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Biomedical subjects

W D Chey

Publications and source records attributed to W D Chey.

At least 37 records · Page 2Linked to original sources
PubMed2000

Omeprazole or ranitidine bismuth citrate triple therapy to treat Helicobacter pylori infection: a randomized, controlled trial in Vietnamese patients with duodenal ulcer.

AIM: To evaluate the effectiveness of triple therapy containing either omeprazole or ranitidine bismuth citrate (RBC) to treat H. pylori infection in Vietnamese duodenal ulcer patients. METHODS: Patients infected with H. pylori were randomized to receive either omeprazole (20 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (OAC), or RBC (400 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (RAC). H. pylori eradication and ulcer healing was established by a follow-up oesophagogastroduodenoscopy (EGD) at least 4 weeks after therapy. Side-effects and compliance were assessed. RESULTS: One hundred and four out of 108 (96%) patients with a duodenal ulcer were infected with H. pylori. Eighty per cent of infected patients had detectable CagA IgG antibodies. Fifty-seven patients received OAC and 47 received RAC. OAC eradicated H. pylori in 91 and 86% of patients by per protocol (PP) and intention-to-treat (ITT) analysis, respectively. PP and ITT eradication rates for RAC were 96 and 91%. Ulcer healing at the follow-up EGD was 89% with OAC and 100% with RAC. Side-effects were minor. No patient failed to complete the protocol due to side-effects. CONCLUSION: Triple therapy with either omeprazole or RBC is highly effective in eradicating H. pylori and healing duodenal ulcer in Vietnamese patients.

Adolescent↗
PubMed2000

Routine droperidol pre-medication improves sedation for ERCP.

BACKGROUND: Pre-medication with droperidol has been used to improve sedation during endoscopy, especially in patients with a history of alcohol or narcotic abuse. We studied whether routine use of droperidol pre-endoscopic retrograde cholangiopancreatography (ERCP) could improve patient and physician satisfaction with sedation. METHODS: Sixty-seven patients undergoing routine ERCP were enrolled in this double-blind placebo-controlled study. Patients were given either parenteral normal saline solution or 5 mg of droperidol 15 minutes before the procedure. After the ERCP, several parameters of procedural sedation were scored on an ordinal scale by the endoscopist, the endoscopy nurse, and the recovered patient. In addition, a follow-up telephone call was made to the patient after 24 hours. RESULTS: The mean procedural room time was similar in the two groups. Nearly 25% less meperidine and diazepam was used in the droperidol-treated patients, making the overall medication cost similar in both groups. The mean recovery room time was 113 minutes for the placebo group and 106 minutes for the droperidol group. Droperidol premedication significantly decreased post-procedure nausea and vomiting, reduced gagging at intubation, and decreased retching during the procedure. Droperidol also improved physician (p = 0.001), nurse (p = 0.001), and patient (p = 0.0001) impressions of overall sedation and decreased the need for physical restraint during the procedure. Droperidol significantly increased the number of patients with no memory of the procedure. CONCLUSION: Droperidol improved overall patient, physician, and nurse satisfaction with sedation during ERCP. It also reduced post-ERCP nausea and vomiting without increasing recovery time or medication cost. Droperidol is recommended for routine pre-ERCP sedation. (Gastrointest Endosc 2000;52:362-6).

Adolescent↗
PubMed2000

Appropriate timing of the 14C-urea breath test to establish eradication of Helicobacter pylori infection.

OBJECTIVE: The aim of this study was to determine the performance characteristics of the 14C-urea breath test (UBT) performed 2 wk after the completion of therapy for Helicobacter pylori using a 4 to 6 wk study as the gold standard. METHODS: Patients with active Helicobacter pylori infection at four medical centers received proton pump inhibitor-based triple or quadruple therapy for 10-14 days. Patients underwent the 14C-UBT 2 and 4-6 wk after the completion of therapy. A positive test was defined as 14CO2 excretion of >200 dpm, a negative test as <50 dpm, and an equivocal test as >50 but <200 dpm. Performance characteristics of the 2-wk UBT were calculated using the 4 to 6-wk result as a gold standard. RESULTS: Eighty-five patients were enrolled and 82 patients (mean +/- SD age, 62 +/- 15 yr; 15 women) completed the protocol. Four patients had equivocal UBT results and were excluded from the analysis. Of the 78 patients, 68 (87%) had a negative 4 to 6-wk UBT. The 2-week UBT yielded a sensitivity of 90% (95% confidence interval 72-100%), specificity of 99% (97-100%), and accuracy of 97% (93-100%). In patients with a persistently positive UBT, 14CO2 excretion at 2 wk was significantly lower than at 4-6 wk after therapy (p = 0.03). CONCLUSIONS: A UBT performed 2 wk after therapy yielded results comparable to 4 to 6 wk testing. Further studies to evaluate the optimal time of confirmatory testing in the age of more effective proton pump inhibitor-based triple therapies are warranted.

