Comparison of anorectal function measured using wearable digital manometry and a high resolution manometry system.

There is a need for a lower cost manometry system for assessing anorectal function in primary and secondary care settings. We developed an index finger-based system (termed "digital manometry") and tested it in healthy volunteers, patients with chronic constipation, and fecal incontinence. Anorectal pressures were measured in 16 participants with the digital manometry system and a 23-channel high-resolution anorectal manometry system. The results were compared using a Bland-Altman analysis at rest as well as during maximum squeeze and simulated defecation maneuvers. Myoelectric activity of the puborectalis muscle was also quantified simultaneously using the digital manometry system. The limits of agreement between the two methods were -7.1 ± 25.7 mmHg for anal sphincter resting pressure, 0.4 ± 23.0 mmHg for the anal sphincter pressure change during simulated defecation, -37.6 ± 50.9 mmHg for rectal pressure changes during simulated defecation, and -20.6 ± 172.6 mmHg for anal sphincter pressure during the maximum squeeze maneuver. The change in the puborectalis myoelectric activity was proportional to the anal sphincter pressure increment during a maximum squeeze maneuver (slope = 0.6, R2 = 0.4). Digital manometry provided a similar evaluation of anorectal pressures and puborectalis myoelectric activity at an order of magnitude less cost than high-resolution manometry, and with a similar level of patient comfort. Digital Manometry provides a simple, inexpensive, point of service means of assessing anorectal function in patients with chronic constipation and fecal incontinence.

Deciding on Appropriate Telemetric Intracranial Pressure Monitoring System.

BACKGROUND: The clinical advantage of telemetric intracranial pressure (ICP) monitoring has previously been limited by issues with inaccuracy and zero-drift. Today, 2 comparable telemetric ICP monitoring systems are available performing adequately in these parameters. The objective of this study is to identify appropriate uses of each system. METHODS: The 2 telemetric ICP monitoring systems from Raumedic (implant: Neurovent-P-tel) and Miethke (implant: Sensor Reservoir) are compared in terms of fundamental differences, sensor survival, monitoring possibilities, complications, and cost/benefit. Two illustrative cases are presented highlighting clinical advantages and disadvantages of each system. RESULTS: Both systems provide transdermal (telemetric) ICP measurements through external application of a reader unit cabled to a portable data sampler. Thereby, they allow several ICP monitoring sessions without multiple surgical insertions of a cabled ICP sensor. The Miethke implant has a high sampling frequency (40 Hz) and a long CE (Conformité Européenne) approval (3 years) but cannot be used for long-duration monitoring sessions. In comparison, the Raumedic implant has a lower sampling frequency (5 Hz) and shorter CE approval (90 days) but can be used for long-duration monitoring sessions. The standard 3-year cost for a patient with a Neurovent-P-tel is 17,380 €, and for the Sensor Reservoir it is 15,790 €. CONCLUSIONS: The Miethke system is useful in outpatient clinics where patients have sequential point measurements of ICP performed, whereas the Raumedic system is ideal for long-duration ICP monitoring outside the hospital. When choosing between the 2 systems, it must primarily be decided if the clinical situation requires long-duration monitoring sessions or continuous repeated ambulatory follow-up sessions.

Rethinking the laryngopharyngeal reflux treatment algorithm: Evaluating an alternate empiric dosing regimen and considering up-front, pH-impedance, and manometry testing to minimize cost in treating suspect laryngopharyngeal reflux disease.

