2020 FSA Posters

P077: ADAPTIVE SERVO-VENTILATION USE DURING PROCEDURAL SEDATION FOR ENDOSCOPY ON A MORBIDLY OBESE PATIENT
Timothy Maier, DO; Zulfiqar Fazal, MD; Jeffrey Huang, MD, FASA; HCA Healthcare Oak Hill Hospital

Obesity prevalence has been steadily increasing worldwide. Numerous medical comorbidities are associated with obesity including hypertension, diabetes, stroke, heart failure, and sleep apnea (1, 2, 3).

Obstructive sleep apnea (OSA) is characterized by repeating partial or complete obstruction of the airway, resulting in episodes of apnea lasting greater than ten seconds or hypoxic events (1, 3). OSA patients are known to be vulnerable to cardiopulmonary complications during sedation and anesthesia. To our knowledge, there are no other reported cases of using ASV during sedation for endoscopic procedures.

A 58-year-old male (height 170 cm, weight 191 kg) presented for outpatient colonoscopy for followup of colonic polyps. The patient had a past medical history of obesity (BMI 65) and severe sleep apnea for which he used ASV successfully at home. He took no daily medications, had no allergies, and vaped daily. The patient’s airway exam was notable for an inter-incisor distance of three fingerbreadths, large tongue, Mallampati class IV, short neck, and intact dentition. Home ASV settings were IPAP set to 12 - 24 cm H2O, EPAP set to 12 cm H2O and no supplemental oxygen. During the previous colonoscopy, his airway obstructed and intubation became necessary. He had a prolonged hospital stay at that point with difficulty weaning from the ventilator and was distressed at the thought of being intubated again. After a discussion with the patient, it was determined that due to his history of difficulty weaning from mechanical ventilation, we would utilize his ASV device during his sedation if we could first verify its proper function. The patient demonstrated the device to the anesthesia team. After taking the time to ensure the proper functioning of the device, and backup power supply, the patient positioned the ASV nasal pillows on himself. Supplemental oxygen at a flow rate of 8 L/min was attached to the ASV device. Standard ASA monitors were placed. Initial vital signs were: BP 117/67 mmHg, HR 67 bpm, RR 12/min, SpO2 98% on room air. Backup airway equipment and induction medications were prepared and immediately available in case intubation became necessary. The patient was slowly sedated with propofol infusion, which was titrated to prevent a reaction from the colonoscope while maintaining adequate respirations. Throughout the procedure, no airway intervention from the anesthesia provider was needed, and the patient did not have any desaturation events. The procedure lasted 41 minutes in which 6 polyps were removed, and the patient’s oxygen saturation stayed above 95% throughout. Afterward, he was transported to recovery and discharged home in stable condition.

Procedural sedation in patients with morbid obesity and sleep apnea can be challenging. Our experience demonstrates that ASV can be used successfully to ensure adequate ventilation during sedation for endoscopic procedures in patients with morbid obesity and sleep apnea. This patient had been using ASV successfully at home, and after inspection and demonstration of the device, it was decided the patient would benefit from using ASV during sedation. The anesthesiologist should remain vigilant, and ensure adequate preparation for potential airway intervention.