Breath Tests↗
PubMed2000

A randomized, controlled trial to assess a novel colorectal cancer screening strategy: the conversion strategy--a comparison of sequential sigmoidoscopy and colonoscopy with immediate conversion from sigmoidoscopy to colonoscopy in patients with an abnormal screening sigmoidoscopy.

OBJECTIVE: Our study was a randomized, controlled trial to assess a novel strategy that provides comprehensive colorectal cancer screening in a single visit versus traditional sigmoidoscopy and, where appropriate, colonoscopy on a subsequent day. METHODS: Consecutive patients referred for screening were randomized to control or so-called "conversion" groups. Patients in the control group were prepared for sigmoidoscopy with oral phospho-soda. Those with an abnormal sigmoidoscopy were scheduled for colonoscopy on a future day after oral polyethylene glycol preparation. In the conversion group, patients were prepared with oral phosphosoda. Patients with a polyp >5 mm or multiple diminutive polyps were converted from sigmoidoscopy to colonoscopy, allowing comprehensive screening in a single visit. Clinical outcomes were assessed by postprocedure physician and patient questionnaires. RESULTS: Two hundred thirty-five patients were randomized (control = 121, conversion = 114). In the control group, 28% had an indication for colonoscopy. Three of 33 (9%) with an abnormal sigmoidoscopy did not return for colonoscopy. At colonoscopy, 27% had a proximal adenoma. In the conversion group, 28% had an abnormal sigmoidoscopy and underwent conversion to colonoscopy. Forty-one percent undergoing colonoscopy in the conversion group had a proximal adenoma. Physicians reported no differences in preparation or procedure difficulty, whereas patients reported no differences in the level of comfort or overall satisfaction between groups. When queried regarding preferences for future screening, 96% chose the conversion strategy. CONCLUSIONS: The conversion strategy led to similar outcomes compared to traditional screening while improving compliance with colonoscopy in patients with an abnormal sigmoidoscopy.

Adenoma↗
PubMed1999

Symptom status and the desire for Helicobacter pylori confirmatory testing after eradication therapy in patients with peptic ulcer disease.

BACKGROUND: There is consensus that individuals with Helicobacter pylori-associated peptic ulcer disease should receive a test to confirm H. pylori cure if symptoms recur after eradication therapy. It remains controversial whether individuals who are asymptomatic after therapy should undergo a confirmatory test to establish cure. Patients' desire to know whether their infection has been cured and symptom status after treatment are two important determinants of whether confirmatory H. pylori testing should be undertaken routinely. METHODS: We identified 87 patients with H. pylori-associated peptic ulcer disease scheduled to undergo urea breath testing 4 weeks after H. pylori eradication therapy. At the time of testing, willingness-to-pay methodology was used to estimate patients' desire for confirmatory testing in the absence of symptoms. At a follow-up visit after eradication therapy (mean follow-up, 297 days; range, 143 to 494 days), patients were surveyed to assess gastrointestinal symptom status. RESULTS: Of the 87 patients, 78 (90%) responded that they would prefer to undergo confirmatory testing if asymptomatic, as opposed to delaying testing until symptoms recurred. Patients' median willingness to pay for confirmatory testing in the absence of symptoms was greater than $50. On follow-up, 38% of patients in whom H. pylori was eradicated reported that their symptoms were completely resolved. There was no significant difference in the percentage of patients who reported complete symptom resolution by H. pylori status (H. pylori eradicated 38%, H. pylori infected 28%, P = 0.42, 95% confidence interval, -14% to 34%). CONCLUSIONS: Patients' desire for confirmation of cure, coupled with a frequent need for confirmatory testing as a result of recurrent symptoms after therapy, may justify routine confirmatory testing after H. pylori treatment.