OBJECTIVES/HYPOTHESIS: Empiric proton pump inhibitor (PPI) trials for laryngopharyngeal reflux (LPR) are common. A majority of the patients respond to acid suppression. This work intends to evaluate once-daily, 40 mg omeprazole and once-nightly, 300 mg ranitidine (QD/QHS) dosing as an alternative regimen, and use this study's cohort to evaluate empiric regimens prescribed for LPR as compared to up-front testing with pH impedance multichannel intraluminal impedance (MII) with dual pH probes and high-resolution manometry (HRM) for potential cost minimization. STUDY DESIGN: Retrospective cohort review and cost minimization study. METHODS: A chart review identified patients diagnosed with LPR. All subjects were treated sequentially and outcomes recorded. Initial QD/QHS dosing increased after 3 months to BID if no improvement and ultimately prescribed MII and HRM if they failed BID dosing. Decision tree diagrams were constructed to determine costs of two empiric regimens and up-front MII and HRM. RESULTS: Ninety-seven subjects met the criteria. Responders and nonresponders to empiric therapy were identified. Seventy-two subjects (74%) responded. Forty-eight (67% of responders and 49% of all) improved with QD/QHS dosing. Forty-nine (51%) subjects escalated to BID dosing. Twenty-four subjects (33% of responders and 25% of all) improved on BID therapy. Twenty-five subjects (26%) did not respond to acid suppression. Average weighted cost was $1,897.00 per patient for up-front testing, $3,033.00 for initial BID, and $3,366.00 for initial QD/QHS. CONCLUSIONS: An alternate QD/QHS regimen improved the majority who presented with presumed LPR. Cost estimates demonstrate that the QD/QHS regimen was more expensive than the initial BID high-dose PPI for 6 months. Overall per-patient cost appears less with up-front MII and HRM. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:S1-S13, 2017.

High Cost and Low Yield: The Diagnostic Evaluation of Rumination Syndrome in Pediatrics.

OBJECTIVE: To document the use of diagnostic testing in adolescents who ultimately were diagnosed with rumination syndrome, a functional gastrointestinal disorder. We examined the diagnostic yield of each test as well as the associated costs, and we determined if any demographic or illness-related variables impacted the magnitude of the work-up. STUDY DESIGN: A retrospective chart review was conducted for 68 patients with rumination syndrome admitted to our inpatient treatment program. The cost and findings of patients' diagnostic investigations were gathered, as well as demographic and illness-related variables to determine factors that may be related to evaluation size. RESULTS: The most commonly used tests in the evaluation of rumination syndrome included esophagogastroduodenoscopy, gastric emptying, antroduodenal manometry, upper gastrointestinal series, and abdominal ultrasound scan. Each patient underwent an average of 8.8 tests, with the average cost for each patient's diagnostic work-up being US $19 795. Few tests were found to be beneficial in the diagnosis of rumination syndrome, and few demographic or illness variables were found to be related to the overall extent of the investigation. CONCLUSIONS: Extensive testing for rumination syndrome in adolescents is common in clinical practice, and comes at a high financial cost with low yield, likely delaying diagnosis and treatment. Symptom-based criteria should be used to make the diagnosis of rumination syndrome.

A Lab Assembled Microcontroller-Based Sensor Module for Continuous Oxygen Measurement in Portable Hypoxia Chambers.

BACKGROUND: Hypoxia-based cell culture experiments are routine and essential components of in vitro cancer research. Most laboratories use low-cost portable modular chambers to achieve hypoxic conditions for cell cultures, where the sealed chambers are purged with a gas mixture of preset O2 concentration. Studies are conducted under the assumption that hypoxia remains unaltered throughout the 48 to 72 hour duration of such experiments. Since these chambers lack any sensor or detection system to monitor gas-phase O2, the cell-based data tend to be non-uniform due to the ad hoc nature of the experimental setup. METHODOLOGY: With the availability of low-cost open-source microcontroller-based electronic project kits, it is now possible for researchers to program these with easy-to-use software, link them to sensors, and place them in basic scientific apparatus to monitor and record experimental parameters. We report here the design and construction of a small-footprint kit for continuous measurement and recording of O2 concentration in modular hypoxia chambers. The low-cost assembly (US$135) consists of an Arduino-based microcontroller, data-logging freeware, and a factory pre-calibrated miniature O2 sensor. A small, intuitive software program was written by the authors to control the data input and output. The basic nature of the kit will enable any student in biology with minimal experience in hobby-electronics to assemble the system and edit the program parameters to suit individual experimental conditions. RESULTS/CONCLUSIONS: We show the kit's utility and stability of data output via a series of hypoxia experiments. The studies also demonstrated the critical need to monitor and adjust gas-phase O2 concentration during hypoxia-based experiments to prevent experimental errors or failure due to partial loss of hypoxia. Thus, incorporating the sensor-microcontroller module to a portable hypoxia chamber provides a researcher a capability that was previously available only to labs with access to sophisticated (and expensive) cell culture incubators.

