Technical problem with device in study

Diagnostic and operative procedures of upper gastrointestinal (GI) tract are very common in all patients. Some procedures are difficult to tolerate because of long duration, prone position or significant stimulation of the upper airways. An example are endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic pancreatic ultrasound.

The procedures are generally performed with deep sedation. Many pharmacologic regimens are available and described in literature. The investigator's institute adopts propofol target controlled infusion (TCI), which usually guarantees unconsciousness and unresponsiveness of patients. The main adverse event is dose-related respiratory depression. Pre-existing reasons for hypoventilation can exacerbate this event, especially in the elderly and the chronic obstructive pulmonary disease-patients. Laryngeal mask (LMA) is a useful tool to apply a pressure support ventilation. One specific type of LMA allows to separate the gastric and respiratory tract and, allows the anesthesiologist to support patient's ventilation as (and only if) necessary.

This is a monocentric randomized controlled trial of superiority of LMA use in GI endoscopic procedures. Randomization is centralized. The study is single blind (patient). The study is no-profit. Every patients undergoing scheduled ERCP and endoscopic ultrasound will be screened and consecutive eligible patients will be enrolled. Subjects will be allocated according to a simple randomization list. The study starts after randomization and ends after discharge from the recovery room. After peripheral venous catheter insertion and vital parameters monitoring, patients will receive propofol TCI with a tailored target between 4 and 6 mcg/ml. The treatment group will receive LMA insertion and End-Tidal Carbon Dioxide (ETCO2) monitoring throughout the procedure. In case of hypoventilation, with an ETCO2 above 50 mmHg, the patient will be supported as necessary with PSV. The control group will not receive any airway device, according to the standard treatment. At the end of the procedure, both group will receive a laboratory testing (peripheral arterial sample), when the patient is still sedated. Vital parameters monitoring will continue in recovery room. Patients will be discharge as usual with an Aldrete score > 9.

Data will be collected during the procedure and in recovery room. Data will be stored in electronic database without mention to patient's name.

Inclusion Criteria:

• age >18 years
• written informed consent
• elective ERCP and endoscopic ultrasound procedure

Exclusion Criteria:

• pregnancy
• contraindication to propofol administration
• contraindication to mask insertion (e.g. malformation)
• emergency operation (not scheduled)
• preexisting causes of hypoventilation (e.g. chronic obstructive pulmonary disease, neuromuscular disease…)

Induction of anesthesia and subsequent use (or not) of the device (laryngeal mask)