Prophylactic treatment of acute gastroduodenal stress ulceration. Low-dose antacid treatment without and with additional ranitidine

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.

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.

Prevention and Treatment of Gastrointestinal Complications in Patients on Mechanical Ventilation

There exists a complex, dynamic interaction between mechanical ventilation and the splanchnic vasculature that contributes to a myriad of gastrointestinal tract complications that arise during critical illness. Positive pressure-induced splanchnic hypoperfusion appears to play a pivotal role in the pathogenesis of these complications, the most prevalent of which are stress-related mucosal damage, gastrointestinal hypomotility and diarrhea. Furthermore, characteristics of the splanchnic vasculature make the gastrointestinal tract vulnerable to adverse effects related to positive pressure ventilation. While most of these complications seen in mechanically ventilated patients are reflections of altered gastrointestinal physiology, some may be attributed to medical interventions instituted to treat critical illness. Since maintenance of normal hemodynamics cannot always be achieved, pharmacologic prophylactic therapy has become a mainstay in the prevention of gastrointestinal complications in the intensive care unit. Improved understanding of the systemic effects of mechanical ventilation and greater application of lung-protective ventilatory strategies may potentially minimize positive pressure-induced reductions in splanchnic perfusion, systemic cytokine release and, consequently, reduce the incidence of gastrointestinal complications associated with mechanical ventilation. Herein, we discuss the pathophysiology of gastrointestinal complications associated with mechanical ventilation, summarize the most prevalent complications and focus on preventive strategies and available treatment options for these complications. The most common causes of gastrointestinal hemorrhage in mechanically ventilated patients are bleeding from stress-related mucosal damage and erosive esophagitis. In general, histamine H(2) receptor antagonists and proton pump inhibitors prevent stress-related mucosal disease by raising the gastric fluid pH. Proton pump inhibitors tend to provide more consistent pH control than histamine H(2) receptor antagonists. There is no consensus on the drug of choice for stress ulcer prophylaxis with several meta-analyses providing conflicting results on the superiority of any medication. Prevention of erosive esophagitis include careful use of nasogastric tubes and institution of strategies that improve gastric emptying. Many mechanically ventilated patients have gastrointestinal hypomotility and diarrhea. Treatment options for gastrointestinal motility are limited, thus, preventive measures such as correction of electrolyte abnormalities and avoidance of medications that impair gastrointestinal motility are crucial. Treatment of diarrhea depends on the underlying cause. When associated with Clostridium difficile infection antibacterial therapy should be discontinued, if possible, and treatment with oral metronidazole should be initiated.More studies are warranted to better understand the systemic effects of mechanical ventilation on the gastrointestinal tract and to investigate the impact of lung protective ventilatory strategies on gastrointestinal complications.

GI complications in patients receiving mechanical ventilation

Mechanical ventilation (MV) can be lifesaving by maintaining gas exchange until the underlying disorders are corrected, but it is associated with numerous organ-system complications, which can significantly affect the outcome of critically ill patients. Like other organ systems, GI complications may be directly attributable to MV, but most are a reflection of the severity of the underlying disease that required intensive care. The interactions of the underlying critical illness and MV with the GI tract are complex and can manifest in a variety of clinical pictures. Incorporated in this review are discussions of the most prevalent GI complications associated with MV, and current diagnosis and management of these problems.

