Question | Answer |
---|---|
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 system | no 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 B | Less efficent that mapleson A during spont vent secondary to mixture of gases & FGF required. ***Can be used with any mode of VENT. |
Mapleson C | Like B but shorter expiratory limb.Not efficent or economical****Can be used with any mode of vent |
Mapleson D | Like "A" except APL and FGF are REVERSED. -Efficent CO2 elimination regardless of mode of vent. |
Bain Circuit | Its a version of "D" can WARM FGF*Its disposable but the inner tube can kink |
Mapleson E | Has T-PIECE!Not commonly usedNo reservior Bag |
Mapleson F | Modified T-PieceHAS a reservior Bag. |
Jackson Rees | Used for PediatricsLow resistance minimal dead space. |
What is the order of Circuits for Continously Vented Patients | DEAD BODIES CAN'T ARGUED>B>C>A |
Order of Circuits for spontaneously vented patients | ALL 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 systems | unknown gas concentration and unpredicted O2 amounts. |
What 2 types of noninvasive ventilation and give examples | Negative pressure (iron lung)Possitve pressure (Cpap, bipap, mask PSV) |
4 phases of ventilatory cycle | 1.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 machine | 10-20 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 ventilation | Used 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 |