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Biomedical subjects

M R Stephens

Publications and source records attributed to M R Stephens.

At least 19 recordsLinked to original sources
PubMed2006

Colonoscopy first for iron-deficiency anaemia: a Numbers Needed to Investigate approach.

BACKGROUND: British Society of Gastroenterology guidelines recommend that gastrointestinal investigations should be considered in males and post-menopausal women presenting with iron-deficiency anaemia (IDA). AIM: To compare the diagnostic yields and clinical effectiveness of upper and lower gastrointestinal (GI) investigation in detecting malignancy among patients presenting with IDA. DESIGN: Retrospective review of case notes, endoscopy records and radiology reports. METHODS: We reviewed the results of 3798 investigations in 2600 patients presenting to our hospital with IDA from October 1995 to December 2003. The findings of the 2318 gastroscopies were compared with those of the 896 colonoscopies and the 584 barium enemas. Patients diagnosed with GI malignancy were identified and their outcomes determined. RESULTS: Gastroscopy identified 44 patients with newly-diagnosed upper GI cancer (18 oesophageal, 26 gastric). Thus for patients being gastroscoped for IDA, the Numbers Needed to Investigate (NNI) to detect each cancer was 53. Five-year survival for these 44 patients was 10%, so the NNI to identify each curable upper GI malignancy was 527. Colonoscopy or barium enema identified 111 (7.5%) patients with newly diagnosed colorectal cancer, giving a NNI of 13. Their 5-year survival was 35%, giving a NNI to identify each curable colorectal cancer patient of 38. DISCUSSION: Potentially curable gastrointestinal malignancy was diagnosed over 13 times more commonly using colonoscopy or barium enema vs. gastroscopy. For patients presenting with IDA, our findings favour investigating the lower GI tract first, or performing both gastroscopy and colonoscopy during the same endoscopy list.

Adolescent↗
PubMed2006

Multidisciplinary team management is associated with improved outcomes after surgery for esophageal cancer.

We aim to compare the outcomes of patients undergoing R0 esophagectomy by a multidisciplinary team (MDT) with outcomes after surgery alone performed by surgeons working independently in a UK cancer unit. An historical control group of 77 consecutive patients diagnosed with esophageal cancer and undergoing surgery with curative intent by six general surgeons between 1991 and 1997 (54 R0 esophagectomies) were compared with a group of 67 consecutive patients managed by the MDT between 1998 and 2003 (53 R0 esophagectomies, 26 patients received multimodal therapy). The proportion of patients undergoing open and closed laparotomy and thoracotomy decreased from 21% and 5%, respectively, in control patients, to 13% and 0% in MDT patients (chi2 = 11.90, DF = 1, P = 0.001; chi2 = 5.45, DF = 1, P = 0.02 respectively). MDT patients had lower operative mortality (5.7%vs. 26%; chi2 = 8.22, DF = 1, P = 0.004) than control patients, and were more likely to survive 5 years (52%vs. 10%, chi2 = 15.05, P = 0.0001). In a multivariate analysis, MDT management (HR = 0.337, 95% CI = 0.201-0.564, P < 0.001), lymph node metastases (HR = 1.728, 95% CI = 1.070-2.792, P = 0.025), and American Society of Anesthesiologists grade (HR = 2.207, 95% CI = 1.412-3.450, P = 0.001) were independently associated with duration of survival. Multidisciplinary team management and surgical subspecialization improved outcomes after surgery significantly for patients diagnosed with esophageal cancer.

Adenocarcinoma↗
PubMed2005

Prognostic significance of alarm symptoms in patients with gastric cancer.

