Novel approaches to the treatment of nausea and vomiting

Nausea and vomiting are debilitating symptoms complicating many clinical conditions. Conventional antiemetic agents act as muscarinic, histamine, and dopamine receptor antagonists in the central nervous system. In a retrospective analysis, tricyclic antidepressant drugs demonstrated efficacy in long-term treatment of functional nausea. Some cases of vomiting result from impaired gastrointestinal motor activity. Agents which act on gastric serotonin (5-HT4), dopamine, and motilin receptors accelerate gastric emptying and relieve symptoms in gastroparesis. Recent investigations suggest that some patients with refractory gastroparesis may benefit from gastric electrical pacing. The treatment of acute chemotherapy-induced emesis was revolutionized by 5-HT3 receptor antagonists; however, these agents are less efficacious in delayed vomiting. Neurokinin (NK-1) receptor antagonists show promise in treating delayed chemotherapy-evoked emesis. Furthermore, animal studies indicate a broad spectrum of action for NK-1 antagonists in treating diverse causes of nausea and vomiting. The cyclic vomiting syndrome is characterized by discrete episodes of relentless vomiting separated by asymptomatic intervals and is associated with migraine headaches. Antimigraine therapies including the 5-HT1D receptor agonists sumatriptan reduce the severity of cyclic vomiting attacks. Investigations into these and other novel treatments may provide important advances in the care of difficult cases of nausea and vomiting resulting from disparate illnesses.     

Gastric emptying after autologous haemopoietic stem-cell transplantation: a prospective trial

Gastroparesis may be involved in the pathophysiology of prolonged nausea and vomiting after haemopoietic stem-cell transplantation (HSCT), but this has not been prospectively investigated. Gastric emptying (GE) was investigated in 20 patients before and 2 months after autologous HSCT. Gastrointestinal symptoms were graded prospectively and oral energy intake was recorded in parallel. Before transplant, all patients were asymptomatic and GE was within the reference range. Post transplant GE was delayed in three patients and three patients reported nausea and/or vomiting. Neither gastrointestinal symptoms nor oral energy intake post transplant discriminated between patients with or without delayed GE. Oral energy intake before transplant was lower (P=0.05), and there was a greater need for total parenteral nutrition (TPN) among patients who developed gastroparesis post transplant (P<0.05). Delayed GE after HSCT was found to be less common than had been believed from retrospective studies. Gastroparesis may be involved in some cases of prolonged nausea and vomiting after autologous HSCT but alternative explanations should be considered. Symptoms consistent with gastroparesis did not correlate with GE. Patients at risk of developing gastroparesis may be found among those with nutritional difficulties before and during the transplant course.     

Management of Diabetic Gastroparesis

Symptoms suggestive of gastroparesis occur in 5% to 12% of patients with diabetes. Such a complication can affect both prognosis and management of the diabetes; therefore, practicing clinicians are challenged by the complex management of such cases. Gastroparesis is a disorder characterized by a delay in gastric emptying after a meal in the absence of a mechanical gastric outlet obstruction. This article is an evidence-based overview of current management strategies for diabetic gastroparesis. The cardinal symptoms of diabetic gastroparesis are nausea and vomiting. Gastroesophageal scintiscanning at 15-minute intervals for 4 hours after food intake is considered the gold standard for measuring gastric emptying. Retention of more than 10% of the meal after 4 hours is considered an abnormal result, for which a multidisciplinary management approach is required. Treatment should be tailored according to the severity of gastroparesis, and 25% to 68% of symptoms are controlled by prokinetic agents. Commonly prescribed prokinetics include metoclopramide, domperidone, and erythromycin. In addition, gastric electrical stimulation has been shown to improve symptoms, reduce hospitalizations, reduce the need for nutritional support, and improve quality of life in several open-label studies.     

Metoclopramide suppositories in the treatment of diabetic gastroparesis

Gastroparesis diabeticorum is a common complication that develops in patients with diabetes mellitus. Although the pathogenesis remains unclear, the clinical symptoms of nausea, vomiting, and gastric dilatation frequently respond to metoclopramide hydrochloride, an agent that stimulates gastric emptying in addition to acting centrally as an antiemetic. Occasionally, patients are encountered whose severe gastroparesis is unresponsive to oral metoclopramide and who require intravenous therapy or drainage procedures (eg, pyloroplasty or gastrojejunostomy). Rectal administration of metoclopramide successfully controlled the clinical symptoms of gastroparesis diabeticorum in an outpatient after failure of oral dosing, thus avoiding the need for intravenous therapy. Gastric emptying studies and serum metoclopramide levels following a 25-mg rectal dose of metoclopramide hydrochloride verified the efficacy of therapy.     

