The role of sustained achlorhydria in bleeding peptic ulcer

Interventions for preventing upper gastrointestinal bleeding in people admitted to intensive care units

BACKGROUND

Upper gastrointestinal (GI) bleeding due to stress ulcers contributes to increased morbidity and mortality in people admitted to intensive care units (ICUs). Stress ulceration refers to GI mucosal injury related to the stress of being critically ill. ICU patients with major bleeding as a result of stress ulceration might have mortality rates approaching 48.5% to 65%. However, the incidence of stress-induced GI bleeding in ICUs has decreased, and not all critically ill patients need prophylaxis. Stress ulcer prophylaxis can result in adverse events such as ventilator-associated pneumonia; therefore, it is necessary to evaluate strategies that safely decrease the incidence of GI bleeding.

OBJECTIVES

To assess the effect and risk-benefit profile of interventions for preventing upper GI bleeding in people admitted to ICUs.

SEARCH METHODS

We searched the following databases up to 23 August 2017, using relevant search terms: MEDLINE; Embase; the Cochrane Central Register of Controlled Trials; Latin American Caribbean Health Sciences Literature; and the Cochrane Upper Gastrointestinal and Pancreatic Disease Group Specialised Register, as published in the Cochrane Library (2017, Issue 8). We searched the reference lists of all included studies and those from relevant systematic reviews and meta-analyses to identify additional studies. We also searched the World Health Organization International Clinical Trials Registry Platform search portal and contacted individual researchers working in this field, as well as organisations and pharmaceutical companies, to identify unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs with participants of any age and gender admitted to ICUs for longer than 48 hours. We excluded studies in which participants were admitted to ICUs primarily for the management of GI bleeding and studies that compared different doses, routes, and regimens of one drug in the same class because we were not interested in intraclass effects of drugs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane.

MAIN RESULTS

We identified 2292 unique records.We included 129 records reporting on 121 studies, including 12 ongoing studies and two studies awaiting classification.We judged the overall risk of bias of two studies as low. Selection bias was the most relevant risk of bias domain across the included studies, with 78 studies not clearly reporting the method used for random sequence generation. Reporting bias was the domain with least risk of bias, with 12 studies not reporting all outcomes that researchers intended to investigate.Any intervention versus placebo or no prophylaxisIn comparison with placebo, any intervention seems to have a beneficial effect on the occurrence of upper GI bleeding (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.39 to 0.57; moderate certainty of evidence). The use of any intervention reduced the risk of upper GI bleeding by 10% (95% CI -12.0% to -7%). The effect estimate of any intervention versus placebo or no prophylaxis with respect to the occurrence of nosocomial pneumonia, all-cause mortality in the ICU, duration of ICU stay, duration of intubation (all with low certainty of evidence), the number of participants requiring blood transfusions (moderate certainty of evidence), and the units of blood transfused was consistent with benefits and harms. None of the included studies explicitly reported on serious adverse events.Individual interventions versus placebo or no prophylaxisIn comparison with placebo or no prophylaxis, antacids, H2 receptor antagonists, and sucralfate were effective in preventing upper GI bleeding in ICU patients. Researchers found that with H2 receptor antagonists compared with placebo or no prophylaxis, 11% less developed upper GI bleeding (95% CI -0.16 to -0.06; RR 0.50, 95% CI 0.36 to 0.70; 24 studies; 2149 participants; moderate certainty of evidence). Of ICU patients taking antacids versus placebo or no prophylaxis, 9% less developed upper GI bleeding (95% CI -0.17 to -0.00; RR 0.49, 95% CI 0.25 to 0.99; eight studies; 774 participants; low certainty of evidence). Among ICU patients taking sucralfate versus placebo or no prophylaxis, 5% less had upper GI bleeding (95% CI -0.10 to -0.01; RR 0.53, 95% CI 0.32 to 0.88; seven studies; 598 participants; moderate certainty of evidence). The remaining interventions including proton pump inhibitors did not show a significant effect in preventing upper GI bleeding in ICU patients when compared with placebo or no prophylaxis.Regarding the occurrence of nosocomial pneumonia, the effects of H2 receptor antagonists (RR 1.12, 95% CI 0.85 to 1.48; eight studies; 945 participants; low certainty of evidence) and of sucralfate (RR 1.33, 95% CI 0.86 to 2.04; four studies; 450 participants; low certainty of evidence) were consistent with benefits and harms when compared with placebo or no prophylaxis. None of the studies comparing antacids versus placebo or no prophylaxis provided data regarding nosocomial pneumonia.H2 receptor antagonists versus proton pump inhibitorsH2 receptor antagonists and proton pump inhibitors are most commonly used in practice to prevent upper GI bleeding in ICU patients. Proton pump inhibitors significantly more often prevented upper GI bleeding in ICU patients compared with H2 receptor antagonists (RR 2.90, 95% CI 1.83 to 4.58; 18 studies; 1636 participants; low certainty of evidence). When taking H2 receptor antagonists, 4.8% more patients might experience upper GI bleeding (95% CI 2.1% to 9%). Nosocomial pneumonia occurred in similar proportions of participants taking H2 receptor antagonists and participants taking proton pump inhibitors (RR 1.02, 95% CI 0.77 to 1.35; 10 studies; 1256 participants; low certainty of evidence).

