Biomedical subjects

Peter A Bampton

Publications and source records attributed to Peter A Bampton.

5 recordsLinked to original sources

PubMed2006

Improving surveillance for Barrett's oesophagus.

PROBLEM: A retrospective audit of surveillance for Barrett's oesophagus 1996-2001 identified the need to improve adherence to guidelines for the endoscopic surveillance of patients with Barrett's oesophagus. DESIGN: Prospective audit of the effect of disseminating guidelines in 2002. Prospective audit of the effect of introducing local guidelines and Barrett's oesophagus surveillance officers, 2003-2005. SETTING: Two general hospitals in Australia, 2002-5. All adult patients diagnosed with Barrett's oesophagus were included. KEY MEASURES FOR IMPROVEMENT: Proportions of patients in a Barrett's oesophagus surveillance programme who had appropriate time intervals between follow-up endoscopies and who had appropriate numbers of biopsies collected at endoscopy. STRATEGIES FOR CHANGE: Local guidelines were laid down. Surveillance coordinators for Barrett's oesophagus were introduced to manage the process according to a clinical protocol designed for each patient. EFFECTS OF CHANGE: Disseminating guidelines had little effect on practice. Six months after surveillance coordinators were introduced, adherence to the planned surveillance interval increased from 17% to 92% and the number of endoscopies at which sufficient biopsies were collected increased from 45% to 83%. These changes have been maintained. LESSONS LEARNT: Disseminating guidelines and results of an audit on endoscopic surveillance in Barrett's oesophagus had no effect on practice. Introducing coordinators who proactively managed the process greatly improved adherence to guidelines.

Adult↗

PubMed2006

Many participants in fecal occult blood test population screening have a higher-than-average risk for colorectal cancer.

OBJECTIVES: Population-based colorectal cancer screening by fecal occult blood testing reduces cancer-specific mortality. Current guidelines recommend this strategy for average risk individuals. This study investigated the prevalence of higher-than-average risk characteristics, and rate of prior colonoscopy, in participants in fecal occult blood test screening programs. METHODS: Randomly selected individuals aged 50-74 years in urban Adelaide were offered free fecal occult blood test screening by mail, without prior knowledge of their medical status. Each invitation included a questionnaire to record the prevalence of higher-than-average risk characteristics related to symptoms, family history or comorbidity, as well as prior colonoscopy. The definition of average risk was taken from updated guidelines published by the US Multisociety Task Force on Colorectal Cancer. RESULTS: Of 2538 responses analyzed, 425 individuals had had a colonoscopy within the last 5 years, 106 fulfilled family history criteria for an initial screening colonoscopy, 209 had past polyps and 26 had had colorectal cancer. Eighty-three reported recent rectal bleeding. By current guidelines, 23% of the screened population did not warrant fecal occult blood test, because either prior colonoscopy rendered it unnecessary or particular patient characteristics made colonoscopy a more appropriate initial investigation. CONCLUSIONS: Fecal occult blood test screening programs capture a sizeable number of higher-than-average risk individuals that may warrant colonoscopic rather than fecal occult blood test screening. Other participants have had a recent colonoscopy and probably warrant a delay in screening. Mass population fecal occult blood test-based screening programs need to more effectively target those at average risk and should divert those of higher or lower risk to more individualized assessment.

Aged↗

PubMed2005

Impaired proximal colonic motor response to rectal mechanical and chemical stimulation in obstructed defecation.

