mapleson system types

Answer 1

A, B, C, D, E (T piece) F (Jackson Rees) **difference in each type: 1. location of the pop- off valve 2. position of FGF input 3. presence of reservoir bag ^in relation to pt connection Spontaneous breathing pt: A>D>C>B all dogs can bit A is best for spont breathing bc of location of pop off valve right neat facemark and with spont breathing you have an end expiratory pause, so everything you inhale is fresh gas bc excess. goes out through pop off Controlled ventilation D>B>C>A dog bites can ache

Answer 2

1. Pedi 2. transport of pt 3. procedural sedation 4. weaning tracheal intubation 5. Pre-02 during out of OR airway management (ex: in radiation with pt but can't be in room with them)

Answer 3

loss of return to baseline on etC02 wave = rebreathing increase FGF to eliminate rebreathing **best measure of optimal FGF to prevent rebreathing

Answer 4

1. simple design 2. ability. to rapid change depth of anesthesia 3. Portability 4. 🚫 rebreathing of exhaled gas with adequate FGF

Answer 5

1. 🚫 conservation of heat/ moisture 2. limited ability to scavenge waste gases 3. Not efficient require high FGF (to prevent rebreathing of exhaled gas)

Answer 6

Mapleson A: pop-off near facemark, FGF located at opposite end (opposite of D) *best for. spont breathing Mapleson D,E,F: FGF near facemark, pop-off located at opposite end (opposite of A) *best for controlled vent Mapleson B & C: pop-off and FGF located near facemark *least efficient (wasteful, EVERYTHING leaves through pop-off on expiration

Answer 7

D>B>C>A Dog bites can ache (D, E, F are the same)

Answer 8

A>D>C>B All dogs can bite ranked in order by efficieny

Answer 9

1. FGF rate 2. Minute Vent of pt 3. Mode of ventilation (spontaneous vs controlled) 4. C02 production of pt (increased with fever, catabolism) 5. respiratory waveform characteristics (inspiratory flow, I:E ratio, expiratory pause) * adjusting vent pattern; - slow iTime and low inspiratory flow allows FGF to constitute a larger portion of the inspired gas -long expiratory pause or slow rate more completely rids exhaled gases and reduces rebreathing

Answer 10

"Magill" - most efficient for Spontaneous ventilation - least effective for CV requires up to 20L/min of FGF - impractical design for OR - proximal location of pop-off valve makes scavenging difficult - hard to adjust during head/ neck surgery - heavy valve can dislodge small ETT * NO rebreathing with SV when FGF is at least 1x MV * Requires large FGF to eliminate rebreathing during CV

Answer 11

* Rarely used - Requires high FGF to prevent rebreathing - inefficient/ impractical for SV or CV -corrugated tubing connecting rest of system to reservoir bag (blind limb where fresh gas, dead space and alveolar gas mix) *close proximity of APL valve and FGF provides potential for mixing of inspiratory and expiratory gases

Answer 12

'Water's circuit without absorber' - used in resuscitation situations and pt transfer - same as B, rarely used, requires high FGF to prevent rebreathing * close proximity of APL valve and FGF provides potential for mixing of inspiratory and expiratory gases

Answer 13

'Brain' system; inner tubing that delivers the FGF directly to pt, and exhales down outer corrugated tubing to reservoir bag and APL valve (inner tubing not visible make sure to perform test to check for disconnect) * Most efficient for Controlled Ventilation and second best for Spont. ventilation - FGF close to facemark and pop-off valve located on opposite end (reverse of mapleson A) *Controlled vent FGF = 1-2 x MV *Spont. vent FGF = 2-3 x MV

Answer 14

1. occlude the inner tube at the pt end using finger or end of 2ml syringe, if connected back pressure is created on the FGF and flowmeter bobbins dip 2. Rapid flushing of FGF through an intact system causes reservoir bag to collapse (Venturi effect) * if disconnect present reservoir bag will inflate with rapid flush because it will cause an increased pressure in the expiratory limb