Breath Tests↗
PubMed1999

A comparison of three fingerstick, whole blood antibody tests for Helicobacter pylori infection: a United States, multicenter trial.

OBJECTIVE: We compared three whole blood antibody tests for Helicobacter pylori (H. pylori) in a United States, multicenter trial. METHODS: Patients referred for EGD at three medical centers were recruited. During EGD, biopsies were taken for histology and rapid urease testing (RUT). Immediately after endoscopy, patients underwent the antibody tests (FlexPack HP, Abbott Diagnostics; QuikVue, Quidel Corporation; AccuMeter, ChemTrak) using whole blood obtained by two to three fingersticks. Performance characteristics were calculated for each antibody test using the biopsy-based methods as a gold standard. RESULTS: A total of 131 patients participated; 50 (38%) patients had histological evidence of H. pylori infection. Using histology as a gold standard, the sensitivities of FlexPack HP, QuikVue, and Accumeter were 76%, 78%, and 84%, respectively. Specificity was 79% with FlexPack HP and 90% with QuikVue and Accumeter. There were no significant differences in the performance of the three antibody tests though there was a trend toward superior performance for AccuMeter compared to FlexPack HP (p = 0.019). However, RUT proved superior to FlexPack HP using histology as a gold standard (p = 0.008). Using either concordant histology and RUT results or a positive histology or RUT to define active H. pylori infection, there was no statistically significant difference between the antibody tests. CONCLUSIONS: There were no statistically significant differences in the performance of the three antibody tests. These tests proved only marginally sensitive in detecting patients infected with H. pylori. Clinicians should be aware of the limitations of these tests, particularly when using them as a sole means of testing for H. pylori.

Adult↗
PubMed1999

The 13C-urea blood test accurately detects active Helicobacter pylori infection: a United States, multicenter trial.

OBJECTIVES: Current nonendoscopic tests for Helicobacter pylori include antibody tests and the urea breath test. After the administration of 13C-urea, serum bicarbonate measurement can identify those infected with H. pylori. In this study, our aims were to determine the accuracy of the urea blood test, and to compare the accuracy of the urea blood test with that of rapid urease testing of gastric biopsies. METHODS: This was a multicenter trial conducted at five sites within the U.S. Patients scheduled for endoscopy were recruited. During endoscopy, biopsies were obtained from the gastric body and antrum for histology and rapid urease testing. Patients underwent the urea blood test, which required the ingestion of 125 mg of 13C-urea after endoscopy. Thirty minutes later, a 3-ml blood sample was obtained and later analyzed by mass spectrometry for 13C-bicarbonate. Performance characteristics for the urea blood test were calculated using the endoscopic biopsy tests as a gold standard. RESULTS: One hundred and twenty-one patients (54 infected) were enrolled. The urea blood test yielded sensitivity of 89%, specificity of 96%, positive predictive value of 94%, negative predictive value of 91%, and accuracy of 93% using histology as a gold standard. There was no difference between results obtained with the urea blood test and rapid urease testing of gastric biopsies. CONCLUSIONS: The urea blood test accurately identified active H. pylori infection. The performance characteristics of this nonendoscopic test were similar to those of endoscopic rapid urease testing.

Adult↗
PubMed1998

Pure cut electrocautery current for sphincterotomy causes less post-procedure pancreatitis than blended current.

BACKGROUND: Complications after endoscopic biliary sphincterotomy occur in 8% to 10% of patients when studied prospectively. It is not known whether the type of electrocautery current affects this rate. Theoretically, less edema of the ampulla after a pure cutting current sphincterotomy could decrease the risk of pancreatitis although the risk of postsphincterotomy hemorrhage might be greater. METHODS: One hundred seventy patients undergoing sphincterotomy were prospectively randomized to either a blended or pure cut current on the Valleylab electrosurgical unit. The settings were a blended three current at a power setting of 30 watts/sec for both the cut and coagulation currents or a pure cut current at a power setting of 30 watts/sec. The individual determining whether a complication occurred was blinded to the type of current used, and all patients were hospitalized for 24 hours post-procedure. Pancreatitis was defined as mild if fewer than 5 days, moderate if 5 to 14 days, and severe if more than 14 days of hospitalization were required. RESULTS: Indications for sphincterotomy were choledocholithiasis in 111 patients, sphincter of Oddi dysfunction in 36 patients, stent placement in 15 patients, and miscellaneous in 8 patients. There were a total of 16 complications in 170 patients (9%); 4 (5%) were in the pure cut current group of 86 patients (one episode of bleeding that required transfusion of 4 U and three episodes of mild pancreatitis), and 12 (14%) were in the blended current group of 84 patients (7 mild, 2 moderate, and 1 severe pancreatitis; 1 case of cholangitis; and one episode of bleeding that required transfusion of 2 U). There were significantly fewer complications in the pure cut group (p < 0.05 by chi-square). CONCLUSION: The use of pure cut current is associated with a lower incidence of pancreatitis, the most common ERCP complication, than with blended current sphincterotomy. An insufficient number of patients were studied to comment on the relative risk of hemorrhage. However, because the complication of hemorrhage is much less common than pancreatitis, pure cut current is safer overall.