Prokinetics in Diabetic Gastroparesis

Within the last 50 years, diabetic gastroparesis has become a well recognized complication of type 1 and type 2 diabetes. It is a syndrome characterized by abnormal gastric function, resulting in delayed emptying of the stomach in the absence of any evident mechanical obstruction, predominantly manifested by early satiety, postprandial fullness, nausea, vomiting, and weight loss. The past five years have shown significant advances in its pathophysiology and in new diagnostic tests. Prokinetic medications remain the therapeutic focus for improving clinical symptoms of gastroparesis through enhanced gastric emptying. This article summarizes the present knowledge of prokinetics, with emphasis on medications currently available, as well as drugs under clinical investigation, including some agents in advanced clinical trials that are likely to be used in the treatment of diabetic gastroparesis in the future. These include the ghrelin agonists and newer 5-HT4 agonists devoid of cardiac side effects.     

Ischemic gastroparesis: resolution after revascularization

Patients with chronic nausea and vomiting frequently present challenging diagnostic and therapeutic problems. In such patients, gastroparesis of unknown cause, or "idiopathic" gastroparesis, may be the only objective finding. Two middle-aged women with nausea, vomiting, and weight loss of 10 and 26 kg over 6 and 18 months, respectively, were evaluated. Routine laboratory and barium study results were normal. Solid-phase gastric emptying studies showed severe gastroparesis in both patients. Upper endoscopies excluded gastric outlet obstruction. Gastric dysrhythmias (4-cpm and 1-cpm patterns) were recorded using cutaneous electrodes. An abdominal bruit was ascultated in one patient. Abdominal arteriograms in both patients showed total occlusion of all three major mesenteric vessels with collaterals supplied via hemorrhoidal arteries. Bypass grafting procedures of the celiac and superior mesenteric arteries in one patient and of the celiac artery in the other patient were performed. Six months after mesenteric artery revascularization, upper gastrointestinal symptoms had resolved and original weights were regained. Furthermore, normal 3-cpm gastric myoelectrical activity and normal gastric emptying of solids were restored in both patients. In these patients, chronic mesenteric ischemia resulted in a novel and reversible cause of gastroparesis, gastric dysrhythmias, and accompanying symptoms.     

Severe gastroparesis: new treatment alternatives

Dopamine antagonists, such as metoclopramide and domperidone, and the motilin receptor agonist erythromycin have been the cornerstones in drug treatment of severe gastroparesis for more than a decade. No new drugs have been approved for treatment of this disorder in this period. Instead, the 5-HT4 agonist cisapride has been withdrawn due to side-effects. The effectiveness of intrapyloric botulinum toxin for gastroparesis remains to be shown. In the last decade, gastric electrical stimulation (GES) with a fully implantable device has evolved as a promising treatment, with significant effects on nausea and vomiting in most patients with severe, drug-refractory diabetic gastroparesis and postsurgical gastroparesis. A proportion of patients with severe idiopathic gastroparesis and patients with idiopathic nausea and vomiting also respond. More research is needed to achieve precise selection of responders/non-responders to GES, and to study the potential benefit of GES in other patient groups suffering from severe nausea or vomiting.     

