CICM SAQ 2015.2 Q1

Rationale

NIV provides ventilatory support for patients with respiratory failure via a sealed face-mask, nasal mask, mouthpiece, full face visor or helmet without the need for intubation. Ventilatory support may be with CPAP or bi-level modes and delivered by a range of ventilators from specifically designed devices to full-service ICU ventilators.

NIV decreases resource utilisation compared with invasive ventilation and avoids the associated complications.

Patient selection and a well-designed clinical protocol are important to avoid delaying intubation in patients who are not suitable for and/or failing NIV.

Indications

• APO – alveolar recruitment, decreased afterload, decreased work of breathing
• COPD – decrease work of breathing and unload respiratory muscles Immunosuppressed
• Planned strategy post extubation in selected patients
• OSA / Obesity hypoventilation syndrome
• Asthma
• Patients with not for intubation/ treatment limitation orders who may qualify for HDU admission or admission to respiratory care units
• Post-operative patients – in selected patients
• Rib fractures
• Cystic fibrosis as bridge to transplantation

Evidence for its use:

• APO – studies show decreased intubation rate and faster time to resolution of respiratory failure and reduction in mortality and hospital length of stay
• COPD – RCTs and Cochrane review (14 RCTs) showed significant improvement in intubation rates, complications, length of hospital stay and mortality rates for NIV compared with invasive ventilation
• Immunocompromised – – 2 studies, one looking at solid organ transplant recipients and one looking at patients with haematological malignancy showed benefit with NIV, i.e. fewer intubations, complications and reduced ICU and hospital mortality
• Asthma – probably beneficial but limited evidence
• Rib fractures – fewer episodes of pneumonia but no mortality benefit and limited evidence

Evidence against its use:

• Use as rescue strategy for failed extubation – delays time to re-intubation. May be of benefit as part of weaning strategy and planned intervention post extubation especially in COPD patients
• ARDS – not recommended as first line therapy

Predictors of success

• Younger age
• Unimpaired conscious state
• Moderate rather than severe hypercarbia
• Rapid improvement in physiological parameters

Contra-indications

• Coma
• Cardiac / respiratory arrest
• Cardiac instability – shock, ventricular dysrhythmias, severe acute myocardial ischaemia GI bleeding
• Intractable vomiting
• Inability to protect airway – poor cough, excessive secretions, decreased conscious state Upper airway obstruction
• Following upper GI surgery (some debate about this)

Complications

• Facial and nasal trauma and pressure sores
• Gastric distension
• Dry mucous membranes
• Aspiration of gastric contents

Alternatives

• Invasive ventilation
• HFNP – may provide CPAP 5mm Hg

Summary statement / My Practice

Such as:

Role of NIV in critically ill includes APO and respiratory failure in COPD and immunosuppressed patients. In my practice I use NIV as a planned strategy post-extubation in selected patients and as ventilatory support for patients with respiratory failure and treatment directives limiting care. I do allow its use to delay or withhold intubation in those who need this.