Controlled trial of medical therapy for active upper gastrointestinal bleeding and prevention of rebleeding

Acute Gastrointestinal Bleeding

A greater understanding of the pathophysiology of gastrointestinal bleeding has been accompanied by a rapid advancement in therapeutic technology. Newer endoscopic and radiologic techniques are being tested to determine their appropriate uses, but pharmacologic therapy has yet to be proved beneficial. A discussion of the newer as well as some traditional therapies is presented.

Stress Ulcer Syndrome

Stress ulcer syndrome refers to gastroduodenal erosions or ulcers that develop acutely in relation to major physi ological stress, usually manifested clinically as upper gastrointestinal (UGI) bleeding. These lesions occur most often in the gastric fundus. Endoscopy has shown gastroduodenal mucosal lesions in 75 to 100% of inten sive care unit (ICU) patients within 72 hours of admis sion. Patients at high risk for stress ulcer include those with large body surface area burns, intracranial lesions associated with coma, fulminant hepatic failure, sepsis, and trauma and abdominal, cardiovascular, and thoracic surgery patients. Also considered high risk are ICU pa tients with superimposed complications such as shock, mechanical ventilation for more than 3 days, coagulopa thy, jaundice, and sepsis. Approximately 15% of ICU pa tients will experience UGI bleeding from stress ulcer. Patients bleeding from stress ulcer have an overall mor tality rate approaching 65% compared with 9 to 22% mortality in patients without stress ulcer. When strati fied according to occult blood loss versus clinically significant bleeding, mortality can be as high as 90% in patients overtly bleeding; 30% of deaths are directly related to bleeding. Both antacids and H2 receptor an tagonists are effective in prophylaxis for stress ulcer bleeding.

The role of acid in upper gastrointestinal haemorrhage due to ulcer and stress-related mucosal damage

A peptic ulcer is a lesion in which acid and pepsin are essential components of pathogenesis. Regardless of the type of patient or the setting in which the ulcer presents, the basic pathogenetic scheme is the same. The primary event is disruption of mucosal integrity. In the presence of acid and pepsin, such disruption of integrity leads to an ulcer. While rarely sufficient by itself to cause ulceration, the presence of acid is a necessary cofactor. The causes of disruption of mucosal integrity include nonsteroidal anti-inflammatory drugs (NSAIDs), Helicobacter pylori and critical illness. With the latter, tissue ischaemia may be the primary event, leading to back-diffusion of H+ ions through increased membrane permeability. Impaired mucosal buffering then leads to intramural acidosis and cell death. Risk factors for bleeding peptic ulcer in the intensive care unit (ICU) include severe trauma, sepsis, respiratory failure, and coagulopathy. Potential roles for decreasing gastric acidity in the treatment of bleeding peptic ulcer include cessation of active bleeding, prevention of rebleeding in hospital and primary prevention of bleeding. Most published studies dealing with the first two situations suggest no benefit with antisecretory therapy. However, the optimal pH for clot and platelet function may be > or = 7.0. Can such pH levels be maintained with antisecretory agents such as the proton pump inhibitors? Are the published trials adequate to demonstrate any benefit from antisecretory agents? Primary prevention of bleeding ulcer in the outpatient setting includes avoidance of NSAIDs, use of antisecretory agents and eradication of H. pylori.(ABSTRACT TRUNCATED AT 250 WORDS)

Antacids for preventing oesophagogastric variceal bleeding and rebleeding in cirrhotic patients

BACKGROUND

Ruptured gastroesophageal varices are the most severe and frequent cause of gastrointestinal bleeding in cirrhotic patients, leading to death in 5% to 8% of patients during the first 48 hours and oesophagogastric varices account for 60% to 80% of first bleeding in patients with portal hypertension. Antacids are often used for emergency treatment of bleeding oesophageal varices in patients with cirrhosis of the liver.

OBJECTIVES

To evaluate the beneficial and harmful effects of antacids for preventing oesophagogastric bleeding and rebleeding.

SEARCH STRATEGY

We identified relevant randomised clinical trials by searching The Cochrane Hepato-Biliary Group Controlled Trials Register (June 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 2, 2007), MEDLINE (1950 to June 2007), EMBASE (Excerpta Medica Database) (1980 to June 2007), and the Science Citation Index Expanded (SCI-EXPANDED) (1945 to June 2007). Additional randomised trials were sought from the reference lists of the trials found and reviews identified by the electronic searches.

SELECTION CRITERIA

We planned to include randomised clinical trials.

DATA COLLECTION AND ANALYSIS

We planned to summarise data using Cochrane Collaboration methodologies.

MAIN RESULTS

We could not find any randomised clinical trials on antacids for preventing oesophagogastric variceal bleeding and bleeding in cirrhotic patients.

AUTHORS' CONCLUSIONS

it is not possible to determine whether antacids are beneficially effective or harmful for preventing oesophagogastric variceal bleeding and rebleeding in cirrhotic patients since randomised clinical trials investigating it are lacking.

