Measurement Of Gastric Emptying Research Articles

Impaired Hyperglycemia-Induced Delay in Gastric Emptying in Patients With Type 1 Diabetes Deficient for Islet Amyloid Polypeptide

OBJECTIVE—Slowing of gastric emptying by hyperglycemia, a physiological response to minimize postprandial hyperglycemia, may be impaired in patients with type 1 diabetes. The causes and consequences on glucose homeostasis are unknown.RESEARCH DESIGN AND METHODS—Consequences of euglycemia- and hyperglycemia-induced changes in gastric emptying on postprandial glucose fluxes and excursions were studied in 10 healthy subjects and 15 type 1 diabetic subjects after ingestion of a mixed meal using the double isotope approach ([6,6-2H2] and [1-13C]glucose) and scintigraphic measurements of gastric emptying.RESULTS—Gastric emptying was greater in type 1 diabetic subjects (90–120 min, P < 0.03), and 50% retention times were comparable in healthy subjects and type 1 diabetic subjects (167 ± 8 vs. 152 ± 10, P = 0.32). Hyperglycemia markedly delayed gastric emptying in healthy subjects but did not alter it in type 1 diabetic subjects (50% retention time 222 ± 18 vs. 167 ± 8 min, P = 0.003 and 148 ± 9 vs. 152 ± 10 min, P = 0.51). Plasma islet amyloid polypeptide (IAPP) increased approximately fourfold in healthy subjects (P < 0.001), whereas it was undetectable in type 1 diabetic subjects. IAPP replacement, using the analog pramlintide, in type 1 diabetic subjects slowed gastric emptying to a comparable extent, as did hyperglycemia in healthy subjects (P < 0.14), and greatly reduced postprandial hyperglycemia (P < 00.1). Meal-derived glucose appearance in plasma (10.7 ± 0.5 vs. 6.8 ± 0.7 μmol · kg−1 · min−1, P < 0.001) was reduced, and splanchnic glucose sequestration increased (14.0 ± 3.0 vs. 25.0 ± 6.0%, P = 0.04).CONCLUSIONS—In patients with type 1 diabetes the ability to delay gastric emptying in response to hyperglycemia is impaired. This impairment contributes to exaggerated rates of meal-derived glucose appearance and, ultimately, postprandial glucose excursions.

Ultrasound measurement of gastric emptying of a solid test meal. Correlation with scintigraphy in diabetic patients and reproducibility in healthy probands

Measurement of gastric emptying of liquids by sagittal antral planimetry is established. Ultrasonic measurement of gastric emptying of solids has not been assessed although gastroparesis often reveals a delayed gastric emptying of solids first. Therefore in this prospective study we used a solid meal (50 g rye bread, 1 egg, 40 g butter, 200 ml orange juice; 280 kcal) to examine intraindividual reproducibility of ultrasound in 20 healthy volunteers. Moreover, in 20 diabetics antral planimetry assessed by ultrasound was compared to scintigraphy. Antral planimetry showed a coefficient of variation, that was nearly three times greater between subjects than between two measurements performed on the same subject. This results reflect a good intraindividual reproducibility. Gastric emptying half-times assessed by ultrasound and scintigraphy did not correlate in diabetics (R = 0.2). However, correlation between sonographic measurement of antral area and scintigraphy at defined times (60, 120, 180, 240 min) was significant (R = 0.7; p < 0.001). These results imply that ultrasonic antral planimetry is a suitable orientating method for measuring gastric emptying of solids.

Gastric emptying rate in subjects with experimentally shortened dental arches: a pilot study

Although a shortened dental arch has been reported to provide sufficient subjective chewing ability, the loss of molar occlusion significantly reduces trituration ability, and may result in an impaired digestive function including delayed gastric emptying. This study investigated the effect of the experimental loss of molar occlusion on gastric emptying rate. Thirteen healthy dentate males underwent two sessions of gastric emptying rate measurement after ingestion of the same test meal that contained ham, bread and an egg mixed with carbon-labelled octanoic acid. A test food was divided into nine equal portions, and each was consumed in 60 cycles of chewing. In one of the two sessions, the subjects wore an intraoral appliance devised to simulate the occlusal conditions of the shortened dental arches. Two parameters of gastric emptying; namely, the lag phase (T(lag)) and gastric half-emptying time (T(1/2)), were evaluated by means of a (13)C-octanoic acid breath test. Following the measurement of gastric emptying in each session, masticatory performance was evaluated by a conventional sieve test. Masticatory performance decreased significantly in case of loss of molar occlusion (78.1 +/- 11.1% versus 33.4 +/- 18.2%, P <0.001); however, no significant changes were observed in terms of the gastric emptying parameters (T(lag): 99 +/- 19 versus 105 +/- 34 min; T(1/2): 168 +/- 32 versus 178 +/- 48 min). Within the limitations of this study, it was concluded that reduction in food trituration caused by shortening of the dental arch does not significantly affect gastrointestinal digestive function.