Acute Disease↗
PubMed1998

Low- versus high-dose azithromycin triple therapy for Helicobacter pylori infection.

BACKGROUND: We report a clinical trial which evaluated the effectiveness of triple therapy containing low- and high-dose azithromycin to treat Helicobacter pylori infection. METHODS: From March 1997 to March 1998, patients infected with H. pylori were assigned to receive either: Treatment 1: ranitidine bismuth citrate (RBC) (400 mg b.d.) and amoxycillin (1 g b.d.) for 10 days with azithromycin 500 mg o.m. for 3 days: or Treatment 2: RBC and amoxycillin for 10 days with azithromycin 1 g o.m. for 3 days. H. pylori eradication was established by a urea breath test at least 4 weeks after therapy. Side-effects and compliance were assessed using a diary. RESULTS: Sixty-eight patients were enrolled. Fifty-seven per cent of patients were treated for active peptic ulcer disease or a history of peptic ulcer disease. Treatment 1 cured H. pylori in 44% and 44% by per protocol and intention-to-treat analysis, respectively. The corresponding eradication rates for Treatment 2 were 79% and 75%. Two patients taking Treatment 2 dropped out of the study because of side-effects. CONCLUSIONS: With RBC and amoxycillin for 10 days, azithromycin at a dose of 1 g/day for 3 days was significantly better at curing H. pylori infection than azithromycin 500 mg/day for 3 days.

Adult↗
PubMed1998

The ChemTrak Hp Chek fingerstick whole blood serology test for the detection of Helicobacter pylori infection.

OBJECTIVE: To evaluate a new whole blood serology test (Hp Chek; ChemTrak) that detects IgG antibodies to Helicobacter pylori. METHODS: The study was conducted at 10 sites within the United States. Patients undergoing upper endoscopy for dyspepsia were recruited for enrollment. Those treated for H. pylori infection within a year of endoscopy and those who had regularly used proton pump inhibitors, bismuth compounds, or antibiotics within a month of endoscopy were not eligible. During endoscopy, specimens were obtained from the corpus and antrum for histological examination, which was performed by a single experienced pathologist. The Hp Chek was tested using whole blood and serum. Serum was also tested with a reference enzyme-linked immunosorbent assay (ELISA) at a centralized location. Test characteristics for the Hp Chek and ELISA were calculated using histology as the "gold standard." RESULTS: Two hundred eighty-seven patients (140 women and 147 men; mean age 53 +/- 6 yr) were enrolled. The Hp Chek was easy to perform and yielded results 9 min after inoculation of the test cassette with whole blood or serum. When the Hp Chek used with whole blood was compared with histology as the gold standard, the sensitivity was 88%, specificity 85%, positive predictive value 83%, negative predictive value 90%, and percent agreement 86%. There were no statistically significant differences among the results obtained with the Hp Chek using whole blood, the Hp Chek using serum, or reference ELISA. CONCLUSIONS: The Hp Chek whole blood serology test was easy to perform and rapid and yielded performance characteristics comparable to those of a reference ELISA or the Hp Chek used with serum.

Analysis of Variance↗
PubMed1998

Differential effects of amitriptyline on perception of somatic and visceral stimulation in healthy humans.

