ABSTRACT
BACKGROUND: Ischaemic preconditioning (IPC) and intermittent ischaemia (INT) reduce liver injury after ischaemia reperfusion (IR). Steatotic livers are at a higher risk of IR injury, but the protection offered by IPC and INT is not well understood. The aim of the present study was to determine the effectiveness of IPC and INT in maintaining liver function in steatotic livers. MATERIAL AND METHODS: A model of segmental hepatic ischaemia (45 min) and reperfusion (60 min) was employed using lean and obese Zucker rats. Bile flow recovery was measured to assess dynamic liver function, hepatocyte fat content quantified and blood electrolytes, metabolites and bile calcium measured to assess liver and whole body physiology. Liver marker enzymes and light and electron microscopy were employed to assess hepatocyte injury. RESULTS: IPC was not effective in promoting bile flow recovery after IR in either lean or steatotic livers, whereas INT promoted good bile flow recovery in steatotic as well as lean livers. However, the bile flow recovery in steatotic livers was less than that in lean livers. In steatotic livers, ischaemia led to a rapid and substantial decrease in fat content. Steatotic livers were more susceptible to IR injury than lean livers, as indicated by increased blood ALT concentrations and major histological injury. CONCLUSION: INT is more effective than IPC in restoring liver function in the acute phase of IR in steatotic livers. In obese patients, INT may be useful in promoting better liver function after IR after liver resection.
Subject(s)
Fatty Liver/physiopathology , Ischemic Preconditioning , Liver/physiopathology , Obesity/physiopathology , Reperfusion Injury/prevention & control , Reperfusion/adverse effects , Alanine Transaminase/blood , Animals , Bile/metabolism , Biomarkers/blood , Calcium/metabolism , Disease Models, Animal , Electrolytes/blood , Fatty Liver/etiology , Fatty Liver/metabolism , Fatty Liver/surgery , Lipid Metabolism , Liver/metabolism , Liver/surgery , Liver/ultrastructure , Male , Obesity/complications , Obesity/metabolism , Rats , Rats, Zucker , Reperfusion Injury/etiology , Reperfusion Injury/metabolism , Reperfusion Injury/physiopathology , Time FactorsABSTRACT
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.