Paracetamol absorption test with Wagner-Nelson analysis for safe and accurate measurements of gastric emptying in women

The physiological and pharmacological aspects of gastric emptying in fertile or pregnant women have been studied. Scintigraphy is the reference method for measuring gastric emptying. However, it should be applied very cautiously to women of childbearing age because of the risk of substantial irratiation. In such a population, paracetamol absorption has been used safely as an index of gastric emptying, but its accuracy has been challenged. The Wagner-Nelson method is a traditional tool used to precisely evaluate drug absorption kinetics. To clarify whether the absorption kinetics of paracetamol assessed by the Wagner-Nelson method is as accurate as scintigraphy in evaluating gastric emptying in young women, gastric emptying of a 200-kcal liquid meal was measured simultaneously by scintigraphy and the paracetamol test in 10 healthy young female volunteers. Paracetamol absorption systemically overestimated the rate of gastric emptying measured by scintigraphy. By introducing a correction factor into the paracetamol test, the overestimation could be adjusted. The paracetamol test with Wagner-Nelson analysis can be a safe and accurate method for measuring gastric emptying in women of childbearing age.

Rabeprazole delays gastric emptying of a nutrient liquid

It is generally considered that gastric acid suppression delays gastric emptying of solid meals because gastric hypoacidity impairs peptic digestion and antral triturition. Rabeprazole is one of the most potent acid suppressants. We conducted this cross-over study to investigate if rabeprazole delays gastric emptying of liquid nutrients, for which peptic digestion is unnecessary. On two randomized occasions, 13 healthy male volunteers underwent the (13)C-acetate breath test following ingestion of a 300 kcal-liquid meal. On one occasion, they had received 20 mg rabeprazole for the preceding 2 days and 1 h before the test. On another, they took no pretreatment. Based on 4 h breath samples, the half (13)CO(2) excretion time (t(1/2b)) and the time of maximal excretion (t(max)) were calculated as overall measures of gastric emptying. In addition, time profiles of gastric emptying were generated using the Wagner-Nelson analytical method, which creates the gastric emptying curve as accurately as the scintigraphy. Rabeprazole significantly prolonged t(max) but unchanged t(1/2b). The gastric emptying profiles showed that rabeprazole evoked a segmental slowing of gastric emptying during 0.5-1.25 h of post-meal ingestion. Rabeprazole suppresses gastric emptying of a liquid nutrient 0.5 h after meal ingestion. We have speculated that: (i) rabeprazole delays gastric emptying via a mechanism other than acid-pepsin maldigestion; and (ii) rabeprazole may intensify the post-gastric feedback regulation system (>0.5 h of post-meal).

Prokinetics effect on gastric emptying in critically ill ventilated patients measured by the C13 breath test with a novel device

Gastroparesis in critically ill ventilated patients is relieved by prokinetics. The best prokinetic combination is not known and may be identified by BreathID measurement of gastric emptying (GE).

Erythromycin Dose of 70 mg Accelerates Gastric Emptying as Effectively as 200 mg in the Critically Ill

