Ventilator Modes

Introduction to BiPAP Therapy

BiPAP therapy is indicated for patients with COPD exacerbation and persistent respiratory acidosis (pH <7.35) despite maximum medical treatment on controlled oxygen therapy, as recommended by the British Thoracic Society 1
BiPAP therapy is also indicated for patients with chest wall deformity or neuromuscular disease causing acute or acute-on-chronic hypercapnic respiratory failure, according to the British Thoracic Society 1

Initial BiPAP settings should include IPAP of 8-12 cmH2O, EPAP of 3-5 cmH2O, and a backup rate set slightly below the patient's spontaneous rate, as suggested by the American Academy of Sleep Medicine 2
The American Academy of Sleep Medicine recommends setting the backup rate 2-4 breaths below the patient's spontaneous respiratory rate to prevent excessive ventilation 3
Inspiratory time (IPAP time) should be set to 30-40% of the respiratory cycle, with a goal of shorter inspiratory times (closer to 30%) for respiratory alkalosis, as recommended by the American Academy of Sleep Medicine 3
Rise time (pressure transition from EPAP to IPAP) should be adjusted for patients with obstructive or restrictive disease, with shorter rise times (100-400 ms) often preferred by patients with obstructive disease and longer rise times (300-600 ms) often preferred by patients with restrictive disease, as recommended by the American Academy of Sleep Medicine 3

Continuous oxygen saturation monitoring is essential, with a target oxygen saturation of 88-92%, and repeat blood gas measurements within 1-2 hours of initiation, and adjust IPAP to improve ventilation and reduce PaCO2, as recommended by 4
Low PCO2 levels may be predictive of BiPAP failure in some conditions, according to the American College of Emergency Physicians, and close monitoring is essential in these patients, including blood gas analysis, oxygen saturation, and respiratory rate, to adjust settings and prevent complications, as recommended by the American College of Chest Physicians 5, 2, 6
Potential complications of BiPAP include CO2 rebreathing and mask leaks, which can be minimized by using proper equipment and ensuring proper functioning of exhalation ports, as noted by the American Academy of Sleep Medicine 1, 6

Contraindications to BiPAP include hemodynamic instability, severe bleeding, pneumothorax, severely depressed mental status, copious secretions, and facial trauma/anatomical abnormalities preventing mask seal, as recommended by the American Thoracic Society and other guideline societies 7, 8, 6
Hemodynamically stable patients with preserved swallowing function may tolerate oral intake, and patients using BiPAP only during sleep may eat during the day when not on the device, but prolonged NPO status can lead to poor nutritional outcomes, longer hospital stays, and decline in swallowing function, emphasizing the need for a balanced risk vs. benefit assessment, as recommended by 8

NIV can be discontinued when there has been normalization of blood gas results and general improvement in the patient's condition, with a tapering of NIV use over 2-3 days before discontinuing overnight use, as recommended by 4
Inadequate pressure settings can lead to NIV failure, ensure IPAP is progressively increased to reach 20-30 cmH2O within 10-30 minutes in severe cases, as recommended by the British Thoracic Society 4

BiPAP has been shown to reduce intubation rates, ICU length of stay, and hospital days when used appropriately for respiratory failure, as supported by the European Respiratory Society and other guideline societies 7