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Biomedical subjects

G D Bell

Publications and source records attributed to G D Bell.

At least 55 records · Page 3Linked to original sources
PubMed1995

Prospective audit of perforation rates following upper gastrointestinal endoscopy in two regions of England.

After cardiopulmonary complications, perforation is the second most important cause of complications following flexible upper gastrointestinal endoscopy. A recent audit of 14,149 procedures detected a perforation rate of 0.05 per cent (overall mortality rate 0.008 per cent) during diagnostic endoscopy, and a perforation rate of 2.6 per cent (overall mortality rate 1.0 per cent) following oesophageal intubation or dilatation. The incidence of perforation following both diagnostic and therapeutic upper gastrointestinal endoscopy has not changed over the past 10 years. The risk factors are numerous but this audit demonstrated that inexperience increases the likelihood of perforation.

Aged↗
PubMed1995

Quantitative analysis of anterior cruciate ligament instability.

The purpose of this study was to quantify end-feel by evaluating instantaneous stiffness and change in stiffness of the tibiofemoral joint. Normal (n = 26), anterior cruciate ligament (ACL) deficient (n = 6), and posterior cruciate ligament (PCL) deficient (n = 2) subjects were tested using the KT 2000 knee ligament arthrometer. Analogue force and displacement data were digitized, filtered, and calibrated. Force-displacement curves in the region of anterior tibial displacement were approximated using 5th degree polynomial functions. Stiffness and change in stiffness were determined analytically by the first and second derivatives of these functions. Subjects with confirmed ACL deficiency had lower values for stiffness and change in stiffness in the region of the curves believed to be indicative of ACL function, compared to contralateral knees and control subjects. RELEVANCE: First and second derivatives of tibiofemoral force-displacement curves give the stiffness and the change in stiffness respectively for anterior displacement of the tibia relative to the femur. This information concerning knee stability in vivo may be useful for diagnosis and follow-up.

Journal Article↗
PubMed1995

Localization of knee joint cartilage pathology by multichannel vibroarthrography.

This paper proposes non-invasive techniques to localize sound or vibroarthrographic (VAG) signal sources in human knee joints. VAG signals from normal subjects, patients who subsequently underwent arthroscopy, and cadavers with arthroscopically-created lesions, obtained by stimulation with a finger tap over the mid-patella and swinging movement of the leg, were analyzed for time delays using cross-correlation functions for source localization. Correct results were obtained for 13 of the 14 subjects tested by finger stimulation, and for 11 of the 12 subjects whose VAG signals during swinging movement were analyzed. The techniques could be valuable in the diagnosis and treatment of knee pathology before and after joint surgery or drug therapy.

Arthroscopy↗
PubMed1995

Rapid eradication of Helicobacter pylori infection.

BACKGROUND/AIMS: Current Helicobacter pylori eradication therapy for peptic ulcer disease usually involves a 2-week course of either a bismuth preparation or omeprazole in combination with antibiotics. We have studied a shorter, 7-day course of treatment to assess efficacy and tolerability. METHODS: Four hundred and thirty-six patients, in three non-randomized groups, received omeprazole (40 mg mane), amoxycillin (500 mg t.d.s.) and metronidazole (400 mg t.d.s.): 308 patients received the triple combination for 14 days; 80 patients were treated for 7 days; and 48 patients received omeprazole and amoxycillin for 7 days but metronidazole for only 5 days. RESULTS: Helicobacter pylori was eradicated in 89.5%, 91.1% and 87.5%, respectively (98.3%, 92.9% and 100% of metronidazole-sensitive isolates and 75.6% and 88.2% of metronidazole-resistant isolates in the first two groups). Side effects were significantly more frequent in patients who received 14 days (49%) compared with 7 days of treatment (33%); only 8/308 and 1/128 patients, respectively, failed to complete the course. CONCLUSIONS: On the basis of efficacy, tolerability and cost, we conclude that a 7-day course of the omeprazole (40 mg mane), amoxycillin (500 mg t.d.s.) plus metronidazole (400 mg t.d.s.) combination is effective therapy for the eradication of H. pylori.

