Lecture 3 - Ventilatory Support II

Question 1

Describe CMV

Answer 1

Controlled Mandatory ventilation

• set RR, VT
• patient effort is ignored
• patient is sedated
• airway pressure alwasy +

Question 2

Describe SIMV

Answer 2

Synchronized Intermittent Mandatory Ventilation
- set number of size and vent breaths per min
- trigger by patient effort
no risk of stacking

Question 3

Describe ACV

Answer 3

Assist Control Ventilation

• set RR, set VT
• any patient effort triggers ventilator breath
• recognizes when patient wants to take breath on their own
• risk of hyperventilation

Question 4

Describe IMV

Answer 4

intermittent Mandatory Ventilation

• set number and size of vent breaths per min
• unlimited number of patient breaths in between, of any vol
• risk of stacking

Question 5

Pressure Support Ventilation

Answer 5

• rate set by patient
• volume augmented by ventilator
• promotes use of resp muscles
• gives flow until preset pressure limit

Question 6

Bi-Level Ventilatory Support (BiPAP)

Answer 6

• intubated patients

- PS = IPAP - EPAP

Question 7

Intermittent positive pressure breathing (IPPB)

Answer 7

• non-intubated patient
• rate set by patient
• volume set by ventilator
• used by physio to increase VT

Question 8

Describe Physio techniques for Hypercapnic patients

Answer 8

• reduce load on resp muscles
• decrease obstruction to airflow
• increase pulmonary compliance
• reduce unnecessary activity
• improve diaphragm length/tension relationship

Question 9

If you have a PaO2 <60 mmHG and Co2 is normal or low what do you have?

Answer 9

Type 1 Respiratory Failure

Question 10

If you have a PaCo2 >45 mmHG and PaO2 lower than normal what do you have?

Answer 10

Type 2 respiratory failure

Question 11

What is the management rationale for use of ventilatory support of patients with hypercapnic RF?

Answer 11

1. Hypercapnic RF d/t high CO2 - this is d/t PUMP and/or LOAD failure
2. Ventilation replaces the PUMP

Question 12

Iron lung - example of negative or positive pressure?

Answer 12

Negative pressure
- used during polio epidemic; pt put in chamber and negative pressure around the chest to suck air in; suction is released and pt passively breathes out

Question 13

Hand bagging - example of negative or positive pressure?

Answer 13

Positive pressure

- use during polio epidemic; bag is squeezed to push air in via tracheostomy