Dumping Syndrome

Understanding Clinical Issues in Postoperative Nutrition After Pancreaticoduodenectomy

Postoperative nutrition support for patients undergoing pancreaticoduodenectomy (Whipple's procedure) may be complicated due to gastrointestinal tract dysfunction (gastroparesis, dumping, and malabsorption) subsequent to the procedure. Clinical management of these patients may be adversely affected by procedure-specific knowledge deficits (method of gastrointestinal [GI] reconstruction), common and expected surgical complications, and the available route for alimentation. It is the aim of this report to provide the reader with an overview of the procedure, common postoperative nutrition issues, and available interventions.

Gastric emptying and glycaemia in health and diabetes mellitus

The rate of gastric emptying is a critical determinant of postprandial glycaemia and, accordingly, is fundamental to maintaining blood glucose homeostasis. Disordered gastric emptying occurs frequently in patients with longstanding type 1 diabetes mellitus and type 2 diabetes mellitus (T2DM). A complex bidirectional relationship exists between gastric emptying and glycaemia--gastric emptying accounts for ∼35% of the variance in peak postprandial blood glucose concentrations in healthy individuals and in patients with diabetes mellitus, and the rate of emptying is itself modulated by acute changes in glycaemia. Clinical implementation of incretin-based therapies for the management of T2DM, which diminish postprandial glycaemia, in part by slowing gastric emptying, is widespread. Other therapies for patients with T2DM, which specifically target gastric emptying include pramlintide and dietary-based treatment approaches. A weak association exists between upper gastrointestinal symptoms and the rate of gastric emptying. In patients with severe diabetic gastroparesis, pathological changes are highly variable and are characterized by loss of interstitial cells of Cajal and an immune infiltrate. Management options for patients with symptomatic gastroparesis remain limited in their efficacy, which probably reflects the heterogeneous nature of the underlying pathophysiology.

Measurement of gastric emptying in diabetes

There has been a substantial evolution of concepts related to disordered gastric emptying in diabetes. While the traditional focus has hitherto related to the pathophysiology and management of upper gastrointestinal symptoms associated with gastroparesis, it is now apparent that the rate of gastric emptying is central to the regulation of postprandial glycemia. This recognition has stimulated the development of dietary and pharmacologic approaches to optimize glycemic control, at least in part, by slowing gastric emptying. With the increased clinical interest in this area, it has proved necessary to expand the traditional indications for gastric emptying studies, and consider the relative strengths and limitations of available techniques. Scintigraphy remains the 'gold standard' for the measurement of gastric emptying, however, there is a lack of standardization of the technique, and the optimal test meal for the evaluation of gastrointestinal symptoms may be discordant from that which is optimal to assess impaired glycemic control. The stable isotope breath test provides an alternative to scintigraphy and can be performed in an office-based setting. The effect of glucagon-like peptide-1 (GLP-1) and its agonists to reduce postprandial glycemia is dependent on the baseline rate of gastric emptying, as well as the magnitude of slowing. Because the effect of exogenous GLP-1 to slow gastric emptying is subject to tachyphylaxis with sustained receptor exposure, 'short acting' or 'prandial' GLP-1 agonists primarily target postprandial glycemia through slowing of gastric emptying, while 'long acting' or 'non-prandial' agents lower fasting glucose primarily through insulinotropic and glucagonostatic mechanisms. Accordingly, the indications for the therapeutic use of these different agents are likely to vary according to baseline gastric emptying rate and glycemic profiles.

Pyloric resection and delayed gastric liquid emptying in rats

BACKGROUND

Surgical resection of the distal stomach impairs gastric emptying. Generally, pylorus and the antrum are removed in the distal gastrectomy, however, the pylorus is removed individually under specific circumstances. We focus on the relation between the pyloric resection and the gastric liquid emptying.

AIMS

The present investigation aimed to explore the pylorectomy how to influence gastric liquid emptying in rats.

METHODS

Pylorectomy and end-to-end gastroduodenal anastomosis were conducted in rats. Electrodes were implanted in the gastrointestinal serosal surface near the stoma. Total stomach, proximal stomach, distal stomach and duodenal liquid emptying, myoelectricities in the gastrointestinal tract near the stoma, and structures were examined with scintigraphy, electrode recording in vivo, and electron microscopy, respectively.

RESULTS

Delayed total stomach and distal stomach emptying were found in pylorectomy rats (p<0.001). However, there was no difference in the proximal stomach and the duodenal liquid emptying compared to the controls (p>0.05). The myoelectricity of 3-5 cpm (cycles/min) in antrum and 10-12 cpm in duodenum were found in the controls and no retrograde or antegrade myoelectricities were recorded in the duodenum and antrum. High-frequency myoelectricities (tachygastria) were recorded in the antrum near the stoma (p<0.01), the retrograde and antegrade myoelectricities propagating through the stoma were recorded, and the regenerated interstitial cells of Cajal were found in stoma under electron microscope observation in pylorectomy rat.

