Guidelines for oesophageal manometry and pH monitoring 1 Guidelines for oesophageal manometry and pH monitoring Keith Bodger1 and Nigel Trudgill2 1 Aintree Centre for Gastroenterology, University Hospital Aintree, Liverpool, L9 7AL 2 Department of Gastroenterology, Sandwell General Hospital, Lyndon, West Bromwich, West Midlands, B71 4HJ EXECUTIVE SUMMARY & RECOMMENDATIONS tion for their symptoms. A high dose therapeutic trial of a pro- n patients with suspected oesophageal symptoms, flexible ton pump inhibitor is indicated in such patients (Evidence endoscopy and/or contrast radiology (eg. barium swallow) grade B). In patients with throat or respiratory symptoms Ishould be performed before considering manometric this trial should be for four months, as a symptomatic assessment (Evidence grade C). response may be delayed (Evidence grade B). Ambulatory Oesophageal manometry is indicated for the evaluation of oesophageal pH monitoring off therapy may be of value to dysphagia not definitively diagnosed by means of endoscopy exclude excess acid gastro-oesophageal reflux when this and/or radiology, as manometry is the most accurate method appears unlikely or pH monitoring on a proton pump inhibitor for diagnosing the well-characterised primary oesophageal may be of value when there is an inadequate response to a motility disorders (achalasia and diffuse oesophageal spasm) therapeutic trial, to judge whether further dose escalation is (Evidence grade C). appropriate (Evidence grade C). Oesophageal manometry is the most accurate method for Patients with endoscopic oesophagitis and a good response pH electrode placement (Evidence grade B). to a proton pump inhibitor do not require an ambulatory Acid gastro-oesophageal reflux accounts for a significant oesophageal pH study prior to anti-reflux surgery. Patients proportion of non-specific manometric abnormalities and a with symptoms suggestive of acid reflux without endoscopic therapeutic trial of a proton pump inhibitor is recommended oesophagitis and a good response to a proton pump inhibitor in the initial management of patients with suspected should undergo ambulatory oesophageal pH monitoring off oesophageal symptoms, who have non-specific motility therapy prior to anti-reflux surgery (Evidence grade abnormalities identified at manometry (Evidence grade C) C).Patients with symptoms potentially due to acid reflux who Pre-operative oesophageal manometry is of limited value fail to respond to a high dose proton pump inhibitor should but does prevent anti-reflux surgery in the rare patients who undergo ambulatory oesophageal pH monitoring on a proton present with clinical features suggestive of acid gastro- pump inhibitor prior to anti-reflux surgery and a good corre- oesophageal reflux and have a primary motility disorder, such lation between the patient’s symptoms and acid reflux as achalasia, and is therefore recommended (Evidence grade episodes, as assessed by the symptom index, established C). (Evidence grade C). Ambulatory oesophageal pH monitor- In the absence of locally determined ranges for defining the ing should be undertaken in patients with persistent limits of physiological acid reflux, the following data should symptoms following anti-reflux surgery, particularly if further be utilised: percentage total time oesophageal pH<4 <5%; surgery is planned, to ensure there is evidence of persistent percentage upright time oesophageal pH<4 <8%; percentage acid reflux and a good correlation between the patient’s supine time oesophageal pH<4 <3%; number of episodes symptoms and acid reflux episodes (Evidence grade C). pH<4 for >5 minutes <3 (Evidence grade B). Oesophageal manometry and ambulatory oesophageal pH Ambulatory oesophageal pH monitoring has clear limita- monitoring are associated with minor morbidity, largely vaso- tions in defining pathological acid reflux due to false negative vagal episodes, discomfort from the catheter and a runny studies, but it is the only investigation that provides informa- nose, and restrictions affecting diet and activity. Patients with tion on whether patients’ symptoms are related to acid reflux. a heart valve replacement or a previous episode of bacterial The optimal period for analysis is from two minutes before to endocarditis should receive antibiotic prophylaxis (Evidence the time the event marker on the data logger was pressed grade C). All patients undergoing oesophageal manometry or (Evidence grade B). A measure of the association of the ambulatory oesophageal pH monitoring should give written patient’s symptoms and acid reflux episodes, such as the informed consent (Evidence grade C). symptom index, and the number of symptomatic events, To ensure high clinical standards in oesophageal function should be included in the