The role of delayed gastric emptying and impaired oesophageal body motility

Pathophysiology of gastroesophageal reflux disease-which factors are important?

Background

Pathophysiology of gastroesophageal reflux disease (GERD) shows a multifactorial background. Different anatomical and functional alterations can be determined such as weakness of the lower esophageal sphincter (LES), changes in anatomy by a hiatal hernia (HH), an impaired esophageal motility (IEM), and/or an associated gastric motility problem with either duodeno-gastro-esophageal reflux (DGER) or delayed gastric emptying (DGE). The purpose of this study is to assess a large GERD-patient population to quantitatively determine different pathophysiologic factors contributing to the disease.

Methods

For this analysis only patients with documented GERD (pathologic esophageal acid exposure) were selected from a prospectively maintained databank. Investigations: history and physical, body mass index, endoscopy, esophageal manometry, 24 h-pH-monitoring, 24 h-bilirbine-monitoring, radiographic-gastric-emptying or scintigraphy, gastrointestinal quality of life index (GIQLI).

Results

In total, 728 patients (420 males; 308 females) were selected for this analysis. Mean age: 49.9 years; mean BMI: 27.2 kg/m² (range, 20-45 kg/m²); mean GIQLI of 91 (range: 43-138; normal level: 121); no esophagitis: 30.6%; minor esophagitis (Savary-Miller type 1 or Los Angeles Grade A): 22.4%; esophagitis [2-4]/B-D: 36.2%; Barrett's esophagus 10%. Presence of pathophysiologic factors: HH 95.4%; LES-incompetence 88%, DGER 55%, obesity 25.6%, IEM 8.8%, DGE 6.8%.

Conclusions

In our evaluation of GERD patients, the most important pathophysiologic components are anatomical alterations (HH), LES-incompetence and DGER.

Gastrointestinal pharmacology: practical tips for the esophagologist

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, and its pathogenesis is multifactorial. As a consequence, treatment should be able to address the underlying pathophysiology. Proton pump inhibitors (PPIs) are the mainstay of medical therapy for GERD, but these drugs only provide the control of symptoms and lesions without curing the disease. However, continuous acid suppression with PPIs is recommended for patients with Barrett's esophagus because of their potential chemopreventive effects. In addition to the antisecretory activity, these compounds display several pharmacological properties, often overlooked in clinical practice. PPIs can indeed affect gastric motility, exert a mucosal protective effect, and an antioxidant, anti-inflammatory, and antineoplastic activity, also protecting cancer cells from developing chemo- or radiotherapeutic resistance. Even in the third millennium, current pharmacologic approaches to address GERD are limited. Reflux inhibitors represent a promise unfulfilled, effective and safe prokinetics are lacking, and antidepressants, despite being effective in selected patients, give rise to adverse events in a large proportion of them. While waiting for new drug classes (like potassium-competitive acid blockers), reassessing old drugs (namely alginate-containing formulations), and paving the new avenue of esophageal mucosal protection are, at the present time, the only reliable alternatives to acid suppression.

Cystic Fibrosis and gastroesophageal reflux disease

Gastroesophageal reflux is common in children and adults with cystic fibrosis (CF). Pathological gastroesophageal reflux disease (GERD) is also frequent in patients of all ages with CF. This article reviews the pathophysiology, diagnostic work-up, management options, complications, and future directions in the evaluation and management of GERD - unique to and pertinent for - patients with CF in particular.

Non-alcoholic fatty liver disease and the development of reflux esophagitis: A cohort study

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of the metabolic syndrome, is associated with gastroesophageal reflux disease in cross-sectional studies, but a prospective association has not been evaluated. The current study aimed to determine whether NAFLD increases the risk of incident reflux esophagitis in a large cohort study.

METHODS

We conducted a cohort study of 34 063 men and women without reflux esophagitis or other upper gastrointestinal disease at baseline who underwent health checkup examinations between January 2003 and December 2013. Fatty liver was diagnosed by ultrasound based on standard criteria. Reflux esophagitis was defined by the presence of at least grade A mucosal break on esophagogastroduodenoscopy.

RESULTS

The prevalence of NAFLD at baseline was 33.2%. During 153 520.2 person-years of follow-up, the cumulative incidences of reflux esophagitis for participants without and with NAFLD were 9.6% and 13.8%, respectively (P < 0.001). The age-adjusted and sex-adjusted hazard ratio for the risk of reflux esophagitis development in participants with NAFLD compared with those without NAFLD was 1.15 (95% confidence interval 1.07-1.23; P < 0.001). However, this association disappeared after adjusting for body mass index and other metabolic factors (hazard ratio 1.01, 95% confidence interval 0.94-1.09; P = 0.79). Similarly, in multivariable-adjusted models, there was no significant association between NAFLD severity and the risk of developing reflux esophagitis.