Adult↗
PubMed1995

Addition of metronidazole to omeprazole/amoxycillin dual therapy increases the rate of Helicobacter pylori eradication: a double-blind, randomized trial.

AIMS: To compare the efficacy, safety and tolerability of an omeprazole/amoxycillin (OA) dual therapy Helicobacter pylori eradication regimen with an omeprazole/amoxycillin/metronidazole (OAM) triple therapy regimen. METHODS: In this double-blind trial, conducted in 19 hospitals, 119 patients with symptomatic duodenal ulcer disease were randomized to receive either 14 days treatment with omeprazole 40 mg daily, amoxycillin 500 mg t.d.s. and placebo followed by a further 14 days' treatment with omeprazole 20 mg daily (n = 59) or 14 days treatment with omeprazole 40 mg daily, amoxycillin 500 mg t.d.s., and metronidazole 400 mg t.d.s., followed by a further 14 days' treatment with omeprazole 20 mg daily (n = 60). H. pylori status was assessed by 13C-urea breath test at entry and at 4 weeks post-treatment. RESULTS: H. pylori infection was eradicated in 46% of the OA treated patients and in 92% of the OAM treated patients, a mean difference of 46% (P < 0.0001, 95% CI for the difference: +30 to +62). In only one patient was the duodenal ulcer not endoscopically healed after 4 weeks of treatment (OA 100%; OAM 98% healed). There were no significant differences in speed of symptom relief or improvement in symptoms between the two groups. Both regimens were well tolerated, with 96% of patients completing the course, and only one patient withdrawing due to an adverse event. The only side-effect with a significantly higher incidence in the OAM group was diarrhoea, which occurred in 36% of patients compared to 16% of patients in the OA group (P < 0.05). CONCLUSIONS: A regimen consisting of omeprazole 40 mg daily, amoxycillin 500 mg t.d.s. and metronidazole 400 mg t.d.s. for 14 days gives an appreciably higher H. pylori eradication rate than omeprazole and amoxycillin alone, with acceptable tolerability.

Administration, Oral↗
PubMed1995

Prospective audit of upper gastrointestinal endoscopy in two regions of England: safety, staffing, and sedation methods.

A prospective audit of upper gastrointestinal endoscopy in 36 hospitals across two regions provided data from 14,149 gastroscopies of which 1113 procedures were therapeutic and 13,036 were diagnostic. Most patients received gastroscopy under intravenous sedation; midazolam was the preferred agent in the North West and diazepam was preferred in East Anglia. Mean doses of each agent used were 5.7 mg and 13.8 mg respectively, although there was a wide distribution of doses reported. Only half of the patients endoscoped had some form of intravenous access in situ and few were supplied with supplementary oxygen. The death rate from this study for diagnostic endoscopy was 1 in 2000 and the morbidity rate was 1 in 200; cardiorespiratory complications were the most prominent in this group and there was a strong relation between the lack of monitoring and use of high dose benzodiazepines and the occurrence of adverse outcomes. In particular there was a link between the use of local anaesthetic sprays and the development of pneumonia after gastroscopy (p < 0.001). Twenty perforations occurred out of a total of 774 dilatations of which eight patients died (death rate 1 in 100). A number of units were found to have staffing problems, to be lacking in basic facilities, and to have poor or virtually non-existent recovery areas. In addition, a number of junior endoscopists were performing endoscopy unsupervised and with minimal training.

Adult↗
PubMed1995

First clinical results with a real time, electronic imager as an aid to colonoscopy.

The early clinical results are described of a real time, electromagnetic imaging system as an aid to colonoscopy. After gaining experience with the use of the system, one experienced endoscopist was randomised to perform consecutive colonoscopies either with (n = 29) or without (n = 26) the imager view. All procedures were recorded on computer disk and replayed for retrospective analysis. Total colonoscopy was achieved in all patients except one (imager view not available). Comparing intubation time and duration of loop formation per patient, there was no significant difference between the two study groups. The number of attempts taken to straighten the colonoscope pre patient, however, was less when the endoscopist was able to see the imager view, p = 0.03. Hand pressure was also more effective when the endoscopist and endoscopy assistant could see the imager display, p = 0.02. Preliminary experience suggests that real time, electronic imaging of colonoscopy is safe, effective, and will improve the accuracy of the procedure.