Answer 15

- more efficient system - factors affecting rebreathing (Minute Vent & Flow rate) are controlled by anesthetist allows for a lower FGF = more efficient FGF 70mL/kg/ min = 𝑉˙𝐴V˙A *higher FGF >100 ml/kg/min PaC02 dependent on MV *lower FGF <90 ml/kg/min PaC02 independent of MV * increasing RR to eliminate PaC02 decreases the expiratory pause and increases rebreathing which increases inspired C02 (FiC02) and no change to PaC02 * adjustments to vent that reduce rebreathing 1. slower iTime or lower inspiratory flow = larger proportion of FGF in inspired gas 2. long expiratory pause or slow RR = more wash out of exhaled gases

Answer 16

- modification of Mapleson D - FGF enters circuit near reservoir bag BUT fresh gas delivered at pt end of circuit - FGF tubing within large bore corrugated tubing * *this allows exhaled gas to warm inspired gas (preserves heat and humidity with no added weight to circuit) Risk for inner tube leaks, kinks, disconnections

Answer 17

T-piece - open ended corrugated tubing acts as inspiratory reservoir, length of tubing must exceed pt tidal volume - NO reservoir bag - expiratory tubing acts as reservoir - NO POP-OFF valve - on expiration tubing fills with dead space and alveolar gas which is then flushed out by FGF - commonly used to administer 02 in ICU and PACU settings ** SV: FGF = 2-3 x MV

Answer 18

Jackson-Rees *most used* (modification of mapleson E 'T- piece') -unofficial 6th mapleson - commonly used for controlled ventilation during transport of intubated pt - adjustable pop-off valve at the end of reservoir bag - flow inflating - allows application of continuous positive airway pressure or hand ventilation - provides visual indictor of respiration with reservoir bag - degree of rebreathing depends on ventilation (spontaneous versus controlled) and adjustment of the pressure-limiting overflow valve (venting). * FGF = 2-3 x MV to prevent rebreathing of exhaled gases

Answer 19

- minimal circuit dead space - minimal resistance - can be used for SV and CV - inexpensive - used with facemark or ETT - lightweight - easily repositioned - scavenging systems can be added to reduce pollution of anesthetic gas into atmosphere

Answer 20

- high FGF to prevent rebreathing. - risk of occlusion of popoff valve creating high airway pressures increasing risk of barotrauma to pt - lack of humidification (offset it by allowing. FGF to pass through in-line heated humidifier)

Answer 21

'manual resuscitator' *critical piece of equipment and part of morning check* - non rebreathing valve - self inflating bag - can deliver high Fi02 w/ 02 reservoir attached - reservoir self fills w/ intake valve - elimination of C02 depends on MV

Answer 22

*biggest risk is barotrauma* -ambu adult Mark IV; uses elasticity of outer cover go bag to limit the pressure developed 7kPa = 70 cmH20) - pedi versions uses pressure limited valve (4kPa = 40cm H20) - Laerdal range also used pressure limiting features

Answer 23

- located at opposite end of bag from gas inlet - have PEEP valve JOB - ensures gas flows out of bag and ONLY into pt port on inhalation - exhaled gas escapes through expiratory port without mixing with fresh gas stored in bag on exhalation

Answer 24

1. one- way flap valve 2. small bore nipple 3. wide bore inlet 4. reservoir system

Answer 25

* final concentration of 02 delivered is dependent on added 02 and how diluted it is from room air in the self inflating bag - store the oxygen brought into system from nipple - must have overflow valve to prevent overfilling of 02 - must have entrainment valve to allow access to room air for when 02 not available or need lower concentration of 02 * when minute vent (TV x RR) is greater than volume given bag will expand and supply all the gas for ventilation (100% 02)

Answer 26

- allows admixture of 02 | * mounted on gas inlet

Answer 27

-supplies bulk of gas entering bag (usually air)

