Age-related impairment of esophagogastric junction relaxation and bolus flow time

AIM

To investigate the functional effects of abnormal esophagogastric (EGJ) measurements in asymptomatic healthy volunteers over eighty years of age.

METHODS

Data from 30 young controls (11 M, mean age 37 ± 11 years) and 15 aged subjects (9 M, 85 ± 4 years) were compared for novel metrics of EGJ-function: EGJ-contractile integral (EGJ-CI), “total” EGJ-CI and bolus flow time (BFT). Data were acquired using a 3.2 mm, 25 pressure (1 cm spacing) and 12 impedance segment (2 cm) solid-state catheter (Unisensor and MMS Solar GI system) across the EGJ. Five swallows each of 5 mL liquid (L) and viscous (V) bolus were analyzed. Mean values were compared using Student’s t test for normally distributed data or Mann Whitney U-test when non-normally distributed. A P value < 0.05 was considered significant.

RESULTS

EGJ-CI at rest was similar for older subjects compared to controls. “Total” EGJ-CI, measured during liquid swallowing, was increased in older individuals when compared to young controls (O 39 ± 7 mmHg.cm vs C 18 ± 3 mmHg.cm; P = 0.006). For both liquid and viscous bolus consistencies, IRP4 was increased (L: 11.9 ± 2.3 mmHg vs 5.9 ± 1.0 mmHg, P = 0.019 and V: 14.3 ± 2.4 mmHg vs 7.3 ± 0.8 mmHg; P = 0.02) and BFT was reduced (L: 1.7 ± 0.3 s vs 3.8 ± 0.2 s and V: 1.9 ± 0.3 s vs 3.8 ± 0.2 s; P < 0.001 for both) in older subjects, when compared to young. A matrix of bolus flow and presence above the EGJ indicated reductions in bolus flow at the EGJ occurred due to both impaired bolus transport through the esophageal body (i.e., the bolus never reached the EGJ) and increased flow resistance at the EGJ (i.e., the bolus retained just above the EGJ).

CONCLUSION

Bolus flow through the EGJ is reduced in asymptomatic older individuals. Both ineffective esophageal bolus transport and increased EGJ resistance contribute to impaired bolus flow.

Effect of sample storage temperature and buffer formulation on faecal immunochemical test haemoglobin measurements

Objectives

Faecal immunochemical test accuracy may be adversely affected when samples are exposed to high temperatures. This study evaluated the effect of two sample collection buffer formulations (OC-Sensor, Eiken) and storage temperatures on faecal haemoglobin readings.

Methods

Faecal immunochemical test samples returned in a screening programme and with ≥10 µg Hb/g faeces in either the original or new formulation haemoglobin stabilizing buffer were stored in the freezer, refrigerator, or at room temperature (22℃–24℃), and reanalysed after 1–14 days. Samples in the new buffer were also reanalysed after storage at 35℃ and 50℃. Results were expressed as percentage of the initial concentration, and the number of days that levels were maintained to at least 80% was calculated.

Results

Haemoglobin concentrations were maintained above 80% of their initial concentration with both freezer and refrigerator storage, regardless of buffer formulation or storage duration. Stability at room temperature was significantly better in the new buffer, with haemoglobin remaining above 80% for 20 days compared with six days in the original buffer. Storage at 35℃ or 50℃ in the new buffer maintained haemoglobin above 80% for eight and two days, respectively.

Conclusion

The new formulation buffer has enhanced haemoglobin stabilizing properties when samples are exposed to temperatures greater than 22℃.

Modulation of individual components of gastric motor response to duodenal glucose

AIM: To evaluate individual components of the antro-pyloro-duodenal (APD) motor response to graded small intestinal glucose infusions in healthy humans.

METHODS: APD manometry was performed in 15 healthy subjects (12 male; 40 ± 5 years, body mass index 26.5 ± 1.6 kg/m²) during four 20-min intraduodenal infusions of glucose at 0, 0.5, 1.0 and 1.5 kcal/min, in a randomised double-blinded fashion. Glucose solutions were infused at a rate of 1 mL/min and separated by 40-min “wash-out” period. Data are mean ± SE. Inferential analyses are repeated measure analysis of variance with Bonferroni post-hoc testing.

RESULTS: At 0 kcal/min frequency of pressure waves were: antrum (7.5 ± 1.8 waves/20 min) and isolated pyloric pressure waves (IPPWs) (8.0 ± 2.3 waves/20 min) with pyloric tone (0.0 ± 0.9 mmHg). Intraduodenal glucose infusion acutely increased IPPW frequency (P < 0.001) and pyloric tone (P = 0.015), and decreased antral wave frequency (P = 0.007) in a dose-dependent fashion. A threshold for stimulation was observed at 1.0 kcal/min for pyloric phasic pressure waves (P = 0.002) and 1.5 kcal/min for pyloric tone and antral contractility.

CONCLUSION: There is hierarchy for the activation of gastrointestinal motor responses to duodenal glucose infusion. An increase in IPPWs is the first response observed.

Nutritional support teams increase percutaneous endoscopic gastrostomy uptake in motor neuron disease

AIM: To examine factors influencing percutaneous endoscopic gastrostomy (PEG) uptake and outcomes in motor neuron disease (MND) in a tertiary care centre.

