Meta-analysis of the effectiveness of histamine-2 receptor antagonists as prophylaxis for gastrointestinal bleeding in intensive care unit patients

Background: The risk of upper gastrointestinal bleeding increases in critically ill patients admitted to an intensive care unit (ICU), with 50–77% mortality. Histamine-2 receptor antagonists (H2RAs) are frequently used to prevent gastrointestinal bleeding in ICU patients, but the tests on its effectiveness and safety are still conflicting.Objective: To determine the effectiveness and safety of H2RA in preventing gastrointestinal bleeding in ICU patients. Methods: Data on randomised controlled trials (RCTs) were collected from the MEDLINE database, ScienceDirect, ClinicalKey, and The Cochrane Library. Two investigators assessed the quality of the trials using the critical appraisal skills program (CASP) checklist for RCT studies, and fixed-effects meta-analysis was carried out using Review Manager software.Results: The 12 RCTs showed a reduced risk of gastrointestinal bleeding (RR = 0.40; 95% CI = 0.30 ‒ 0.53; I-square = 38%; p <0.00001) and a decreased number of patients requiring blood transfusion in H2RA group (RR = 0.44; 95% CI = 0.23 ‒ 0.82; I-square = 8%; p = 0.01), and these effects were significantly different from the placebo group. However, there was no significant difference in mortality between the two groups (RR = 0.99; 95% CI = 0.74 ‒ 1.33; I-square = 0%; p = 0.96). Regarding its safety, the administration of H2RAs did not affect the incidence of nosocomial pneumonia (RR = 1.13; 95% CI = 0.82 ‒ 1.55; I-square = 30%; p = 0.46). A sensitivity analysis with a random-effects model was also performed on eight articles with a low risk of bias. The statistical analyses of eight and 12 articles showed the same results—that H2RAs significantly reduced the risk of gastrointestinal bleeding. Conclusion: H2RA proves effective and safe in reducing the incidence of gastrointestinal bleeding, but not reducing the mortality in ICU patients.