Test 1 Ch. 4 Establishing the Need for Mechanical Ventilation Flashcards
Objectives of MV: Physiological (box 4.1)
- Support or manipulate pulmonary gas exchange
- Alveolar ventilation (PaCO2)
- Alveolar oxygenation (PAO2) - Increase lung volumes
- Prevent or treat atelectasis
- Restore and maintain adequate FRC - Reduce the WOB
Objectives of MV: Clinical (box 4.1) (reverse)
- Reverse ARF
- Reverse Respiratory distress
- Reverse hypoxemia
- Prevent or reverse atelectasis and maintain FRC
- Reverse respiratory muscle fatigue
Thoughtful clinical judgment is essential, as is attention to the goals of therapy for a mechanical ventilated pt. What are the 5 goals?
- Support of pulmonary system so it can maintain an adequate level of alveolar ventilation
- Reduce the WOB
- Restore arterial and systemic acid-base balances to the levels that are normal for the pt
- Increase oxygen delivery to and oxygenation of the body organs and tissue
- Prevent complications associated w/ MV
What is the standard criteria for instituting MV? (Box 4.5)
- Apnea or absence of breathing
- Acute vent failure
- Impending vent failure
- Refractory hypoxemia respiratory failure w/ increased WOB or an ineffective breathing pattern
The normal spontaneous (not on a vent) Vt for a healthy adult is about….. w/ a spontaneous RR… (range)
5 to 7 mL/kg;
12 to 18 breaths/ min
When determining Vt for ventilated pts, the range for adults is….
And children and infants is….
6 to 8 mL/kg of IBW;
4 to 8 mL/kg
What is the goal for selecting a specific FIo2
to achieve a clinically acceptable PaO2 tension (60 to 100 mm Hg)
Should a baseline ABG be performed?
Yes
If the pt’s PaO2 is within the desired range before beginning vent support then the Fio2
the pt’s was receiving at the time of the baseline ABG is accetable
If a baseline ABG is not available, select….
initial Fio2 of 1.0 (100%), and then reduce ASAP
When reducing FIO2, a Spo2 (sats) >
92% (PaO2 greater than or equal to 60) is acceptable
What is the initial settings for PEEP (range)
3 to 5 cm H2O
PEEP can be increased in
increments of 3 to 5
What are the two levels of PEEP employed called?
- minimum or low PEEP (physiological PEEP)
- Therapeutic PEEP
The intial Pressure support ventilation (PSV) level is equal to the
transairway pressure
PIP-Pplat
(peak inspiratory pressure- plateau pressure)
What is the initial settings for peak flow
about 60 L/min (range 40 -80 L/min)
What is the intial I-time?
about 1 second (range 0.8 to 1.2 seconds)
A second method to initiate pressure ventilation is to start at a
low pressure (10 to 15 cm H2O) and check the Vt before readjusting the pressure to attain the desired volume
The goals of adjusting PSV is threefold:
- To help increase Vt (4 to 8mL/kg)
- To decrease RR (to fewer than 30 breaths/min)
- To decrease the WOB associated w/ breathing through an artificial airway
What is the criteria for Acute Respiratory Failure (ARF) for MV
pH, PaCO2, PaO2
- PaO2 below the predicted normal range
- PaCO2 greater than 50 and rising
- A failing pH of 7.25 and lower
What is the IBW equation for Males and Females
M: 106+6(H-60)/2
F: 105+5(H-60)/2
Then x by 6 and 8 (initial)
OR
4 and 6 ( ARDS)
What happens if you increase the sensitivity dial?
It will make the machine less sensitive to the pt inspiratory trigger
What happens if the pt effort dial is set to low?
More sensitive and May cause auto-triggering
______________ is a measurement of the frictional forces that must be overcome during breathing.
Resistance
