Patients Undergoing Elective Coronary Artery Bypass Graft Clinical Trial
Official title:
A Prospective, Randomized, Double-Blind Protocol to Compare the Efficacy of Lansoprazole to Ranitidine in Healing Pre-Existing and/or Preventing the Development of Gastroduodenal Stress Ulceration and Postoperative Bleeding in Patients Undergoing Elective Coronary Artery Bypass Graft or Cardiac Valve Replacement Surgery
The primary objective of this study is to determine whether lansoprazole, administered
intravenously, can protect patients undergoing cardiac surgery from the development of
and/or progression of previously undetected acid/peptic disorders (erosive esophagitis,
gastric ulcer, duodenal ulcer, diffuse gastritis, duodenitis) as measured by the Lanza score
and LA classification for esophageal injury.
The secondary objectives of this study are:
1. To determine if intravenous lansoprazole protects against the development of clinically
important gastrointestinal bleeding in this population (overt bleeding or requiring
blood transfusion).
2. To determine if intravenous lansoprazole maintains the intragastric pH above that for
placebo throughout the study period.
This is a randomized, double-blind single center study which compares the efficacy of
lansoprazole by IV infusion daily (60 mg bolus followed by 6 mg per hour) compared to
ranitidine 50 mg IV q12 h in healing pre-existing and preventing perioperative stress ulcers
and associated upper GI bleeding.
Patients will undergo a complete history including a medication history for intake of
ASA/NSAIDs/anticoagulants/antiplatelet agents, physical examination, complete blood count,
complete metabolic profile, ECG's and chest x-rays which rule out an exclusionary illness.
Female subjects will have a urine pregnancy test performed. They will then sign an informed
consent to participate in this randomized, double-blind study protocol. Patients will be
excluded if they are currently using acid suppressive therapy or if they have a history of
gastric/duodenal ulcers or gastroesophageal reflux disease that has required acid
suppressive therapy.
Patients will be randomized to receive either lansoprazole or ranitidine intravenously by
continuous intravenous infusion on the morning of surgery and on each of the subsequent 4
days. Computer randomization will be used with the code kept by pharmacy. The allocation
will be concealed. Medication will be delivered in a sealed, unlabeled container from the
pharmacy. Patients will be stratified between placebo and lansoprazole by preceding
ASA/NSAID use. Lansoprazole will be given as a 60 mg bolus preoperatively followed by 6 mg
per hour throughout the duration of the study. At the time of airway intubation in the
operating room for the surgery, a nasogastric tube with a built-in intragastric pH electrode
(Zinetics, Inc) will be passed into the mid-stomach by the anesthesiologist in place of the
standard nasogastric tube. Intragastric pH will be measured during the perisurgical period
until the morning of postoperative day 4, 72 hours after surgery. At that time, the
nasogastric tube/pH probe will be removed and patients will undergo
esophagogastroduodenoscopy (EGD) under sedation with midazolam and fentanyl. During the
endoscopy, the maximum number of submucosal hemorrhages and erosions in an endoscopic field
from the anterior and posterior walls of the antrum will be counted. Modified Lanza scores
for both the stomach and the duodenum will be determined to quantify gastric and duodenal
erosions and ulcerations6. We will also determine the LA classification of esophageal injury
and inflammation. Before removal of the endoscope, a wireless pH capsule (Bravo pH capsule;
Medtronic, Inc) will be placed in the body of the stomach 12 cm below the squamocolumnar
junction for an additional two day measurement of intragastric pH or until the time of
discharge from the hospital if less than 48 hours from the EGD. Thus, intragastric pH will
be monitored from the morning that the patient undergoes surgery for 6 days or until the
time of discharge.
After completion of surgery, all patients will be followed with hemoglobin and hematocrit
every 12 hours; all stools will be tested for blood qualitatively (Hemoccult) and
quantitatively (Hemaquant). Postoperatively, hemoglobin level will be maintained at or above
10 gm% using packed red blood cell transfusions as needed. Transfusion requirements will be
quantified. The times at which patients resume oral intake will be noted along with specific
data on oral liquid and solid food composition.
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Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double-Blind, Primary Purpose: Prevention