Objective: To compare the effectiveness of 70‐mg and 200‐mg doses of IV erythromycin in improving gastric emptying in critically ill patients. Design: Gastric emptying was measured on consecutive days; day 1 (pretreatment), day 2 (posttreatment) after an IV infusion of either 70 or 200 mg erythromycin or saline placebo (0.9%), in a randomized double‐blind fashion. Setting: Mixed medical/surgical intensive care unit, tertiary referral. Patients and Participants: Thirty‐five randomly selected, mechanically ventilated, enterally fed critically ill patients (median APACHE II score 19 on admission). Interventions: On day 2, either 70 or 200 mg erythromycin or saline was administered IV over 20 min. Measurements and Results: Gastric emptying was measured using the [13C]octanoic acid breath test. The gastric emptying coefficient (GEC) and half‐emptying time (t½) were calculated from the area under the 13CO2‐recovery curve. Pretreatment gastric emptying measurements were similar in all 3 patient groups. Treatment with both doses of erythromycin significantly reduced the gastric t½: 70 mg, 98 min (IQR 88–112); 200 mg, 86 min (75–104); vs placebo, 122 min (102–190) (p &lt; .05). The GEC was higher with both doses of erythromycin: 70 mg, 3.8 (3.3–4.0); 200 mg, 4.0 (3.6–4.2); vs placebo, 2.9 (2.5–3.7) (p &lt; .05). There was no difference in gastric emptying posttreatment between the 2 doses of erythromycin. The effect of erythromycin was greatest in patients with delayed gastric emptying. Conclusions: Treatment with 70 and 200 mg IV erythromycin is equally effective in accelerating gastric emptying in the critically ill.

Measurements of gastric emptying of low‐ and high‐nutrient liquids using 3D ultrasonography and scintigraphy in healthy subjects

Scintigraphy represents the 'gold standard' for the measurement of gastric emptying. Recent studies suggest that three-dimensional (3D) ultrasonography may allow a precise measure of gastric emptying, given the capacity for accurate volume calculations of the stomach. The aim of this study was to compare measurements of gastric emptying of both low- and high-nutrient drinks by 3D ultrasonography with scintigraphy. Ten healthy young subjects (6M, 4F, age 23.5 +/- 1.5 years) were studied on 2 days. Concurrent measurements of gastric emptying by scintigraphy and 3D ultrasonography were performed after ingestion of 500 mL beef soup (12 kcal) or 300 ml dextrose (25% w/v) (314 kcal) labelled with 20 MBq (99m)Tc-sulphur colloid. There was no significant difference between scintigraphic and ultrasonographic 50% emptying times (T50s) (soup: 27.7 +/- 4.8 min vs 23.8. +/- 4.8 min; dextrose: 122.2 +/- 13.3 min vs 131.9 +/- 10.2 min). There was a close correlation between scintigraphic and ultrasonographic T50s for both soup (r = 0.92, P = 0.0005) and dextrose (r = 0.88, P = 0.0007). For the T50s, the limits of agreement were -15.2 min and +8.1 min for the soup (mean difference -3.6 min) and -35.3 min and +47.6 min for dextrose (mean difference +6.2 min). 3D ultrasonography provides a valid measure of gastric emptying of liquid meals in healthy subjects.

Measurements of gastric emptying during continuous nasogastric infusion of liquid feed: Electric impedance tomography versus gamma scintigraphy

Continuous nasogastric infusion is commonly used to deliver enteral feed but current methods used to assess tolerance based on aspiration and measurement of gastric residual volume have been criticised. Electric impedance tomography (EIT) measures gastric emptying by monitoring changes in epigastric impedance when a meal progressively empties from the stomach. (1) to establish whether EIT was a valid method for measuring gastric emptying during continuous nasogastric infusion by comparing it with gamma scintigraphy (GS) and (2) to provide data on gastric emptying patterns during continuous nasogastric infusion. Gastric emptying of 400 ml of enteral feed given over 200 min was measured simultaneously using EIT and GS in 10 healthy volunteers (five male and five female). Gastric emptying curves were obtained in 10 subjects by EIT but only eight by GS. Visual examination of the curves showed reasonable agreement. Patterns of emptying and filling during continuous nasogastric infusion were variable between individuals; the prevailing pattern was a trend towards a steady-state volume of approximately 50-125 ml. While EIT does not provide an accurate estimate of gastric volume during continuous infusion, it does show patterns of gastric emptying over time. With further development this could make it a useful tool for monitoring gastric emptying in patients at risk of gastroparesis.

