Thomas L. Abell

Assessment of gastric emptying using a low fat meal: establishment of international control values.

OBJECTIVE:The diagnosis of gastroparesis implies delayed gastric emptying. The diagnostic gold standard is scintigraphy, but techniques and measured endpoints vary widely among institutions. In this study, a simplified scintigraphic measurement of gastric emptying was compared to conventional gastric scintigraphic techniques and normal gastric emptying values defined in healthy subjects.METHODS:In 123 volunteers (aged 19–73 yr, 60 women and 63 men) from 11 centers, scintigraphy was used to assess gastric emptying of a 99Tc-labeled low fat meal (egg substitute) and percent intragastric residual contents 60, 120, and 240 min after completion of the meal. In 42 subjects, additional measurements were taken every 10 min for 1 h. In 20 subjects, gastric emptying of a 99Tc-labeled liver meal was compared with that of the 99Tc-labeled low fat meal.RESULTS:Median values (95th percentile) for percent gastric retention at 60, 120, and 240 min were 69% (90%), 24% (60%) and 1.2% (10%) respectively. A power exponential model yielded similar emptying curves and estimated T50 when using images only taken at 1, 2 and 4 h, or with imaging taken every 10 min. Gastric emptying was initially more rapid in men but was comparable in men and women at 4 h; it was faster in older subjects (p < 0.05) but was independent of body mass index.CONCLUSIONS:This multicenter study provides gastric emptying values in healthy subjects based on data obtained using a large sample size and consistent meal and methodology. Gastric retention of >10% at 4 h is indicative of delayed emptying, a value comparable to those provided by more intensive scanning approaches. Gastric emptying of a low fat meal is initially faster in men but is comparable in women at 4 h; it is also faster in older individuals but is independent of body mass.

Predominant symptoms in irritable bowel syndrome correlate with specific autonomic nervous system abnormalities

BACKGROUND/AIMSnIrritable bowel syndrome may be influenced by the autonomic nervous system. Abnormalities in autonomic function, colon transit time, and psychological profiles in 21 patients were assessed.nnnMETHODSnUsing modified Manning criteria for irritable bowel syndrome, patients were classified as constipation-predominant or diarrhea-predominant. Autonomic function was determined by one vagal cholinergic and two sympathetic adrenergic measures. Colon transit was assessed by radiopaque markers, and psychological profiles were determined by three inventories.nnnRESULTSnAutonomic function tests showed that diarrhea-predominant subgroup values for one sympathetic adrenergic measure (postural adjustment ratio) were significantly different from controls (P < 0.01). Constipation-predominant subgroup values were significantly lower for the vagal cholinergic measure R-R interval (P < 0.05). Colon transit measures differed by subgroup in left, right, rectosigmoid, and total colon transit times. Both subgroups differed significantly from controls on psychological measures; the constipation subgroup showed more psychological distress.nnnCONCLUSIONSnIrritable bowel syndrome specific-symptom subgroups had different patterns of autonomic functioning, colonic transit, and psychological measures. The constipation subgroup is associated with a cholinergic abnormality and the diarrhea-predominant subgroup with an adrenergic abnormality. These findings suggest specific associations between the autonomic nervous system, predominant physical symptoms, colon transit time, and psychological factors in patients with irritable bowel syndrome.

Symptom improvement from prokinetic therapy corresponds to improved quality of life in patients with severe dyspepsia

Prokinetic therapy has been shown to improve patients symptoms associated with gastrointestinal motility disorders and quality of life. This study investigated the correlation between clinical improvement and quality of life after 12 months of treatment with cisapride or domperidone in patients with severe dyspepsia. Psychological and quality-of-life measures were assessed at baseline and after 12 months of therapy using three patient-administered, standardized questionnaires: the Minnesota Multiphasic Personality Inventory, the Millon Behavioral Health Inventory, and the Sickness Impact Profile. Changes in clinical symptoms were correlated with changes in these measures. Twenty-seven patients with symptoms of severe dyspepsia were treated with cisapride or domperidone (60–80 mg/day) for 12 months. Symptoms and quality-of-life measures were improved at the end of therapy. There were significant correlations between improvement in clinical symptoms and improvement in quality of life parameters. Patients with more marked symptom improvement had more significant improvements in quality of life measures. We conclude that prokinetic therapy improved symptoms and quality of life. Standardized questionnaires can be used to quantify response to prokinetic therapy and to individualize treatment regimens for patients with dyspepsia who have specific psychologic or behavioral characteristics.

Gastric electrical stimulation has an immediate antiemetic effect in patients with gastroparesis

Electrical stimulation has been successfully employed to treat diseases involving electro-pathology in the heart, skeletal muscles, and the brain, but not in the GI tract. Aim: This study examined the clinical feasibility and efficacy of GES in treating patients with severe gastroparesis. Nausea, vomiting, GEA, and liquid and solid gastric emptying were monitored in eleven patients with refractory gastroparesis at baseline and after one week of continuous electrical stimulation administered at 12 cycles/min. Eight patients were subsequently implanted with permanent stimulation devices. Follow-up studies were conducted after 1, 3, 6, and 12 mo. of stimulation. After one week of stimulation, patients quantified symptoms of nausea and vomiting decreased significantly, and liquid emptying and GEA improved. This improvement was maintained over time in the patients who continued to receive stimulation. Emptying of solids showed progressive improvement that became significant after 3 mo. The three patients who did not receive stimulation after the trial period showed significantly higher symptoms at 12 mo. This paper demonstrates that GES at a frequency of 12 cycles/min has an immediate antiemetic effect, followed by an improvement in disordered gastric emptying.