Tricyclic antidepressants treat chronic pain both in patients with somatic illness and with functional bowel disorders. We compared the effects of amitriptyline on perception of cutaneous and gastrointestinal stimulation to assess differential analgesic effects of tricyclics on somatic and visceral pain. Cutaneous electrical stimulation and rectal and esophageal distension were performed before and after 21 days of double-blind 50 mg amitriptyline vs. placebo in healthy volunteers. Amitriptyline increased currents that elicited cutaneous threshold, moderate discomfort, and moderate pain compared with basal (P < 0.05), whereas placebo had no effect. Amitriptyline had no effect on perception of rectal and esophageal distension and did not alter luminal compliance; thus the lack of effect on perception is not due to altered visceral elastic wall properties. In conclusion, amitriptyline reduces perception of cutaneous stimulation but does not alter visceral perception or compliance. This investigation demonstrates differential effects of tricyclics on somatic and visceral afferent function in healthy humans and provides insight into mechanisms of action in chronic pain both from somatic disease and from functional bowel disorders.

Adult↗
PubMed1998

Differential 5-HT3 mediation of human gastrocolonic response and colonic peristaltic reflex.

Colonic motor function is modulated by extended and local neural reflexes involving unknown mediators. To test the role of serotonin (5-HT3) pathways, increases in colonic tone during antral distension and duodenal lipid perfusion (gastrocolonic responses) and changes in orad and caudad colonic tone in response to local colonic distension (peristaltic reflex) were measured after double-blind granisetron (10 microg/kg) or placebo infusion in healthy human volunteers. Antral distension evoked increases in colonic tone, which were blunted by granisetron (P < 0.05) without effects on antral compliance. Intraduodenal lipid perfusion also evoked increased colonic tone, which was reduced by granisetron (P < 0.05). In contrast, orad colonic contractions and caudad relaxations and contractions during colonic distension were unaffected by granisetron. In conclusion, 5-HT3 receptor antagonism blunts both the mechano- and chemoreceptor components of the human gastrocolonic response without altering antral compliance. In contrast, 5-HT3 pathways play no role in the ascending or descending components of the colonic peristaltic reflex. These findings demonstrate different roles for 5-HT3 receptors in the control of colonic motor function by the proximal gastrointestinal tract and by local neural reflexes.

Adult↗
PubMed1997

Role of plasma vasopressin as a mediator of nausea and gastric slow wave dysrhythmias in motion sickness.

The possible role of vasopressin in nausea and gastric dysrhythmias in motion sickness was tested by electrogastrography in 14 subjects during circular vection (60 degrees/s) and vasopressin infusion. Tachygastria was expressed as the signal percent >4.5 cycles/min. Vection evoked nausea scores of 2.6 +/- 0.2 (0 = none to 3 = severe) in 10 subjects with increases in tachygastric activity (15 +/- 2 to 45 +/- 3%) and plasma vasopressin (4.5 +/- 1.5 to 8.4 +/- 2.5 pg/ml) that were blocked by atropine but not indomethacin. Four asymptomatic subjects had no tachygastria or vasopressin release. Vasopressin at 0.2 U/min (plasma level = 322.1 +/- 10.3 pg/ml) evoked nausea (2.6 +/- 0.4) and increases in tachyarrhythmic activity (41 +/- 5%) that were blunted by atropine but not indomethacin. There were no differences in nausea or dysrhythmias with vasopressin infusion in subjects who noted nausea during vection versus those who did not. To conclude, vection evokes nausea, dysrhythmias, and vasopressin release in motion sickness-susceptible humans via cholinergic prostaglandin-independent pathways. Supraphysiological vasopressin infusions evoke nausea and dysrhythmias by similar pathways to equal degrees in motion sickness-susceptible and -resistant subjects. Thus central but not peripheral actions of vasopressin may contribute to nausea and slow wave disruption with vection. Blunting of both the release and action of vasopressin by atropine may explain its beneficial action in motion sickness.

Adult↗
PubMed1997

Lansoprazole and ranitidine affect the accuracy of the 14C-urea breath test by a pH-dependent mechanism.