PURPOSE: Both motor and sensory dysfunction have been implicated in the pathogenesis of obstructed defecation. We have found that despite preservation of a defecatory urge, patients with obstructed defecation have lost the normal predefecatory augmentation in frequency and amplitude of colonic propagating pressure waves. This observation might be explainable by either altered rectal sensory thresholds or by dysfunction in the colonic motor apparatus. By measuring rectal sensory thresholds and proximal colonic motor responses to rectal mechanical and chemical stimuli, we tested the hypotheses that central perception of rectal stimuli is enhanced and that the proximal colonic motor response to rectal stimulation is attenuated. METHODS: In seven patients with obstructed defecation and ten healthy volunteers we measured proximal colonic motor responses and sensory thresholds in response to both rectal balloon distention and rectal instillation of chenodeoxycholic acid. RESULTS: In controls, but not in patients, rectal mechanical distention significantly reduced and chemical stimulation significantly increased the frequency of proximal colonic propagating sequences (P = 0.01). There was no significant difference in rectal sensory thresholds between patients and controls. Prior instillation of chenodeoxycholic acid significantly reduced (P < 0.03) maximum tolerated balloon volume and defecatory urge volume to comparable degree in both patients and controls. CONCLUSIONS: In obstructed defecation, 1) the normal rectocolonic pathways mediating stimulation-induced proximal colonic propagating pressure waves are nonfunctioning, and. 2) central perception of these rectal stimuli is normal.

Adult↗

PubMed2004

Abnormal predefecatory colonic motor patterns define constipation in obstructed defecation.

BACKGROUND & AIMS: The pathophysiology of constipation in the syndrome of obstructed defecation is unknown. Using 24-hour pancolonic manometric recordings of the unprepared colon to record basal pressures and spontaneous defecation episodes, we tested the hypothesis that the frequency, timing, or spatial distribution of propagating colonic pressure waves is abnormal in patients with obstructed defecation. METHODS: In 11 patients with obstructed defecation and 16 healthy controls, pressures were recorded using a nasocolonic catheter that was positioned such that 16 recording sites spanned the unprepared colon at 7.5-cm intervals. RESULTS: The overall frequency of propagating sequences (PS) in the colon did not differ between patients and controls. When compared with controls, patients had a significant increase in the frequency of retrograde and antegrade PS (P < 0.05) in the left colon and a significant reduction in the amplitude of propagating pressure waves throughout the entire colon (P < 0.03). Defecation occurred in 6 of 11 patients and 9 of 16 controls. In the 15 minutes before defecation, controls showed a highly significant increase in frequency (P = 0.001) and amplitude (P = 0.01) of PS. In contrast, patients did not demonstrate this or the typical spatiotemporal organization of PS normally observed before expulsion of stool. CONCLUSIONS: Patients with obstructed defecation lack the normal predefecatory augmentation in frequency and amplitude of propagating pressure waves and lack the normal stereotypic spatiotemporal patterning of colonic pressure waves that would normally culminate in effective expulsion of stool.

Adult↗

PubMed2002

Applying evidence-based guidelines improves use of colonoscopy resources in patients with a moderate risk of colorectal neoplasia.

OBJECTIVES: To determine whether applying National Health and Medical Research Council (NHMRC) guidelines for colorectal cancer prevention would reduce the number of follow-up colonoscopies. DESIGN: A prospective audit of colonoscopic surveillance decisions before and after the intervention. SETTING: The endoscopy suite at a metropolitan tertiary hospital three months before and after January 2000. INTERVENTION: Dissemination of NHMRC guidelines, and supervision of application of the guidelines by a nurse coordinator. SUBJECTS: We compared colonoscopic surveillance decisions before and after the intervention in two groups of 100 consecutive patients after polypectomy and in two groups of 50 consecutive patients with a family history of colorectal cancer after a normal colonoscopy. MAIN OUTCOME MEASURES: Change in concordance of decisions with NHMRC guidelines; and effect on number of follow-up colonoscopies. RESULTS: After the intervention, the proportion of postpolypectomy surveillance decisions matching the guidelines increased from 37% to 96% (P < 0.05). The mean time to repeat colonoscopy after polypectomy increased from 2.7 to 3.5 years (P < 0.005) (ie, a 23% reduction in the number of postpolypectomy surveillance colonoscopies performed per year). Likewise, the proportion of family-history surveillance decisions matching the guidelines increased from 63% to 96%. Adhering to the guidelines resulted in a 17% reduction in colonoscopies performed on the basis of a family history of colorectal cancer. CONCLUSIONS: Supervised application of evidence-based guidelines to a colorectal cancer surveillance program significantly reduces the number of surveillance colonoscopies performed.

Adenoma↗