2 Endoscopic temporary gastric electrical stimulation – results of 140 consecutive patients

Introduction: Gastric electrical stimulation (GES) is now an accepted therapy for drug refractory gastroparesis, but requires surgical device implantation. We recently described techniques for placement of temporary GES electrodes via PEG tube or endoscope (GIE 2005: 61:455–461). We now report on a larger series of consecutive patients referred for endoscopic temporary stimulation.Patients: 140 consecutive patients, 29 male, 114 female, mean age 41 years, with the diagnosis of diabetes (DM, n = 44), post‐surgical (PS, n = 14) or idiopathic disorders (ID, n = 82) were evaluated. We investigated those patients who were successfully implanted, and those who completed a full evaluation of symptoms and gastric emptying tests.Methods: All patients underwent baseline assessment of Symptoms (SX, as Nausea = N, Vomiting = V, Total GI Sx = TSS) and measurements of Gastric emptying (GET) and again after a minimum of 3 days of GES with standard parameters (GIE, above). Patients were reported by descriptive statistics and by t‐tests for symptoms and emptying.Results: 139 (99%) of patients were successfully implanted and 125 (88%) of patients completed at least 3 days of therapy. Of thepatients who completed a full evaluation, there were significant improvements in symptoms and improvements in gastric emptying for some patients: particularly PS and DM (See table).Conclusion: Temporary endoscopic gastric electrical stimulation is feasable and reproducible in a large numbers of patients. The availability of this technique, combined with an emerging technology of gastrointestinal electrical stimulation techniques, gives endoscopists the ability to screen patients before implantation of permanent devices. The availability of endoscopic implanted electrical stimulation offers other potential therapeutic uses, including dyspepsia, post‐surgical disorders and obesity. Category B T B T B T B/ T Measure N N V v TSS TSS 4 Hr/ 4 Hr All 3.4 0.9 2.5 0.6 15.2 5.1 20.7 20.6 DM 3.2 0.7 2.6 0.3 14.3 3.2 23.4 20.5 ID 3.2 0.8 2.2 0.6 14.7 4.7 12.9 13.1 PS 3.2 0.2 2.6 0.2 14.1 2.1 28.3 15.8 P &lt;0.0001 &lt;0.0001 &lt;0.0001

32 How common is rapid gastric emptying in gastroparesis? Comparison of area under the curve, total gastric emptying and 1‐hour values in patients and normal volunteers

Introduction: Rapid gastric emptying has been described not only in patients with nausea and vomiting and gastroparesis but also in obesity and dyspepsia. We investigated the use of three measures of rapid gastric emptying in a large group of patients with gastroparesis as compared to normal controls.Patients: From a pool of 214 consecutive patients with the symptoms of gastroparesis we reviewed the results of standardized solid gastric emptying tests and compared the results to a group of normal controls as previously described (AJG 95: 1456‐14622000). Patients were 39 males, 175 females mean age 42 years, with diagnosis of 42 Diabetes Mellitus, 26 Post Surgical and 146 Idiopathic diseases.Methods: Gastric emptying was compared by three models: Area under the emptying curve (AUC, rapid &lt; 0.257), total gastric emptying (TGE: the sum of 1, 2 and 4 hours; rapid &lt; 47), and percentage remaining at 1 hour (&lt;37%) for rapid and/or at 4 hours (&gt;10%) for delayed emptying, using data and techniques previously described (AGJ2004; 99: S45 and NGM 2005; 17: 470).Results: Measurable gastric emptying could be determined for 4 hours emptying in 146 patients; 87 patients had complete 1, 2 and 4 hours emptying. 44 patients had delayed emptying by 4 hour% &gt;10%, seven patients (8%) had rapid gastric emptying by AUC and eight pts (9%) had rapid emptying by the TGE values; and 16 (18%) pts had rapid emptying by the 1 hour value alone.Conclusion: Rapid gastric emptying of a solid meal is not uncommon in patients with the symptoms of gastroparesis. The AUC and TGE models identified approximately the same number of patients with rapid emptying, while the 1‐hour model identified approximately twice as many patients. Using the three techniques described to determine rapid gastric emptying awaits prospective use in other patients, including dyspepsia and obesity. Standardized measure for rapid gastric emptying may be useful in evaluating therapeutic outcomes for these disorders.