OBJECTIVES: To determine the effect of lansoprazole and high dose ranitidine on the accuracy of the 14C-urea breath test (UBT). Using intragastric pH recordings, we correlated the effect of these agents on the UBT with their potency of gastric acid suppression. METHODS: Patients with active Helicobacter pylori infection underwent a baseline UBT before receiving 14 days of lansoprazole (30 mg/day) or ranitidine (300 mg b.i.d.). During therapy, patients were asked to undergo 24-h intragastric pH monitoring. Repeat breath testing was performed 1 day after completion of the study drugs. If the UBT was equivocal or negative (14CO2 excretion was < 200 dpm), further UBTs were completed until the 14CO2 excretion was > 200 dpm. RESULTS: Thirteen patients received lansoprazole. Eight of thirteen patients developed a negative or equivocal UBT. All patients had 14CO2 excretion > 200 dpm 5 days after the cessation of lansoprazole. Eleven patients received ranitidine. Ranitidine led to equivocal or false negative UBTs in 2 of 11 cases. This effect resolved within 5 days of stopping ranitidine. Intragastric pH recordings revealed that the patients who experienced the most profound gastric acid suppression were those that developed equivocal or false negative UBTs. CONCLUSIONS: Lansoprazole significantly affected the accuracy of the UBT, causing equivocal or false negative results in 61%. High dose ranitidine affected the breath test in only 18%. The ability of these drugs to suppress gastric acid secretion predicted those patients who developed equivocal or false-negative UBTs. The effect on the accuracy of the UBT resolved within 5 days of drug cessation.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1997

Bismuth subsalicylate instead of metronidazole with lansoprazole and clarithromycin for Helicobacter pylori infection: a randomized trial.

OBJECTIVE: We evaluated the efficacy of lansoprazole, clarithromycin, and metronidazole (LCM) administered twice daily for 7 days. Because there is growing concern about the development of metronidazole-resistant H. pylori (HP) strains, we also tested a novel regimen consisting of lansoprazole, clarithromycin, and bismuth subsalicylate (LCB). METHODS: Patients with active HP infection and peptic ulcer, a history of peptic ulcer, or nonulcer dyspepsia were randomized to either lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and metronidazole 500 mg b.i.d. or lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and bismuth subsalicylate 524 mg b.i.d. (LCB) for 7 days. Compliance and side effects were recorded by using a diary. RESULTS: "Per protocol" eradication with LCM was achieved in 41 of 47 (87%). By using "intention to treat" analysis, LCM eradicated HP infection in 43 of 53 patients (81%). By using "per protocol" analysis, LCB eradicated HP infection in 40 of 47 patients (85%). On an "intention to treat" basis, LCB led to HP eradication in 42 of 52 (81%). The most common significant side effects observed with LCM were altered taste (39%) and abdominal pain (19%). With LCB, the most common significant side effects were altered taste (23%) and dark stools (23%). CONCLUSIONS: LCB for 7 days was as effective in eradicating HP infection as a 7-day course of LCM. Further studies evaluating the role of bismuth compounds in proton-pump inhibitor based triple therapy are warranted. Such therapy may have particular importance in areas where high metronidazole resistance is a concern.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Nicotine effects on prostaglandin-dependent gastric slow wave rhythmicity and antral motility in nonsmokers and smokers.

BACKGROUND & AIMS: Mechanisms of antral hypomotility with smoking are unknown. Slow wave disruption, which may be prostaglandin dependent, inhibits gastric motility. This study tested if nicotine reproduces motor effects of smoking and assessed the role of slow wave disruption in inducing hypomotility and the prostaglandin dependence of dysrhythmic responses. METHODS: Electrogastrography and antroduodenal manometry were performed in 9 nonsmokers and 9 smokers during transdermal nicotine treatment (14 mg). Studies were repeated after administration of 150 mg indomethacin daily for 3 days to test prostaglandin requirements of nicotine responses. RESULTS: Antral migrating motor complex periodicity and fasting and fed motility indices, not different in the groups under control conditions, decreased similarly in nonsmokers and smokers with nicotine. Tachygastria (> 4.5 cycle/min) increased from 2% +/- 2% to 16% +/- 3% of recording time, and arrhythmias (frequency instability index) increased from 0.5 +/- 0.1 to 1.1 +/- 0.2 cycle/min with nicotine in nonsmokers (P < 0.05), which normalized with indomethacin. Electrogastrography results were unchanged in smokers. CONCLUSIONS: Nicotine evokes antral hypomotility in nonsmokers and smokers but evokes prostaglandin-dependent gastric dysrhythmias only in nonsmokers. Smokes show desensitization to nicotine-stimulated dysrhythmias. Thus, slow wave disruption is not essential to inhibit motor activity. This provides a model for the motor and myoelectric effects of smoking.

Adolescent↗