CONCLUSIONS

Non-alcoholic fatty liver disease is not independently associated with the risk of the development of reflux esophagitis, but rather, reflux esophagitis is primarily the consequence of increased body mass index commonly associated with NAFLD.

Gastroesophageal Reflux Disease and Aerodigestive Disorders

This relationship between gastroesophageal reflux and airway disorders is complex, possibly bidirectional, and not clearly defined. The tools used to investigate gastroesophageal reflux are mostly informative about involvement of gastroesophageal reflux within the gastrointestinal tract, although they are often utilized to study the relationship between gastroesophageal reflux and airway issues with are suspected to occur in relation to reflux. These modalities often lack specificity for reflux-related airway disorders. Co-incidence of gastroesophageal reflux and airway disorders does not necessarily infer causality. While much of our focus has been on managing acidity, controlling refluxate is an area that has not been traditionally aggressively pursued. Our management approach is based on some of the evidence presented, but also often from a lack of adequate study to provide further guidance.

Review article: gastro-oesophageal reflux disease in asthma and chronic obstructive pulmonary disease

BACKGROUND

When gastro-oesophageal reflux is causing symptoms or lesions in the oesophagus, this is referred to as gastro-oesophageal reflux disease (GERD). GERD can manifest itself through typical symptoms (heartburn, regurgitation) or may lead to extra-oesophageal symptoms. Extra-oesophageal manifestations of GERD gained increasing attention over the last decade, especially respiratory disorders, because of the prevalent co-occurrence with GERD. The role of GERD in the pathogenesis of respiratory disorders has become a topic of intense discussion.

AIM

To provide an overview of the current knowledge on the role of GERD in asthma and chronic obstructive pulmonary disease (COPD).

METHODS

PubMed was searched for relevant articles using the keywords: GERD, asthma, COPD, prevalence, treatment. Case reports were excluded, only English language articles were considered.

RESULTS

Estimates for the prevalence of GERD in asthma range from 30% to 90%, compared to an average of 24% in controls. In COPD patients, the prevalence of GERD ranges from 19% to 78% compared to an average of 18% in controls. These data indicate an increased prevalence of GERD in patients with asthma and COPD, although causality is not established and GERD treatment yielded inconsistent effects. Literature supports GERD as a risk factor for COPD-exacerbations and a predictor of the 'frequent-exacerbator'-phenotype.

CONCLUSIONS

Despite the high prevalence of GERD in asthma and COPD, a causal link is lacking. The results of anti-reflux therapy on pulmonary outcome are inconsistent and contradictory. Future studies will need to identify subgroups of asthmatics and COPD patients that may benefit from anti-reflux therapy (nocturnal or silent reflux).

Prevalence of Dyspepsia in Individuals With Gastroesophageal Reflux-Type Symptoms in the Community: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Dyspepsia and gastroesophageal reflux are highly prevalent in the general population, but they are believed to be separate entities. We conducted a systematic review and meta-analysis to estimate the prevalence of dyspepsia in individuals with gastroesophageal reflux symptoms (GERS), and to quantify overlap between the disorders.

METHODS

We searched MEDLINE, EMBASE, and EMBASE Classic databases to identify population-based studies reporting the prevalence of dyspepsia and GERS in adults, defined using specific symptom-based criteria or based on answers to questionnaires. We calculated pooled prevalence values, according to study location and criteria used to define weekly GERS or dyspepsia, as well as odds ratios (ORs) with 95% CIs. The degree of overlap between dyspepsia and GERS was examined.

RESULTS

Of 14,132 papers evaluated, 79 reported prevalence of weekly GERS. Nineteen of these study populations, comprising 111,459 participants, also reported the proportion of individuals with dyspepsia. The prevalence of dyspepsia in individuals with weekly GERS was 43.9% (95% CI, 35.1%-52.9%). The pooled OR for dyspepsia in individuals with weekly GERS, compared with those without, was 6.94 (95% CI, 4.33%-11.1%). The OR for dyspepsia in individuals with weekly GERS was significantly higher in all geographical regions studied and for all diagnostic criteria. The pooled degree of overlap between dyspepsia and GERS was 25.9% (95% CI, 19.9%-32.4%).