METHODS: Case notes from all patients with a confirmed diagnosis of MND who had attended the clinic at the Repatriation General Hospital between January 2007 and January 2011 and who had since died, were audited. Data were extracted for demographics (age and gender), disease characteristics (date of onset, bulbar or peripheral predominance, complications), date and nature of discussion of gastrostomy insertion, nutritional status [weight measurements, body mass index (BMI)], date of gastrostomy insertion and subsequent progress (duration of survival) and quality of life (QoL) [Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R)]. In addition, the type of clinician initiating the discussion regarding gastrostomy was recorded as Nutritional Support Team (involved in providing nutrition input viz Gastroenterologist, Speech Pathologist, Dietitian) and other (involved in non-nutritional aspects of patient care). Factors affecting placement and outcomes including length of survival, change in weight and QoL were determined.

RESULTS: Case records were available for all 86 patients (49 men, mean age at diagnosis 66.4 years). Thirty-eight patients had bulbar symptoms and 48 had peripheral disease as their presenting feature. Sixty-six patients reported dysphagia. Thirty-one patients had undergone gastrostomy insertion. The major indications for PEG placement were dysphagia and weight loss. Nine patients required immediate full feeding, whereas 17 patients initially used the gastrostomy to supplement oral intake, 4 for medication administration and 1 for hydration. Initially the PEG regime met 73% ± 31% of the estimated total energy requirements, increasing to 87% ± 32% prior to death. There was stabilization of weight in patients undergoing gastrostomy [BMI at 3 mo (22.6 ± 2.2 kg/m²) and 6 mo (22.5 ± 2.0 kg/m²) after PEG placement compared to weight at the time of the procedure (22.5 ± 3.0 kg/m²)]. However, weight loss recurred in the terminal stages of the illness. There was a strong trend for longer survival from diagnosis among MND in PEG recipients with limb onset presentation compared to similar patients who did not undergo the procedure (P = 0.063). Initial discussions regarding PEG insertion occurred earlier after diagnosis when seen by nutrition support team (NST) clinicians compared to other clinicians. (5.4 ± 7.0 mo vs 11.9 ± 13.4 mo, P = 0.028). There was a significant increase in PEG uptake (56% vs 24%, P = 0.011) if PEG discussions were initiated by the NST staff compared to other clinicians. There was no change in the ALSFRS-R score in patients who underwent PEG (pre 34.1 ± 8.6 vs post 34.8 ± 7.4), although in non-PEG recipients there was a non-significant fall in this score (33.7 ± 7.9 vs 31.6 ± 8.8). Four patients died within one month of the procedure, 4 developed bacterial site infection requiring antibiotics and 1 required endoscopic therapy for gastric bleeding. Less serious complications attributed to the procedure included persistent gastrostomy site discomfort, poor appetite, altered bowel function and bloating.

CONCLUSION: Initial discussion with NST clinicians increases PEG uptake in MND. Gastrostomy stabilizes patient weight but weight loss recurs with advancing disease.

Pharmacological interventions for geriatric cachexia: a narrative review of the literature

OBJECTIVE

The objective of this review was to investigate the range of pharmacological interventions that have been studied for treatment of geriatric cachexia, and to evaluate their effect on selected clinical outcomes in this population.

METHODS

Databases including Medline and Cochrane Central Register of Controlled Trials were searched up to March 2010 with search terms including "cache*", "intervention", "megestrol acetate" and "cytokine inhibitors". Studies investigating subjects with mean age <60y or disease-related cachexia were excluded. Outcomes assessed were weight or BMI, body composition, appetite and laboratory parameters indicative of cachexia.

RESULTS

Fifteen publications met the selection criteria, reporting on ten studies. Seven studies investigated use of megestrol acetate (MA): two randomised controlled trials, one case control study, two pre-test/post-test studies and two retrospective chart reviews. Weight/BMI was common amongst outcomes and these studies showed an improvement in weight compared with baseline. MA studies which investigated body composition, appetite and/or laboratory parameters provided some evidence for improvement in these outcomes. Three randomised controlled trials investigated the use of other interventions: ghrelin, growth hormone and vitamin supplementations. All demonstrated a significant increase in lean body mass. The only other outcome of interest in these three trials was weight in one study with a significant increase demonstrated.

CONCLUSION

Little investigation has been conducted in this population and the diagnosis of cachexia is problematic however these trials provide preliminary evidence for beneficial outcomes in older adults likely to have cachexia. Further high quality adequately powered prospective studies are necessary to provide effective treatment for geriatric cachexia.

Gastric emptying of a liquid nutrient meal in the critically ill: relationship between scintigraphic and carbon breath test measurement

OBJECTIVE

It is assumed that delayed gastric emptying (GE) occurs frequently in critical illness; however, the prevalence of slow GE has not previously been assessed using scintigraphy. Furthermore, breath tests could potentially provide a convenient method of quantifying GE, but have not been validated in this setting. The aims of this study were to (i) determine the prevalence of delayed GE in unselected, critically ill patients and (ii) evaluate the relationships between GE as measured by scintigraphy and carbon breath test.

DESIGN

Prospective observational study.

SETTING

Mixed medical/surgical intensive care unit.

PATIENTS

25 unselected, mechanically ventilated patients (age 66 years (49-72); and 14 healthy subjects (age 62 years (19-84)).

INTERVENTIONS

GE was measured using scintigraphy and (14)C-breath test. A test meal of 100 ml Ensure (standard liquid feed) labelled with (14)C octanoic acid and (99m)Technetium sulphur colloid was placed in the stomach via a nasogastric tube.

MAIN OUTCOME MEASURES

Gastric 'meal' retention (scintigraphy) at 60, 120, 180 and 240 min, breath test t(50) (BTt(50)), and GE coefficient were determined.

