Contraindications and adverse events relating to NIV therapy
| Absolute contraindications | Relative contraindications | Major adverse event | Transient physiological event |
| Cardiac or respiratory arrest | Mildly decreased level of consciousness | Anastomotic leak | Hypotension, defined as a decrease in blood pressure >20 mm Hg determined by pre/post blood pressure observations |
| Severe agitation or encephalopathy | Progressive severe respiratory failure as reported by the treating physician | Severe hypotension requiring increase in medical management | Decrease in SpO2 oxygen saturations >10% from baseline or<85% for >60 s |
| Undrained pneumothorax or intraoperative pneumothorax with ICC in situ | Uncooperative patient who can be calmed or comforted | Cardiac or respiratory arrest | Gastric distention as clinically reported by the treating surgeon |
| Uncontrolled vomiting | SpO2 falls below >10% below resting level of <85% for >60 s | Deterioration in medical condition requiring an increase in medical management | Vomiting during the NIV therapy |
| Inability to protect airway | MAP<target pressure despite vasopressor | Nasal bridge or facial erythema or ulceration | |
| Severe upper GI bleeding or haemoptysis | Resting HR <50 or >140 or new untreated arrhythmia develops | ||
| Need for immediate intubation | RR <5 or >40 b/min | ||
| Facial trauma |
HR, heart rate; ICC, intercostal catheter; MAP, mean arterial pressure; NIV, non-invasive ventilation; RR, respiratory rate; SpO2, saturation of peripheral oxygen; upper GI, upper gastrointestinal.