What may occur if IPAP settings exceed 20 cm H2O in BiPAP?

Exceeding an IPAP (Inspiratory Positive Airway Pressure) setting of 20 cm H2O in BiPAP can lead to gastric distension. This occurs because higher pressure settings can cause air to be forced into the stomach during inhalation, especially if the patient's mouth is open or there is an improper fit of the mask. As the air enters the stomach, it can lead to increased intra-abdominal pressure and discomfort for the patient, which can impede diaphragmatic movement and proper lung inflation.

In contrast, improved oxygenation typically results from optimal pressure settings but may be countered by excessive pressures that lead to complications such as gastric distension. Increased heart rate may occur as a response to discomfort or stress rather than as a direct consequence of high IPAP settings. Decreased respiratory rate is unlikely, as higher pressures can stimulate increased ventilation rather than suppress it.