‘Gastric’ hypoglycaemia – an important concept in diabetes management

The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) and UK Prospective Diabetes Studies (UKPDS) have established that both the development and progression of the microvascular (i.e. neuropathy, nephropathy and retinopathy), and probably macrovascular (i.e. cardiovascular disease), complications of type 1 (insulin-dependent) and type 2 (non-insulin dependent) diabetes mellitus are related to average glycaemic control, as assessed by measurement of glycated haemoglobin. This evidence provides a persuasive rationale for the widespread use of intensive therapy for diabetes directed at the normalization of glycaemia. For example, in the recently reported DCCT/EDIC study which involved type 1 patients, a period of intensive , as opposed to conventional , therapy for a mean period of 6.5 years during the DCCT study (i.e. between 1983 and 1993) was associated with a reduction in the risk of a subsequent (i.e. between 1994 and 2005) cardiovascular event of 42%. Hence, a major goal in treating diabetes is to achieve blood glucose levels as close as possible to the normal, fasting, range. This is compatible with the American Diabetes Association recommendation of a target glycated haemoglobin of <7.0%, which may in fact be conservative given that a specific healthy glycaemic threshold has hitherto not been demonstrated. To achieve current targets, the majority of type 2 patients will require treatment with insulin within 10 years of the diagnosis of diabetes. In practice, however, glycaemic targets are not often met in either type 1 or type 2 patients. There is a natural reluctance to initiate insulin therapy in type 2 patients because of the potentially deleterious consequences of insulininduced hypoglycaemia, especially in those patients whose ability to recognize impending hypoglycaemia is impaired. In the DCCT study, the reduction in microvascular complications seen in the intensive care group was accompanied by a threefold increase in the rate of severe hypoglycaemia. Effective management of recurrent hypoglycaemia is, of course, dependent on the correction of the underlying cause(s), which include excessive insulin dosage, inadequate carbohydrate intake, psychiatric disorders, various endocrinopathies, coeliac disease and vomiting (whether self-induced or associated with gastroparesis). However, in a substantial minority of patients a cause is not clearly identifiable. The interesting study by Lysy et al. reported in this issue of the Journal indicates that delayed gastric emptying represents a significant risk factor for hypoglycaemia in insulin-treated type 1 and type 2 diabetes. The authors evaluated gastric emptying in 31 insulin-treated patients who had recurrent episodes of hypoglycaemia early in the postprandial period. Gastric emptying of a scrambled egg meal was significantly slower when compared to a control group of patients with diabetes who did not have recurrent hypoglycaemia; in about 30% of patients, the magnitude of the delay in emptying was marked, even though none of them reported upper gastrointestinal symptoms such as nausea or bloating. Strengths of the study include the relatively large number of patients and the prospective design, although demographic differences (e.g. in age Address for correspondence Prof Michael Horowitz, Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, North Terrace, Adelaide, SA 5000, Australia. Tel: 61 8 8222 4327; fax: 61 8 8223 3870; e-mail: michael.horowitz@adelaide.edu.au Received: 11 April 2006 Accepted for publication: 11 April 2006 Neurogastroenterol Motil (2006) 18, 405–407 doi: 10.1111/j.1365-2982.2006.00804.x

Measurement of gastric emptying by the 13C-octanoate breath test—rationalization with scintigraphy

The 13C-octanoate breath test has not achieved universal acceptance for the measurement of solid phase gastric emptying, largely because the results are not comparable with those from direct methods such as scintigraphy. To convert breath-test data to their scintigraphic equivalent scale corrections are applied which have been obtained from population studies, but there is no guarantee that these are applicable in all cases. We propose an alternative method applicable on an individual basis based upon a simple physiological model which does not require any change to the breath-test protocol. It is demonstrated by comparison with scintigraphy and the octanoate saliva test. Results from an existing dataset of simultaneous breath test, saliva test and scintigraphic determinations of solid phase gastric emptying from nine healthy subjects were re-analysed. The corrected breath tests gave gastric emptying curves which were shown to be not significantly different to those obtained from scintigraphy. The method provides a simple but effective way of generating gastric emptying curves from breath-test data that are directly comparable with direct measurement methods, which is advantageous since it allows the whole of the gastric emptying profile to be generated, not just values for the lag phase and half-emptying times.