Current guidelines on stress ulcer prophylaxis

Acute uppergastrointestinal bleeding in intensive care unit (ICU) patients may occur due to peptic ulcer disease, adverse drug effects, gastric tube lesions, acute renal failure, liver failure or stress-induced gastric mucosal lesions. Gastric acid hypersecretion can be observed in patients with head trauma or neurosurgical procedures. Gastric mucosal ischaemia due to hypotension and shock is the most important risk factor for stress ulcer bleeding. Preventive strategies aim to reduce gastric acidity (histamine H2 receptor antagonists, antacids), strengthen mucosal defensive mechanisms (sucralfate, antacids, pirenzepine) and normalise gastric mucosal microcirculation (sucralfate, pirenzepine). However, the most important prophylactic measure is an optimised resuscitation and ICU regime aiming to improve oxygenation and microcirculation. All drugs approved for stress ulcer prophylaxis in Europe (H2 antagonists, antacids, pirenzepine, sucralfate) have been shown to be effective in prospective controlled randomised trials. However, due to insufficient clinical data, prostaglandins and omeprazole cannot be recommended for this use. Stress ulcer prophylaxis is indicated only in patients at risk, and not in every ICU patient. The selection of drugs today depends not only on efficacy but also on possible adverse effects and on costs. In this regard, the most cost-effective drug is sucralfate. The clinical relevance of nosocomial pneumonia due to gastric bacterial overgrowth has decreased during the past decade due to several changes in the management of critically ill patients.

Frequency of stress lesions of the upper gastrointestinal tract in paediatric patients after cardiac surgery: effects of prophylaxis

BACKGROUND

Stress lesions of the upper gastrointestinal tract are well recognised in adult patients in intensive care. There are no controlled studies of the incidence of these lesions and the effects or side effects of prophylactic treatment in high risk paediatric patients.

METHODS

79 paediatric patients in intensive care were studied prospectively after operation for congenital heart disease. All patients had at least one endoscopic examination. The first 36 patients were not given prophylactic medication: later 43 children were treated randomly either with pirenzepine (n = 21) or with famotidine (n = 22). Gastric and tracheal secretions were taken daily for culture in those patients given prophylactic medication.

RESULTS

Severe inflammation or ulceration of the upper gastrointestinal tract was less common in those patients who were given prophylactic medication (18% v 44%). Prophylactic treatment did not, however, reduce the total incidence of postoperative stress lesions: it shifted the severity of these changes towards mild lesions and reduced the incidence of ulcerations from 25% to 2%. None of the patients developed a pneumonia caused by an organism previously isolated from the stomach.

CONCLUSIONS

The incidence of stress lesions in children after cardiac surgery resembles that in high risk adult patients. Children in intensive care after cardiac surgery should be treated prophylactically with famotidine or pirenzepine until they can be fed by mouth.

Ranitidine. An updated review of its pharmacodynamic and pharmacokinetic properties and therapeutic use in peptic ulcer disease and other allied diseases

Ranitidine, a histamine H2-receptor antagonist, is now well established as a potent inhibitor of gastric acid secretion effective in the treatment and prophylaxis of gastrointestinal lesions aggravated by gastric acid secretion. Therapeutic trials involving several thousands of patients with peptic ulcer disease confirm that ranitidine 300mg daily administered orally in single or divided doses is at least as effective as cimetidine 800 to 1000mg daily in increasing the rate of healing of duodenal and gastric ulcers. Similar dosages of ranitidine have been shown to relieve the symptoms of reflux oesophagitis and heal or prevent gastrointestinal damage caused by ulcerogenic drugs. Ranitidine 150mg orally at night maintains ulcer healing in the long term. Ranitidine has also demonstrated good results in the treatment of Zollinger-Ellison syndrome and in the prevention of aspiration pneumonitis when given prior to surgery and to pregnant women at full term. It may also have a place in the management of acute upper gastrointestinal bleeding and in the prevention of stress ulcers in the intensive care setting, although these areas require further investigation. Ranitidine has been used safely in obstetric patients during labour, in children, the elderly, and in patients with renal impairment when given in appropriate dosages. The drug is very well tolerated and is only infrequently associated with serious adverse reactions or clinically significant drug interactions. Even at high dosages, ranitidine appears devoid of antiandrogenic effects. Ranitidine is clearly comparable or superior to most other antiulcer agents in the treatment and prevention of a variety of gastrointestinal disorders associated with gastric acid secretion. With its favourable efficacy and tolerability profiles, ranitidine must be considered a first-line agent when suppression of gastric acid secretion is indicated.