Non-Invasive Ventilation (NIV)

Last updated 25/12/15

Definition

• A form of mechanical ventilation which administers positive pressure to a patients airway during spontaneous respiration whilst conscious

NIV Face Mask

Features

• Provides ventilatory assistance without an invasive airway (LMA, ETT or a surgical airway)
• Airway support which may prevent the need for intubation
• Requires a co-operative and compliant patient
• Requires special attention for patients who are hypoxic and aggitated
• Requires a sealed mask
• Patient should be
• Haemodynamically stable
• Protecting their own airway
• Catious use of IPAP >20cmH20
• May force open lower oesophageal sphincter and air into stomach leading to vomiting and possible aspiration
• Pressure-cycled or volume-cycled modes
  • Volume-cycled mode not commonly used: set volume applied
  • Generally poory tolerated by patients
• Can be delivered by face masks or nasal masks
• Nasal masks reuire mouth to be kept close to maintain pressures

Types

• Pressure Cycled Modes: most common
• Delivers set pressue on inspiration and expiration
• Continuous Positive Airway Pressure (CPAP): fixed positive pressure
• Bilevel Positive Airway Pressure (BPAP): variable positive pressure between inspiration and expiration

Indications

• Respiratory failure or imminent danger of
• An attempt to avoid intubation
• Respiratory muscle fatigue due to work of breathing
• Significant hypoxaemia
• Alveolar hypoventilation
• Chronic Obstructive Pulmonary Disease (COPD)
• Asthma
• Acute Pulmonary Oedema (APO)
• Obstructive Sleep Apnoea (OSA)
• Atelectasis

Equipment

• Ventilator
• Phillips V60
• OxyLog 3000
• Hamilton T1
• Patient tubing and filter
• Face mask & straps
• Gas sampling line
• +/- Humidifier
• +/- Ketamine

Procedure

• Consider resuscitation status and degree of intervention escalation
• If NIV is not effective typical next step is for intubation and mechanical ventilation
• Should be haemodynamically stable prior to commencing
• Baseline investigations
• ABG or VBG
• +/- Arterial line for serial ABGs
• CXR
• Setup ventilator
• Position patient semi-recumbent
• Face mask
• In adults encourage self application of mask prior to attaching straps
• Ensure good seal to reduce leak
• Shave heavy beards
• Vasoline/gel to chin
• In neonates/young children consider using a cut off or short nasal ETT with sedation
• Measure length from nares to tragus
• Cut proximal end
• Consider Ketamine sedation to improve tolerance
• Monitoring
• ECG
• Respiratory rate
• Pulse oximetry
• BP for hypotension
• 5 minutely observations for 15 minutes then hourly
• 1:1 nursing initially then 1:2 when stable

Complications

• Non-compliance
• Encourage patient to relax and not work against NIV
• Consider Ketamine
• Claustrophobia
• Pressure sores
• Gas trapping
• Carbon dioxide retention
• Pulmonary aspiration
• Vomiting from high IPAP forcing open lower oesophageal sphincter
• Deterioration requiring intubation and ventilation
• Pneumothorax

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References

1. Khilnani G, Banga A. Noninvasive ventilation in patients with chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis. 2008;3(3):351-357.