BACKGROUND: The aim of this study was to determine the incidence and spectrum of alarm symptoms in patients with newly diagnosed gastric cancer, and to examine the relationship between symptoms and outcome. METHODS: Three hundred consecutive patients with gastric adenocarcinoma were studied prospectively. The outcomes of 40 patients (13.3 per cent) without alarm symptoms (21 men; median age 69 years) were compared with those of the 260 patients (86.7 per cent) with alarm symptoms (175 men; median age 72 years). RESULTS: It was possible to perform an R0 gastrectomy more often in patients without alarm symptoms (21 patients; 52 per cent) than in those with alarm symptoms (71 patients; 27.3 per cent) (chi(2) = 10.35, 1 d.f., P = 0.001). The cumulative survival rate at 5 years was 38 per cent for patients without alarm symptoms versus 15.0 per cent for those with alarm symptoms (chi(2) = 10.18, 1 d.f., P = 0.001). In a multivariate analysis, distant metastasis (hazard ratio (HR) 2.73 (95 per cent confidence interval (c.i.) 2.04 to 3.66); P < 0.001), overall stage of cancer (HR 1.83 (95 per cent c.i. 1.53 to 2.19); P < 0.001) and persistent vomiting at diagnosis (HR 1.66 (95 per cent c.i. 1.26 to 2.18); P < 0.001) were independently associated with length of survival. CONCLUSION: Alarm symptoms are absent in a significant minority of patients with gastric cancer at diagnosis; these patients stand a better chance of curative surgery and long-term survival than those with alarm symptoms.

Adenocarcinoma↗
PubMed2001

Differentiation between pathologic and physiologic left ventricular hypertrophy by tissue Doppler assessment of long-axis function in patients with hypertrophic cardiomyopathy or systemic hypertension and in athletes.

To identify new echocardiographic indexes of long-axis function that might differentiate between pathologic and physiologic left ventricular (LV) hypertrophy, we compared 60 subjects with different types of LV hypertrophy (group I: 15 patients with hypertrophic cardiomyopathy, group II: 15 patients with systemic hypertension, and group III: 30 athletes) with 20 normal subjects (group IV). The peak velocities of mitral annular motion at 4 sites were measured from the apex by tissue Doppler echocardiography. There were no differences in mean age and global ejection fraction between groups. Groups I and II had lower long-axis systolic and early diastolic velocities than the athletes (p <0.01) for all 4 sites. The best differentiation of pathologic from physiologic hypertrophy was provided by a mean systolic annular velocity <9 cm/s (sensitivity 87%, specificity 97%). Heterogeneity of annular velocities discriminated between group I and group II. Thus, long-axis systolic and early diastolic velocities are decreased in patients with pathologic hypertrophy, but preserved in athletes. These simple new echocardiographic parameters can differentiate between pathologic and physiologic hypertrophy.

Adult↗
PubMed1993

Management of hospital survivors of pre-hospital ventricular fibrillation.

The objective of our study was to characterise 52 hospital survivors of pre-hospital ventricular fibrillation and record their initial management in hospital. A retrospective review was undertaken of ambulance report forms, hospital notes, and electrocardiograms, in one teaching hospital and three district general hospitals in South Wales, of 53 patients discharged from hospital between February 1987 and April 1992 after resuscitation from pre-hospital ventricular fibrillation by ambulance personnel. Twenty patients showed evidence of acute myocardial infarction (group 1), eight patients had a diagnosis of 'possible acute myocardial infarction' (group 2), and 25 patients had no evidence of acute myocardial infarction (group 3). Nineteen patients in group 1 experienced chest pain before collapse compared with only six patients in group 3 (p < 0.001). Five patients in group 1 had a previous history of ischaemic heart disease compared with 17 patients in group 3 (p < 0.01). A greater proportion of patients in group 3 were taking diuretic medication (15 of 25 vs 4 of 20: p < 0.01) but there was no difference in potassium levels on admission to hospital. Cardiologists were involved in the management of a minority of patients (21 of 53); only eight patients underwent cardiac catheterisation; and only three were referred for electrophysiological studies. Patients in group 3 were more likely to be discharged taking empiric antiarrhythmic drugs (13 of 25) than patients in group 1 (2 of 20) (p < 0.01). Not enough use is made of noninvasive and invasive investigations in the management of survivors of pre-hospital ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Adenosine-induced respiratory stimulation in man depends on site of infusion. Evidence for an action on the carotid body?

Adenosine is an endogenous nucleoside which stimulates respiration in man and other mammals. In animals adenosine appears to initiate respiratory stimulation within the carotid body, but whether this is the site of action in man is not known. We administered adenosine by intra-aortic infusion to 12 subjects undergoing cardiac catheterisation. When adenosine was infused at three sites proximal to the carotid circulation, minute ventilation was significantly higher than baseline values or those during adenosine infusion at a more distal site. These results support the hypothesis that adenosine-induced respiratory stimulation in man is mediated in the carotid body.