RESULTS

Of the 24 patients with scintigraphic data, GE was delayed at 120 min in 12 (50%). Breath tests correlated well with scintigraphy in both patients and healthy subjects (% retention at 120 min vs BTt(50); r(2)=0.57 healthy; r(2)=0.56 patients; p≤0.002 for both).

CONCLUSIONS

GE of liquid nutrient is delayed in approximately 50% of critically ill patients. Breath tests correlate well with scintigraphy and are a valid method of GE measurement in this group.

Lower esophageal sphincter relaxation is impaired in older patients with dysphagia

AIM: To characterize the effects of age on the mechanisms underlying the common condition of esophageal dysphagia in older patients, using detailed manometric analysis.

METHODS: A retrospective case-control audit was performed on 19 patients aged ≥ 80 years (mean age 85 ± 0.7 year) who underwent a manometric study for dysphagia (2004-2009). Data were compared with 19 younger dysphagic patients (32 ± 1.7 years). Detailed manometric analysis performed prospectively included basal lower esophageal sphincter pressure (BLESP), pre-swallow and nadir LESP, esophageal body pressures and peristaltic duration, during water swallows (5 mL) in right lateral (RL) and upright (UR) postures and with solids. Data are mean ± SE; a P-value < 0.05 was considered significant.

RESULTS: Elderly dysphagic patients had higher BLESP than younger patients (23.4 ± 3.8 vs 14.9 ± 1.2 mmHg; P < 0.05). Pre-swallow LESP was elevated in the elderly in both postures (RL: 1 and 4 s P = 0.019 and P = 0.05; UR: P < 0.05 and P = 0.05) and solids (P < 0.01). In older patients, LES nadir pressure was higher with liquids (RL: 2.3 ± 0.6 mmHg vs 0.7 ± 0.6 mmHg, P < 0.05; UR: 3.5 ± 0.9 mmHg vs 1.6 ± 0.5 mmHg, P = 0.01) with shorter relaxation after solids (7.9 ± 1.5 s vs 9.7 ± 0.4 s, P = 0.05). No age-related differences were seen in esophageal body pressures or peristalsis duration.

CONCLUSION: Basal LES pressure is elevated and swallow-induced relaxation impaired in elderly dysphagic patients. Its contribution to dysphagia and the effects of healthy ageing require further investigation.

Exogenous glucagon-like peptide-1 attenuates the glycaemic response to postpyloric nutrient infusion in critically ill patients with type-2 diabetes

INTRODUCTION

Glucagon-like peptide-1 (GLP-1) attenuates the glycaemic response to small intestinal nutrient infusion in stress-induced hyperglycaemia and reduces fasting glucose concentrations in critically ill patients with type-2 diabetes. The objective of this study was to evaluate the effects of acute administration of GLP-1 on the glycaemic response to small intestinal nutrient infusion in critically ill patients with pre-existing type-2 diabetes.

METHODS

Eleven critically ill mechanically-ventilated patients with known type-2 diabetes received intravenous infusions of GLP-1 (1.2 pmol/kg/minute) and placebo from t = 0 to 270 minutes on separate days in randomised double-blind fashion. Between t = 30 to 270 minutes a liquid nutrient was infused intraduodenally at a rate of 1 kcal/min via a naso-enteric catheter. Blood glucose, serum insulin and C-peptide, and plasma glucagon were measured. Data are mean ± SEM.

RESULTS

GLP-1 attenuated the overall glycaemic response to nutrient (blood glucose AUC30-270 min: GLP-1 2,244 ± 184 vs. placebo 2,679 ± 233 mmol/l/minute; P = 0.02). Blood glucose was maintained at < 10 mmol/l in 6/11 patients when receiving GLP-1 and 4/11 with placebo. GLP-1 increased serum insulin at 270 minutes (GLP-1: 23.4 ± 6.7 vs. placebo: 16.4 ± 5.5 mU/l; P < 0.05), but had no effect on the change in plasma glucagon.

CONCLUSIONS

Exogenous GLP-1 in a dose of 1.2 pmol/kg/minute attenuates the glycaemic response to small intestinal nutrient in critically ill patients with type-2 diabetes. Given the modest magnitude of the reduction in glycaemia the effects of GLP-1 at higher doses and/or when administered in combination with insulin, warrant evaluation in this group.

TRIAL REGISTRATION

ANZCTR:ACTRN12610000185066.

Bench-to-bedside review: the gut as an endocrine organ in the critically ill

In health, hormones secreted from the gastrointestinal tract have an important role in regulating gastrointestinal motility, glucose metabolism and immune function. Recent studies in the critically ill have established that the secretion of a number of these hormones is abnormal, which probably contributes to disordered gastrointestinal and metabolic function. Furthermore, manipulation of endogenous secretion, physiological replacement and supra-physiological treatment (pharmacological dosing) of these hormones are likely to be novel therapeutic targets in this group. Fasting ghrelin concentrations are reduced in the early phase of critical illness, and exogenous ghrelin is a potential therapy that could be used to accelerate gastric emptying and/or stimulate appetite. Motilin agonists, such as erythromycin, are effective gastrokinetic drugs in the critically ill. Cholecystokinin and peptide YY concentrations are elevated in both the fasting and postprandial states, and are likely to contribute to slow gastric emptying. Accordingly, there is a rationale for the therapeutic use of their antagonists. So-called incretin therapies (glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide) warrant evaluation in the management of hyperglycaemia in the critically ill. Exogenous glucagon-like peptide-2 (or its analogues) may be a potential therapy because of its intestinotropic properties.

