Postoperative secondary aggravation of obstructive sleep apnea-hypopnea syndrome and hypoxemia with bilateral carotid body tumor: A case report

Figure 2 Manual pressure titration and pressure profile of the whole night manual pressure titration. A: Manual pressure titration before oxygen therapy: During the whole-night pressure titration, at 1:43 am, the patient had no respiratory events or snoring, but saturation of pulse oximetry (SpO₂) fluctuated between 85% and 88%; B: Manual pressure titration after oxygen therapy: Oxygen therapy at 1 L/min was given at 4:28 am. He reported no respiratory events or snoring during rapid eye movement sleep, and SpO₂ fluctuated between 89% and 92%; C: Pressure profile of the whole night manual pressure titration: The whole-night pressure titration was 90% expiratory positive airway pressure 7.5 cmH₂O and 90% inspiratory positive airway pressure 11 cmH₂O. Pressure titration achieved good effects. IPAP: Inspiratory positive airway pressure; EPAP: expiratory positive airway pressure.