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Biomedical subjects

R F Logan

Publications and source records attributed to R F Logan.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1988

Devastating diarrhoea caused by azathioprine: management difficulty in inflammatory bowel disease.

Azathioprine toxicity complicated the management of four patients with inflammatory bowel disease. All patients received the drug as adjunctive therapy to steroids when responses to the latter were poor. After a variable sensitising period the patients developed severe diarrhoea and abdominal pain and this was believed at first to be a manifestation of their underlying diseases but rechallenge with azathioprine reproduced the problem. During three episodes described emergency admission to hospital and resuscitation with intravenous fluids was required. The cases illustrate the difficulty clinicians have in recognising drug induced effects which mimic the underlying disease. When a patient suspects a reaction to azathioprine we believe any rechallenge should only be undertaken in the controlled hospital environment.

Adolescent↗
PubMed1988

Smoking and sugar intake are separate but interactive risk factors in Crohn's disease.

Previous studies have consistently found strong positive associations between refined sugar intake and Crohn's disease (CD) and recently between smoking and CD. As refined sugar intake and smoking are themselves associated we have enquired about smoking and added sugar intake (AS) and smoking in CD using a postal questionnaire sent to 104 CD patients and 153 community controls. Smoking and AS were associated with one another. After adjusting for AS, smoking showed a significant association with CD with a relative risk of 1.8. After adjusting for smoking habit, AS was also strongly associated with CD in never and exsmokers and in a dose response pattern, with the relative risks for no AS, less than 50 g/day and greater than 50 g/day being respectively 1.0, 1.8, and 4.6 (chi 2 = 12.1; p less than 0.005). No association between CD and AS was evident in smokers. The AS relationship was supported by a separate association between frequency of confectionery consumption and CD. These findings indicate that while smoking and AS are individually associated with CD combined exposure results in no further increase in risk, suggesting that they may operate through a common mechanism.

Adolescent↗
PubMed1987

Cigarette smoking and inflammatory bowel disease.

In a case-control study 280 patients with inflammatory bowel disease and matched community controls taken from general practitioner lists were questioned about their smoking habits. Whether assessed by current or previous habits, patients with Crohn's disease were more likely to be or have been smokers than their matched controls and the association appeared strongest at disease onset (matched relative risk 4.1, p less than 0.001). In contrast, patients with ulcerative colitis assessed in the same way were less likely to be smokers compared with their matched controls, with the association being equally strong at disease onset and currently (matched relative risk 0.17, p less than 0.001). Among patients with ulcerative colitis who were exsmokers, 76% reported stopping smoking before disease onset compared with 13% of exsmokers with Crohn's disease. Contrary to earlier reports, there were only small and nonsignificant increases in the risk of Crohn's disease or ulcerative colitis in exsmokers. The strength, temporal precedence, and contrasting nature of the associations are evidence that smoking has an important etiologic role in inflammatory bowel disease. Smoking appears to be a factor in determining whether Crohn's disease or ulcerative colitis develops in predisposed individuals.

Adult↗
PubMed1987

Twenty-four-hour intragastric acidity and clinical trial of bedtime enprostil 70 micrograms compared with ranitidine 300 mg in duodenal ulcer.

The effects of bedtime 70 micrograms and twice daily 35 micrograms doses of enprostil on 24-hour intragastric acidity were investigated in nine duodenal ulcer patients in remission. Median nocturnal acidity decreased significantly by 30% with 35 micrograms twice daily, and by 48% with 70 micrograms at bedtime. In a clinical trial using bedtime dosing, 102 duodenal ulcer patients randomly received either ranitidine 300 mg or enprostil 70 micrograms. More ulcers healed after 4 and 8 weeks treatment with ranitidine than with enprostil (76% ranitidine vs 52% enprostil, at 4 weeks p = 0.0065 and 94% vs 68%, respectively at 8 weeks, P = 0.0007). However, 6 months after cessation of treatment there was no material difference in overall outcome. Despite combining mucosal protection with acid inhibition enprostil treatment conferred no advantage over simple acid inhibition.