Gastroparesis following bone marrow transplantation

Patients often develop nausea, vomiting and bloating after bone marrow transplantation (BMT). These symptoms may interfere with nutrition and the ability to take oral medications. Gastroparesis is a recognized cause of these symptoms in non-transplant patients but less is known about patients who undergo BMT. Between January 1996 and March 1997, a total of 151 patients underwent BMT. Eighteen patients (12%) developed persistent symptoms suggestive of gastroparesis (persistent nausea, vomiting or bloating). Scintigraphic gastric emptying studies were performed to assess for gastroparesis. Prokinetic agents were administered at the time of study. The records on these patients were compared with those of all other patients undergoing BMT during the same time period without these symptoms. Nine patients who demonstrated delayed gastric emptying were further evaluated with esophagastroduodenoscopy and biopsy. Biopsy samples were reviewed for evidence of graft-versus-host disease (GVHD). Fourteen of 18 patients demonstrated delayed gastric emptying and most responded to prokinetic agents given at the time of study. Age, conditioning regimen, cytomegalovirus antigenemia and acute GVHD did not appear to be associated with the development of gastroparesis. Allogeneic BMT recipients were at higher risk than autologous BMT patients (26% vs 0%, P < 0.0001). of allogeneic bmt recipients, there was a nonsignificant trend of patients receiving tacrolimus to be less likely to experience gastroparesis than those receiving cyclosporine (27% vs 48%, P = 0.08). For the nine patients undergoing upper endoscopy, GVHD on gastric biopsy was an uncommon finding and was mild when present. Gastroparesis appears to be a common cause of nausea, vomiting and bloating following allogeneic BMT. This may occur less often with tacrolimus than cyclosporine because of the former agent's prokinetic properties. Patients usually respond to prokinetic drugs at the time of scintigraphy. GVHD and CMV infection do not appear to be major contributing factors.     

Delayed gastric emptying: Whom to test, how to test, and what to do

Opinion statement Gastroparesis, or delayed gastric emptying, is a common cause of chronic nausea and vomiting as seen in a gastroenterology practice. Diabetic, postsurgical, and idiopathic causes remain the three most common forms of gastroparesis. In addition to nausea and vomiting, symptoms of gastroparesis may include early satiety, postprandial fullness, and abdominal pain. Physiologic changes that may explain symptoms in patients with gastroparesis, in addition to delayed gastric emptying, include impaired fundic accommodation, antral hypomotility, gastric dysrhythmias, pylorospasm, and perhaps visceral hypersensitivity. Diagnosis of gastroparesis is best determined using a radioisotope-labeled solid meal with scintigraphic imaging for at least 2 hours, and preferably 4 hours, postprandially. Most commonly, a 99mTc sulfur colloid-labeled egg sandwich with imaging at 0, 1, 2, and 4 hours is used. Extension of the gastric emptying test to 4 hours improves the accuracy of the test, but unfortunately, this is not commonly performed at many centers. Emptying of liquids remains normal until the late stages of gastroparesis and is less useful. The aims of treatment should be to control symptoms and maintain adequate nutrition and hydration. Patients should be advised to eat small meals and to limit their intake of fat and fiber. Additional dietary recommendations may include increasing caloric intake in the form of liquids. For diabetic patients, control of blood glucose levels is important, as symptom exacerbation is frequently associated with poor glycemic control. Specific treatment often begins with metoclopramide, 10 mg, up to four times daily, after a discussion of possible side effects with the patient. An antiemetic agent, such as prochlorperazine, 5 to 10 mg orally or 25 mg by suppository, can be added on an as-needed basis every 4 to 6 hours to control nausea. If these antiemetic medications are not effective, or if side effects develop, orally dissolving ondansetron, 8 mg every 8 to 12 hours, can be tried on an as-needed basis. If this regimen is unsuccessful, then alternative prokinetic agents—erythromycin, 125 mg, or tegaserod, 6 mg, prior to meals—can be tried. For cases refractory to these treatments, referral to a center with US Food and Drug Administration permission to use domperidone should be considered. Alternatively, symptom modulators such as low-dose tricyclic antidepressants can be tried to reduce symptoms, but these do not improve gastric emptying. In patients for whom all medical therapy fails, other options that are tried at experienced centers include the injection of botulinum toxin into the pylorus, placement of a feeding jejunostomy, and/or placement of a gastric electrical stimulator.     

Diabetische Gastroparese

Symptoms of gastroparesis include nausea and vomiting, early satiety, post-prandial fullness, bloating and abdominal pain, but it is also frequently be asymptomatic. Patients with difficult metabolic control should be considered to have a disordered gastric emptying. Nuclear scintigraphy is the gold standard for quantifying delayed gastric emptying, but noninvasive methods, such as 13C-octanoic acid breath tests, exhibit a highly significant positive correlation to scintigraphy. The main goal of treatment is to minimize the symptoms and accelerate gastric emptying. The basic measures for achieving this are improved glucose control and low fat/low fibre diets that are easy to digest. The prokinetic agents metoclopramide, domperidone and erythromycin are successful in controlling symptoms in the majority of patients with gastroparesis due to diabetes. Patients with persistent symptoms or intermittent but severe symptoms may require surgical techniques such as the gastrostomy and jejunostomy. The significance of gastric pacing devices on gastric emptying and specific symptom controls have to be elucidated in further studies.     