Glucose absorption and gastric emptying in critical illness

INTRODUCTION

Delayed gastric emptying occurs frequently in critically ill patients and has the potential to adversely affect both the rate, and extent, of nutrient absorption. However, there is limited information about nutrient absorption in the critically ill, and the relationship between gastric emptying (GE) and absorption has hitherto not been evaluated. The aim of this study was to quantify glucose absorption and the relationships between GE, glucose absorption and glycaemia in critically ill patients.

METHODS

Studies were performed in nineteen mechanically-ventilated critically ill patients and compared to nineteen healthy subjects. Following 4 hours fasting, 100 ml of Ensure, 2 g 3-O-methyl glucose (3-OMG) and 99mTc sulphur colloid were infused into the stomach over 5 minutes. Glucose absorption (plasma 3-OMG), blood glucose levels and GE (scintigraphy) were measured over four hours. Data are mean +/- SEM. A P-value < 0.05 was considered significant.

RESULTS

Absorption of 3-OMG was markedly reduced in patients (AUC240: 26.2 +/- 18.4 vs. 66.6 +/- 16.8; P < 0.001; peak: 0.17 +/- 0.12 vs. 0.37 +/- 0.098 mMol/l; P < 0.001; time to peak; 151 +/- 84 vs. 89 +/- 33 minutes; P = 0.007); and both the baseline (8.0 +/- 2.1 vs. 5.6 +/- 0.23 mMol/l; P < 0.001) and peak (10.0 +/- 2.2 vs. 7.7 +/- 0.2 mMol/l; P < 0.001) blood glucose levels were higher in patients; compared to healthy subjects. In patients; 3-OMG absorption was directly related to GE (AUC240; r = -0.77 to -0.87; P < 0.001; peak concentrations; r = -0.75 to -0.81; P = 0.001; time to peak; r = 0.89-0.94; P < 0.001); but when GE was normal (percent retention240 < 10%; n = 9) absorption was still impaired. GE was inversely related to baseline blood glucose, such that elevated levels were associated with slower GE (ret 60, 180 and 240 minutes: r > 0.51; P < 0.05).

CONCLUSIONS

In critically ill patients; (i) the rate and extent of glucose absorption are markedly reduced; (ii) GE is a major determinant of the rate of absorption, but does not fully account for the extent of impaired absorption; (iii) blood glucose concentration could be one of a number of factors affecting GE.

The effect of exogenous glucagon-like peptide-1 on the glycaemic response to small intestinal nutrient in the critically ill: a randomised double-blind placebo-controlled cross over study

INTRODUCTION

Hyperglycaemia occurs frequently in the critically ill, affects outcome adversely, and is exacerbated by enteral feeding. Furthermore, treatment with insulin in this group is frequently complicated by hypoglycaemia. In healthy patients and those with type 2 diabetes, exogenous glucagon-like peptide-1 (GLP-1) decreases blood glucose by suppressing glucagon, stimulating insulin and slowing gastric emptying. Because the former effects are glucose-dependent, the use of GLP-1 is not associated with hypoglycaemia. The objective of this study was to establish if exogenous GLP-1 attenuates the glycaemic response to enteral nutrition in patients with critical illness induced hyperglycaemia.

METHODS

Seven mechanically ventilated critically ill patients, not previously known to have diabetes, received two intravenous infusions of GLP-1 (1.2 pmol/kg/min) and placebo (4% albumin) over 270 minutes. Infusions were administered on consecutive days in a randomised, double-blind fashion. On both days a mixed nutrient liquid was infused, via a post-pyloric feeding catheter, at a rate of 1.5 kcal/min between 30 and 270 minutes. Blood glucose and plasma GLP-1, insulin and glucagon concentrations were measured.

RESULTS

In all patients, exogenous GLP-1 infusion reduced the overall glycaemic response during enteral nutrient stimulation (AUC30-270 min GLP-1 (2077 +/- 144 mmol/l min) vs placebo (2568 +/- 208 mmol/l min); P = 0.02) and the peak blood glucose (GLP-1 (10.1 +/- 0.7 mmol/l) vs placebo (12.7 +/- 1.0 mmol/l); P < 0.01). The insulin/glucose ratio at 270 minutes was increased with GLP-1 infusion (GLP-1 (9.1 +/- 2.7) vs. placebo (5.8 +/- 1.8); P = 0.02) but there was no difference in absolute insulin concentrations. There was a transient, non-sustained, reduction in plasma glucagon concentrations during GLP-1 infusion (t = 30 minutes GLP-1 (90 +/- 12 pmol/ml) vs. placebo (104 +/- 10 pmol/ml); P < 0.01).

CONCLUSIONS

Acute, exogenous GLP-1 infusion markedly attenuates the glycaemic response to enteral nutrition in the critically ill. These observations suggest that GLP-1 and/or its analogues have the potential to manage hyperglycaemia in the critically ill.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry number: ACTRN12609000093280.