CONCLUSIONS

The odds of dyspepsia in individuals with weekly GERS is almost 7-fold that of individuals without GERS; dyspepsia and GERS overlap in more than 25% of individuals. Reasons for this remain speculative, but might include shared pathophysiological mechanisms or residual confounding factors. However, patients with GERS should be questioned about coexistent dyspepsia, to optimize treatment approaches.

Reflux episodes and esophageal impedance levels in patients with typical and atypical symptoms of gastroesophageal reflux disease

To determine the relationship between baseline impedance levels and gastroesophageal reflux, we retrospectively enrolled 110 patients (54 men and 56 female; mean age, 51 ± 14 years) with suspected gastroesophageal reflux disease (GERD) who underwent 24-h multichannel intraluminal impedance and pH monitoring. Patients were stratified according to symptom (typical or atypical) and reflux types (acid reflux, nonacid reflux [NAR], or no abnormal reflux). Mean nocturnal baseline impedance (MNBI) were measured 3 cm (distal esophagus) and 17 cm (proximal esophagus) above the lower esophageal sphincter. Median distal esophageal MNBI was lower in the acid reflux group (1244 Ω; 647-1969 Ω) than in the NAR (2586 Ω; 1368-3666 Ω) or no abnormal reflux groups (3082 Ω; 2495-4472 Ω; all P < .05). Distal MNBI were negatively correlated with DeMeester score and acid exposure time. Atypical symptoms were more frequently associated with NAR than typical symptoms (P < .01). Among patients with positive symptom-association probability (SAP) for NAR, median proximal MNBI tended to be lower in patients with typical symptoms (median, 3013 Ω; IQR, 2535-3410 Ω) than in those with atypical symptoms (median, 3386 Ω; IQR, 3044-3730 Ω, P = .05). Thus, atypical GERD symptoms were more likely to be associated with NAR. The mucosal integrity of the proximal esophagus might be relatively impaired in GERD patients with typical symptoms for NAR.

A review of pharmacotherapy for treating gastroesophageal reflux disease (GERD)

INTRODUCTION

Medical therapy of gastroesophageal reflux disease (GERD) is based on the use of proton pump inhibitors (PPIs) as first choice treatment. Despite their effectiveness, about 20-30% of patients report an inadequate response and alternative drugs are required. Areas covered: This review provides an overview of current pharmacotherapy for treating GERD by showing the results of PPIs, reflux inhibitors, antidepressants and mucosa protective medications. Expert opinion: Medical therapy of GERD does not definitely cure the disease, because even PPIs are not able to change the key factors responsible for it. However, they remain the mainstay of medical treatment, allowing us to alleviate symptoms, heal esophagitis and prevent complications in the majority of cases. Nevertheless, many patients do not respond, because acid does not play any pathogenetic role. Prokinetics and reflux inhibitors have the potential to control motor abnormalities, but the results of clinical trials are inconsistent. Antidepressant drugs are effective in specific subgroups of NERD patients with visceral hypersensitivity, but larger, controlled clinical studies are necessary. Protective drugs or medical devices have been recently adopted to reinforce mucosal resistance and preliminary trials have confirmed their efficacy either combined with or as add-on medication to PPIs in refractory patients.

[Gastric and duodenal secretory and motor-evacuatory activity in patients with gastroesophageal reflux disease associated with different types of reflux]

AIM

To estimate esophageal and gastric pH values on an empty stomach and after stimulation of gastric secretion and gastric and duodenal motor-evacuatory activity in patients with gastroesophageal reflux disease (GERD) associated with pathological refluxes, such as gastroesophageal reflux (GER) and duodenogastroesophageal reflux (DGER).

SUBJECTS AND METHODS

The observational cross-sectional study was conducted to investigate and compare the parameters of intraesophageal and intragastric pH metry and peripheral electrogastroenterography in 103 GERD patients with endoscopically positive distal reflux esophagitis in GER and DGER.

RESULTS

The patients with GERD developed pathological esophageal refluxes (both GER and DGER) in various degrees of impaired gastric production, from anacidity to hyperacidity. The patients with predominant DGER were found to have gastric hyperacidity and normal acidity slightly less frequently than those with predominant GER. The patients with GERD developing in the presence of predominant GER had moderate gastric stasis with discoordinated antroduodenal propulsion resulting from hypomotor dyskinesia of the stomach and duodenum. When DGER was predominant in the patients with GERD, the signs of gastric stasis and duodenal hyperkinesia were concurrent with discoordinated antroduodenal and duodenojejunal propulsion.

