Background: Patients undergoing upper GI endoscopy often receive sedation and O2 via nasal cannula. Over-sedation/airway obstruction may cause severe desaturation, especially in obese patients with obstructive sleep apnoea (OSA) or patients in prone position (swimmer) during endoscopic retrograde cholangiopancreatography (ERCP). A novel nasal TSE-PAP mask assembly using a paediatric mask and existing anesthesia equipment/machine was shown to maintain spontaneous respiration and improve oxygenation in sedated obese patients with OSA(1-3). We report its use in a high-risk patient during ERCP in swimmer position. 

Case Report: A 51 y/o male (BMI 27 kg/m2) with HTN, anxiety and s/p multiple injuries sustained from a motor cycle accident 2 years prior presented for ERCP with removal of biliary stent. 

The patient underwent multiple surgeries including splenectomy, cholecystectomy, partial pancreatectomy, appendectomy, and recent complex abdominal wall  reconstruction for his post-traumatic ventral hernia. He had a tracheostomy and was in coma for two months. 

He had a Class I airway and a deep retracted tracheostomy scar, and room air SpO2 of 97%. After discussing with him and the endoscopist, the procedure was to proceed under MAC with video-laryngoscopy standby. He gave consent for photography and case report. 

After he assumed a swimmer position, an infant mask with fully inflated air cushion was placed over his nose and secured with a hook ring and rubber head straps and connected to a breathing circuit and the anaesthesia machine (Fig. 1-3). 

The APL valve was adjusted to deliver 6 cm H2O CPAP with 4 L/min O2. His SpO2 increased to 99%. He then received midazolam (2x2 mg), lignocaine (100 mg) and propofol bolus (50 mg) and infusion (175 mcg/kg/min) (Fig. 3). 

He maintained spontaneous ventilation and 99-100% SpO2 throughout. He tolerated the procedure well without any complication. He was elated that intubation was avoided. He was discharged home without any problem. 

Discussion: This simple nasal TSE-PAP assembly maintained spontaneous ventilation and oxygenation in a high-risk patient in a swimmer position under deep sedation during ERCP. It utilizes existing anaesthesia equipment and machine and may improve patient safety at a low cost. 

References: 1. www.TSEMask.com; 2. SAMBA 28th AM, 2013; 3. IARS AM: MCC1080, 2015

Learning Points: How to prepare a nasal mask assembly using existing anaesthesia equipment and to maintain spontaneous ventilation by providing nasal CPAP in prone position.

A novel nasal PAP mask assembly maintained spontaneous ventilation and oxygenation in a high-risk patient during ERCP in swimmer position