Is esophageal dysphagia in the extreme elderly (>or=80 years) different to dysphagia younger adults? A clinical motility service audit

Dysphagia in elderly patients has major effects on nutrition and quality of life. Although aging itself is associated with changes in esophageal motility, the impact of this on symptoms such as dysphagia is unclear. Data in the extreme elderly are also limited. Symptoms and manometric diagnoses from 23 consecutive older patients (older dysphagia [OD]) >or=80 reporting esophageal dysphagia (12 female, mean age 83 (range 80-93) were compared with those from 23 gender matched younger patients (young dysphagia [YD]) also with dysphagia (mean age 35, range [17-46]). More older patients reported dysphagia as their primary symptom (OD 22/23 vs YD 14/23, P = 0.005). Overall, dysphagia was most common for solids only (OD 16/23 vs YD 15/23) and rare for liquids only (OD 1/23 vs YD 3/23). Dysphagia for both liquids and solids was more frequent in older patients (OD 6/23 vs YD 1/23, P < 0.05). Fewer older patients reported heartburn (OD 3/23 vs YD 14/23, P = 0.001). Manometric diagnoses were generally similar between OD and YD patients with the most common diagnoses being 'nonspecific esophageal motility disorder' (nine each) and 'ineffective peristalsis' (OD = 6, YD = 7). There was a trend for diagnoses related to lower esophageal sphincter failure to be more frequent in younger subjects (OD 1 vs YD 7, P = 0.053). Despite differences in symptom patterns, broad manometric diagnoses in the extreme elderly with dysphagia are similar to younger dysphagia patients. Further studies are required to determine whether this relates to insensitivity in recording or reporting of esophageal manometry (or perceptual differences associated with aging).

Gastric emptying and the organization of antro-duodenal pressures in the critically ill

The motor dysfunctions underlying delayed gastric emptying (GE) in critical illness are poorly defined. Our aim was to characterize the relationship between antro-duodenal (AD) motility and GE in critically ill patients. AD pressures were recorded in 15 mechanically ventilated patients and 10 healthy volunteers for 2 h (i) during fasting, (ii) following an intragastric nutrient bolus with concurrent assessment of GE using the (13)C-octanoate breath test and (iii) during duodenal nutrient infusion. Propagated waves were characterized by length and direction of migration. Critical illness was associated with: (i) slower GE (GEC: 3.47 +/- 0.1 vs 2.99 +/- 0.2; P = 0.046), (ii) fewer antegrade (duodenal: 44%vs 83%, AD: 16%vs 83%; P < 0.001) and more retrograde (duodenal: 46%vs 12%, AD: 38%vs 4%; P < 0.001) waves, (iii) shorter wave propagation (duodenal: 4.7 +/- 0.3 vs 6.0 +/- 0.4 cm; AD: 7.7 +/- 0.6 vs 10.9 +/- 0.9 cm; P = 0.004) and (iv) a close correlation between GE with the percentage of propagated phase 3 waves that were antegrade (r = 0.914, P = 0.03) and retrograde (r = -0.95, P = 0.014). In critical illness, the organization of AD pressure waves is abnormal and associated with slow GE.

Functional association between proximal and distal gastric motility during fasting and duodenal nutrient stimulation in humans

A functional integration exists between proximal and distal gastric motor activity in dogs but has not been demonstrated in humans. To determine the relationship between proximal and distal gastric motor activity in humans. Concurrent proximal (barostat) and distal (antro-pyloro-duodenal (APD) manometry) gastric motility were recorded in 10 healthy volunteers (28 +/- 3 years) during (i) fasting and (ii) two 60-min duodenal infusions of Ensure((R)) (1 and 2 kcal min(-1)) in random order. Proximal and APD motor activity and the association between fundic and propagated antral waves (PAWs) were determined. During fasting, 32% of fundic waves (FWs) were followed by a PAW. In a dose-dependent fashion, duodenal nutrients (i) increased proximal gastric volume, (ii) reduced fundic and antral wave (total and propagated) activity, and (iii) increased pyloric contractions. The proportion of FWs followed by a distal PAW was similar between both infusions and did not differ from fasting. During nutrient infusion, nearly all PAWs were antegrade, propagated over a shorter distance and less likely to traverse the pylorus, compared with fasting. In humans, a functional association exists between proximal and distal gastric motility during fasting and duodenal nutrient stimulation. This may have a role in optimizing intra-gastric meal distribution.

Gastric feed intolerance is not increased in critically ill patients with type II diabetes mellitus

OBJECTIVE

To examine the occurrence of feed intolerance in critically ill patients with previously diagnosed type II diabetes mellitus (DM) who received prolonged gastric feeding.

DESIGN AND SETTING

Retrospective study in a level 3 mixed ICU.

PATIENTS

All mechanically ventilated, enterally fed patients (n = 649), with (n = 118) and without type II DM (n = 531) admitted between January 2003 and July 2005.

INTERVENTIONS

Patients with at least 72 h of gastric feeding were identified by review of case notes and ICU charts. The proportion that developed feed intolerance was determined. All patient received insulin therapy.

RESULTS

The proportion of patients requiring gastric feeding for at least 72 h was similar between patients with and without DM (42%, 50/118, vs. 42%, 222/531). Data from patients with DM were also compared with a group of 50 patients matched for age, sex and APACHE II score, selected from the total non-diabetic group. The occurrence of feed intolerance (DM 52% vs. matched non-DM 50% vs. unselected non-diabetic 58%) and the time taken to develop feed intolerance (DM 62.6 +/- 43.8 h vs. matched non-DM 45.3 +/- 54.6 vs. unselected non-diabetic 50.6 +/- 59.5) were similar amongst the three groups. Feed intolerance was associated with a greater use of morphine/midazolam and vasopressor support, a lower feeding rate and a longer ICU length of stay.

CONCLUSIONS

In critically ill patients who require prolonged enteral nutrition, a prior history of DM type II does not appear to be a further risk factor for feed intolerance.

Fasting and nutrient-stimulated plasma peptide-YY levels are elevated in critical illness and associated with feed intolerance: an observational, controlled study

INTRODUCTION

Delayed gastric emptying and feed intolerance occur frequently in the critically ill. In these patients, gastric motor responses to nutrients are disturbed. Peptide YY (PYY) slows gastric emptying. The aim of this study was to determine fasting and nutrient-stimulated plasma PYY concentrations and their relationship to cholecystokinin (CCK) in critically ill patients.