Abdomen↗
PubMed1994

Adaptive cancellation of muscle contraction interference in vibroarthrographic signals.

Vibroarthrography (VAG) is an innovative, objective, non-invasive technique for obtaining diagnostic information concerning the articular cartilage of a joint. Knee VAG signals can be detected using a contact sensor over the skin surface of the knee joint during knee movement such as flexion and/or extension. These measured signals, however, contain significant interference caused by muscle contraction that is required for knee movement. Quality improvement of VAG signals is an important subject, and crucial in computer-aided diagnosis of cartilage pathology. While simple frequency domain high-pass (or band-pass) filtering could be used for minimizing muscle contraction interference (MCI), it could eliminate possible overlapping spectral components of the VAG signals. In this work, an adaptive MCI cancellation technique is presented as an alternative technique for filtering VAG signals. Methods of measuring the VAG and reference signals (MCI) are described, with details on MCI identification, characterization, and step size optimization for the adaptive filter. The performance of the method is evaluated by simulated signals as well as signals obtained from human subjects under isotonic contraction.

Adult↗
PubMed1994

Appropriate use of upper gastrointestinal endoscopy--a prospective audit. Steering Group of the Upper Gastrointestinal Endoscopy Audit Committee.

Work by this group has shown that there is a wide range of opinion as to patients' suitability for endoscopy. In a recent study, 1297 questionnaires were sent to a random selection of doctors, including 350 general physicians, 400 surgeons, 477 gastroenterologists, and 70 general practitioners. The respondent was asked to indicate whether or not he would refer the patient described by each case vignette for endoscopy. Depending on the indication, the positive referral rate varied from 4.5% to 99% overall, and from 4.5% to 63.8% for all those clinical situations that the working party felt to be inappropriate. A second study examined the appropriateness of 400 consecutive cases referred from four units within one health region; these cases were judged independently, and without conferring, by a panel of seven gastroenterologists. The same cases were rated by software that incorporated American opinion (the Rand criteria). Although only 45 (11%) of the cases were classed as inappropriate by the British panel, 120 cases (31%) assessed by the American software were rated inappropriate. These differences occurred largely because in the USA it is recommended that one month's antiulcer treatment be tried before considering endoscopy for dyspepsia and thus many referrals were seen as inappropriate by the American database. Of the 45 cases found to be inappropriate by the British doctors no important abnormality was found at endoscopy; whereas of 120 cases judged inappropriate by the Rand criteria, three duodenal and two gastric ulcers, and one gastric cancer were diagnosed at gastroscopy. This study attempts a quantitative assessment of inappropriate use and serves to encourage further work to define appropriateness.

Adult↗
PubMed1994

Helicobacter pylori eradication in patients with peptic ulcer disease: clinical consequences and financial implications.

We assessed clinical consequences and financial implications of Helicobacter pylori eradication in 175 patients with peptic ulceration, of whom 106 had been free from H. pylori infection for a mean of 3.2 years, while 69 remained infected. We used quarterly questionnaires to examine consumption of ulcer-healing medication and antacids. In the 106 successfully treated patients, gastrointestinal haemorrhage as a complication of peptic ulcer complications during the 344 patient years after eradication (0.003 per patient year) was 18-fold lower than during the 912 patient years before eradication (0.056 per patient year). Of the H. pylori-negative patients, 12-18% used ulcer-healing medication during any one of the three-month periods of the survey, compared with 34-51% of the patients with residual H. pylori infection. The average cost of the ulcer-healing drugs consumed by the H. pylori-negative patients was 30.59 pounds during the 12 months of the survey, compared with 99.05 pounds for H. pylori-positive patients. Consumption of antacids was also lower in the H. pylori-negative group. Successful eradication of H. pylori significantly reduced the annual cost of ulcer-healing drugs consumed by the patients with ulcer disease. Maintenance of ulcer remission following successful eradication of H. pylori also significantly reduced ulcer complications.

Antacids↗
PubMed1993

Clinical aspects of infection with Helicobacter pylori.