Gastric electrical stimulation is associated with improvement in pancreatic exocrine function in humans.

Objective: To define the possible effects of gastric electrical stimulation (GES) for gastroparesis on pancreatic function, we performed 2 related human studies. Methods: Fecal elastase values were compared in 2 patient groups: (1) GES devices ON and (2) GES devices OFF and (2) in 3 control groups: (1) no response (NR) to prokinetic medications, (2) positive response (RES) to medications, and (3) normal controls. Polypeptide levels in 7 of 9 GES patients with device ON and OFF, elastase results, GI symptoms (TSS), and heart rate variability (HRV) were compared by paired t tests and/or ANOVA and reported as mean ± SE. Results: Elastase was different for GES-ON and OFF (508.0 ± 92.2 vs. GES-OFF 378.6 ± 87.4, P < 0.05). Elastase was lower in medication NR and RES than in normal controls. Postprandial pancreatic polypeptide was greater with GES ON than OFF (P = 0.07). HRV revealed a lower percentage of change with device ON versus OFF (44.2 ± 5.5 vs. 48.5 ± 5.2, P = 0.08) and lower TSS with ON versus OFF (15.9 ± 4.5 vs. 25.7 ± 5.3, P < 0.05). Conclusions: GES improves exocrine pancreatic release, effects autonomic control, and improves GI symptoms, suggesting a possible role for GES in the treatment of pancreatic insufficiency associated with gastroparesis.

Cutaneous Exposure to Warfarin-Like Anticoagulant Causing an Intracerebral Hemorrhage: A case Report

A case of intercerebral hematoma due to warfarin-induced coagulopathy is presented. The 39-year-old woman had spread a warfarin-type rat poison around her house weekly using her bare hands, with no washing post application. Percutaneous absorption of warfarin causing coagulopathy, reported three times in the past, is a significant risk if protective measures, such as gloves, are not used. An adverse drug interaction with piroxicam, which she took occasionally, may have exacerbated the coagulopathy.

Electrical pacing of the stomach in dogs

Motor function in the stomach is regulated by an intrinsic electrical activity. Therefore, external intervention with an electrical signal is a possible remedy for gastric motor dysfunction. This paper presents a canine model for the systematic investigation of electrical pacing of the stomach. The results confirm that pacing can improve gastric motility. Higher frequency pacing signals have more efficacy.

Assessment of gastric electrical activity and autonomic function among diabetic and nondiabetic patients with symptoms of gastroesophageal reflux.

Gastroesophageal reflux disease (GERD) may present differently in patients with diabetes mellitus (DM) than in nondiabetics (NDM). We compared three tests in two patient groups with GERD symptoms: a DM group (n = 10) and a NDM group (n = 13). The tests were 24-hr esophageal pH, autonomic function testing (AFT), and electrogastrography (EGG). Analysis of the 23 patients revealed the DM group had normal 24-hr pH values (9 of 10 patients, mean pH 3.1 ± 1.7), while NDM displayed abnormal pH values (9 of 13 patients, mean pH 21.2 ± 5.9). AFT results were abnormal in DM (demonstrating cholinergic/adrenergic dysfunction), but normal in NDM. EGG values were abnormal in both groups (mean 3.31 ± 0.1 in each). We conclude that in GERD-symptomatic patients, those with DM frequently have normal 24-hr pH, but abnormal autonomic functioning, in contrast to NDM, who have abnormal 24-hr pH but normal autonomic function. Both groups had identically abnormal mean EGG values.

Case report: Interaction of rifampin and nortriptyline

Rifampin is well documented to cause numerous clinically significant drug interactions because of its induction of the hepatic cytochrome P450 system. The metabolism of nortriptyline and other tricyclic antidepressants is induced and inhibited by this enzyme system. To the authors knowledge, this is only the second case report in the literature regarding a possible interaction between rifampin and a tricyclic antidepressant. Nortriptyline serum concentrations were not detectable while rifampin was given concurrently. Two weeks after discontinuation of rifampin, nortriptyline concentrations increased dramatically. Further study of this possible interaction is warranted.

Interaction of Rifampin and Nortriptyline

Rifampin is well documented to cause numerous clinically significant drug interactions because of its induction of the hepatic cytochrome P450 system. The metabolism of nortriptyline and other tricyclic antidepressants is induced and inhibited by this enzyme system. To the authors knowledge, this is only the second case report in the literature regarding a possible interaction between rifampin and a tricyclic antidepressant. Nortriptyline serum concentrations were not detectable while rifampin was given concurrently. Two weeks after discontinuation of rifampin, nortriptyline concentrations increased dramatically. Further study of this possible interaction is warranted.