AUTHORS' CONCLUSIONS

This review shows that antacids, sucralfate, and H2 receptor antagonists might be more effective in preventing upper GI bleeding in ICU patients compared with placebo or no prophylaxis. The effect estimates of any treatment versus no prophylaxis on nosocomial pneumonia were consistent with benefits and harms. Evidence of low certainty suggests that proton pump inhibitors might be more effective than H2 receptor antagonists. Therefore, patient-relevant benefits and especially harms of H2 receptor antagonists compared with proton pump inhibitors need to be assessed by larger, high-quality RCTs to confirm the results of previously conducted, smaller, and older studies.

Omeprazole as adjuvant therapy to endoscopic combination injection sclerotherapy for treating bleeding peptic ulcer

BACKGROUND

Therapeutic endoscopy has provided a new means of treating bleeding peptic ulcers. Additional medical therapy may enhance the therapeutic benefit. Hemostasis is highly pH dependent and is severely impaired at low pH. Proton pump inhibitors, by achieving a significantly higher inhibition of gastric acidity, may improve the therapeutic outcomes after endoscopic treatment of ulcers.

PATIENT AND METHODS

We enrolled 166 patients with hemorrhage from duodenal, gastric, or stomal ulcers and signs of recent hemorrhage, as confirmed by endoscopy. Twenty-six patients had ulcers with an arterial spurt, 41 patients had active ooze, 37 had a visible vessel, and 62 patients had an adherent clot. All patients received endoscopic injection sclerotherapy using 1:10,000 adrenaline and 1% polidocanol and were randomly assigned to receive omeprazole (40 mg orally) every 12 hours for 5 days or an identical-looking placebo. The outcome measures used were recurrent bleeding, surgery, blood transfusion, and hospital stay.

RESULTS

Six (7%) of 82 patients in the omeprazole group had recurrent bleeding, as compared with 18 (21%) in the placebo group (P = 0.02). Two patients in the omeprazole group and 7 patients in the placebo group needed surgery to control their bleeding (P = 0.17). One patient in the omeprazole group and 2 patients in the placebo group died (P = 0.98). Twenty-nine patients (35%) in the omeprazole group and 61 patients (73%) in the placebo group received blood transfusions (P <0.001). The average hospital stay was 4.6 +/- 1.1 days in the omeprazole group and 6.0 +/- 0.7 days in the placebo group (P <0.001).

CONCLUSION

The addition of oral omeprazole to combination injection sclerotherapy decreases the rate of recurrent bleeding, reduces the need for surgery and transfusion, and shortens the hospital stay for patients with stigmata of recent hemorrhage.

Maintenance of gastric pH above 6 with intravenous famotidine in patients with a bleeding duodenal ulcer

BACKGROUND

The secondary prevention of bleeding from ulcers may be improved if antisecretory drugs are able to maintain a 24-h gastric pH close to neutral.

AIM

To evaluate the effect of intravenous famotidine at a conventional dose of 40 mg/day on 24-h intragastric pH in patients with a bleeding duodenal ulcer, and to determine the dose required to maintain gastric pH > 6 by use of a Gastrojet (MIC, Switzerland) device (a pH meter-controlled programmable pump).

METHODS

Twelve patients (nine men, three women), aged 24-78 years, admitted for a bleeding duodenal ulcer, were studied after active bleeding had stopped for at least 6 h. Gastric pH was recorded for two consecutive 24-h periods, each starting at 16.00 hours. The patients were fasted during these periods and received an infusion of 2.5 L of isotonic glucose. They were given famotidine, as a continuous i.v. infusion of 40 mg during one period, and at a rate determined by the Gastrojet during the other period (in a random sequence), with the aim of maintaining the gastric pH above 6.

RESULTS

The 24-h median (interquartile range) pH and the mean (+/- S.E.M.) percentage of the 24-h period with a gastric pH > 6 were both significantly higher during the Gastrojet period than during the continuous infusion: 6.4 (6.3-6.5) vs. 5.7 (2.7-6.4) (P < 0.01) and 74 +/- 5% vs. 44 +/- 7% (P < 0.002), respectively. The mean dose of famotidine delivered by the Gastrojet was 172 mg (range: 101-200 mg). The entire available amount of famotidine (200 mg) was delivered in four of the 12 patients. The percentage of time at pH > 6 (mean +/- S.E.M.) was significantly higher at night (22.00 to 07.00 hours) than during the rest of the day (88 +/- 2 vs. 70 +/- 6%; P < 0.005) and the mean quantity of famotidine delivered per hour was significantly lower during the night (6.3 +/- 0.8 mg/h vs. 8.4 +/- 0.5 mg/h; P < 0.02).

CONCLUSION

We conclude that 40 mg of famotidine delivered as a continuous i.v. infusion is not sufficient to maintain gastric pH > 6 for 24 h in duodenal ulcer patients. Our study with the Gastrojet device shows that it may be possible to achieve this goal by using a much larger dose, preferably delivered during the day.

Treating bleeding peptic ulcer with sustained achlorhydria

A controlled randomized study and a subsequent prospective therapeutic trial have demonstrated the efficacy of an intensive therapy comprising hourly intravenous injections of 100 mg of cimetidine along with a continuous nasogastric infusion of a liquid antacid at the rate of 0.5 ml per minute in achieving achlorhydria and controlling bleeding in patients with bleeding peptic ulcer. We recommend that this regimen should be routinely employed for treating patients with bleeding peptic ulcer, at least in center that do not practise topical therapeutic modalities for control of bleeding.