Answer 28

-fitted to inlet of self inflating bag -bag squeezed, increased pressure inside bag, valve closes (prevents gas going to back through inlet) -bag released, bc its self inflating fresh gas from gas inlet it drawn in (can be air or 02 or mixture of both)

Answer 29

* almost all anesthesia machines use some form a circle system * C02 absorption during low flow (semi closed & closed system dependent on APL valve) * C02 elimination via pop off valve during with FGF during high flow anesthesia (semi open system aka NO rebreathing) - minimizes environmental pollution - lower FGF than mapleson - conserves heat/ humidity and anesthetic agent (rebreathing other exhaled agents) - circular flow (unidirectional)

Answer 30

1. accept FGF (with semi-open circle system) 2. eliminate C02 3. give pt enough volume of gas from reservoir to meet inspiratory flow and volume needs 4. both can be semi open systems 5. both low resistance (mapleson a little lower)

Answer 31

circle system =unidirectional flow mapleson = bidirectional flow circle system uses C02 absorber mapleson uses FGF to rid C02 circle system can be be semi- closed or closed system circle system bulkier and more complex design

Answer 32

1. FGF source 2. unidirectional valves 3. inspiratory and expiratory limbs (with corrugated tubing) 4. Y- piece 5. APL valve/ Pop-off/ Over-flow 6. Reservoir bag 7. C02 absorber

Answer 33

-large bore 22mm, non rigid, 1 meter long corrugated tubing (resistance to gas flow very small < 1cm H20/ L/ min of flow) - internal volume 400-500 mL/m of length - clear plastic (used to be rubber) - 22 mm female fitting w/ machine - patient end -- T-piece 22 mm male and 15 mm female coaxial fitting

Answer 34

- flexible - low resistance - lightweight connection - reservoir

Answer 35

from y- connector to terminal bronchioles

Answer 36

No rebreathing with very high FGF (10-15L/ min) to eliminate C02 and rebreathing *C02 absorber not doing much, will last longer - no conservation of waste gases - no conservation of heat and moisture - APL valve open all the way or vent in use

Answer 37

**most commonly used breathing system - PARTIAL rebreathing of agents and exhaled gases (not C02 bc of absorber) - relatively low flow rate (1-3L/ min) - FGF less than minute vent - conserves some heat and gases - APL valve PARTIALLY closed, adjust as needed, or vent in use

Answer 38

- used for LONG surgical cases - third world countries (conserves gas) -inflow gas EXACTLY matches metabolic demands 02 consumption of pt using very low flow rates - complete rebreathing of all exhaled gases after C02 absorption - APL valve closed - change in gas concentration is VERY SLOW (increase volatile again and FGF)

Answer 39

1. stable concentration of inspired gas 2. conservation of heat and moisture 3. saves money on anesthetics and gases 4. low resistajnce (mapleson lower) 5. fairly low FGF with no rebreathing of C02 6. can be used for closed- system anesthesia 7. can scavenge waste gases preventing OR pollution

Answer 40

1. complex design 2. ATLEAST 10 connections (risk of leaks, obstruction, disconnect) **1/3 malpractice claims are r/t disconnects or misconnects of circuit 3. Risk of malfunctioning valve stuck open = hypercarbia stuck closed = airway obstruction 4. increased resistance to breathing ( > than mapleson) 5. Bulkier; less portable/ convenient than mapleson 6. increased dead space; which ends at end of y-piece where insp and expiratory separate

Answer 41

- set all gas flows to zero - occlude y- piece - close APL valve - pressurize circuit to 30 cm H20 by using 02 flush valve - ensure pressure hold for 10 seconds and activates sustained pressure alarm - open APL valve and ensure pressure decreases * does NOT assess unidirectional valves separate test)

Answer 42

- assess integrity of unidirectional valves - attach breathing bag to y-piece - turn vent on - assess integrity of valves

Answer 43

1. misconnections and disconnections 2. leaks 3. valve failure 4. C02 absorber defect 5. bacterial filter occlusion