Use of acid-suppression therapy for treatment of non-variceal upper gastrointestinal bleeding

PURPOSE

Prognostic factors in patients with peptic ulcer bleeding and therapeutic strategies for preventing the recurrence of bleeding are described.

SUMMARY

The risk of complications and death in a patient with acute upper gastrointestinal bleeding can be predicted based on certain clinical factors, the most important being the endoscopic findings. Proton pump inhibitors (PPIs) are the drugs of choice for patients with peptic ulcer bleeding because the drugs are more effective than histamine H2-receptor antagonists for maintaining the target intragastric pH (6 or higher) and preventing the recurrence of peptic ulcer bleeding, although an impact on mortality has not been demonstrated. High-dose intravenous PPI therapy should be used for patients at high risk of rebleeding (based on endoscopic findings). Oral PPI therapy may be used for low-risk patients. Underlying causes of ulcers should also be addressed and treated as necessary.

CONCLUSION

Acid-suppression therapy using PPIs is effective for reducing the risk for recurrence of peptic ulcer bleeding.

Acid suppression in critically ill patients: what does the evidence support?

Stress-related mucosal disease is a frequent complication in critically ill patients. A wealth of evidence suggests that hypoperfusion to the upper gastrointestinal tract can lead to ulceration and is associated with increased morbidity. Management of stress ulcers depends on aggressive therapy that includes acid-suppressive agents. Proton pump inhibitors (PPIs) have gained recognition as a potentially important therapy for treatment and prevention of upper gastrointestinal bleeding in critically ill patients. Patients who present to the hospital with acute gastrointestinal bleeding benefit from potent acid inhibition. Whereas histamine2-receptor antagonists have questionable efficacy in preventing ulcer rebleeding in this patient population, PPIs are highly effective. They should be considered first-line therapy for patients undergoing endoscopic hemostasis and for those with stigmata of upper gastrointestinal bleeding.

Comparison of oral omeprazole and endoscopic ethanol injection therapy for prevention of recurrent bleeding from peptic ulcers with nonbleeding visible vessels or fresh adherent clots

OBJECTIVES

Omeprazole is a potent inhibitor of gastric acid secretion. Recently it was reported that p.o. omeprazole therapy reduced the rebleeding rate in patients with nonbleeding visible vessels or adherent clots. The aim of this study was to ascertain whether p.o. administration of omeprazole can be an effective alternative to endoscopic injection therapy in peptic ulcers with stigmata of recent hemorrhage.

METHODS

A total of 101 patients who had peptic ulcer bleeding based on endoscopic findings of nonbleeding visible vessels or fresh adherent clots were randomly assigned to receive omeprazole (40 mg p.o. every 12 h) or endoscopic ethanol injection therapy.

RESULTS

Rebleeding rates were 22.9% (11 of 48) in the omeprazole group and 20.8% (11 of 53) in the endoscopic injection therapy group. The rebleeding rates of clinical significance were 14.6% and 13.2%, respectively. There was no significance difference in the rebleeding rate, requirement for surgery, total units of blood transfused, or mortality between the two groups.

CONCLUSIONS

Oral omeprazole administration is comparable to endoscopic ethanol injection therapy for prevention of rebleeding in patients with nonbleeding visible vessels or adherent clots.

Acute gastrointestinal bleeding in the intensive care unit. The gastroenterologist's perspective

Although SRES-associated hemorrhage previously constituted a significant cause of bleeding in the ICU, improvements in ICU management and the institution of prophylactic measures in high-risk patients have significantly reduced SRES-associated hemorrhage since the 1980s. Antacids, H2-receptor antagonists, and sucralfate have been shown to be effective in preventing clinically significant bleeding resulting from SRES, particularly when the intragastric pH is maintained at greater than 4. A selective approach should be adopted in SRES prophylaxis: Patients on mechanical ventilation, with coagulopathy, or with two of the other known risk factors should receive prophylaxis. Although the drug of choice depends to some extent on local preferences, an H2-receptor antagonist by continuous intravenous infusion may represent the best option. No pharmacologic therapy is of proven value once hemorrhage begins, but the current interventional techniques are effective in controlling hemorrhage. Gastrointestinal bleeding from NOMV has become less common with improvements in the hemodynamic monitoring of critically ill patients, but this disease must always be considered when lower gastrointestinal bleeding occurs in the context of relative hypoperfusion. For SRES and NOMV, treatment of the underlying disease or diseases is the optimal route to prevention.

The efficacy of proton-pump inhibitors in acute ulcer bleeding: a qualitative review

Despite remarkable progress in the treatment of chronic peptic ulcer disease, acute gastroduodenal ulcer hemorrhage remains a therapeutic challenge. Numerous trials of H-2 receptor antagonists have not consistently shown a significant benefit in such patients. Proton-pump inhibitors, which more profoundly suppress gastric acid, are being increasingly evaluated. We have performed a qualitative systematic review to analyze the results of these trials to determine if a reasonable consensus can be reached. We searched for all published, randomized, controlled studies that evaluated proton-pump inhibitors in patients with acute peptic ulcer hemorrhage. The primary outcomes evaluated were: (A) persistent or recurrent bleeding; (B) need for surgery; and (C) mortality. Sixteen trials were evaluated, enrolling 3154 patients. Four of the sixteen studies showed a statistically significant decrease in overall rebleeding rate, and two described specific benefit in patients with Type IIa and IIb endoscopic stigmata. Four studies also showed a significantly decreased surgery rate, but none demonstrated a significant mortality reduction. Proton-pump inhibitors may improve outcome in acute peptic ulcer bleeding, but the available clinical data remain inconsistent. Further study is necessary to define the optimal dosage, route of administration, duration of therapy, and subsets of patients most likely to benefit.