CONCLUSIONS

The gastroduodenal incoordination and abnormal myoelectricity related to impaired contraction in the antrum caused the delayed liquid gastric emptying in pylorectomy rats.

Octreotide: Dumping Syndrome

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. A summary of the most relevant data is provided, including background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to hospital pharmacy@drugfacts.com .

Tumors of the esophagus, gastroesophageal junction, and stomach

OBJECTIVES

To review the incidence, risk factors, staging, and diagnosis of esophageal, gastroesophageal junction, and stomach cancers, as well as nursing challenges associated with managing patients with these tumors.

DATA SOURCES

Published research reports, epidemiologic data, published patient management guidelines, and institution-based clinical tools.

CONCLUSION

While survival is slowly increasing, morbidity and mortality associated with upper gastrointestinal (UGI) cancers remain high. Research is needed to identify therapeutic approaches that will effectively decrease tumor burden and minimize physical consequences associated with disease and treatment.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be familiar with risk factors, disease course, and future therapies of UGI cancers to provide education relevant to preventive approaches, assist patients with treatment decision-making, and manage disease and treatment-induced sequela. Early identification and management of postoperative complications and nutritional issues can avoid life-threatening effects.

Consensus recommendations for gastric emptying scintigraphy: a joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine

This consensus statement from the members of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine recommends a standardized method for measuring gastric emptying (GE) by scintigraphy. A low-fat, egg-white meal with imaging at 0, 1, 2, and 4 h after meal ingestion, as described by a published multicenter protocol, provides standardized information about normal and delayed GE. Adoption of this standardized protocol will resolve the lack of uniformity of testing, add reliability and credibility to the results, and improve the clinical utility of the GE test.

Female reproductive issues following bariatric surgery

One in 3 adult American women is obese. Almost half of the approximately 100,000 bariatric surgeries performed in 2004 were on reproductive-aged women. Anatomic and physiologic changes resulting from such surgery may have significant clinical implications for preconception, pregnancy, and postpartum care. This review summarizes these issues and the available related literature, and offers guidelines for care of these patients.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that bariatric surgery has many anatomic and physiologic changes that potentially will affect future pregnancies, and state that attention to these physiologic changes and attention to potential nutritional deficiencies significantly improves the chances of a good pregnancy outcome.

A possible role of GLP-1 in the pathophysiology of early dumping syndrome

Exaggerated plasma concentrations of GLP-1 precede reactive hypoglycemia after oral glucose in gastrectomy patients, resulting in late dumping syndrome. Recently, we showed that GLP-1 elicits the activation of sympathetic outflow. Because sympathetic activation is thought to be a cause of early dumping, we hypothesized that exaggerated GLP-1 may contribute to the pathophysiology of early dumping syndrome. In 11 patients after gastrectomy and 14 controls, blood pressure, heart rate, and plasma concentrations of norepinephrine, epinephrine, GLP-1, glucagon, insulin, and glucose were measured after oral glucose. In gastrectomy patients, GLP-1, norepinephrine, and heart rate peaked 15 to 30 min after oral glucose. Significant positive correlations were found among GLP-1, norepinephrine, and heart rate at 30 min, and these parameters at 30 min were significantly higher in patients with early dumping syndrome. These results suggest that GLP-1 is involved in the pathophysiology of early dumping syndrome.

Anatomy and Physiology of the Stomach

In this article, key concepts in gastric anatomy and physiology are reviewed. Attention is given to historical development of concepts of acid secretion, to the role of stomach in digestion, and to the mechanisms that protect gastric mucosa from acid and hostile luminal conditions. Evolving ideas that may influence understand-ing of the physiologic consequences of emerging therapeutics, and procedures that target anatomy or function of the stomach are also reviewed.

A prospective study of gastric emptying and its relationship to the development of nausea, vomiting, and anorexia after autologous stem cell transplantation

BACKGROUND AND AIMS

Gastric motor dysfunction may be responsible, in some patients, for the nausea and emesis that occur following high-dose chemotherapy (HDT) and autologous stem cell transplantation (SCT). We sought to define the prevalence of gastric emptying abnormalities and their relationship to the development of nausea, vomiting, and anorexia in patients undergoing HDT and autologous SCT.

METHODS

We prospectively studied patients with a variety of malignancies who received standard transplantation doses of chemotherapeutic agents and antiemetics. Gastric emptying was assessed prior to HDT and on Days 0 (day of stem cell infusion), +7, and +14 from SCT. Symptom assessment was obtained daily from initiation of HDT to 28 days after SCT.