Effect of metoclopramide in diabetic gastroparesis

The aims of our study were to: determine the effect of metoclopramide parenterally and orally on delayed gastric emptying of a radionuclide test meal in symptomatic patients with diabetic gastroparesis not explained by ulceration or other mechanical problems; and evaluate in a double-blind crossover fashion the efficacy of metoclopramide in relieving the symptoms of diabetic gastroparesis. Thirteen patients with subjective evidence of gastric stasis had delayed gastric emptying of an isotope-labeled semisolid meal which was significantly accelerated (p less than 0.05) after 10 mg of metoclopramide parenterally. Patients then received metoclopramide 10 mg and placebo before meals and prior to retiring for 3 weeks in a randomized double-blind crossover design. During metoclopramide therapy nausea, vomiting, anorexia, fullness, and bloating were significantly (p less than 0.05) ameliorated compared to placebo with an overall mean symptom reduction of 52.6%. Gastric emptying studies after completion of the trial is seven patients, subjectively improved and receiving open-labeled metoclopramide, showed significantly less gastric retention. Individual improvements in gastric emptying after parenteral or oral metoclopramide, however, could not be correlated with symptom change during the treatment trial. We conclude that metoclopramide is an important therapeutic adjunct in the management of diabetic gastroparesis and its therapeutic effects are mediated through its prokinetic properties as well as centrally mediated antiemetic actions.     

Unexplained nausea and vomiting

Opinion statement Nausea and vomiting are debilitating symptoms for patients, and can be challenging problems in diagnosis and management for physicians. Initial efforts must be made to establish a specific diagnosis that represents the pathophysiological cause of the nausea and vomiting. If a specific diagnosis is made (for example, antral ulceration), then specific therapy for the lesion will usually eradicate the nausea and vomiting associated with the specific disease. When standard gastrointestinal diseases are eliminated as a cause of nausea and vomiting, then gastric neuromuscular disorders (disorders of motility) should be considered as potential causes of these symptoms. Gastric neuromuscular disorders range from gastric dysrhythmias and abnormalities of gastric accommodation to frank gastroparesis. Treatments for nausea and vomiting due to gastric neuromuscular dysfunction include: 1) patient education and dietary counseling; 2) gastrokinetic drugs; 3) visceral, sensory afferent and CNS drugs; 4) gastrostomy for stomach venting; 5) jejunostomy for enteral feeding access; and 6) acustimulation and gastric pacemaker therapies. Treatment approaches based on the pathophysiology of gastric neuromuscular dysfunction(s) and on patient education aid in the successful management of unexplained nausea and vomiting.     

Clinical application prospects of gastric pacing for treating postoperative gastric motility disorders

Similar to the heartbeat, gastric peristalsis is regulated by an electrical rhythm generated by a pacemaker. Thus, electrical dysrhythmia of gastric slow waves will inevitably affect gastric peristalsis and emptying. The recurrence of postoperative gastroparesis is thereby closely related to the abnormalities of electrical dysrhythmia and ectopic pacemakers, resulting in postoperatively persistent gastric motility disorders in some severe cases, despite the use of prokinetic and antiemetic drugs. Recent studies have demonstrated that gastric pacing, analogous to pacing the human heart, is an attractive and promising therapy that is both feasible and safe. Gastric pacing has been shown to be strikingly effective in normalizing gastric dysrhythmia, increasing the activity of the gastric slow wave and thereby prompting gastric dynamia and emptying. Furthermore, the long-term utilization of gastric pacing can (i) relieve patients from clinical symptoms, such as nausea and vomiting; (ii) release patients with severe postoperative gastroparesis from relying on prokinetic drugs and the jejunal feeding tube; (iii) return patients to normal oral nutritional intake and provide a more satisfactory nutritional status and most importantly; and (iv) give patients a better quality of life. Overall, research focused on gastric pacing has demonstrated excellent prospects for clinical application in the treatment of postoperative gastroparesis disorders, especially for those unresponsive to prokinetic drugs.     