Recent developments in gastrointestinal motility

In the past decade, the results of many studies on gastrointestinal motility and perception have been published that may be relevant to the clinician. A new classification of oesophageal motor disorders has been proposed in which “ineffective oesophageal motility” largely replaces the former “non-specific oesophageal motor disorders”. Recent studies have shown that the incidence of transient lower oesophageal sphincter relaxations can be reduced pharmacologically, and this may open doors to a new therapeutic approach in gastro-oesophageal reflux disease. The mechanisms through which hiatus hernia promotes reflux have become clearer. The recently developed technique of intraluminal impedance monitoring has made it possible to study oesophageal transit, non-acid reflux and its role in the generation of reflux symptoms, as well as the characteristics of belching. Measurement of gastric emptying by means of a non-radioactive isotope and breath-testing has become widely available but, unfortunately, this development has not yet been accompanied by the advent of new therapeutic options for gastroparesis. The term “enteric dysmotility” has been coined for the condition in which upper abdominal symptoms are associated with distinct small intestinal bowel motility disorders in the absence of ileus-like episodes. The role of high-amplitude propagated contractions in the pathogenesis of constipation has been further defined. In cases of suspected sphincter of Oddi dysfunction, manometry of both sphincters (IBD and pancreatic) is now felt to be advisable.

Short- and medium-term reproducibility of gastric emptying of a solid meal determined by a low dose of13C-octanoic acid and nondispersive isotope-selective infrared spectrometry

To evaluate the reproducibility of a modified 13C breath test-based measurement of solid phase gastric emptying (GE) within the frames of a simple-repeated measure study protocol. Twelve healthy subjects (6 females and 6 males, mean age 24.9+/-0.7 years) were recruited to undergo three identical GE examinations. In six subjects the first two examinations were performed 2 d apart, and the third session was carried out at a median interval of 19.5 d (range 18-20 d) from the second one. In another six subjects the first two measurements were taken 20 d apart (median, range: 17-23 d), whereas the third session took place 2 d after the second one. Probes of expiratory air collected before and during six hours after intake of a solid meal (378 kcal) labelled with 75 microL (68 mg) 13C-octanoic acid, were measured for 13CO2 enrichment with the nondispersive isotope-selective infrared spectrometry NDIRS apparatus. Taking coefficients of variation for paired examinations into account, the short-term reproducibility of the GE measurement was slightly but not significantly better than the medium-term one: 7.7% and 11.2% for the lag phase (T-Lag), 7.3% and 10.9% for the gastric half emptying time (T1/2). The least differences in GE parameters detectable at P=0.05 level in the 12 paired examinations were 9.6 and 15.6 min for T-Lag, 11.6 and 19.7 min for T1/2 by a two-day or two to three-week time gap, respectively. The low-cost modification of the breath test involving a lower dose of 13C-octanoic acid and NDIRS, renders good short- and medium-term reproducibility, as well as sensitivity of the measurement of gastric emptying of solids.

Measurement of gastric emptying after gastric bypass surgery using radionuclides.

The pattern of gastric emptying has been assessed after gastric bypass surgery using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. Eleven control subjects and 12 patients, 12 months post-gastric bypass, were studied. Stomal and gastric pouch size were assessed at endoscopy. Solid emptying was slower and liquid emptying was more rapid after gastric bypass surgery. Initial rapid emptying of solid occurred in the 4 patients with the smallest pouch diameters. There was no correlation between stomal size and rates of solid or liquid emptying nor between the weight loss produced by the operation and the rates of solid or liquid emptying, stoma or pouch size.

Postoperative gastric emptying.

Postoperative intolerance of oral fluids in common after abdominal surgery, and their premature administration may result in abdominal distension, nausea and vomiting. The ability of the stomach to empty 100 ml of water was investigated in patients undergoing elective cholecystectomy. Patients were studied preoperatively and on the first postoperative day using a radio-isotopic method of measurement of gastric emptying. Factors such as age, electrolyte disturbance, duration of operation and the many drugs used during the perioperative period were analysed in relation to postoperative gastric emptying rates. Postoperative gastric emptying showed wide variation, being normal in some patients but absent in others. No correlation was found between postoperative gastric emptying and age, plasma potassium and the duration of operation and anaesthetic. A significant correlation was found, however, between gastric emptying and drugs administered in the perioperative period. In particular, gastric emptying was grossly retarded following an injection of opiate, but this returned to normal if more than 5 h had elapsed since the last injection of opiate. It is suggested that opiate therapy is a major factor in a patient's inability to tolerate fluids following cholecystectomy.