Development of an electronic manometer for intrapleural pressure monitoring.

BACKGROUND: Measurement of intrapleural pressure is useful during various pleural procedures. However, a pleural manometer is rarely available. OBJECTIVES: The aim of this study was to (1) construct an electronic pleural manometer, (2) assess the accuracy of the measurements done with the new device, (3) calculate the costs of the manometer construction and (4) perform an initial evaluation of the device in a clinical setting. METHODS: Only widely accessible elements were used to construct the device. A vascular pressure transducer was used to transform pressure into an electronic signal. Reliability of the measurements was evaluated in a laboratory setting in a prospective, single-blind manner by comparing the results with those measured by a water manometer. Functionality of the device was assessed during therapeutic thoracentesis. The cost of the new pleural manometer was calculated. RESULTS: We built a small, portable device which can precisely measure intrapleural pressure. The measurement results showed very high agreement with those registered with a water manometer (r = 0.999; p < 0.001). The initial evaluation of the electronic manometer during therapeutic thoracentesis showed it was easy to use. The total time needed for 6 measurements after withdrawal of different volumes of pleural fluid in 1 patient did not exceed 6 min. The total cost of the device was calculated to be <2,000 EUR. CONCLUSIONS: In the face of very limited offer of commercially available pleural manometers, it is possible to successfully construct a self-made, reliable, electronic pleural manometer at modest costs. The device is easy to use and enables data display and storage in the personal computer.

[Health economical aspects of telemedical glaucoma monitoring]. / Gesundheitsökonomische Aspekte des telematischen Glaukom-Monitorings.

BACKGROUND: Telemedical home monitoring of glaucoma patients is not covered by health insurance in Germany. Various clinical studies have indicated that 24 h monitoring of intraocular and blood pressure of glaucoma patients allows a better evaluation of the individual disease condition. If the necessary parameters can be collected with telemedical home monitoring it will be possible to reduce the number of 24 h intraocular pressure profiles which necessitate hospital admission. Therefore inpatient 24 h profiles have been chosen as a health economical allocation base with a presentable economical value for the comparative examination. Assuming an at least identical or even higher clinical outcome of the telemedical glaucoma home monitoring inpatient 24 h profiles were chosen as a health economical allocation base to compare and contrast these methods. METHODS: All procedures of the inpatient 24 h profiles at the ophthalmic clinic of Greifswald were measured using the stopwatch method. In a 1 day test run all activities of the medical staff were identified and documented in a list and afterwards measurements were carried out over 7 days with several stopwatches to allow the documentation of parallel activities. To determine the consumption of resources in telemedical home monitoring the self-documentation of all employees involved in the research project TT-MV were evaluated. Expert interviews helped to determine the economically relevant data about the applied medical technology, e.g. measuring devices, server and electronic health records. RESULTS: The number and complexity of the subprocesses of the inpatient 24 h intraocular pressure profiles were significantly higher compared to telemedical home monitoring. The total costs of the inpatient 24 h profiles were 571.21 € per patient including 291.21 € for medical care and 280 € for accommodation. In contrast the total costs of telemedical home monitoring were 288.72 € per patient. A direct cost comparison shows that telemedical home monitoring resulted in lower costs compared to hospital admission of glaucoma patients. CONCLUSION: Telemedical home monitoring of glaucoma patients is not only effective but also cost-efficient. As modern health care systems have to consider cost efficiency, a randomized, controlled longitudinal clinical study of both methods would be required.

