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Purpose of Review: Combined impedance-manometry was introduced just over 20 years ago for the assessment of esophageal motor function. Since then, technical developments have led to the introduction of high-resolution impedance-manometry (HRIM). However, analysis of the impedance and manometry recordings has remained separate and relatively unchanged since the introduction of HRIM, and it is unclear whether the addition of impedance has had a significant impact on the management of esophageal motor disorders., Recent Findings: The major technical advance over the past 12 months or so has been the development of automated impedance-manometry (AIM) analysis, in which the impedance and manometric data are analyzed together to assess the interactions between pressure and flow. This analysis has revealed subtle abnormalities in esophageal function in patients with nonobstructive dysphagia who have normal manometry and conventional impedance analyses. AIM analysis has also revealed preoperative characteristics in patients that may predict the occurrence of postfundoplication dysphagia., Summary: Through ongoing technical development, impedance-manometry is becoming increasingly useful clinically to assess esophageal motility disorders as well as to provide further insights into esophageal physiology.

Objective: To investigate late objective outcomes 14 years after laparoscopic anterior 180-degree partial versus Nissen fundoplication., Background: Clinical outcomes from randomized clinical trials suggest good outcomes for anterior 180-degree partial fundoplication, with similar control of reflux symptoms and less side effects, compared with Nissen fundoplication. However, objective outcomes at late follow-up have not been reported., Methods: A subset of participants from a randomized trial of anterior 180-degree versus Nissen fundoplication underwent stationary esophageal high-resolution manometry and ambulatory 24-hour impedance-pH monitoring at 14 years' follow-up. The subset and other patients in the trial also completed a standardized clinical questionnaire to ensure that they were representative of the overall trial., Results: Eighteen patients (8 anterior, 10 Nissen) underwent objective testing and had a symptom profile similar to those who did not (n = 59) have testing. Total esophageal acid exposure time and the total number of acid and weakly acidic reflux episodes per 24 hours were higher after anterior fundoplication than after Nissen fundoplication. Proximal, midesophageal and distal reflux were proportionately increased after anterior 180-degree fundoplication. The number of liquid and mixed reflux episodes was also higher after anterior fundoplication, which was accompanied by higher clinical heartburn scores. There were no differences in gas reflux, gastric belches, and supragastric belches, which is in line with the observation that gas-related symptoms were similar for both groups. Mean LES resting and relaxation nadir pressure were lower after anterior fundoplication, which was reflected by lower dysphagia scores. Patient satisfaction was similar after both procedures., Conclusions: At 14 years after randomization, this study demonstrated that acid, weakly acidic, liquid and mixed reflux episodes are more common after anterior 180-degree fundoplication than after Nissen fundoplication. On the contrary, gas reflux and gastric belching and patient satisfaction are similar for both procedures. Mean LES resting and relaxation nadir pressure are lower after anterior fundoplication. Overall, these findings suggest less effective reflux control after anterior 180-degree partial fundoplication, offset by less dysphagia, leading to a clinical outcome that is equivalent to Nissen fundoplication at late follow-up.

Objective: Inadequate nutrition is common in critical illness due in part to gastric stasis. However, recent data suggest that altered small intestinal mucosal function may be a contributing factor. The aim of this study was to examine the effects of critical illness on sucrose absorption, permeability, and mucosal morphology., Design: Prospective, observational study., Setting: Tertiary critical care unit., Subjects: Twenty mechanically ventilated patients (19 men; 52.2 ± 20.5 yr; 9 feed intolerant; Acute Physiology and Chronic Health Evaluation II score 16.2 ± 6.0) and 20 healthy subjects (14 men; 51.6 ± 21.5 yr)., Interventions: Following a 4-hr fast, a "meal" (100 kcal Ensure, 20-g enriched C-sucrose, 1.1 g rhamnose, 7.5 mL lactulose) was administered into the small intestine. Sucrose absorption was evaluated by analyzing 13CO2 concentration (cumulative percent of administered 13C dose recovered) in expiratory breath samples taken at timed intervals. At 90 minutes, a plasma lactulose/rhamnose concentration was also measured, with lactulose/rhamnose ratio, a marker of small intestinal mucosal permeability. When possible duodenal biopsies were taken in critically ill patients on insertion of the small intestinal feeding catheter and examined for disaccharidase levels and histology. Data are mean ± SD., Results: When compared with healthy subjects, critically ill patients had significantly reduced cumulative CO2 recovery (90 min: 1.78% ± 1.98% vs. 8.04% ± 2.55%; p < 0.001) and increased lactulose/rhamnose ratio (2.77 ± 4.24 vs.1.10 ± 0.98; p = 0.03). The lactulose/rhamnose ratio was greater in feed-intolerant patients (4.06 ± 5.38; p = 0.003). In five patients, duodenal mucosal biopsy showed mild to moderate epithelial injury. Sucrase levels were normal in all patients., Conclusions: Sucrose absorption is reduced and intestinal permeability increased in critically ill patients, possibly indicating an impairment of small intestinal mucosal function. These results, however, are discordant with duodenal mucosal histology and sucrase levels. This may reflect an inactivation of sucrase in vivo or inadequate nutrient exposure to the brush border due to small intestinal dysmotility.