CONCLUSION

The specific features of the esophagogastroduodenal secretory and motor evacuatory disorders found create conditions for the pathological refluxes into the esophagus, which differ in the composition of refluxate.

Lifestyle Intervention in Gastroesophageal Reflux Disease

BACKGROUND & AIMS

Gastroesophageal reflux disease (GERD) affects up to 30% of adults in Western populations and is increasing in prevalence. GERD is associated with lifestyle factors, particularly obesity and tobacco smoking, which also threatens the patient's general health. GERD carries the risk of several adverse outcomes and there is widespread use of potent acid-inhibitors, which are associated with long-term adverse effects. The aim of this systematic review was to assess the role of lifestyle intervention in the treatment of GERD.

METHODS

Literature searches were performed in PubMed (from 1946), EMBASE (from 1980), and the Cochrane Library (no start date) to October 1, 2014. Meta-analyses, systematic reviews, randomized clinical trials (RCTs), and prospective observational studies were included.

RESULTS

Weight loss was followed by decreased time with esophageal acid exposure in 2 RCTs (from 5.6% to 3.7% and from 8.0% to 5.5%), and reduced reflux symptoms in prospective observational studies. Tobacco smoking cessation reduced reflux symptoms in normal-weight individuals in a large prospective cohort study (odds ratio, 5.67). In RCTs, late evening meals increased time with supine acid exposure compared with early meals (5.2% point change), and head-of-the-bed elevation decreased time with supine acid exposure compared with a flat position (from 21% to 15%).

CONCLUSIONS

Weight loss and tobacco smoking cessation should be recommended to GERD patients who are obese and smoke, respectively. Avoiding late evening meals and head-of-the-bed elevation is effective in nocturnal GERD.

Physiology and pathogenesis of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common problems treated by primary care physicians. Almost 20% of the population in the United States experiences occasional regurgitation, heartburn, or retrosternal pain because of GERD. Reflux disease is complex, and the physiology and pathogenesis are still incompletely understood. However, abnormalities of any one or a combination of the three physiologic processes, namely, esophageal motility, lower esophageal sphincter function, and gastric motility or emptying, can lead to GERD. There are many diagnostic and therapeutic approaches to GERD today, but more studies are needed to better understand this complex disease process.

Upper gastrointestinal motility: prenatal development and problems in infancy

Deglutition, or swallowing, refers to the process of propulsion of a food bolus from the mouth into the stomach and involves the highly coordinated interplay of swallowing and breathing. At 34 weeks gestational age most neonates are capable of successful oral feeding if born at this time; however, the maturation of respiration is still in progress at this stage. Infants can experience congenital and developmental pharyngeal and/or gastrointestinal motility disorders, which might manifest clinically as gastro-oesophageal reflux (GER) symptoms, feeding difficulties and/or refusal, choking episodes and airway changes secondary to micro or overt aspiration. These problems might lead to impaired nutritional intake and failure to thrive. These gastrointestinal motility disorders are mostly classified according to the phase of swallowing in which they occur, that is, the oral preparatory, oral, pharyngeal and oesophageal phases. GER is a common phenomenon in infancy and is referred to as GERD when it causes troublesome complications. GER is predominantly caused by transient relaxation of the lower oesophageal sphincter. In oesophageal atresia, oesophageal motility disorders develop in almost all patients after surgery; however, a congenital origin of disordered motility has also been proposed. This Review highlights the prenatal development of upper gastrointestinal motility and describes the most common motility disorders that occur in early infancy.

New insights in gastroesophageal reflux, esophageal function and gastric emptying in relation to dysphagia before and after anti-reflux surgery in children

In children with gastroesophageal reflux (GER) disease refractory to pharmacological therapies, anti-reflux surgery (fundoplication) may be a treatment of last resort. The applicability of fundoplication has been hampered by the inability to predict which patient may benefit from surgery and which patient is likely to develop post-operative dysphagia. pH impedance measurement and conventional manometry are unable to predict dysphagia, while the role of gastric emptying remains poorly understood. Recent data suggest that the selection of patients who will benefit from surgery might be enhanced by automated impedance manometry pressure-flow analysis (AIM) analysis, which relates bolus movement and pressure generation within the esophageal lumen.

