Preparation, premedication, and surveillance

Abstract

In the year since the last review, continuing pressure on endoscopy suites to improve efficiency and reduce costs without compromising patient care has led to growing interest in alternatives to pharmacological sedation and in the use of short-acting sedatives. Relaxation music, acupuncture, and the use of small-caliber endoscopes for unsedated peroral gastroscopy have therefore been suggested as ways of increasing tolerance and reducing discomfort. With regard to ultrathin and superthin endoscopes, the results are interesting, but further data from controlled trials and in studies including larger numbers of patients are still needed. The form of sedation for gastrointestinal endoscopy that has attracted greatest interest over the last year is the use by nonanesthetists of intravenous propofol, administered either alone at standard doses to achieve deep sedation, or at lower doses combined with benzodiazepines and opioids to achieve moderate sedation/analgesia. In comparison with benzodiazepines/opioids, the results were in favor of propofol: the mean time to sedation was shorter and the depth of sedation was greater. In addition, patients receiving propofol reached full recovery earlier and were discharged sooner. However, in the survey of patient satisfaction at discharge, it was found that the sedation methods did not have a significant impact on overall patient satisfaction. Some important issues concerning the narrow therapeutic range of propofol and the need for adequate training of endoscopists to deal with any problems related to deep sedation are still open - despite the growing amount of data suggesting that the drug is safe even when administered by registered nurses, an approach that is possibly more cost-effective than delivery by gastroenterologists or anesthetists. The morbidity and mortality associated with cardiopulmonary complications continue to be a significant concern during gastrointestinal endoscopy. Professional societies and national expert peer groups have issued practice guidelines for sedation and analgesia that call for continuous monitoring of the patient's hemodynamic and ventilatory status and consciousness. Direct observation is facilitated by electronic devices (pulse oximetry, capnography), directly indicating the patient's ventilatory status and the depth of sedation. Recently, it has been proposed that the bispectral index (BIS), an electroencephalography-based technique, can be used to monitor the depth of sedation during gastrointestinal endoscopy. However, the results of a recent study cast some doubt on the usefulness of the BIS, in its current version, for titrating boluses of propofol to an adequate level of sedation. Further data therefore appear to be needed to assess whether or not BIS values can help avoid unnecessary propofol dosage and can replace continuous assessment of the ventilatory effort.