Lack of effect of ranitidine on gastric luminal pH and mucosal PCO2 during the first day in the ICU

Efficacy and safety of gastrointestinal bleeding prophylaxis in critically ill patients: an updated systematic review and network meta-analysis of randomized trials

PURPOSE

Motivated by a new randomized trial (the PEPTIC trial) that raised the issue of an increase in mortality with proton pump inhibitors (PPIs) relative to histamine-2 receptor antagonists (H2RAs), we updated our prior systematic review and network meta-analysis (NMA) addressing the impact of pharmacological gastrointestinal bleeding prophylaxis in critically ill patients.

METHODS

We searched for randomized controlled trials that examined the efficacy and safety of gastrointestinal bleeding prophylaxis with PPIs, H2RAs, or sucralfate versus one another or placebo or no prophylaxis in adult critically ill patients. We performed Bayesian random-effects NMA and conducted analyses using all PEPTIC data as well as a restricted analysis using only PEPTIC data from high compliance centers. We used the GRADE approach to quantify absolute effects and assess the certainty of evidence.

RESULTS

Seventy-four trials enrolling 39 569 patients proved eligible. Both PPIs (risk ratio (RR) 1.03, 95% credible interval 0.93 to 1.14, moderate certainty) and H2RAs (RR 0.98, 0.89 to 1.08, moderate certainty) probably have little or no impact on mortality compared with no prophylaxis. There may be no important difference between PPIs and H2RAs on mortality (RR 1.05, 0.97 to 1.14, low certainty), the 95% credible interval of the complete analysis has not excluded an important increase in mortality with PPIs. Both PPIs (RR 0.46, 0.29 to 0.66) and H2RAs (RR 0.67, 0.48 to 0.94) probably reduce clinically important gastrointestinal bleeding; the magnitude of reduction is probably greater in PPIs than H2RAs (RR 0.69, 0.45 to 0.93), and the difference may be important in higher, but not lower bleeding risk patients. PPIs (RR 1.08, 0.88 to 1.45, low certainty) and H2RAs (RR 1.07, 0.85 to 1.37, low certainty) may have no important impact on pneumonia compared with no prophylaxis.

CONCLUSION

This updated NMA confirmed that PPIs and H2RAs are most likely to have a similar effect on mortality compared to each other and compared to no prophylaxis; however, the possibility that PPIs may slightly increase mortality cannot be excluded (low certainty evidence). PPIs and H2RAs probably achieve important reductions in clinically important gastrointestinal bleeding; for higher bleeding risk patients, the greater benefit of PPIs over H2RAs may be important. PPIs or H2RAs may not result in important increases in pneumonia but the certainty of evidence is low.

Prophylactic use of acid suppressants in adult acutely ill hospitalised patients: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Acutely ill patients are at risk of stress-related gastrointestinal (GI) bleeding and prophylactic acid suppressants are frequently used. In this systematic review, we assessed the effects of stress ulcer prophylaxis (SUP) with proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) versus placebo or no prophylaxis in acutely ill hospitalised patients.

METHODS

We conducted the review according to the PRISMA statement, the Cochrane Handbook and GRADE, using conventional meta-analysis and trial sequential analysis (TSA). The primary outcomes were all-cause mortality, clinically important GI bleeding and serious adverse events (SAEs). The primary analyses included overall low risk of bias trials.

RESULTS

We included 65 comparisons from 62 trials (n = 9713); 43 comparisons were from intensive care units. Only three trials (n = 3596) had overall low risk of bias. We did not find an effect on all-cause mortality (RR 1.03, 95% CI 0.94 to 1.14; TSA-adjusted CI 0.90 to 1.18; high certainty). The rate of clinically important GI bleeding was lower with SUP (RR 0.62, 95% CI 0.43 to 0.89; TSA-adjusted CI 0.14 to 2.81; moderate certainty). We did not find a difference in pneumonia rates (moderate certainty). Effects on SAEs, Clostridium difficile enteritis, myocardial ischaemia and health-related quality of life (HRQoL) were inconclusive due to sparse data. Analyses of all trials regardless of risk of bias were consistent with the primary analyses.

CONCLUSIONS

We did not observe a difference in all-cause mortality or pneumonia with SUP. The incidence of clinically important GI bleeding was reduced with SUP, whereas any effects on SAEs, myocardial ischaemia, Clostridium difficile enteritis and HRQoL were inconclusive.

STUDY REGISTRATION

PROSPERO registration number CRD42017055676; published study protocol: Marker, et al 2017 in Systematic Reviews.