About 90% of patients with duodenal ulcer and 65% of those with gastric ulcer are infected with Helicobacter pylori. H. pylori infection can be diagnosed by examination of biopsy material obtained at endoscopy; by 14C or 13C-urea breath tests, or by serological means. The relapse rate of duodenal and gastric ulcers can be considerably reduced if the bacteria are eradicated. Some of the current treatment regimens are discussed.

Dyspepsia↗
PubMed1993

Non-radiological technique for three-dimensional imaging of endoscopes.

A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal hospital environment. Clinical trials are described in which the system is validated in terms of its suitability for the application. Magnetic and conventional X-ray images obtained ex vivo with the endoscope held in various configurations and comparisons in the patients confirm the practical applicability of the new system.

Colonoscopes↗
PubMed1993

Biotype and molecular fingerprints of metronidazole-resistant strains of Helicobacter pylori from antral gastric mucosa.

Biotypes, ribosomal RNA gene restriction patterns (ribopatterns), whole-cell protein patterns and plasmid profiles of paired Helicobacter pylori isolates from 17 patients were examined. Each pair comprised a pre- and a post-treatment isolate; nine of the 17 post-treatment isolates were obtained after treatment with tripotassium dicitrate bismuthate (De-Nol) and metronidazole. All strains of H. pylori had identical biotypes, but exhibited diversity between pairs in their molecular fingerprints. Each of the 17 strain pairs had unique ribopatterns; the pre- and post-treatment isolates in most pairs (16 of 17) were similar or identical, irrespective of metronidazole susceptibility. DNA subtype variants were detected in three patient sets. Although nine post-treatment isolates had acquired resistance to metronidazole, most (six of nine) resembled the pre-treatment isolates in their ribopattern, protein and plasmid profiles. No significant correlation was observed between metronidazole resistance and plasmid content in these H. pylori isolates. Emergence of post-treatment metronidazole-resistant isolates of H. pylori was associated only rarely with colonisation by a novel strain or acquisition of a plasmid and, in most patients, probably resulted from spontaneous emergence of resistance in the original infecting strain.

Bacterial Proteins↗
PubMed1993

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.

Adolescent↗
PubMed1993

Eradication of Helicobacter pylori and its effect in peptic ulcer disease.

Since Helicobacter pylori was first cultured 10 years ago, there have been remarkable changes in our approach to the therapy of peptic ulcer disease. We now know that 90% of duodenal ulcer patients and 70% of all gastric ulcer patients are infected with H. pylori. Evidence is presented that the relapse rate of both duodenal and gastric ulcers can be substantially reduced if the bacterium is eradicated from the patient's stomach. Some of the anti-H. pylori eradication regimens currently available are discussed, with particular emphasis on the relative merits of standard triple therapy and an omeprazole/amoxycillin combination.

Amoxicillin↗
PubMed1993

Reinfection or recrudescence after apparently successful eradication of Helicobacter pylori infection: implications for treatment of patients with duodenal ulcer disease.

Helicobacter pyloris is considered to be aetiologically implicated in gastritis and peptic ulceration, since if H. pyloris infection can be eradicated the risk of subsequent ulcer relapse is markedly reduced. The rate of 'reinfection' following treatment ranges from 0% to 45%, but its origin remains controversial (reappearance of uneradicated original infection or a fresh infection). To distinguish temporary suppression of H. pylori from fresh infection we conducted a retrospective analysis of the criteria used to establish eradication of the original infection in 304 patients. We used the [14C]urea breath test, in which an integrated area under the curve (AUC) value of < 40 in 2 h is considered to indicate eradication of H. pylori in patients tested 1 month after treatment. The results suggest that relapsed infection with H. pylori usually represents recrudescence of the original infection rather than a fresh infection; there was a higher relapse rate in patients with a breath test AUC > 20 < 40, compared with those with an AUC < 20. All 'reinfections' occurred within 24 months of the original treatment. 'Reinfection' was uncommon in patients receiving powerful therapeutic regimens (e.g. triple therapy) compared with those receiving monotherapy or relatively ineffective dual therapy combinations. In patients whose urea breath test remains negative 12 months after treatment the subsequent reinfection rate is only 0.44%/year. This supports the strategy of eradicating H. pylori infection from suitable peptic ulcer patients.

Adolescent↗