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↗
PubMed1987

Intravenous midazolam: a study of the degree of oxygen desaturation occurring during upper gastrointestinal endoscopy.

Intravenous midazolam (mean dose of 6.3 mg) was given to 100 consecutive patients coming to endoscopy. All patients had an ear oximeter attached throughout the procedure to record continuously their levels of oxygen saturation. Eighty-five of the 100 patients had pre-endoscopy respiratory function tests measured, and 82 wore an induction plethysmograph vest to get a continuous qualitative estimate of respiratory rate and excursion throughout the procedure. Following intravenous midazolam a reduction in respiratory excursion was observed in 80% of patients. The initial baseline oxygen saturation of 95.4% fell 3.3% (P less than 0.0005) following intravenous midazolam to 92.1%. During the endoscopic procedure there was a further 3.1% decrease in oxygen saturation to 89.0% (P less than 0.0005) and in 7% the level fell to below 80%. Age, sex, dose of midazolam given and pre-endoscopy respiratory function tests failed to identify those patients at risk of hypoxia during the endoscopy.

Adult↗
PubMed1986

Role of drugs in fractures of the femoral neck.

To investigate the role of drugs in the rising incidence of fractures of the femoral neck in the elderly a case-control study inquiring about the use of prescribed drugs was carried out. The drug histories of 102 patients with femoral neck fractures were obtained from general practice records and compared with those of 204 controls matched for age and sex from the same practices. At the time of fracture 41 patients with fractures and 126 controls were receiving at least one prescription (relative risk of fracture of the femoral neck in patients taking drugs = 0.42, p = 0.0006). For all types of prescribed drugs except antibiotics the risk of fracture of the femoral neck was less in patients taking drugs than in those not doing so, and this was true at all times in the year before fracture. Six patients with fractures were receiving thiazide diuretics compared with 37 controls (relative risk 0.28, p = 0.004). These results indicate that, contrary to popular belief, drugs that sedate or that impair postural control are not important factors in fractures of the femoral neck. The results are consistent with the hypothesis that the hypocalciuria induced by thiazides protects against fracture, but the degree of protection is not significantly greater than that associated with other drugs.

Aged↗
PubMed1986

Prevalence and "incidence" of celiac disease in Edinburgh and the Lothian region of Scotland.

After review of hospital records and jejunal biopsy sections, 703 cases of celiac disease, including 74 cases with dermatitis herpetiformis, were identified in Edinburgh and the Lothian region up to December 31, 1979. Of these, 469 were resident in Lothian, resulting in an overall prevalence of 50/100,000 in men and 74/100,000 in women. The prevalence in men showed no significant variation with age, whereas in women age-specific prevalence varied markedly, with a peak of 126/100,000 at ages 35-44 yr and a low of 28/100,000 at ages 45-54 yr. This variation could not readily be explained, although reduced case ascertainment among women born between 1925 and 1934 could be the basis of a modest cohort effect. There was no evidence that migration or increased mortality at particular ages might be alternative explanations. In children the incidence of celiac disease, as measured by cumulative prevalence with age, increased more than twofold between 1960 and 1975, but since 1976 it has fallen sharply. The fall in incidence in children and the unexplained variations in prevalence in women provide epidemiologic evidence for the role of environmental factors other than gluten ingestion in the etiology of celiac disease.

Adolescent↗
PubMed1986

Research in epidemiology and community health in the medical curriculum: students' opinions of the Nottingham experience.

Medical students in Nottingham all complete an honours Bachelor of Medical Sciences course in one department including a research project. The honours programme in community health is described, with results from a survey of the 122 graduates since the medical school started. The 98 (80%) responses showed high levels of satisfaction and gain from the programme, the great majority regarding the course as valuable, enjoyable, and giving both research skills and skills in interpersonal relationships.

Attitude to Health↗