Non-Invasive Ventilation

Question 1

Define Non-Invasive Ventilation

Answer 1

Any assisted ventilation that does not use an artificial airway

Question 2

How does Non-Invasive Positive Pressure Ventilation (NIPPV) work?

Answer 2

• Positive pressure at the end of each breath splints the airways and alveoli open thereby:
  > ^ SA for GE (by preventing alveoli from collapsing at the end of each breath)
  > Improves V/Q matching (by improving ventilation)
  > ^ lung compliance (less pressure is needed to get the same amount of air into lung bc alveoli are already partially inflated and dont need high pressures to open them)
  > Reduces trauma to aveoli
  > ^ FRC (as more air is in lungs at end of each breath - increases Oxygenation)

Question 3

What are the goals of NIPPV?

Answer 3

• Alleviate respiratory distress by
  1) improving GE
  2) reducing WOB
  3) augmenting alveolar ventilation
• Achieve patient-to-ventilator synchrony
• Reverse atelectasis
• Minimise risks and avoid complications associated with ET intubation

Question 4

What are the indications for NIPPV

Answer 4

• Type 1 respiratory failure

- Type 2 respiratory failure

Question 5

What is the difference between type 1 and type 2 respiratory failure?

Answer 5

• Type 1: hypoxic
  > Failure of pulmonary system (tissue)
  PaO2 decreased + PaCo2: normal/decreased
• Type 2: hypercapnic
  > Failure of ventilation
  PaO2 decreased + PaCO2 elevated

Question 6

List some contraindications for NIPPV

Answer 6

• Lack of respiratory drive
• Airway compromise
• Hypotension
• Pneumothorax
• Decreased LOC
• Uncontrolled cardiac arrhythmias
• Poor tolerance of face mask

Question 7

List some complications of NIPPV

Answer 7

• Pneumothorax
• Hypotension
• SAH
• Gastric distension/aspiration
• Pressure areas

Question 8

What is pressure support?

Answer 8

Use of pressure to augment ventilation

Question 9

What types of NIPPV are used?

Answer 9

• CPAP (continuous positive airway pressure)

- BPAP (bi-level positive airway pressure)

Question 10

What is CPAP

Answer 10

Continuous positive airway pressure

- +ve pressure is applied throughout entire breath cycle to keep alveoli open

Question 11

What is BPAP

Answer 11

Bi-level positive airway pressure

• on expiration: baseline pressure (EPAP) delivered
• on inspiration: a higher level of pressure (IPAP) delivered
• Difference (pressure support) splints airways open and allows more volume to be expired and CO2 to be exhaled

EPAP = CPAP = PEEP

Question 12

Compare and contrast BPAP and CPAP

Answer 12

See pp. 6

CPAP

• ^ SA for GE
• ^ FRC (volume of air left in lungs after expiration)
• ^ oxygenation –> Used for hypoxic respiratory failure

BPAP

• ^ SA for GE
• Pressure support ^ tidal volume
• ^ ventilation/oxygenation –> Used for hypercapnic respiratory failure / mixed respiratory failure

Question 13

How do you fit a NIPPV mask

Answer 13

• Bridge of nose to cleft of chin
• Fit from chin upwards
• Adjust headstraps simultaneously
• Educate patient on how to remove mask in emergency
• Patient must not be left alone if unable to remove mask themselves

Question 14

Monitoring and Nursing Considerations for NIPPV

Answer 14

• Nurse 1:1 until stable then can be nursed 1:2 in resus
• Continuous cardiac monitoring + Spo2 + NIBP
• Regular blood gasses to assess pCo2 and PO2
• Regular mouth + facial pressure area care
• Humidification if on for longer than 4 hours
• Assess for abdominal distension and give patient regular breaks