Review
Patient related risk factors
Immediate NIV failure
Indications:
| |
A- Gas exchange:
| |
• | Acute or acute on chronic ventilator failure (best indication), PaCO2 > 45 mmHg |
• | Ph < 7.35 |
• | Hypoxemia (use with caution), PaO2/FIO2 ratio < 200 |
B- Bedside observations:
| |
• | Increased dyspnea- moderate to severe |
• | Tachypnoea (24 breaths per minute in obstructive, >30 per minute in restrictive) |
• | Signs of increased work of breathing, accessory muscle use, and abdominal paradox |
Absolute contraindications:
| |
• | Cardiac or respiratory arrest |
• | Unable to fit mask |
Relative contraindications:
| |
• | Non-respiratory organ failure (severe encephalopathy with GCS < 10, severe upper gastrointestinal bleeding, hemodynamic instability or unstable cardiac arrthythmia) |
• | Inability to cooperate/protect the airway |
• | Inability to clear respiratory secretions |
• | High risk of aspiration |
• | Recent facial surgery, trauma, or deformity |
• | Upper airway obstruction |
Time | Risk factors | Suggested interventions | References |
---|---|---|---|
Immediate
| 1. Weak cough reflex and/or excessive secretions | 1a. Manual or mechanic chest physiotherapeutic techniques; b. Early fiberoptic bronchoscopy. | |
2. Hypercapnic encephalopathy and coma | 2a. Set a back-up rate ~ 15 b/min and/or use PCV; b. Decrease the FİO2 level. | ||
3. Intolerance and psychomotor agitation | 3. Judicious sedation | ||
4. “Fighting with the machine”: Patient-ventilator asynchrony | 4a. Closely monitor ventilator waveforms; b. Judicious sedation; c. Use a ventilator with an NIV platform; d. Change ventilatory parameters; e. Minimize air-leaks. | ||
Early Hypoxemic ARF
| 1. Baseline ABG and inability to correct gas exchange (P/F < 150)* | ||
2. Baseline severity scores (SAPS II >35)* | |||
3. The presence of ARDS/pneumonia/sepsis/multiorgan failure (OR: 4-28)* | |||
4. Increased respiratory rate (>25 breaths/min)* | |||
5. Miscellaneous: Delay between admission and NIV use, Number of fiberoptic bronchoscopes performed, Duration of NIV use, Increase in radiographic infiltrates within the first 24 hours, Causal diagnosis (as ‘de novo’) | |||
Hypercapnic ARF
| 1. Baseline ABG and inability to correct gas exchange (pH < 7.25)* | ||
2. Increased severity of disease | |||
3. Increased respiratory rate (>35 breaths/min, OR for baseline and after 2 hours of NIV: 2.66 and 4.95)* | |||
4. Mixed indices: | |||
GCS, APACHE II score, respiratory rate and pH | [3] | ||
Respiratory rate, random glucose level and APACHE II | [66] | ||
Anemia and World Health Organization Performance Status (WHO-PS) | [67] | ||
5. Miscellaneous: Poor nutritional status, Increased heart rate, Higher baseline C-reactive protein/white blood cell count, Lower serum potassium, Airway colonization by non-fermenting gram-negative bacilli | |||
Late
| 1. Sleep disturbance | 1a. Improve quality of sleep; b. Avoid excessive noise and light in the unit | [70] |
2. Functional limitation | [2] | ||
3. Possible initial improvement in pH | 3a. Close and continuous monitoring of vital parameters; b. Repeat frequent ABGs during NIV, even when gas exchange reach a satisfactory value | ||
4. Hyperglycemia | |||
4. Check glucose levels | [2] |