Mechanical Ventilation Flashcards
(52 cards)
On the Hallowell ventilator, the Maximum Working Pressure should be set to ____ cmH2O unless otherwise instructed.
a. 5
b. 10
c. 20
d. 40
C
What are two inappropriate intraoperative “rescues” when patients become “light”?
a. Bolus propofol & treat for pain
b. Treat for pain & anxiety
c. Turn up the isoflurane & put the patient on a ventilator
d. Bolus propofol & put the patient on a ventilator
C
_____________________ is a significant indicator to provide mechanical ventilation. (select all that apply)
a. Hypertension under anesthesia
b. Use of neuromuscular blocking agents
c. Bradycardia under anesthesia
d. Hypercapnia under anesthesia
e. Intrathoracic surgery
f. Tachycardia under anesthesia
g. Hypoventilation under anesthesia
h. Inadequate staffing
B, D, E, G
You should _____________ the gas anesthetic vaporizer setting when mechanically ventilating a patient.
lower
mechanical ventilation will make the patient go deeper
Over-ventilation can __________ respiratory alkalosis.
cause
What three parameters on the ventilator can be set by the operator? (choose 3 answers)
a. Respiratory Rate (RR)
b. Tidal Volume (TV)
c. Maximum Working Pressure Limit
d. PaCO2
e. Waste Removal Rate (WRR)
A, B, C
MWPL acts as a backup so the lungs are not injured
When weaning a patient from a mechanical ventilator, reducing the respiratory rate to ______ breathes per minute may be necessary before the patient will begin to breathe on their own.
a. 1-2
b. 2-5
c. 4-8
A
PEEP valves _______________ the pressure within the breathing circuit.
a. increase
b. decrease
c. have no effect
A
Using the numbers supplied, please choose the correct numbers to fill in the blanks.
- Patient’s weight = 22 lbs
- Tidal Volume = 10 ml/kg
- MWP valve = 20 cmH2O
- Respiration rate = 15 breaths per minute
This patient’s Tidal Volume would be ______ mls and its Minute Volume would be ______ mls.
a. 150 and 1350
b. 330 and 4950
c. 300 and 4500
d. 220 and 3300
e. 100 and 1500
Vt = 10 ml/kg x 11 kg = 110 mL
MV = Vt x RR = 100 x 15 = 1500
E
Dead space is:
a. Part of the respiratory tract where no gas exchange takes place
b. The negative pressure gradient created between the alveoli and the atmosphere
c. When the patient stops spontaneous ventilation
d. Created by inadequate ventilation
A
During _________________ ventilation, a negative pressure gradient is created between the alveoli and atmosphere.
spontaneous
The Hallowell Ventilator’s Inspiratory to Expiratory Ratio (I:E) is preset to _______________ .
a. 1: 2
b. 2: 1
c. 2: 2
d. 1: 1
A
Mechanical ventilation _______________________. (select all that apply)
a. Can quickly make a patient too deep
b. Can make a patient very cold
c. Produces a lot of waste anesthesia
d. Provides good pain control to the patient
e. Can cause a pneumothorax
f. Is intended to relieve the anesthetist of the necessity of patient monitoring
g. Can cause oxygen toxicity
A, B, C, E (barotrauma), G
True or false: Capnography is a useful tool in monitoring a patient on mechanical ventilation.
TRUE —> measures ETCO2
True or false: Most patients become bradycardic while being mechanically ventilated.
FALSE
All anesthetic agents depress normal instinct to breath. Healthy patients under anesthesia receive assisted ventilation intermittently to help prevent ______.
atelectasis (lung collapse)
What are the 6 major indications for the use of mechanical ventilation?
- large patient size, obesity
- space-occupying CNS disease
- hypoventilation
- intrathoracic surgery (open chest)
- intraoperative use of neuromuscular agents where paralysis of the patient is required
- inability to maintain steady anesthesia despite administering pain, stress, or inflammation
Why are ventilators that are able to adjust the amount of oxygen the patient breathes helpful?
can lower oxygen to avoid oxygen toxicity in surgeries longer than 6 hours
- room air levels = 21%
At what PaCO2 levels is hypoventilation defined? What is the major cause of hypoventilation?
PaCO2 > 45 mmHg (hypercarbia)
low respiratory rate or low tidal volume —> anesthesia/sedatives, respiratory muscle fatigue, brain disease, lung disease
At what PaCO2 levels is hyperventilation defined? When does this occur?
PaCO2 < 35 mmHg (hypocarbia)
rapid breathing or deep breaths, decreased cellular metabolism (hypothermia)
What is FiO2?
fraction of inspired oxygen, % of oxygen inspired
- 21% at sea level
- 100% on anesthesia machines
What is the purpose of a PEEP valve?
(positive end expiratory pressure)
added to the exhalation limb of the anesthesia machine to maintain a certain pressure in the lungs at the end of exhalation, preventing the alveoli from collapsing —> increases the pressure within the breathing circuit
What is a normal PaO2? What are hypoxic levels?
PaO2 = 80-120 mmHg (generally 4-5x FiO2) —> those breathing 100% O2 should be 400-500 mmHg
PaO2 < 60 mmHg
What are 6 causes of hypoxia?
- low inspired concentrations of oxygen delivered to the patient
- hypoventilation
- diffusion impairment caused by lung disease severe enough to slow the passage of O2 from alveoli to the blood stream
- shunt causing perfusion imbalance - air enters alveoli, but there is no circulation
- V/Q mismatch - perfusion without ventilation or vice versa
- severe anemia, carbon monoxide poisoning, methemoglobinemia (acetaminophen poisoning)