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Biomedical subjects

G D Bell

Publications and source records attributed to G D Bell.

At least 91 records · Page 5Linked to original sources
PubMed1991

Recommendations for standards of sedation and patient monitoring during gastrointestinal endoscopy.

(1) Safety and monitoring should be part of a quality assurance programme for endoscopy units. (2) Resuscitation equipment and drugs must be available in the endoscopy and recovery areas. (3) Staff of all grades and disciplines should be familiar with resuscitation methods and undergo periodic retraining. (4) Equipment and drugs necessary for the maintenance of airway, breathing, and circulation should be present in the endoscopy unit and recovery area (if outside the unit) and checked regularly. (5) A qualified nurse, trained in endoscopic techniques and adequately trained in resuscitation techniques, should monitor the patient's condition during procedures. (6) Before endoscopy, adverse risk factors should be identified. This may be aided by the use of a check list. (7) The dosage of all drugs should be kept to the minimum necessary. There is evidence that benzodiazepine/opioid mixtures are hazardous. (8) Specific antagonists for benzodiazepines and opioids exist and should be available in the event of emergency. (9) A cannula should be placed in a vein during endoscopy on 'at risk' patients. (10) Oxygen enriched air should be given to 'at risk' patients undergoing endoscopic procedures. (11) The endoscopist should ensure the well being and clinical observation of the patient undergoing endoscopy in conjunction with another individual. This individual should be a qualified nurse trained in endoscopic techniques or another medically qualified practitioner. (12) Monitoring techniques such as pulse oximetry are recommended. (13) Clinical monitoring of the patient must be continued into the recovery area. (14) Records of management and outcome should be collected and will provide data for appropriate audit.

Anesthesia Recovery Period↗
PubMed1990

Review article: premedication and intravenous sedation for upper gastrointestinal endoscopy.

Upper gastrointestinal endoscopy can be performed without intravenous sedation but the evidence suggests that, in the United Kingdom and United States, most patients and endoscopists prefer that some form of premedication is given. Intravenous diazepam or midazolam are used by the majority of endoscopists. In the UK, the ratio of diazepam to midazolam users is approximately 2:1, while in the USA more endoscopists are now using midazolam. Midazolam is approximately twice as potent as diazepam but, when allowance is made for this, there is probably little or no difference in the propensity of the two drugs to produce respiratory depression. The antegrade amnesic effect of midazolam is significantly superior to that of diazepam. A benzodiazepine/narcotic combination can achieve a smoother and more rapid induction with less gagging and choking, but the incidence of adverse outcomes--particularly respiratory depression--is increased significantly. Over 50% of the deaths that are associated with upper gastrointestinal endoscopy are due to cardiopulmonary problems. Hypoxia is very common if measured using non-invasive monitoring equipment, such as a pulse oximeter. Methods of preventing oxygen desaturation and thus, by inference, most cardiac arrhythmias associated with endoscopy are discussed, as is the role of flumazenil, the new benzodiazepine antagonist.

Endoscopy, Gastrointestinal↗
PubMed1990

Bolus or slow titrated injection of midazolam prior to upper gastrointestinal endoscopy? Relative effect on oxygen saturation and prophylactic value of supplemental oxygen.

A total of 131 patients undergoing upper gastrointestinal endoscopy were sedated with midazolam given as a bolus injection over 5 seconds. The oxygen saturation was continuously measured using a pulse oximeter. Supplemental oxygen was given via nasal cannulae at a rate of 3 litres per minute to 54 patients, while the remaining 77 patients only received oxygen if their oxygen saturation dropped below 85%. Both groups in the present series were compared with 3 previously published series of patients, in whom we had used intravenous midazolam as a slow titrated injection. Despite using on average only two-thirds of the dose of midazolam, following bolus injection the degree of oxygen desaturation during the endoscopic procedure was greater, and the ability of supplemental oxygen delivered via nasal cannulae to prevent hypoxia was less (P less than 0.01), than with a slow titrated injection.

Adult↗
PubMed1990

Helicobacter pylori infection treated with a tripotassium dicitrato bismuthate and metronidazole combination.

Seventy-two patients with H. pylori infection in their antral mucosa took part in the study. Forty-three received metronidazole 400 mg t.d.s. for two weeks, plus De-Nol tabs 2 b.d. for four weeks, and the remaining 29 patients received metronidazole 400 mg t.d.s. for two weeks plus De-Nol liquid 5 ml q.d.s. for four weeks. Seven of 57 H. pylori isolates were found to have pre-treatment metronidazole resistance. Success, in terms of eradication of H. pylori, was assessed using a one-month post-treatment 14C urea breath test. Successful eradication of H. pylori was achieved in 72% and 79%, respectively, of the metronidazole/De-Nol tablet and metronidazole/De-Nol liquid groups. These figures increased to 87% and 84%, respectively, if the patients whose organisms were known to be metronidazole-sensitive were considered in isolation. H. pylori was successfully eradicated in only one of seven patients with a metronidazole-resistant organism.

Aged↗
PubMed1990

Speed of reversal of midazolam-induced respiratory depression by flumazenil--a study in patients undergoing upper G.I. endoscopy.

