Breathing systems

Which breathing system adds the least resistance?Open
What are some sources of resistance (5)Connectors, HME, CO2 absorbers, ETT, Tubing
Where is the most resistance in the intubated patient?@ the connection between the ETT and "Y" piece



Where is the most resistance in the unintubated patient?@ expiratory valve in a semi closed system
2 types of Non-rebreathing systems-Open(insufflation)-Semi-Open(mapleson)
2 types of Circle systems-Semi-Closed (partial rebreathing)-Close (rebreathing)
How are circuits classified in terms of presence or absence of????? (5)-Fresh gas in flow rate-Gas reservior bag-Rebreathing exhaled gas-Chemical neutralization of CO2-Unidirectional valves
What are the characteristics of an open systemno reservoir bag,rebreathing, CO2 neutralization or valves. IT HAS NOTHING!
What is insufflation in an open system?Delivery of gas from the anesthesia machine via circuit or mask held above the pts face
What is open drop?also classified as open & semi-open used in wther or chloroform. (drop liquid on a cone)
What are the characteristics of a semi-open system?has a gas reservior bag, corregated tubing(except mapleson C) an APL (except mapleson E) and a common source of fresh gas.
What is Mapleson A used for?**Spontaneously Breathing patients**APL is open during expiration so you can't truely vent someone.No Rebreathing, so it is most efficent for CO2 elimination during spont. ventilation
Mapleson BLess efficent that mapleson A during spont vent secondary to mixture of gases & FGF required. ***Can be used with any mode of VENT.
Mapleson CLike B but shorter expiratory limb.Not efficent or economical****Can be used with any mode of vent
Mapleson DLike "A" except APL and FGF are REVERSED. -Efficent CO2 elimination regardless of mode of vent.
Bain CircuitIts a version of "D" can WARM FGF*Its disposable but the inner tube can kink
Mapleson EHas T-PIECE!Not commonly usedNo reservior Bag
Mapleson FModified T-PieceHAS a reservior Bag.
Jackson ReesUsed for PediatricsLow resistance minimal dead space.
What is the order of Circuits for Continously Vented PatientsDEAD BODIES CAN'T ARGUED>B>C>A
Order of Circuits for spontaneously vented patientsALL DOGS CAN BITEA>D>C>B
What is the most commonly used system today?Semi-closed circle system
How long are the Corregated tubing limbs?22mm
What is the volume of Gas in a reservior Bag?60L/min
What is are features of the closed systems?APL is closed, Maintains humidification,
Problem of Closed systemsunknown gas concentration and unpredicted O2 amounts.
What 2 types of noninvasive ventilation and give examplesNegative pressure (iron lung)Possitve pressure (Cpap, bipap, mask PSV)
4 phases of ventilatory cycle1.inspiration2.inspiration to expiration3.expiration4. expiration to inspiration
what is a volumed cycled vetilation aka Controlled Mechanical Vent (CMV)Varies with inspiration duration and pressure to give preset volume, TV and rate. ***Pt is entirely under vent control
What is Assit control Ventilation?(ACV)Preset tidal volumes and rate but allow pt to trigger breath and assures preset TV with each breath.**Has apneic function
What is intermitten Mandatory Vent (IMV)allows pt to breathe spontanous with own TV between controlled breaths. Intermittently delivers preset TV and rate
What is synchronized intermittent mandatory vent (SIMV)prevents vent from giving preset breath when the pt initates a breath. **Prevents fighting the vent.
How do you determine TV?Based on weight and pathophysiology of lung injury.
What is a normal Tidal Volume set on the machine?10-12 ml/kg
Tidal volume adjustment for compromised lungs set on the anesthesia machine?6-10 ml/kg
What is the typical respiratory range set on the anesthesia machine10-20 bpm
What is the formula for minute vent.Total ventilation/minTV X RR = Min. Volume
What is a normal min. ventilation range?5-10 L/min
What is Peep?Airway pressure at end expiration that remains above ambient pressure. It prevents aveolar collapse
What is the typical peep range?initially @ 5 and increase in SMALL increments to 15-20 cm H20
What Can Peep do to vitals?Decrease Cardiac output, decrease BP increase intrathoracic pressure, decrease venous return
What is pressure support ventilation(PSV)?Pt initates breath preset pressure auguments the tidal volume
What is pressure Control?the pt receives positive breaths that cease when a preset MAX pressure is reached. (TV will vary) **you may need to paralyze the pt.
What is Inverse ratio?I time is extended beyond max of 50% Respiration cycle. Used to increase oxygenation.
What is the purpose of controlled hypoventilation?-Prevents over inflation of aveoli-Used in ARDS
What is an absolute contraindication of contolled hypoventilation?Neuro patients: Causes increased ICP
What is the purpose of proning a pt?it improves VQ matching
Explain Airway pressure release ventilation(ARPV)Support vent during CPAP in a SPONTANEOUSLY breathing pt. Periodic release of CPAP to a low level of positive pressure
Explain High Frequency Jet ventilationUsed in the OR through a small cath. Rate 60-120 bpm small TV @ fast rate. It is part of difficult airway algorhythm .
What is High frequency oscillating jet vent?Used more in the ICU setting. Uses piston mechanism with rate 600-3000 bpm

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