When does testing for GERD become cost effective in an integrated health network?

BACKGROUND: Gastroesophageal reflux (GERD) is the most common gastrointestinal disorder, affecting as many as 14% of the US population. Rising rates of esophageal adenocarcinoma are seen in this population, and chronic proton pump inhibitor (PPI) use does not normalize cancer risk. It has also been demonstrated that up to one-third of patients on PPI therapy did not actually have GERD and could be taken off the medication. These facts form the basis for a quality-assurance study of care provided to patients in an integrated health care network who were on high-dose, long-term PPI therapy. METHODS: A cost-benefit analysis of patients who were on double-dose PPI therapy for more than 6 months was performed. Pharmacy, facility, physician reimbursement, and radiologic data from a cohort who were both primary-care patients and insured in our system were utilized. RESULTS: Two hundred and twenty-four patients were prescribed a double dose of this medication for over 6 months. Utilizing a 4.5% discount rate, our break-even analysis showed that Bravo testing [with esophagogastroduodenoscopy (EGD)] needed to identify those patients who could be taken off PPI therapy paid for itself in 33 months. Bravo + EGD + manometry testing needed to screen for other possible pathologies paid for itself in 38 months. Bravo + barium swallow + EGD testing to screen patients for possible esophageal adenocarcinoma paid for itself in 42 months. Bravo + barium swallow + manometry + EGD testing paid for itself in 47 months. CONCLUSIONS: Significant savings can be realized through early use of upper endoscopy, Bravo testing, barium swallow, and manometry to identify patients that are taking double-dose PPIs unnecessarily based on presumptive diagnosis of GERD. This early testing also has the potential to diagnose a variety of other clinically important pathologic conditions more readily.

The use of one-channel water cystometry in patients with a spinal cord lesion: practicalities, clinical value and limitations for the diagnosis of neurogenic bladder dysfunction.

STUDY DESIGN: Investigational technique evaluation. OBJECTIVE: To evaluate the clinical value and limitations of one-channel cystometry as a method for urodynamic testing in patients with spinal cord lesion (SCL). SETTING: Spinal Cord Injury Centers Asia. METHODS: Protocol, equipment and practical performance of the one-channel cystometry as used in Ho Chi Minh City and Chiang Mai were studied. RESULTS: One-channel cystometry permits to accurately evaluate bladder pressure development at constant filling speed. It shows detrusor muscle behaviour as detrusor overactivity and allows evaluating sensation of bladder filling. It can strongly suggest detrusor external sphincter dyssynergia. The need of bladder-relaxant drugs and their effectiveness can be evaluated. The major limitation is that the one pressure line will show changes of intravesical pressure independent of their cause, which makes a continuous thorough observation mandatory throughout the test. Other limitations are a filling rate higher than physiological and a filling solution at room temperature. As in more elaborate urodynamic testing, the observations do therefore not necessarily reflect the function of the lower urinary tract in daily life. CONCLUSION: One-channel cystometry is easy to perform, cheap and clinically valid. The results need to be integrated in the overall knowledge of the patient's neurological situation. The method permits one to gather a lot of information on bladder function in persons with SCL. With proper interpretation and a clear understanding of the shortcomings, it is a good guide for bladder management. It is applicable everywhere.

Implantable telemetric pressure measurement.

Highly miniaturised implantable pressure sensors can be used for wireless monitoring of different therapeutic procedures. This article presents an outlook on the market potential of these systems.

Suspected sphincter of Oddi dysfunction type II: empirical biliary sphincterotomy or manometry-guided therapy?

