Chapter 5 - Selecting Ventilator and Mode Flashcards
What are the percentages of patients connected to the ventilator?
ETT vs. Trach
ETT: 75%
Trach: 25%
What are 3 methods of Noninvasive Support?
- NPV
- CPAP
- NPPV
What is CPAP used for?
- Improve Oxygenation
- OSA
- Tx of COPD Exacerbation
Describe what Full Ventilatory Support is
Ventilator provides all the energy of ventilation
What are the Ventilator settings for Full Ventilatory Support?
- Normal Vt
- Normal RR
- Adequate alveolar ventilation
- AC/VC or AC/PC
Describe what Partial Ventilatory Support is
Ventilator provides some of the energy, but pt. must actively participate in WOB
What are the ventilator settings for Partial Vent Support?
- RR is 6 or less
- Vt is set for mandatory breaths, patient generated on spontaneous
- Pt needs to work to maintain normal or adequate alveolar ventilation
What is Partial Ventilatory Support not ideal for?
Pts with high WOB or muscle fatigue
What are modes determined by?
- Type of Breath
- Targeted Control variable
- Timing of Breath delivery
What are Mandatory Breaths?
Vent controls timing, Vt, or Both
What are Spontaneous breaths?
- Pt controls timing and Vt
- Affected by pt demand and lung characteristics
What are Assisted Breaths?
- Pt receives some support from vent
- When pressure on inspiration is higher than baseline (Pressure Support)
- Helps pt overcome some WOB
What occurs when Targeting Volume as the Control Variable?
- Guarantees Vt
- Maintains a minimum MV
- Volumes are unaffected by changes in lung characteristics and patient effort.
What are Hazards of Targeting Volume as the Control Variable?
Increased Peak Airway Pressures due to Increased Resistance and Decreased Compliance
What are Disadvantages of Targeting Volume as the Control Variable?
- Flow may be fixed on some ventilators
- Sensitivity may be set incorrectly
- Either of these can lead to Patient-vent. Dyssynchrony
What settings are allowed in Targeting Volume as the Control Variable?
-Vt, RR, I-Flow Rate, Flow Pattern
What are Advantages of Targeting Pressure as the Control Variable?
- Reduced risk of overdistention due to pressure control
- Descending flow pattern
- Pts I-Flow demands met with variable flow rates
- Reduction in WOB
What are Disadvantages of Targeting Pressure as the Control Variable?
-Variable Vt and MV
What occurs with Targeting Pressure as the Control Variable?
- Preset pressure target without guaranteed Vt
- Pressure is not affected by changes in lung characteristics
- Vol. WILL be affected by changes in lung characteristics
What occurs in CMV?
- All breaths are mandatory
- Ventilator(Controlled) or Patient(Assist/Control) triggered
- Set Rate ate Vt or Pressure
What is considered Controlled Ventilation?
- If pt does not trigger
- If pt is “locked out” from taking an extra breath
- If pt is medically prevented from assisting ventilation
What factors can trigger a breath with a fully sedated patient?
A Hiccup and Cardiac contraction
What occurs in Assist/Controlled Ventlation?
- Pt is triggering breaths over set rate
- Pt receives the preset vol or pressure when triggered
- Pt can become hyperventilated with excessive triggering
- May require increased lvls of sedation to reduce over triggering
What occurs in Volume-Targeted CMV?
- Set RR and Vt
- Not all work is done by vent unless settings are appropriate
- Pt can do up to 50% of WOB if flow rate is inadequate
- Flow must be set high so that pressure rise is immediate with the beginning of inspiration