RESULTS

Twenty-four patients were studied. Prior to HDT, gastric emptying was rapid in two patients. Nausea, emesis, and anorexia occurred in all patients, peaked in severity at Day +7 after SCT and, with the exception of anorexia, had returned toward baseline levels by Day +28. As a group, gastric emptying was significantly slower on Days 0 and +7 and returned to baseline level by Day +14. Twenty-six percent and 44% of patients demonstrated delayed gastric emptying (T(1/2) >90 min) on Days 0 and +7, respectively, while 13% and 31% of patients had rapid gastric emptying (T(1/2) <30 min) on Days 0 and +7, respectively. Thirty-nine percent and 75% of patients had either rapid or delayed gastric emptying on Days 0 and +7, respectively. There was an association between delayed gastric emptying and moderate-severe anorexia on Day +7 and between delayed gastric emptying and at least mild vomiting on Day 0. Additionally, there was an association between rapid gastric emptying and at least mild vomiting on Day +7. Finally, an association was found between either rapid or delayed gastric emptying and at least mild nausea on Day +7.

CONCLUSION

Both delayed and rapid gastric emptying occur commonly during the 2-wk period following HDT and autologous SCT and may be responsible, at least in part, for upper gastrointestinal symptoms that occur in these patients.

Contributions of gastric volumes and gastric emptying to meal size and postmeal symptoms in functional dyspepsia

BACKGROUND & AIMS

The aim was to assess relative contributions of gastric volumes (GV) and gastric emptying (GE) to meal size and postprandial symptoms in patients with functional dyspepsia.

METHODS

Patients with chronic upper gastrointestinal symptoms were prospectively evaluated. GV during fasting and after 300 mL Ensure was measured with 99m Tc-single-photon emission computed tomography imaging and solid GE (99m Tc-egg) by scintigraphy. Maximum tolerated volume (MTV) and symptoms were measured after Ensure challenge.

RESULTS

Of 57 adult patients evaluated, 39 (23 women, 16 men) met Rome II criteria for functional dyspepsia and had no other diagnosis to account for dyspepsia. The most frequent symptoms were abdominal pain (90%), pain predominantly after meals (76%), nausea (85%), and early fullness after meals (79%). Relative to established laboratory normal values, MTV was abnormal in 82%, aggregate symptom score >209 in 72%, GE (at 1 hour) accelerated in 41%, GE (at 4 hours) delayed in 41%, and postmeal GV reduced in 52%. Lower body mass was associated with lower MTV and higher postchallenge symptoms. Lower fasting (not postprandial) GV and faster GE were independent predictors of lower MTV, explaining 18% of the variance after adjusting for body weight (32% of variance). GE was an independent predictor of postchallenge symptoms (10% of variance) after adjusting for volume ingested (10%), age (20%), and weight (10%).

CONCLUSIONS

In adults with functional dyspepsia seen in a tertiary referral practice, decreased meal size and postmeal symptoms are associated with low fasting GV and faster GE. These data provide physiologic targets for ameliorating symptoms of functional dyspepsia.

Glucagon-like peptide-1-responsive catecholamine neurons in the area postrema link peripheral glucagon-like peptide-1 with central autonomic control sites

Glucagon-like peptide-1 (GLP-1) released from the gut is an incretin that stimulates insulin secretion. GLP-1 is also a brain neuropeptide that has diverse central actions, including inhibition of food and water intake, gastric emptying, and stimulation of neuroendocrine responses characteristic of visceral illness. Both intravenous and intracerebroventricular administration of GLP-1 receptor (GLP-1R) agonists increase blood pressure and heart rate and induce Fos-like immunoreactivity (Fos-IR) in autonomic regulatory sites in the rat brain. The area postrema (AP) is a circumventricular organ and has been implicated in processing visceral sensory information. GLP-1Rs are densely expressed in the AP, and peripheral GLP-1R agonists induce Fos-IR in AP neurons to a greater degree than intracerebroventricular administration. Because the AP lacks a blood-brain barrier, we hypothesized that the AP is a key site for peripheral GLP-1 to activate central autonomic regulatory sites. In this study, we found that many tyrosine hydroxylase (TH)-containing neurons in the AP expressed GLP-1Rs and Fos-IR after intravenous GLP-1R agonists. Furthermore, intravenous but not intracerebroventricular GLP-1R agonists induced TH transcription in the AP in vivo. In addition, GLP-1R agonists directly activated TH transcription in an in vitro cell system. Finally, we found that GLP-1-responsive TH neurons in the AP innervate autonomic control sites, including the parabrachial nucleus, nucleus of solitary tract, and ventrolateral medulla. These findings suggest that catecholamine neurons in the AP link peripheral GLP-1 and central autonomic control sites that mediate the diverse neuroendocrine and autonomic actions of peripheral GLP-1.