BACKGROUND AND STUDY AIMS: Sphincter of Oddi manometry is considered to be the gold standard for diagnosing sphincter of Oddi dysfunction (SOD). Elevated basal sphincter pressures are found in about half of the patients with findings consistent with biliary type II SOD, and most of these patients will symptomatically improve after endoscopic sphincterotomy. Since manometric sphincter evaluation is not widely available, a decision analysis was used to compare the overall costs and outcomes of manometry-directed therapy with "empirical" sphincterotomy in patients with suspected biliary type II SOD. PATIENTS AND METHODS: A decision analysis model was constructed using a software program. In a hypothetical cohort of 100 patients with suspected type II SOD, the following strategies were evaluated: a). endoscopic retrograde cholangiopancreatography (ERCP) with manometry followed by biliary sphincterotomy only if an elevated sphincter of Oddi basal pressure was found; and b). "empirical" biliary sphincterotomy without manometry. Data on the probability of an elevated sphincter of Oddi basal pressure at the time of ERCP in patients with suspected biliary SOD type II, the proportion of patients who improved after biliary sphincterotomy (with and without elevated basal pressures), the proportion of patients who improved without biliary sphincterotomy, complications, and death were obtained from the literature and from our center. The procedural and hospitalization costs represented the average Medicare reimbursement at our institution. The expected overall costs and numbers of patients improving with each strategy were compared.[nl] RESULTS: The strategy of ERCP with manometry resulted in total costs of US dollars 2790 per patient, whereas a strategy of "empirical" biliary sphincterotomy resulted in total costs of US dollars 2244. In a cohort of 100 patients with suspected SOD, 55 % of patients would be expected to improve if manometry were performed, compared to 60 % of patients improving with "empirical" biliary sphincterotomy. Univariate sensitivity analyses demonstrated that "empirical" biliary sphincterotomy continued to be a cost-saving strategy in comparison with ERCP with manometry as long as the probability of spontaneous improvement in patients with "normal" manometry was less than 41 %, the probability of complications associated with manometry was greater than 6 %, and the probability of complications due to biliary sphincterotomy was less than 19 %. CONCLUSIONS: For patients with suspected biliary SOD type II, empirical biliary sphincterotomy performed by experienced endoscopists appears to be cost-saving in comparison with a strategy based on the results of manometry.

Selective use of esophageal manometry and 24-Hour pH monitoring before laparoscopic fundoplication.

BACKGROUND: Preoperative esophageal manometry and 24-hour pH monitoring commonly are used in preoperative evaluation of patients undergoing fundoplication. Here we review our experience with the selective preoperative workup of patients undergoing fundoplication to treat gastroesophageal reflux disease. STUDY DESIGN: A series of 628 consecutive antireflux procedures was reviewed. History and physical examination, upper endoscopy, and upper gastrointestinal videofluoroscopy were obtained preoperatively on all patients; the first 30 patients also underwent esophageal manometry and pH monitoring (routine evaluation group). Thereafter, pH monitoring only was performed for atypical reflux symptoms, and manometry only was performed for a history of dysphagia, odynophagia, or for abnormal motility on videofluoroscopy (selective evaluation group). All patients underwent a laparoscopic floppy Nissen fundoplication, and then endoscopy and fluoroscopy at 3 months and 12 months postoperatively. RESULTS: Eighty-five of the patients in the selective evaluation group (14%) required manometry, and 88 (15%) underwent pH monitoring. Eighteen of the 115 patients who underwent manometry (16%) had evidence of dysmotility. None of these 18 patients had increased dysphagia postoperatively; 8 of 18 reported improvement with swallowing. Five patients in the selective group (0.8%) had persistent postoperative dysphagia caused by technical error (four patients) or with no identifiable cause (one patient). The estimated charge or collection reduction with use of the selective evaluation was 1,253,100 US dollars or 395,000 US dollars, respectively. CONCLUSIONS: Selective use of manometry and pH monitoring was cost effective and safe in this series. Although esophageal manometry and 24-hour pH monitoring might be necessary with abnormal findings on videofluoroscopy or atypical symptoms, in our experience, their routine use is not essential in preoperative evaluation of patients undergoing fundoplication for gastroesophageal reflux disease.