Treatment of gastroparesis with electrical stimulation

Electrically stimulating the stomach to treat gastroparesis has been proposed by investigators for decades. With the development of techniques of implantable pacing devices and electrodes and promising preliminary results in chronic pacing studies, gastric electrical stimulation (GES) has received increasing attention recently among researchers and clinicians. A number of studies have been performed to investigate the effects of GES on gastric motility, gastric emptying, and gastrointestinal symptoms in both dogs and humans. Based on the frequency of the electrical stimulus used for chronic treatment of gastroparesis, gastric electrical stimulation can be classified into low-frequency stimulation (LFS) and high-frequency stimulation (HFS). Although some of the results are still controversial, the majority of these studies seem to indicate that LFS is able to normalize gastric dysrhythmias and entrain gastric slow waves and accelerate gastric emptying. On the other hand, HFS has no effect on gastric emptying but is able to significantly reduce symptoms of nausea and vomiting in gastroparetic patients. GES has provided an exciting new advance in the treatment of gastroparesis and management of upper gastrointestinal symptoms. This paper will review the available studies of GES in the treatment of gastroparesis and current status of this field.     

Gastric electric stimulation for the treatment of gastroparesis

Gastric electric stimulation is an emerging therapy for refractory gastroparesis. Several methods have been used to electrically stimulate the stomach. Initial studies used gastric electrical pacing, which entrains and paces the gastric slow waves at a slightly higher rate than the patient’s normal myoelectric frequency of 3 cycles per minute (cpm). The technique currently practiced uses high-frequency, low-energy stimulation at four times the basal rate (12 cpm). Results from published studies with high-frequency stimulation reveal an improvement in symptoms, primarily of nausea and vomiting, and primarily in patients with diabetic gastroparesis, with only a modest change in gastric emptying. As treatment with gastric electric stimulation evolves, further delineation of its overall effectiveness, the type of patient that will likely respond, optimal electrode placement(s), and stimulus parameters should be explored.     

Effect of cisapride on gastric emptying of indigestible solids in patients with gastroparesis diabeticorum. A comparison with metoclopramide and placebo

Cisapride is a prokinetic agent believed to facilitate acetylcholine release from the myenteric plexus of the gut. The effect of cisapride on gastric emptying of solids was studied in 9 diabetic patients, all of whom had delayed gastric emptying of indigestible solids (gastroparesis). Six patients had chronic nausea and vomiting, and 3 had no symptoms. Cisapride (5 mg) was given intravenously 15 min before ingestion of a 400-kcal test meal and 10 indigestible solid radiopaque markers. On separate days and in random order each patient also received intravenous metoclopramide (10 mg) or placebo 15 min before ingestion of the meal and markers. Mean gastric emptying of radiopaque markers, assessed by serial radiographs of the gastric region, was accelerated by metoclopramide and cisapride, but the difference reached significance only with cisapride (p less than 0.05). There was considerable intersubject variability in gastric emptying responses to cisapride and metoclopramide. No side effects occurred with either drug. This study indicates that acute, intravenous administration of cisapride accelerates gastric emptying of indigestible solids in patients with diabetic gastroparesis.     

不同阶段糖尿病胃运动障碍诊治对策

糖尿病患者常见胃运动障碍,表现为上腹胀、早饱、上腹不适、恶心、呕吐等症状以及胃排空延迟,胃排空延迟影响降血糖药的药代动力学,造成餐后血糖升高与降血糖药或胰岛素的血浓度高峰不匹配,进而影响血糖的控制与稳定。糖尿病不同阶段胃运动障碍表现形式不同。核素法是最常用的胃排空诊断方法。糖尿病胃运动障碍的处理包括饮食调节、促动力药以减轻症状、控制血糖,针对胃轻瘫的治疗包括胃电刺激、内镜下幽门注射肉毒杆菌毒素A、内镜下放置鼻胃空肠营养管或经皮内镜下胃（空肠）造瘘、外科手术等。     

Granisetron Transdermal System Improves Refractory Nausea and Vomiting in Gastroparesis

Background

Symptoms of gastroparesis include nausea and vomiting, which can markedly diminish quality of life. Nausea and vomiting can also make treatment with oral antiemetics problematic.

Aim

Our aim was to determine whether treatment-resistant nausea and vomiting in patients with gastroparesis improve after granisetron transdermal patch (GTP) therapy.