METHODS

Studies were performed in 19 unselected mechanically ventilated critically ill patients (12 males; 48 +/- 7 years old) in a randomised, single-blind fashion. Subjects received a 60-minute duodenal infusion of Ensure at either 1 or 2 kcal/minute. Blood samples were collected at baseline and at 20, 40, 60, and 180 minutes following commencement of the nutrient infusion for the measurement of plasma PYY and CCK concentrations (using radioimmunoassay). Patient data were compared to 24 healthy subjects (17 males; 43 +/- 2 years old).

RESULTS

Fasting PYY concentration was higher in patients (P < 0.05), particularly in those with feed intolerance (P < 0.05). Plasma PYY concentrations were higher in patients during nutrient infusion (area under the curve [AUC] at 1 kcal/minute: 2,265 +/- 718 versus 1,125 +/- 138 pmol/l.min, P < 0.05; at 2 kcal/minute: 2,276 +/- 303 versus 1,378 +/- 210 pmol/l.min, P = 0.01) compared to healthy subjects. The magnitude of PYY elevation was greater in patients during the 1 kcal/minute infusion (AUC: 441 +/- 153 versus 186 +/- 58 pmol/l.min, P < 0.05), but not the 2 kcal/minute infusion. Fasting and nutrient-stimulated plasma CCK concentrations were higher in patients (P < 0.05). There was a relationship between plasma PYY and CCK concentrations during fasting (r = 0.52, P < 0.05) and nutrient infusion (r = 0.98, P < 0.0001).

CONCLUSION

In critical illness, both fasting and nutrient-stimulated plasma PYY concentrations are elevated, particularly in patients with feed intolerance, in conjunction with increased CCK concentrations.

Stimulation of small intestinal burst activity in the postprandial state differentially affects lipid and glucose absorption in healthy adult humans

Small intestinal motor activity is important for the optimal digestion and absorption of nutrients. These motor responses to feeding are frequently abnormal during critical illness, with the persistence of migrating bursts of contractions during enteral feeding. Whether this disturbance influences nutrient absorption is not known. In this study, the effects of small intestinal burst activity on lipid and glucose absorption were evaluated in 10 healthy human adults (6 males, 4 females, 19-47 yr). Upper gastrointestinal manometry was recorded for 6 h during and shortly after a 20-min intravenous infusion of either erythromycin (1 mg/kg), to stimulate burst activity, or saline (0.9%) in a double-blind randomized fashion. Simultaneously with the start of the intravenous infusion, 60 ml liquid feed mixed with 200 microl 13C-triolein and 2 g 3-O-methylglucose (3-OMG) was infused intraduodenally for 30 min. Absorption of lipid and glucose was assessed using the [13C]triolein breath test and plasma concentrations of 3-OMG, respectively. Infusion of erythromycin was followed by a more rapid onset of burst activity following commencement of the duodenal infusion compared with saline (30 +/- 6.1 vs. 58 +/- 10.7 min; P < 0.05). Erythromycin was associated with a slower recovery of 13CO2 (P < 0.01). A positive correlation existed between the time to onset of burst activity and 13CO2 recovery (P < 0.001). Erythromycin had no effect on 3-OMG absorption. In conclusion, stimulation of small intestinal burst activity reduces the rate of lipid absorption but not glucose absorption in healthy human adults.

Antropyloroduodenal, cholecystokinin and feeding responses to pulsatile and non-pulsatile intraduodenal lipid infusion

The contribution of the pulsatile nature of gastric emptying to small intestinal feedback mechanisms modulating antropyloroduodenal motility and appetite is unknown. On separate days, eight healthy male volunteers (18-34 years) received randomized, single-blind, intraduodenal (ID) infusions of 10% Intralipid (2 kcal min(-1)), either continuously [CID], or in a pulsatile manner [PID] (5 s on/15 s off) and 0.9% saline (control) administered continuously, each at a rate of 1.8 mL min(-1) for 3 h. During each infusion, subjective ratings of appetite were assessed and antropyloroduodenal pressures recorded with a 16-lumen manometric assembly incorporating a pyloric sleeve sensor. Plasma cholecystokinin was measured from blood collected at regular intervals throughout the infusion. At the end of each infusion the manometric assembly was removed, subjects were offered a buffet meal and the energy and macronutrient content of the meal was measured. Both ID lipid infusions stimulated isolated pyloric pressure waves (IPPWs) (P < 0.001) and basal pyloric pressure (P < 0.01) and suppressed antral (P < 0.05) and duodenal (P < 0.05) pressure waves when compared to controls; there was no difference in the effects of CID and PID lipid on antropyloroduodenal pressures. Infusions of lipid significantly increased plasma CCK concentrations (P < 0.05) compared with saline, but concentrations were not different between the two modes of lipid delivery (P > 0.05, CID vs. PID). Both intraduodenal lipid infusions decreased hunger (P < 0.05), increased fullness (P < 0.05) and reduced energy intake (P < 0.05) when compared with controls; again there was no difference between CID and PID lipid. We conclude that at the infusion rate of similar 2 kcal min(-1), the acute effects of intraduodenal lipid on antropyloroduodenal pressures, plasma CCK concentration and appetite are not modified by a pulsatile mode of lipid delivery into the duodenum.

Effect of a lacto-ovo vegetarian diet on fasting small intestinal motility

BACKGROUND

Changes in diet can alter gastric and small intestinal (SI) motility. The effects of a vegetarian diet on fasting SI motility are unknown.