Objective: Motilin receptors are rapidly down-regulated by exposure to erythromycin, and its progressive loss of clinical prokinetic effect may relate to higher plasma drug concentrations. This study aimed to evaluate the relationship between plasma erythromycin concentrations and feeding outcomes in critically ill patients., Design: Observational comparative study., Setting: Tertiary critical care unit., Patients: Twenty-nine feed-intolerant (gastric residual volume >250 mL) mechanically ventilated, medical critically ill patients., Interventions: Patients received intravenous erythromycin 200 mg twice daily for feed intolerance., Measurements: Plasma erythromycin concentrations were measured 1 and 7 hrs after drug administration on day 1. Success of enteral feeding, defined as 6-hourly gastric residual volume of ≤ 250 mL with a feeding rate ≥ 40 mL/h, was recorded over 7 days., Results: At day 7, 38% (11 of 29) of patients were feed tolerant. Age, Acute Physiology and Chronic Health Evaluation scores, serum glucose concentrations, and creatinine clearance were comparable between successful and failed feeders. Both plasma erythromycin concentrations at 1 and 7 hrs after drug administration were significantly lower in successfully treated patients compared to treatment failures (1 hr: 3.7 ± 0.8 mg/L vs. 7.0 ± 1.0 mg/L, p = .02; and 7 hr: 0.7 ± 0.3 mg/L vs. 2.8 ± 0.6 mg/L, p = .01). There was a negative correlation between the number of days to failure of feeding and both the 1-hr (r = -.47, p = .049) and 7-hr (r = -.47, p = .050) plasma erythromycin concentrations. A 1-hr plasma concentration of >4.6 mg/L had 72% sensitivity and 72% specificity, and a 7-hr concentration of ≥ 0.5 mg/L had 83% sensitivity and 72% specificity in predicting loss of response to erythromycin., Conclusions: In critically ill feed-intolerant patients, there is an inverse relationship between plasma erythromycin concentrations and the time to loss of clinical motor effect. This suggests that erythromycin binding to motilin receptors contributes to variations in the duration of prokinetic response. The use of lower doses of erythromycin and tailoring the dose of erythromycin according to plasma concentrations may be useful strategies to reduce erythromycin tachyphylaxis.

Purpose of Review: Over the past year, further insights into the control of esophageal motility and disturbances associated with motor disorders, and additional information about the treatment of esophageal motor disorders has emerged. This review outlines the major developments in these areas., Recent Findings: The pharyngeal and esophageal phases of swallowing appear to be controlled by different areas within the vagal nuclei. Differences in the density and activation of calcium channels may explain differences in activity between the circular and clasp fibers of the lower esophageal sphincter and in the peristaltic function of the esophageal body. Tonic cholinergic input is the major determinant of esophageal tone. Experimental diabetes mellitus alters the mechanics of the esophageal body. Subtle abnormalities of peristalsis have been identified by high-resolution manometry and 24-hour ambulatory manometry that are not evident on standard manometry in patients with non-obstructive dysphagia. In achalasia, additional support has been provided for vagal damage in some patients with achalasia as well as evidence for a viral-induced immune damage to the myenteric plexus. The three main treatments for achalasia - botulinum toxin, pneumatic dilatation, and minimally invasive myotomy have been re-evaluated. Myotomy continues to provide the best results. Intraoperative manometry would seem to be a useful aid to minimize the risk of incomplete myotomy. The usefulness of glucagon in relieving food bolus obstruction has been revisited in a retrospective study., Summary: These studies provide further information with which to more effectively manage esophageal motor disorders.

Globally, gastroesophageal reflux disease (GERD) remains a common and important clinical disorder. This review summarizes the major advances in the understanding and treatment of GERD that have been made in the past 12 months. Epidemiologic studies have yielded additional data on the clinical presentation and natural history of GERD in the East. Further insights have been presented on the pathogenesis of GERD, including the immunoregulatory environment of GERD, the neurophysiology of transient lower esophageal sphincter relaxation (TLESR), the mechanics of the esophagogastric junction as well as the influence of Helicobacter pylori. Diagnostically, a new acid exposure sensor may be a helpful cost-effective tool. Developments have been made in pharmacotherapy for TLESR. There is ongoing interest in endoscopic therapy and further developments have been made in laparoscopic fundoplication. The cost-effectiveness of several management strategies has been evaluated, aiming to reduce the cost impact of GERD on the health care system.