Methods

In an open-label pilot study, patients with gastroparesis and symptoms of nausea and vomiting refractory to conventional treatment were treated with GTP. After 2 weeks, patients were asked to assess their therapeutic response using the Clinical Patient Grading Assessment Scale (CPGAS; +7 = completely better; 0 = no change; ?7 = very considerably worse). Responders were defined as CPGAS score >0, non-responders as ≤0.

Results

Patients (n = 36) were treated with GTP. Of these 36 patients, one patient discontinued treatment due to the GTP not adhering to the skin. Of the remaining 35 patients, 18 improved, 15 remained the same, and two worsened. The average CPGAS score was +1.8 ± 0.4 (SEM) (P < 0.05 vs 0). Of the 18 patients with improvement, the average CPGAS score was +3.7 ± 0.3 (SEM), corresponding to “somewhat” to “moderately better” improvement in nausea/vomiting. Side effects occurred in nine patients: four developed constipation, three patients had skin rash, and two reported headaches.

Conclusions

GTP was moderately effective in reducing refractory symptoms of nausea and/or vomiting from gastroparesis in 50 % of patients. Mild side effects were reported by 25 % of patients. GTP may be an effective treatment for nausea and vomiting in gastroparesis, and further study is warranted.     

Gastric electrical stimulation for the treatment of diabetic gastroparesis

Diabetic gastroparesis is a component of autonomic neuropathy, and is the most common manifestation of gastrointestinal neuropathy. Diabetes is responsible for about one quarter of gastroparesis. The upper gastrointestinal symptoms are often non-specific and dominated by nausea, vomiting, early satiety, fullness, bloating. We also have to look for diabetic gastroparesis in case of metabolic instability, such as postprandial hypoglycaemia. The pathophysiology of diabetic gastroparesis is complex, partly due to a vagus nerve damage, but also to changes in secretion of hormones such as motilin and ghrelin. A decrease in the stem cell factor (SCF), growth factor for cells of Cajal (gastric pacemaker), was found in subjects with diabetic gastroparesis. These abnormalities lead to an excessive relaxation in the corpus, a hypomotility of antrum, a desynchronization antrum-duodenum-pylorus, and finally an abnormal duodenal motility. The treatment of diabetic gastroparesis is based on diabetes control, and split meals by reducing the fiber content and fat from the diet. The antiemetic and prokinetic agents should be tested primarily in people with nausea and vomiting. Finally, after failure of conventional measures, the use of gastric neuromodulation is an effective alternative, with well-defined indications. Introduced in the 1970s, this technology works by applying electrical stimulation continues at the gastric antrum, particularly in patients whose gastric symptoms are refractory to other therapies. Its efficacy has been recently reported in different causes of gastroparesis, especially in diabetes. Gastric emptying based on gastric scintigraphy, gastrointestinal symptoms, biological markers of glycaemic control and quality of life are partly improved, but not normalized. Finally, a heavy nutritional care is sometimes necessary in the most severe forms. The enteral route should be preferred (nasojejunal and jejunostomy if possible efficiency). However, in case of failure especially in patients with small bowel neuropathy, the long-term parenteral nutrition is sometimes required.     

Measurement by epigastric impedance of gastric emptying in diabetic autonomic neuropathy

Changes in impedance across the epigastrium form the basis of a new non-invasive method of assessing gastric emptying of liquids. The apparatus is simple to use at the bedside and, in conjunction with conventional investigations, is of value in diagnosing gastroparesis in patients with diabetic autonomic neuropathy and symptoms of recurrent vomiting. We measured gastric emptying of liquids in 22 diabetics aged 33.4 +/- 9 years (mean +/- SD) with severe symptomatic autonomic neuropathy (mean heart rate variability 4.9 +/- 2.2 SD beats/min), and 15 normal controls. Median 'half emptying' time in the diabetics with autonomic neuropathy was prolonged overall but it was not always abnormal (12.25 min, range 6.5-greater than 30 compared to 8.0 min, range 3-17; p less than 0.01). Results in five diabetics with symptoms of recurrent vomiting corresponded with those using conventional radiological methods, confirming gastroparesis in three instances and excluding it in two. The effect of metoclopramide was also studied and was shown to accelerate gastric emptying in some but not all of the patients. Assessment of gastric emptying using the impedance method assists in establishing the diagnosis of gastroparesis and is of value for repeated measurements.