Adenosine↗
PubMed1986

Plasma amiodarone concentrations during intravenous infusion.

Amiodarone is a useful antiarrhythmic agent whose pharmacokinetics are incompletely characterised. In order to optimise efficacy of an antiarrhythmic drug, information regarding plasma concentrations achieved during use of the drug is necessary. We report plasma amiodarone and desethylamiodarone concentrations in eight patients following intravenous infusion at a rate of 175 mg h-1 for the first 2 h, followed by infusion at a rate of 50 mg h-1 for a further 46 h a regimen very similar to that recommended by the manufacturers. In at least three of eight patients plasma concentrations were below the suggested therapeutic range of 1.0-2.5 mg l-1 from 3 to 16 h after the infusion was started. Our data suggests that larger doses of intravenous amiodarone than those previously recommended may be necessary to obtain optimal benefit from the drug.

Aged↗
PubMed1986

Intravenous adenosine in the treatment of supraventricular tachycardia: a dose-ranging study and interaction with dipyridamole.

Increasing doses of adenosine were given by rapid intravenous bolus to seven patients with spontaneous supraventricular tachycardia. Adenosine restored sinus rhythm in 10 of 14 episodes of narrow complex tachycardia. In those patients in whom adenosine produced only transient ventricular slowing the underlying rhythm was atrial flutter. Transient dyspnoea occurred in all patients. In two patients taking dipyridamole the mean dose of adenosine which produced an electrophysiologic effect (restoration of sinus rhythm or ventricular slowing to under 100 beats min-1) was 1.0 +/- 0.52 mg, whereas in other patients the mean dose was 8.8 +/- 2.6 mg, suggesting potentiation of the action of adenosine by dipyridamole.

Adenosine↗
PubMed1986

Factors determining symptoms in heart failure: comparison of fast and slow exercise tests.

Factors determining the symptoms of breathlessness and fatigue in patients with congestive heart failure were investigated by comparing the response to slow and fast exercise. Symptom limited oxygen consumption (maximal); minute ventilation, mean pulmonary capillary wedge pressure; and arterial blood gases, pH, and lactate concentrations were measured during treadmill exercise using a slow protocol in 25 men (age 34-67 years) with congestive heart failure (New York Heart Association class II-III). Ten of these patients were also exercised according to a rapid protocol. Exercise was terminated by fatigue in 23/25 patients after the slow test and by breathlessness in all patients after the rapid test. Exercise capacity (maximal oxygen consumption and exercise duration) was not related to resting or exercise pulmonary capillary wedge pressure or the change in pulmonary capillary wedge pressure during exercise, nor was there any difference in pulmonary capillary wedge pressure at the end of exercise within individuals between the fast and slow tests. Minute ventilation was greater (51 vs 43 1/min), peak exercise lactate concentration higher (3.7 vs 2.2 mmol/l), and the change in pH from the resting state was greater (0.06 vs 0.02) during the rapid test than during the slow test. The sensation of breathlessness in congestive heart failure is not simply related to raised pulmonary capillary wedge pressure, but may in part be due to stimulation of peripheral chemoreceptors in response to metabolic acidosis.

Adult↗
PubMed1985

Amiodarone reduces plasma warfarin clearance in man.

Amiodarone is an effective antiarrhythmic agent whose use is associated with several drug interactions one of which is potentiation of the action of warfarin. The mechanism of this interaction has hitherto been unclear. We examined possible mechanisms in eight patients. Total plasma warfarin clearance was found to be reduced by amiodarone. No change was detected in the binding of warfarin to plasma proteins. No relationship was found between plasma amiodarone concentrations and the change in warfarin clearance.

Aged↗
PubMed1985

Peripheral neuropathy during longterm high-dose amiodarone therapy.

Three patients developed peripheral neuropathy after taking amiodarone for more than 18 months. All had high serum concentrations of amiodarone and its desethyl metabolite; in one patient concentrations in a sural nerve biopsy were 80 times higher than in serum. Peripheral neuropathy is a complication of large doses of amiodarone taken over long periods.

Aged↗