METHODS

Manometric studies were performed in 9 lacto-ovo vegetarians (7 women) and 9 omnivores (7 women) of similar age and body mass index. On each study day, manometry was used to assess SI motility for 5 h, or 3 complete cycles of the interdigestive motor complex (IDMC). Lacto-ovo vegetarians were studied once: omnivores were studied twice, on their usual diet, and after consuming a 14-day lacto-ovo vegetarian diet. Diet diaries were kept for 5 days prior to each manometric study. Data were analysed for dietary composition and for cycle length and duration of each phase (I, II and III) of the IDMC.

RESULTS

Dietary intake did not differ between chronic vegetarians and chronic omnivores apart from a trend to higher fibre intake (29 +/- 3 versus 20 +/- 3 g/day; P = 0.058). Omnivores eating a vegetarian diet showed a trend to decreased alcohol consumption (P = 0.068), but did not increase their fibre intake (20 +/- 3 versus 21 +/- 3 g/day). Neither cycle length nor duration of each IDMC phase differed between chronic vegetarians and chronic omnivores. After 14 days of a vegetarian diet, omnivores had a reduction in cycle length (128 +/- 19 versus 86 +/- 12 min; P = 0.02), with a non-significant reduction of Phase II (99 +/- 20 versus 50 +/- 8 min: P = 0.066).

CONCLUSIONS

A chronic vegetarian diet has no major effect on fasting SI motility; but acute dietary change may alter the cycle length and component phases of the IDMC.

Erythromycin improves gastric emptying in critically ill patients intolerant of nasogastric feeding

OBJECTIVE

To evaluate the effect of intravenous erythromycin on gastric emptying and the success of enteral feeding in mechanically ventilated, critically ill patients with large volume gastric aspirates.

DESIGN

Prospective, double-blind, randomized, and placebo-controlled trial.

SETTING

General intensive care unit in a university hospital.

PATIENTS

Twenty critically ill, mechanically ventilated patients intolerant of nasogastric feeding (indicated by a residual gastric volume of > or =250 mL during feed administration at > or =40 mL/hr).

INTERVENTIONS

After a gastric aspirate of > or =250 mL, which was discarded, the enteral feeding was continued at the previous rate for 3 hrs. Intravenous erythromycin (200 mg) or placebo was then administered over 20 mins. The residual gastric contents were again aspirated and the volume was recorded 1 hr after the infusion began.

MEASUREMENTS AND MAIN RESULTS

Gastric emptying was calculated as volume of feed infused into the stomach over 4 hrs minus the residual volume aspirated. Mean gastric emptying was 139+/-37 (+/-SEM) mL after erythromycin and -2+/-46 mL after placebo (p = .027). Nasogastric feeding was successful in nine of ten patients treated with erythromycin and five of ten who received placebo 1 hr after infusion (chi-square p = .05).

CONCLUSION

In critically ill patients who have large volumes of gastric aspirates indicating a failure to tolerate nasogastric feeding, a single small dose of intravenous erythromycin allows continuation of feed in the short term.

Validation of a novel luminal flow velocimeter with video fluoroscopy and manometry in the human esophagus

There is currently no ideal method for concurrently assessing intraluminal pressures and flows in humans with high temporal resolution. We have developed and assessed the performance of a novel fiber-optic laser-Doppler velocimeter, mounted in a multichannel manometric assembly. Velocimeter recordings were compared with concurrent fluoroscopy and manometry following 50 barium swallows in healthy subjects. During these swallows, the velocimeter sensor was situated in either the proximal (24 swallows) or the distal (26 swallows) esophagus. It signaled intraluminal flow following 46 of 50 swallows. A greater mean number of deflections were recorded in the distal compared with the proximal esophagus (4. 3 vs. 2.4, P = 0.001). The maximal flow velocity recorded did not differ between the proximal and distal esophagus (76.7 vs. 73.8 mm/s). No velocimeter signals commenced after fluoroscopic lumen occlusion. The velocimeter signals were closely temporally related to fluoroscopic barium flow. Upward catheter movement on swallowing sometimes appeared to cause a velocimeter signal. Manometrically "normal" swallows were no different from "abnormal" swallows in the number and velocity of deflections recorded by the velocimeter. This novel instrument measures intraluminal flow velocity and pressures concurrently, thus enabling direct study of pressure-flow relationships. Flow patterns differed between the proximal and distal esophagus.

Hyperglycemia affects cardiovascular autonomic nerve function in normal subjects

OBJECTIVE

To evaluate the effect of acute hyperglycemia on autonomic nerve function in normal subjects.

RESEARCH DESIGN AND METHODS

Six healthy volunteers ages 19-32 years underwent paired studies during euglycemia (blood glucose 5.1 +/- 0.04 mmol/l) and hyperglycemia (blood glucose 15.7 +/- 0.48 mmol/l) induced by intravenous infusion of glucose and maintained for 150 min. The order of the two studies was randomized. In each experiment, supine heart rate, heart rate variation with respiration, ratio of the maximum to minimum R-R interval after standing ("30:15" ratio), systolic blood pressure response to standing, and diastolic blood pressure response to sustained handgrip were measured. Data were analyzed using repeated measures analysis of variance.

RESULTS

The supine heart rate was greater (P = 0.04) and the "30:15" ratio less (P = 0.03) during hyperglycemia than during euglycemia. Hyperglycemia had no significant effect on any of the other cardiovascular reflex tests.

CONCLUSIONS

These observations indicate that acute hyperglycemia affects autonomic nerve function in healthy humans.