Pathophysiology of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common digestive diseases in the Western world, with typical symptoms, such as heartburn, regurgitation, or retrosternal pain, reported by 15% to 20% of the general population. The pathophysiology of GERD is multifactorial. Our understanding of these factors has significantly improved in recent years, with increased understanding of the acid pocket and hiatal hernia and how these factors interact. Although our insight has significantly increased over the past years, more studies are required to better understand symptom generation in GERD, especially in patients with therapy-resistant symptoms.

Pathophysiology of gastroesophageal reflux disease

The gastroesophageal junction is structurally complex and functionally designed to ensure the acid secreted by the most proximal gastric mucosa flows towards the stomach and not up onto the oesophageal squamous mucosa. The pattern and mechanism of reflux vary with the severity of reflux disease and this probably represents different ends of a spectrum rather than distinct pathophysiological mechanisms. Nearly all patients with severe reflux disease have hiatus hernia, however, a substantial proportion of patients with mild reflux disease do not, and this may be a result of intermittent or partial hiatus hernia undetectable by current available tools. The acid pocket is an area of post-prandial unbuffered gastric acidity immediately distal to the gastroesophageal junction and which is enlarged in patients with hiatus hernia. The acid pocket provides a reservoir of acid available to reflux when the intrinsic sphincter fails. Central obesity is an important factor in the aetiology of reflux and does this by the increased abdomino-thoracic pressure gradient inducing hiatus hernia and increasing the rate of flow of reflux when sphincter opens. Central obesity also induces short segment intrasphincteric reflux and thereby columnar metaplasia of the most distal oesophagus.

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease is one of the most common disorders of the gastrointestinal tract. Over past decades, considerable shifts in thinking about the disease have taken place. At a time when radiology was the only diagnostic test available, reflux disease was regarded as synonymous with hiatus hernia. After the advent of the flexible endoscope, reflux disease was, for a period, equated to oesophagitis. The introduction of oesophageal pH monitoring made us believe that reflux disease could be defined by an abnormally high proportion of time with oesophageal pH less than 4. Moreover, the successive arrival of histamine-2-receptor antagonists and proton-pump inhibitors changed our idea of treatment for the disease, with swings from and towards surgery, endoscopic techniques, and alternative pharmaceutical options.

Gastroesophageal reflux, esophageal function, gastric emptying, and the relationship to dysphagia before and after antireflux surgery in children

OBJECTIVES

To assess gastroesophageal reflux (GER), esophageal motility, and gastric emptying in children before and after laparoscopic fundoplication and to identify functional measures associated with postoperative dysphagia.

STUDY DESIGN

Combined impedance-manometry, 24-hour pH-impedance, and gastric-emptying breath tests were performed before and after laparoscopic anterior partial fundoplication. Impedance-manometry studies were analyzed with the use of conventional analysis methods and a novel automated impedance manometry (AIM) analysis.

RESULTS

Children with therapy resistent GER disease (n = 25) were assessed before fundoplication, of whom 10 (median age 6.4 years; range, 1.1-17.1 years; 7 male; 4 with neurologic impairment) underwent fundoplication. GER episodes reduced from 97 (69-172) to 66 (18-87)/24 hours (P = .012). Peristaltic contractions were unaltered. Complete lower esophageal sphincter relaxations decreased after fundoplication (92% [76%-100%] vs 65% [29%-91%], P = .038). Four (40%) patients developed postoperative dysphagia, which was transient in 2. In those patients, preoperative gastric emptying was delayed compared with patients without postoperative dysphagia, 96 minutes (71-104 minutes) versus 48 minutes (26-68 minutes), P = .032, and AIM analysis derived dysphagia risk index was greater (56 [15-105] vs 2 [2-6] P = .016). Two patients underwent a repeat fundoplication.

DISCUSSION

Fundoplication in children reduced GER without altering esophageal motility. Four patients who developed dysphagia demonstrated slower gastric emptying and greater dysplasia risk index preoperatively. AIM analysis may allow detection of subtle esophageal abnormalities potentially leading to postoperative dysphagia.

Effect of lateral positioning on gastroesophageal reflux (GER) and underlying mechanisms in GER disease (GERD) patients and healthy controls

BACKGROUND

Posture has been shown to influence the number of transient lower esophageal sphincter relaxation (TLESRs) and gastroesophageal reflux (GER), however, the physiology explaining the influence of right lateral position (RLP), and left lateral position (LLP) is not clear. The aim of this study was to determine the influence of RLP and LLP on TLESRs and GERD after a meal in GER disease (GERD) patients and healthy controls (HC) while monitoring gastric distension and emptying.