Low-cost instrumentation for the diagnosis of Hirschsprung's disease.

In Hirschsprung's disease, the internal anorectal sphincter fails to relax in response to rectal distension, which strongly indicates the absence of rectoanal inhibitory reflex (RAIR). Hirschsprung's disease is a very common case particularly encountered in the newborns in our region. Development of a manometric system targeted specifically for the diagnosis of this disease at a reasonable cost is an urgent need identified by our regional colorectal surgeons. These surgeons indicated that commercially available anorectal manometers are too expensive to acquire. Therefore, in our research we tried to develop a low-cost single balloon-transducer system, which only provides information about RAIR, and hence diagnoses the Hirschsprung's disease. The hardware part of our instrumentation is made of a latex balloon, pressure transducer, amplifier, and A/D converter circuits, which all collects the pressure readings and sends the data to the computer. The manometer system software, programmed based on Delphi, displays these readings and patient information on a computer screen. This designed system was successful enough to perform manometric recording of RAIR in the anorectal ampulla of rabbits and rats.

Outcomes of laparoscopic antireflux procedures.

BACKGROUND: Laparoscopy has increased the number of patients undergoing operative correction of gastroesophageal reflux disease (GERD). Symptom improvement has been most commonly reported as the means to assess operative outcome. We compared symptomatic outcome to postoperative pH testing at short-term follow-up to determine the accuracy of clinical assessment at predicting whether acid exposure would be normal or abnormal. METHODS: Of 640 patients who had antireflux surgery between 1993 and 1999, 228 (36%) agreed to repeat manometry and 24-hour pH monitoring 8 to 12 weeks postoperatively and are the subject of this study. Symptom resolution was assumed if the frequency was less than once per week. Normal acid exposure consisted of a distal esophageal pH below 4 less than 4% of the time and a DeMeester composite score less than 14.7. Accuracy of symptom scoring was calculated using acid exposure as the standard. RESULTS: The primary symptom was improved in 93% of the 228 patients. Acid exposure was reduced from a preoperative DeMeester score of 71 to 16 (P <0.05). Eighty percent of patients had normalization of acid exposure postoperatively. Heartburn was the only symptom to have a significant correlation with acid exposure in the postoperative period (P <0.05). Heartburn resolved in 181 patients, 168 of whom had normal acid exposure (true negative). Thirty-eight patients without symptoms had abnormal acid exposure (false negative). Nine patients had persistent heartburn with abnormal acid exposure (true positive) whereas 13 patients had persistent heartburn with normal acid exposure (false positive). Thus, the positive predictive value of heartburn was 43%, the negative predictive value was 82%, and the overall accuracy was 78%. CONCLUSIONS: Operative treatment improves both the symptoms of GERD and the degree of acid exposure as measured by pH monitoring. The most accurate symptom for predicting acid exposure in the postoperative period is heartburn. Although the absence of heartburn postopertively is fairly reliable at predicting normal acid exposure on pH testing, the presence of heartburn warrants postoperative pH monitoring, as more than half of these patients will have normal acid exposure.

The cost-effectiveness of the omeprazole test in patients with noncardiac chest pain.