Efficacy and safety of gastrointestinal bleeding prophylaxis in critically ill patients: systematic review and network meta-analysis

OBJECTIVE

To determine, in critically ill patients, the relative impact of proton pump inhibitors (PPIs), histamine-2 receptor antagonists (H2RAs), sucralfate, or no gastrointestinal bleeding prophylaxis (or stress ulcer prophylaxis) on outcomes important to patients.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, PubMed, Embase, Cochrane Central Register of Controlled Trials, trial registers, and grey literature up to March 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES AND METHODS

We included randomised controlled trials that compared gastrointestinal bleeding prophylaxis with PPIs, H2RAs, or sucralfate versus one another or placebo or no prophylaxis in adult critically ill patients. Two reviewers independently screened studies for eligibility, extracted data, and assessed risk of bias. A parallel guideline committee (BMJ Rapid Recommendation) provided critical oversight of the systematic review, including identifying outcomes important to patients. We performed random-effects pairwise and network meta-analyses and used GRADE to assess certainty of evidence for each outcome. When results differed between low risk and high risk of bias studies, we used the former as best estimates.

RESULTS

Seventy two trials including 12 660 patients proved eligible. For patients at highest risk (>8%) or high risk (4-8%) of bleeding, both PPIs and H2RAs probably reduce clinically important gastrointestinal bleeding compared with placebo or no prophylaxis (odds ratio for PPIs 0.61 (95% confidence interval 0.42 to 0.89), 3.3% fewer for highest risk and 2.3% fewer for high risk patients, moderate certainty; odds ratio for H2RAs 0.46 (0.27 to 0.79), 4.6% fewer for highest risk and 3.1% fewer for high risk patients, moderate certainty). Both may increase the risk of pneumonia compared with no prophylaxis (odds ratio for PPIs 1.39 (0.98 to 2.10), 5.0% more, low certainty; odds ratio for H2RAs 1.26 (0.89 to 1.85), 3.4% more, low certainty). It is likely that neither affect mortality (PPIs 1.06 (0.90 to 1.28), 1.3% more, moderate certainty; H2RAs 0.96 (0.79 to 1.19), 0.9% fewer, moderate certainty). Otherwise, results provided no support for any affect on mortality, Clostridium difficile infection, length of intensive care stay, length of hospital stay, or duration of mechanical ventilation (varying certainty of evidence).

CONCLUSIONS

For higher risk critically ill patients, PPIs and H2RAs likely result in important reductions in gastrointestinal bleeding compared with no prophylaxis; for patients at low risk, the reduction in bleeding may be unimportant. Both PPIs and H2RAs may result in important increases in pneumonia. Variable quality evidence suggested no important effects of interventions on mortality or other in-hospital morbidity outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019126656.

Stress ulcer prophylaxis with proton pump inhibitors or histamin-2 receptor antagonists in adult intensive care patients: a systematic review with meta-analysis and trial sequential analysis

PURPOSE

Most intensive care unit (ICU) patients receive stress ulcer prophylaxis. We present updated evidence on the effects of prophylactic proton pump inhibitors (PPIs) or histamine 2 receptor antagonists (H2RAs) versus placebo/no prophylaxis on patient-important outcomes in adult ICU patients.

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) of randomised clinical trials assessing the effects of PPI/H2RA versus placebo/no prophylaxis on mortality, gastrointestinal (GI) bleeding, serious adverse events (SAEs), health-related quality of life (HRQoL), myocardial ischemia, pneumonia, and Clostridium (Cl.) difficile enteritis in ICU patients.

RESULTS

We identified 42 trials randomising 6899 ICU patients; 3 had overall low risk of bias. We did not find an effect of stress ulcer prophylaxis on mortality [relative risk 1.03, 95% confidence interval (CI) 0.94-1.14; TSA-adjusted CI 0.94-1.14], but the occurrence of any GI bleeding was reduced as compared with placebo/no prophylaxis (0.60, 95% CI 0.47-0.77; TSA-adjusted CI 0.36-1.00). The conventional meta-analysis indicated that clinically important GI bleeding was reduced (RR 0.63, 95% CI 0.48-0.81), but the TSA-adjusted CI 0.35-1.13 indicated lack of firm evidence. The effects of stress ulcer prophylaxis on SAEs, HRQoL, pneumonia, myocardial ischemia and Cl. difficile enteritis are uncertain.

CONCLUSIONS

In this updated systematic review, we were able to refute a relative change of 20% of mortality. The occurrence of GI bleeding was reduced, but we lack firm evidence for a reduction in clinically important GI bleeding. The effects on SAEs, HRQoL, pneumonia, myocardial ischemia and Cl. difficile enteritis remain inconclusive.