METHODS

Ten GERD patients and 10 HC were studied for 90 min (30 min test meal infusion, 30 min postprandial in either RLP or LLP (randomly assigned) and 30 min in alternate position). The study was repeated on a separate day in reverse position order. TLESRs, GER, and gastric emptying rate were recorded using manometry, multichannel intraluminal impedance, and (13) C-octanoate breath tests. Gastric distension was visualized by five serial gastric volume scintigraphy scans during the first 30 min.

KEY RESULTS

Gastroesophageal reflux, (GER) disease patients had increased numbers of TLESRs in RLP compared to LLP in the first postprandial hour [5 (4-14) and 4.5 (2-6), respectively, P = 0.046] whereas the number of TLESRs was not different in RLP and LLP [4 (2-4) and 4 (3-6), respectively, P = 0.7] in HC. Numbers of GER increased similar to TLESRs in GERD patients. In GERD patients, gastric emptying reached peak (13)CO(2) excretion faster and proximal gastric distension was more pronounced.

CONCLUSIONS & INFERENCES

In GERD patients, TLESRs, GER, distension of proximal stomach, and gastric emptying are increased in RLP compared to LLP. This effect is not seen in HC.

[The Mexican consensus on gastroesophageal reflux disease. Part I]

BACKGROUND

The changes, advances, and new discoveries regarding different aspects of gastroesophageal reflux disease (GERD) have made it necessary to update the Mexican Consensus published in 2002.

AIMS

To elaborate a new Mexican Consensus on GERD.

METHODS

The general project coordinators selected six GERD experts to carry out an extensive review of the literature for the purpose of elaborating statements on the principal aspects of GERD. These were then placed under the consideration of specialists in the study of this disease. Definitive approval by all participants was reached using the modified Delphi method with three rounds of anonymous and iterative voting. The following scale was employed: A- in complete agreement; B- in agreement, but with minor concerns; C- in agreement, but with major concerns; D- in disagreement, but with major concerns; E- in disagreement, but with minor concerns; or F- in complete disagreement. Consensus was declared when 67.00% or more of the participants concurred on a category of agreement (A, B, or C).

RESULTS

A consensus was reached on 160 of the statements upon completion of the voting rounds, with 90.00% concurrence for the majority of them.

CONCLUSIONS

The 2011 Mexican Consensus on Gastroesophageal Disease is a practical and up-to-date consultation tool, providing the opinion of Mexican experts on all the new information available about this disease. It allows there to be homogeneity in diagnostic and therapeutic criteria, all of which serves to benefit our patients.

Comparative effects on glucose absorption of intragastric and post-pyloric nutrient delivery in the critically ill

INTRODUCTION

Studies in the critically ill that evaluate intragastric and post-pyloric delivery of nutrient have yielded conflicting data. A limitation of these studies is that the influence in the route of feeding on glucose absorption and glycaemia has not been determined.

METHODS

In 68 mechanically ventilated critically ill patients, liquid nutrient (100 ml; 1 kcal/ml containing 3 g of 3-O-Methyl-D-glucopyranose (3-OMG), as a marker of glucose absorption), was infused into either the stomach (n = 24) or small intestine (n = 44) over six minutes. Blood glucose and serum 3-OMG concentrations were measured at regular intervals for 240 minutes and the area under the curves (AUCs) calculated for 'early' (AUC60) and 'overall' (AUC240) time periods. Data are presented as mean (95% confidence intervals).

RESULTS

Glucose absorption was initially more rapid following post-pyloric, when compared with intragastric, feeding (3-OMG AUC60: intragastric 7.3 (4.3, 10.2) vs. post-pyloric 12.5 (10.1, 14.8) mmol/l.min; P = 0.008); however, 'overall' glucose absorption was similar (AUC240: 49.1 (34.8, 63.5) vs. 56.6 (48.9, 64.3) mmol/l.min; P = 0.31). Post-pyloric administration of nutrients was also associated with greater increases in blood glucose concentrations in the 'early' period (AUC60: 472 (425, 519) vs. 534 (501, 569) mmol/l.min; P = 0.03), but 'overall' glycaemia was also similar (AUC240: 1,875 (1,674, 2,075) vs. 1,898 (1,755, 2,041) mmol/l.min; P = 0.85).

CONCLUSIONS

In the critically ill, glucose absorption was similar whether nutrient was administered via a gastric or post-pyloric catheter. These data may have implications for the perceived benefit of post-pyloric feeding on nutritional outcomes and warrant further investigation.