Ventilatory Support For Patients With Hypercapnic Respiratory Failure

Question 1

CV

Answer 1

Controlled ventilation

RR set
VT set
Spontaneous breaths ignored haha
Limited RM use

Question 2

ACV

Answer 2

Assist control ventilation

RR set
VT set
Patient effort also triggers breath
Risk of hyperventilation

Question 3

IMV

Answer 3

Intermittent mandatory ventilation

Set n per minute
Set VT
Spontaneous breaths allowed
Risk of breath stacking
More use RM

Question 4

SIMV

Answer 4

Synchronized intermittent mandatory ventilation

Set n
VT set
Patient can spontaneously breathe
Breaths synchronized with patient effort

Question 5

PSV

Answer 5

Pressure support ventilation

RR set by patient
Volume augmented by ventilator
Continuous respiratory effort needed
MV and NIV

Question 6

Bilevel ventilation

Answer 6

HighPEEP and lowPEEP

allows spontaneous breath
If no effort, simulates SIMV
Set times for I:E ratio
Helpful for low lung compliance and ARDS

Question 7

IPPB

Answer 7

Intermittent positive pressure breathing

NIV
Increases VT
RR set by patient

Question 8

Explain the difference between volume, pressure and time-cycled ventilators

Answer 8

Volume - set volume given, increased risk of barotrauma if VC changes, end exploratory pressure is variable
Pressure - prevents barotrauma, volume is variable
Time - set flow rate for set time

Question 9

Discuss the Mx rationale for invasive ventilatory support for patients with hypercapnic respiratory failure

Answer 9

Hypercapnic RF PaCO2 >50mmHg

Invasive ventilation used to increase VE by RR or VT

Question 10

List and describe the rationale for physio interventions to improve PaCO2 levels in intubated and non-intubated patients with hypercapnic RF

Answer 10

Reduce load - decrease Raw, increase pulmonary compliance, reduce unnecessary activity eg support
Improve diaphragm length tension relationship - semi sitting for obese patients