Gastroparesis: diagnosis and management

Gastroparesis occurs frequently and may be associated with gastrointestinal symptoms, impaired oral drug absorption and, in diabetic patients, poor blood glucose control. Although current knowledge of the mechanisms responsible for delayed gastric emptying is limited, it is clear that gastroparesis arises from a spectrum of motor dysfunctions. There is a poor correlation between symptoms and delay in gastric emptying, and objective measurement is therefore required for the diagnosis of gastroparesis. Scintigraphic measurement of gastric emptying is at present the only clinically applicable method, although other techniques, particularly radioisotopic breath tests and ultrasound, show considerable promise. Therapy with the prokinetic drugs, cisapride, domperidone, metoclopramide, and erythromycin, forms the mainstay of treatment. Although there have been few formal comparisons, cisapride is considered to be the drug of first choice. Current knowledge of the etiology, pathophysiology, investigation, and treatment of gastroparesis is discussed in this review.

Postprandial antropyloroduodenal motility and gastric emptying in gastroparesis--effects of cisapride

There is little information about the organisation of antroduodenal contractions or pyloric motility in patients with gastroparesis. The mechanisms responsible for the acceleration of gastric emptying by cisapride in patients with gastroparesis are also poorly understood. Simultaneous manometric and scintigraphic recordings were performed in 12 patients with gastroparesis and nine healthy volunteers before and after cisapride administration. Antropyloroduodenal pressures were recorded with a sleeve/side hole manometric assembly and gastric emptying with a scintigraphic method. Thirty minutes after the solid component of the test meal had begun to empty from the stomach all subjects received 5 mg cisapride intravenously over 10 minutes and recordings continued for a further 60 minutes. In the 30 minutes before cisapride there was no significant difference in the number of antral pressure waves (median 20 v 33, NS), basal pyloric pressure, or the number of isolated pyloric pressure waves between patients and volunteers, but the number of antral waves of extent > or = 6 cm (median 1 v 5, p < 0.05) was less in the patients, as was gastric emptying (8% v 20%, p < 0.05). In the patients, there was no change in the number of antral waves after cisapride, but there was an increase in the number of antral waves > or = 6 cm in extent (median 7 v 1, p < 0.05) and in the rate of gastric emptying (26% v 8%, p < 0.01). In the healthy subjects, cisapride increased gastric emptying (31% v 20%, p < 0.05), but reduced the number of antral waves (10 v 33, p < 0.05). Cisapride had no significant effect on the number of antral waves of extent more than or equal to 6 cm (11 v 5, NS). The number of isolated pyloric pressure waves decreased after cisapride (4 v 11, p < 0.05). There was a relationship between gastric emptying and the number of antral pressure waves of extent more than or equal to 6 cm in both the patients (r=0.38, p<0.05) and healthy subjects (r=0.05, p<0.01). There was no significant relationship between gastric emptying and the number of antral waves. It is concluded that disturbance of the relationship between antral, pyloric, and duodenal pressure waves is a major abnormality of postprandial gastric motor function in patients with gastroparesis. The stimulation of antral pressure waves of extent more than or equal to 6 cm may contribute to the acceleration of gastric emptying produced by cisapride in patients with gastroparesis and in normal subjects.

Hyperglycaemia slows gastric emptying in type 1 (insulin-dependent) diabetes mellitus

In 10 patients with Type 1 (insulin-dependent) diabetes mellitus gastric emptying of a digestible solid and liquid meal was measured during euglycaemia (blood glucose concentration 4-8 mmol/l) and during hyperglycaemia (blood glucose concentration 16-20 mmol/l). Gastric emptying was studied with a scintigraphic technique and blood glucose concentrations were stabilised using a modified glucose clamp. Patients were also evaluated for gastrointestinal symptoms, autonomic nerve function and glycaemic control. When compared to euglycaemia, the duration of the lag phase before any of the solid meal emptied from the stomach (p = 0.032), the percentage of the solid meal remaining in the stomach at 100 min (p = 0.032) and the 50% emptying time for the solid meal (p = 0.032) increased during hyperglycaemia. The 50% emptying time for the liquid meal (p = 0.042) was also prolonged during the period of hyperglycaemia. These results demonstrate that the rate of gastric emptying in Type 1 diabetes is affected by the blood glucose concentration.

Prognosis in intracerebral haemorrhage

A retrospective study of 244 cases of ICH of mixed aetiology was made in respect of clinical course, outcome, and CT findings. Those factors found to be of prognostic significance were: Glasgow coma score on admission, clot volume, degree of midline shift, degree of intraventricular blood, and deterioration in the first postictal 48 hours. Those who required surgical evacuation after 48 hours of onset had a low mortality of 3% compared to 34% in those requiring earlier operation and 27% in the series as a whole. Small haematomas still carried an appreciable mortality and did not bias outcome in the various aetiological groups, although hypertension on admission appeared to be a helpful diagnostic pointer.

Value of radioisotope axial tomography in the diagnosis of a cystic malignant glioma

A case is presented in which the patient had a deep tumour in the posterior aspect of the temporal lobe close to midline. The brain scan including a transverse section view at 8 cm from the vertex was negative and the other neuroradiological examinations inconclusive. One month later a follow up brain scan was performed and the conventional views were negative whereas the transverse section scan done at 10 cm from the vertex showed a lesion in the left temporo-parietal region and near midline. Three months later a repeat brain scan was done, and the lesion was visualized in the conventional views and confirmed by angiogram.

Interstitial Pregnancy after Homolateral Salpingectomy: (Report of a Case)

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