99mTc ovalbumin labelled eggs for gastric emptying scintigraphy: in-vitro comparison of solid food markers

The reliability of solid phase gastric emptying measurements by scintigraphy requires a marker that remains within the solid component of the test meal, and which is not degraded by the gastric juice throughout the scintigraphic procedure. In Europe, foods are most often labelled with 99mTc rhenium sulfide macrocolloid (RSMC) but this solid phase marker was withdrawn from the market in January 2004. To test other potential solid phase markers and to compare them to the reference marker RSMC. These markers were rhenium sulfide nanocolloid (RSNC), tin fluoride colloid (TFC), phytates and two albumins (Alb and AlbC). All were radiolabelled with 99mTc. After quality control, each 99mTc marker was incorporated into the albumin of one egg. Then, egg white and yolk were mixed together, and a well-cooked omelette was prepared. Aliquots of the omelette were incubated with an acidic solution of pepsin at 37 degrees C which mimicked gastric juice. Unbound radioactivity in the supernatant fraction was measured at various times up to 3 h. The radiochemical purity was > 95% for all radiopharmaceuticals. During the in-vitro incubation, the percentage of 99mTc labelled colloids released from the omelette increased continuously: after 3 h, 5% for TFC and RSMC, 8% for phytates, and > 9% for the two albumins and RSNC. Considering quality controls and release of 99mTc during in-vitro incubation of the omelette, TFC showed the same behaviour as the reference marker RSMC. Thus, TFC seems to be the best candidate to replace RSMC for the radiolabelling of the solid phase of the gastric emptying test meal.

Measurement of gastric emptying by octanoate metabolism

Since its introduction just over 10 years ago, there have been a number of studies that have used the octanoate breath test to assess gastric emptying. Although use of the method is on the increase (the number of gastric emptying studies published on PubMed using the octanoate breath test has doubled between the periods 1997-2000 and 2001-2004 compared with a drop of approximately 20% in the use of scintigraphy over the same periods), the methodology has not achieved universal acceptance, primarily because it can provide results comparable to established techniques only indirectly. Recent methods for overcoming this difficulty are reviewed, including modified methods for breath test interpretation and the application of the related saliva test. The latter promises to be useful as a non-invasive proxy for established techniques, such as scintigraphy, for further validation of the breath test. Recent applications of octanoate-based methods are briefly considered. A novel approach detailed in this review for breath test interpretation, where the bicarbonate pool is modelled as a single compartment, could prove useful for obtaining breath test gastric emptying parameters that are directly comparable with those obtained from the gold standard, gamma scintigraphy. In combination with the saliva test, this could add credence to use of the octanoate breath test as a clinically accepted diagnostic tool, in addition to its potential in research.

Klinisch relevante Atemtests in der gastroenterologischen Diagnostik - Empfehlungen der Deutschen Gesellschaft für Neurogastroenterologie und Motilität sowie der Deutschen Gesellschaft für Verdauungs- und Stoffwechselerkrankungen

H (2)- and (13)C-breath tests are valuable non-invasive diagnostic tools for gastroenterological diseases. H (2)-breath tests are clinically established for the diagnosis of carbohydrate intolerance resulting from malabsorption (H (2)-breath tests with lactose, fructose, saccharose, sorbitol), of bacterial overgrowth (glucose H (2)-breath test) and for measurement of orcoceal transit time (lactulose H (2)-breath test). The (13)C-urea breath test is regarded as the "gold standard" procedure for the diagnosis of Helicobacter pylori infection. Moreover, (13)C-breath tests for measurement of gastric emptying can be considered as clinically established, meanwhile. (13)C-breath tests for the evaluation of pancreatic exocrine function or liver function can also be used clinically; however, they currently offer no substantial advantage over other diagnostic procedures. A major disadvantage of all breath tests is that they lack standardization although modifications of the test meal or solution, of the test performance and of the evaluation of data may markedly influence the results. Thus, this article presents the recommendations of the German Society of Neurogastroenterology and Motility and of the German Society of Digestive and Metabolic Diseases for clinically relevant H (2)- and (13)C-breath tests. Indications for the examinations, the procedures to be followed, the analysis of the obtained data and the conclusions to be drawn are delineated. The literature on which the recommendations are based is reviewed. However, personal experience of the authors is also taken into account since numerous questions regarding optimal test performance are not clarified by adequate studies.