Premedication, Preparation, and Surveillance

During the last two years, the well-known positive role of benzodiazepines (midazolam and diazepam) in conscious sedation, both in adults and pediatric patients, has been confirmed by several studies. However, problems concerning the role of sedation and analgesia in nonoperative endoscopy are still a matter of debate.

Particular attention has focused on attempts to identify the “ideal candidate” for conscious sedation, and on the importance of providing patients with information before the procedure, which should be matched to each patient's style of coping. Before detailed information about a medical procedure is given blindly, the clinician should investigate whether such information will benefit or adversely affect the patient receiving it.

An important aspect of the sedation procedure is the prevention of hypoxia and cardiopulmonary complications. Recent endoscopic experience has provided little additional information concerning the well-known risk of oxygen desaturation during conscious sedation. Performing endoscopy in sedated patients reduces, but does not eliminate, the risk of hypoxia. Some independent variables capable of predicting severe desaturation have been recognized, such as basal SaO₂ < 95 %, respiratory disease, more than one attempt needed for intubation, emergency procedure, and an American Society of Anesthesiologists score of III or IV.

As far as preparation is concerned, some light has been cast by a meta-analysis of available studies concerning the role of sodium phosphate and polyethylene glycol electrolyte lavage solution (PEG-ELS). The former preparation has been found to be as effective and less costly compared with the latter. In particular, sodium phosphate may be preferable in patients without cardiovascular or renal co-morbidity, and in those with a tendency to develop nausea or bloating.