report of an ambulatory testing, all clinicians undertaking oesophageal manometry or oesophageal pH study (Evidence grade C). pH monitoring in the United Kingdom should be registered Ambulatory oesophageal pH monitoring has no role in the with the Association of Gastrointestinal Physiologists (AGIP) initial management of patients with symptoms suggestive of (Evidence grade C). acid gastro-oesophageal reflux. A high dose therapeutic trial of a proton pump inhibitor is the diagnostic investigation of 1.0 INTRODUCTION choice (Evidence grade B). In patients with symptoms sug- Oesophageal disorders are among the most common medical gestive of acid gastro-oesophageal reflux, who fail to respond conditions. Symptoms of acid gastro-oesophageal reflux affect during a therapeutic trial of a proton pump inhibitor, ambula- up to a third of the population in the UK. Oesophageal tory oesophageal pH monitoring on a proton ump inhibitor manometry and ambulatory oesophageal pH monitoring have may be of value to obviate the need for repeated, potentially become established clinical tools in the investigation of futile, attempts at dose escalation (Evidence grade C). oesophageal symptoms. There have been significant develop- Chest pain, throat and respiratory symptoms may be due to ments in this field since the previous guidelines were acid gastro-oesophageal reflux, particularly in patients with formulated in 1996, particularly the advent of proton pump heartburn or acid regurgitation and no alternative explana- inhibitors and increasing awareness of the value of therapeu- November 2006 BSG Guidelines in Gastroenterology 2 Keith Bodger and Nigel Trudgill tic trials with these agents. These developments merit a comprises a pressure sensing apparatus that detects changes reassessment of the clinical role of oesophageal manometry in luminal pressure and converts this to an electrical signal, and ambulatory oesophageal pH monitoring and this is the and a recording device that amplifies and stores this informa- purpose of these guidelines. tion for subsequent analysis. Manometric results are presented either as hard copy readouts (using ink or thermal 2.0 FORMULATION OF GUIDELINES writing polygraphs) or via computer-generated reporting These guidelines have been produced in accordance with rec- using analog to digital conversion and software analysis. ommendations of the North of England evidence based guidelines development project.i They are based on a Medline There are two main forms of sensing/transducer device in literature search using the search terms “oesophageal current use: manometry” and “oesophageal pH monitoring”, and on expert opinion and review. The application of oesophageal Water-perfused catheters coupled to volume-displacement studies in the paediatric population is considered beyond the transducers scope of these guidelines. This type of catheter comprises a bundle of thin plastic tubes each with an outward facing side-hole. There are typically 3- 2.1 CATEGORIES OF EVIDENCE 8 pressure-sensing side holes spaced along the length of the The strength of evidence used to formulate these guidelines catheter and radially orientated, thereby allowing simultane- was graded according to the following system: ous measurement of pressures at multiple locations. The tubes are continuously perfused with bubble-free water as a • Ia—Evidence obtained from meta-analysis of randomised non-compressible medium and the pressure in each tube is controlled trials. monitored by a volume-displacement transducer. Water flow • Ib—Evidence obtained from at least one randomised through the side holes is impeded by oesophageal contraction. controlled trial. • IIa—Evidence obtained from at least one well designed Solid-state strain gauges controlled study without randomisation. This type of catheter is composed of a linear arrangement of • IIb—Evidence obtained from at least one other type of well miniature, solid-state strain gauges spatially and radially ori- designed quasi experimental study. entated along a flexible tube. The signal from each strain • III—Evidence obtained from well designed non- gauge provides a direct measure of intraluminal pressure. experimental descriptive studies such as comparative These catheters are technically easier to use and less cumber- studies, correlation studies, and case studies. some than traditional water-perfused systems, but are more • IV—Evidence obtained from expert committee reports or expensive both to buy and repair. There have been no studies opinions, or clinical experiences of respected authorities. to compare the relative running costs of the two alternative systems. Absolute pressure values and normal ranges The evidence category is indicated after the citations in the obtained with water-perfused