Protective effects of a triple-fermented barley extract (FBe) against HCl/EtOH-induced gastric mucosa damage in mice

This study was designed to observe the possible protective effects of a triple-fermented barley (Hordeum vulgare L.) extract (FBe) obtained by saccharification and using Saccharomyces cerevisiae and Weissella cibaria in alleviating gastric damage induced by a hydrochloric acid (HCl) and ethanol (EtOH) mixture in mice. After oral administration of FBe (300, 200, and 100 mg/kg) followed by 1 hr before and after the single treatment of HCl/EtOH (H/E) mixture, the hemorrhagic lesion scores, histopathology of the stomach, gastric nitrate/nitrite content, lipid peroxidation, and antioxidant defense systems including catalase and superoxide dismutase activities were observed. Following a single oral treatment of H/E-induced gastric damages as measured by hemorrhagic gross lesions and histopathological gastric, ulcerative lesions were significantly and dose-dependently (p < 0.01 or p < 0.05) inhibited in mice, when all three different doses of FBe were administered as compared to those in H/E control mice. In particular, FBe also increased gastric nitrate/nitrite content and strengthened the antioxidant defense, with a decrease in the level of gastric lipid peroxidation, but increased the activities of CAT and SOD. Moreover, the effects of FBe are comparable to that of ranitidine, a reference drug. The obtained results suggest that this fermented barley extract prevented mice from H/E-induced gastric mucosal damages through the suppression of inflammatory responses and oxidative stress-responsive free radicals. Thus, FBe can be useful to treat patients suffering from gastric mucosal disorders as a potent food supplement, and thereby, it would increase the necessity of application in the food industry.

Solution-phase synthesis of a highly substituted furan library

A library of furans has been synthesized by iodocyclization and further diversified by palladium-catalyzed coupling processes. The key intermediate 3-iodofurans have been prepared by the electrophilic iodocyclization of 2-iodo-2-alken-1-ones in the presence of various nucleophiles in good to excellent yields under mild reaction conditions. These 3-iodofurans are the key components for library generation through subsequent elaboration by palladium-catalyzed processes, such as Suzuki-Miyaura, Sonagashira, Heck, aminocarbonylation, and carboalkoxylation chemistry to afford a diverse set of 2,3,4,5-tetrasubstituted furans.

Therapy insight: Prophylaxis of stress-induced gastrointestinal bleeding in critically ill patients

Stress-induced gastrointestinal bleeding is associated with increased morbidity and mortality in critically ill patients. Within the past few decades, the incidence of stress-induced gastrointestinal bleeding has decreased. Prophylaxis of stress-induced gastrointestinal bleeding, which is aimed at preventing morbidity and mortality, has to be achieved with as few adverse effects as possible. Data indicate that not all critically ill patients need prophylaxis for stress-induced gastrointestinal bleeding. The main risk factors associated with clinically important hemorrhage are mechanical ventilation for >48 h, and coagulopathy (thrombocyte count <50/nl, partial thromboplastin time (PTT) >2 times the upper limit of the normal range, international normalized ratio (INR) >1.5). Ranitidine is more effective than sucralfate for the prevention of clinically important bleeding. Immediate-release omeprazole is as effective as cimetidine, and is more efficient at increasing the intragastric pH. As yet, however, there is no firm evidence that any of the drugs used for prophylaxis of stress-induced gastrointestinal bleeding in critically ill patients decrease mortality or the length of hospital stay. When to stop prophylaxis is decided on clinical grounds rather than on the basis of data from clinical studies.

Gastric and sublingual capnometry

PURPOSE OF REVIEW

Tissue hypoperfusion is a common pathophysiologic process leading to multiple organ dysfunction and death. Increases in tissue PCO2 can reflect an abnormal oxygen supply to the cells, so that monitoring tissue PCO2 by the use of gastric or sublingual capnometry may help identify circulatory abnormalities and guide their correction. This review provides an update on these technologies.

RECENT FINDINGS

Gastric tonometry aims at monitoring PCO2 in the stomach, an organ that becomes ischemic quite early when the circulatory status is jeopardized. Despite substantial initial enthusiasm, this technique has never been widely implemented due to methodological problems. The measurement of sublingual mucosal PCO2 (PslCO2) by sublingual capnometry is technically simple and noninvasive. Experimental studies have suggested that PslCO2 is a reliable marker of tissue perfusion. Clinical studies have demonstrated that high PslCO2 values are associated with impaired microcirculatory blood flow and a worse prognosis in critically ill patients.

SUMMARY

Gastric tonometry was proposed for regional PCO2 monitoring, but it is prone to a number of technical limitations. Sublingual capnometry could offer a valuable alternative for tissue PCO2 monitoring in clinical practice, representing a simple, noninvasive method to monitor tissue perfusion and titrate therapeutic interventions in critically ill patients.