Intravenous midazolam was given to 17 patients coming to upper G.I. endoscopy. All patients had an ear oximeter and calibrated induction plethysmograph attached to record oxygen saturation and minute volume continuously. Midazolam induced significant depression of respiration. Following removal of the endoscope, a new base line was obtained before giving intravenous flumazenil in an attempt to reverse the sedative and ventilatory effects of midazolam. When 0.5 mg of flumazenil was given over 20 s, followed by 0.1 mg every minute, up to a total of 1.0 mg, all patients were apparently awake in under 2 min. Although the flumazenil had clearly reversed the sedative effects of midazolam, the ventilatory effects were largely uninfluenced. The implications are discussed.

Adult↗
PubMed1990

Skeletal applications of videofluoroscopy.

The use of skeletal videofluoroscopy is spreading as new applications emerge for coupling the fluoroscope with the video cassette recorder to obtain detailed information on moving anatomy. This review compiles the findings of an extensive literature search and summarizes the current state of videofluoroscopy knowledge. It traces the development of this imaging tool, beginning with cineradiography and its early investigations into cervical spine motion in the 1950s. Videofluoroscopy is presently used to evaluate the entire spine and other areas of the skeletal system, as well as diverse systems throughout the body. Because it is the only imaging technique capable of visualizing actual joint motion in real time, it provides details on movement mechanics not available through other methods. Along with presenting current applications of videofluoroscopy, this review points to future research needs.

Cineradiography↗
PubMed1990

Monitoring--the gastroenterologist's view.

Better training standards and widespread adoption of monitoring equipment has resulted in a considerable drop in anaesthetic-related deaths. This fall, however, has not been reflected in the field of endoscopy, in which over 50% of the complications and deaths appear to be due to cardiopulmonary problems, suggesting the involvement of sedative drugs. Improvements in monitoring could substantially reduce these problems. Staff should be fully trained in endoscopic, sedative, and resuscitation procedures; equipment and drugs for resuscitation should be immediately to hand; any risk factors in patients who are to undergo endoscopy should be identified, and, when necessary, additional monitoring and safety procedures should be followed. Pulse oximeters can detect oxygen desaturation very early and should be used where risk factors have been identified. Use of oximetry and continuous ECG monitoring will improve the sensitivity of clinical monitoring and may reduce the number of adverse events encountered in endoscopy. Use of supplemental oxygen should be considered.

Procedural Sedation↗
PubMed1988

A comparison of diazepam and midazolam as endoscopy premedication assessing changes in ventilation and oxygen saturation.

1. One hundred and two consecutive patients undergoing upper gastrointestinal endoscopy were randomised to be sedated with either intravenous diazepam (Diazemuls-Kabi Vitrum) or intravenous midazolam (Hypnovel-Roche). It was assumed that midazolam was likely to be approximately twice as potent as diazepam on the basis of previous work. 2. All patients had an ear oximeter attached throughout the procedure to record continuously their level of oxygen saturation. 3. All 102 patients had pre-endoscopy respiratory function tests measured and 100 wore an induction plethysmograph vest to allow continuous estimation of respiratory rate and excursion. The plethysmograph was calibrated using a pneumotachygraph, so baseline, post-injection and post-endoscopy minute volumes could be estimated. 4. The age, sex ratio and pre-endoscopy respiratory function tests of the 51 patients given intravenous diazepam in a mean dose (s.d.) of 11.5 (5.8) mg over a mean of 3.4 (0.9) min) were similar to that of the 51 patients sedated with intravenous midazolam (mean dose 6.0 (2.8) mg over 3.3 (0.9) min. 5. Both drugs significantly reduced minute volume (P less than 0.001) and oxygen saturation (P less than 0.001). Midazolam appeared to produce slightly greater hypoxaemia with 57% having falls in oxygen saturation of greater than 2.5% compared with only 35% given an equivalent dose of diazepam. 6. Ventilation was still less than baseline when re-checked some minutes after removal of the gastroscope. The speed of recovery appeared faster after diazepam sedation which is in contrast to its longer pharmacological half-life.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Intravenous midazolam for upper gastrointestinal endoscopy: a study of 800 consecutive cases relating dose to age and sex of patient.

In many endoscopy units midazolam is replacing diazepam as the intravenous sedative of first choice. Midazolam is approximately twice as potent as diazepam. Although generally considered a safe drug, there have been a number of recent reports, particularly in the elderly, of the drug causing hypotension, respiratory depression and even death. There have been at least ten studies comparing diazepam with midazolam for upper gastrointestinal endoscopy but many have involved relatively small numbers and none have adequately addressed the question of dosage in the elderly. We have carefully recorded the dose of intravenous midazolam used to produce adequate sedation prior to upper gastrointestinal endoscopy in 800 consecutive patients. The dose of midazolam decreased markedly with age in both male and female patients. There was a highly significant correlation in both sexes between age and the dose of midazolam (rho -0.787, P less than 0.001 for males and rho -0.768, P less than 0.001 for females). There was only a small difference in dose in men and women, an average of 1 mg; and no difference in dose over the age of 70 years. In patients over 70 years of age the dose of midazolam necessary for endoscopy is often so small that overdosage is all too easy.

Adolescent↗