Rapid intravenous low-dose diazepam as sedation for upper gastrointestinal endoscopy

Impairment state of cognitive performance and the affecting factors in outpatients following gastrointestinal endoscopy after single-dose diazepam

Diazepam is commonly used as premedicant for endoscopic procedures. Wide interindividual differences have been observed in the residual cognitive effects of the drug after gastrointestinal endoscopy. Our aim was to clarify the major factors, including pharmacokinetic factors, contributing to this wide variation in residual cognitive effect after gastrointestinal endoscopy in the study. Sixty-one outpatients undergoing gastrointestinal endoscopy participated in the study. Cognitive effects were evaluated in the diazepam group (n=52) by the digit symbol substitution test (DSST) twice before and 30 min after an intravenous administration of 5 mg diazepam; in the intervening time gastrointestinal endoscopy was performed. Plasma concentrations of diazepam were determined by HPLC. The control group (n=9) was tested by DSST in the same manner. The cognitive effects according to the change in DSST score was significantly decline in the diazepam group compared with the control group (by 0.2 versus -4.6; P=0.014). This prospective study confirmed that cognition was significantly impaired after gastrointestinal endoscopy by premedication to subjects with 5 mg diazepam. There were very wide variations in change in DSST score. However we could not identify the independent variables that best predicted DSST score difference in a multiple regression analysis for age, plasma albumin level, and plasma diazepam concentration 30 min after intravenous administration. We should pay attention to patients' individual states in cognitive performance following gastrointestinal endoscopy after single-dose diazepam.

Small bolus injections of intravenous midazolam for upper gastrointestinal endoscopy: a study of 788 consecutive cases

1 A recent audit of upper gastrointestinal endoscopy carried out by the Royal College of Surgeons of England has shown that the majority of endoscopists use a bolus injection rather than a slow intravenous titration of benzodiazepine for intravenous sedation. In this study we have confirmed the theoretical premise that a reduced dose of midazolam is required when given as a bolus. A mean dose of 4.65 mg midazolam intravenously has been found to be effective and safe in sedating patients under 70 years (n = 552). The dose of midazolam needed is reduced in older patients: patients over 70 years (n = 236) needed a mean dose of 1.89 mg. 2 Topical pharyngeal anaesthesia was not required with these doses of midazolam, and it was our impression that the examination was equally well tolerated with a similar degree of anterograde amnesia as in the previous study. 3 Our data, together with the results of the audit, would suggest many endoscopists are employing unnecessarily large and at times potentially dangerous doses of intravenous sedation in elderly patients and that the vast majority of upper gastrointestinal endoscopies can be performed successfully, without topical pharyngeal anaesthesia, using a bolus injection techniquewith a reduced dosage of sedative agent.

Asleep on the job: sedation and monitoring during endoscopy

Gastrointestinal endoscopic procedures are invasive and carry a significant morbidity and mortality, even for diagnostic procedures (mortality of 1 in 2000 for upper gastrointestinal endoscopy). The commonest causes of death are cardiopulmonary complications, which may in part be related to sedative techniques. The clinical end-points for sedation need to be reappraised and should aim to induce amnesia rather than hypnosis. Endoscopists need to be familiar with the pharmacokinetic and pharmacodynamic properties of the benzodiazepines used for sedation. This applies particularly to the protracted half-lives of some benzodiazepines and the major drug interaction with significant synergy that occurs if opioids are used in combination with benzodiazepines. Thus appropriate doses of these drugs should be administered. The use of supplemental oxygen and pulse oximetry, combined with continuous intravenous access during the procedure should be standard practice. Endoscopists should be aware of national guidelines for safe endoscopic practice.

Monitoring and safety in endoscopy

Over 50% of the complications and 60% of the deaths associated with upper GI endoscopy are cardiopulmonary in type. Oxygen desaturation and cardiac arrhythmias at the time of endoscopy are common. Ways of trying to prevent hypoxia occurring are discussed. The most effective of these is the use of supplemental oxygen. Pulse oximeters are being used increasingly frequently by endoscopists. The way in which oximeters work is described in some depth, as are some of the potential errors that may result from their use. The author believes that, as in anaesthetic practice, pulse oximeters will be used ever more frequently by endoscopists and finally become standard equipment in all endoscopy units. The case for using continuous ECG monitoring and blood pressure measurement is briefly discussed. The ASGE have recently published their recommendations on monitoring patients undergoing GI endoscopic procedures. The BSG's own working party on safety and monitoring is in the process of finalizing its recommendations, and the final part of the chapter discusses the views of this working party and gives some insight into what its final recommendations are likely to be.