PURPOSE: Recent evidence suggests that an empiric trial of omeprazole (the "omeprazole test") is sensitive and specific for diagnosing gastroesophageal reflux disease (GERD) as the cause of noncardiac chest pain. Our objective was to examine the clinical, economic, and policy implications of alternative diagnostic strategies for patients with noncardiac chest pain. METHODS: Decision analysis was used to evaluate the clinical and economic outcomes of two diagnostic strategies that begin with the omeprazole test (60 mg daily for 7 days) followed sequentially by invasive testing utilizing endoscopy, ambulatory 24-hour esophageal pH monitoring, and esophageal manometry as necessary, compared with two traditional strategies involving sequential invasive diagnostic tests. Cost estimates were based on Medicare reimbursement and the Red Book of average wholesale drug prices. Probability estimates were derived from a systematic review of the medical literature. RESULTS: The average cost per patient for the four diagnostic strategies varied from $1,859 to $2,313. Strategies utilizing the initial omeprazole test resulted in 84% of patients being symptom free at 1 year, compared with 73% to 74% for the strategies that began with invasive tests. The strategy of the omeprazole test, followed if necessary by ambulatory pH monitoring, then manometry, and then endoscopy, was both most effective and least expensive. It led to an 11% improvement in diagnostic accuracy and a 43% reduction in the use of invasive diagnostic tests, thus yielding an average cost savings of $454 per patient, compared with the strategy of beginning with endoscopy, then pH monitoring, and then manometry. CONCLUSIONS: Among patients with noncardiac chest pain, diagnostic strategies that begin with the omeprazole test result in reduced costs, improved diagnostic certainty, and a greater proportion of symptom-free patients at 1 year than do traditional strategies that begin with invasive diagnostic tests.

Five-year audit of ambulatory 24-hour esophageal pH-manometry in clinical practice.

BACKGROUND: Esophageal function testing was developed to aid diagnosis in patients with negative endoscopy. Although combined 24-h esophageal pH-manometry is now commercially available, its routine clinical effectiveness has not yet been studied. METHODS: From 1992 to 1996 we evaluated 303 consecutive patients who were first-time referrals to our unit for 24-h esophageal pH-manometry. The referral indications were gastroesophageal reflux disease, 47.2%; dysphagia, 18.5%; non-cardiac chest pain, 14.9%; connective tissue disease, 13.2%; and symptomatic patients after antireflux surgery, 6.3%. RESULTS: Overall, esophageal function testing altered the diagnosis of 44% of the patients, confirmed it in 38%, and specifically changed the management of 66%. The final clinical 'diagnosis' was reflux disease, 54% (32% with non-specific esophageal motility disorder); connective tissue disease, 9.9%; achalasia, 9.6%; other specific esophageal motility disorders, 3.3%; non-specific esophageal motility disorders, 6.9%; and normal, 16.2%. The cost per testing was estimated to be US$305 and per change in management US$465. CONCLUSION: Combined 24-h pH-manometry has been shown to be a useful and cost-effective test for the management of selected patients in whom the primary investigation was insufficient.

Small bowel manometry: short or long recording sessions?

The study of small bowel motility in humans is commonly done by one of two techniques: short-term recording in a stationary patient or long-term recording in an ambulatory patient. To compare the diagnostic yield of short- and long-term manometric studies of small intestinal motility, we reviewed all prolonged records performed in our center over the years. Long-term studies that included less than 6 hr of recording during fasting or less than 5 hr during sleep and short-term studies using the perfused tube technique were excluded, leaving 91/121 tracings suitable for review. We analyzed the first 3 hr of the fasting period and the first 2 hr of the postprandial period on one occasion and the whole tracing on another; the fasting, postprandial and sleep period were analyzed separately. This allowed us to compare short and long recording sessions in the same patient. The two analyses agreed in 81/91 of the cases. In 7/10 patients a study was diagnosed as abnormal in the short recording but was considered normal after review of the long recording, while the opposite occurred in the remaining three. Periods of sleep and fasting contributed similarly to the change in diagnosis. In another 6 patients with equivocal abnormalities during the short period, the long period helped to establish the diagnosis of normality with confidence. Most of the improvement in the long-term study came from extension of the studies during fasting to 6-7 hr from 3 hr. Long-term records of small bowel motility, including study during sleep enhance the diagnostic accuracy of the test. Accuracy can be improved also simply by prolonging the recording during fasting.