The use of intravenous H2-receptor antagonists in a tertiary care hospital

OBJECTIVE

The rationale for the widespread use of intravenous H2 receptor antagonists(IVH2 RA) in hospitalized patients is not clear. We therefore examined prescribing patterns and, using strict criteria, determined whether use was appropriate. Cost of administration and potential savings were also determined.

METHODS

Data were obtained prospectively on 100 consecutive patients prescribed intravenous ranitidine and retrospectively on patients admitted with gastrointestinal (GI) bleeding.

RESULTS

For the prospective study, various indications for prescribing intravenous ranitidine were given, including postoperative patients and patients treated with steroids. Using criteria from published literature 80% of the use was considered inappropriate. Nearly 40% of the doses were given while the patient was tolerating oral intake. Creatinine clearance was impaired in 26% of patients, though only one had dosage reduction. Estimated annual cost of intravenous ranitidine was $317,000. The retrospective study of 86 consecutive patients admitted with GI bleeding revealed that all patients received intravenous ranitidine on admission, none of which was considered appropriate. The final diagnoses were peptic ulcer (49), colonic process (11), esophagitis (seven), gastric erosions (five), esophageal varices (five), Mallory-Weiss tears (four), duodenitis (two), no diagnosis (three), and jejunal ulcer (one).

CONCLUSIONS

Inappropriate use of intravenous ranitidine is common. This includes inappropriate indication, dosage, and duration of use. Large financial benefits could have been obtained if close attention was given to prescribing patterns.

A comparison of omeprazole and placebo for bleeding peptic ulcer

BACKGROUND

The role of medical treatment for patients with bleeding peptic ulcers is uncertain.

METHODS

We conducted a double-blind, placebo-controlled trial in 220 patients with duodenal, gastric, or stomal ulcers and signs of recent bleeding, as confirmed by endoscopy. In 26 patients the ulcers showed arterial spurting, in 34 there was active oozing, in 35 there were nonbleeding, visible vessels, and in 125 there were adherent clots. The patients were randomly assigned to receive omeprazole (40 mg given orally every 12 hours for five days) or placebo. The outcome measures studied were further bleeding, surgery, and death.

RESULTS

Twelve of the 110 patients treated with omeprazole (10.9 percent) had continued bleeding or further bleeding, as compared with 40 of the 110 patients who received placebo (36.4 percent) (P<0.001). Eight patients in the omeprazole group and 26 in the placebo group required surgery to control their bleeding (P<0.001). Two patients in the omeprazole group and six in the placebo group died. Thirty-two patients in the omeprazole group (29.1 percent) and 78 in the placebo group (70.9 percent) received transfusions (P<0.001). A subgroup analysis showed that omeprazole was associated with significant reductions in recurrent bleeding and surgery in patients with nonbleeding, visible vessels or adherent clots, but not in those with arterial spurting or oozing.

CONCLUSIONS

In patients with bleeding peptic ulcers and signs of recent bleeding, treatment with omeprazole decreases the rate of further bleeding and the need for surgery.

A cost-effective approach to the patient with peptic ulcer bleeding

The average hospital cost to manage patients hospitalized at Virginia Mason Hospital who bleed from a peptic ulcer is approximately $5000 per patient in our series of 30 patients. Because there are 150,000 admissions per year in the United States for peptic ulcer bleeding, the total hospital cost can be estimated to be $750 million. The actual cost may be higher because our 30 patients had minimal complications and were discharged on average in less than 4 days. The majority of hospital cost is incurred by the intensive care unit or the hospital nursing floor. There is a close to linear relation between the length of stay and the total hospital cost. Upper gastrointestinal endoscopy is a major advance in the treatment of peptic ulcer bleeding. It can provide significant cost savings by identifying some patients with bleeding peptic ulcers who have clean bases on endoscopy who are then eligible for prompt discharge from the hospital. In addition, endoscopic thermal therapy (with multipolar electrocautery or heater probe) and injection therapy cost less than $50 in incremental cost and can reduce further bleeding by 43%, reduce the need for urgent surgery by 63%, and reduce the mortality rate by 60%. Some patients still require urgent surgical intervention, which is substantially more costly than endoscopic hemostasis but is highly effective. Preliminary studies show promise in predicting further bleeding, with clinical scoring systems such as the Baylor Bleeding Score and with the use of Doppler ultrasonography. Better prediction of further bleeding should guide the choice of durable hemostasis early in the hospitalization. Additional studies should clarify the role of NSAID avoidance and H. pylori eradication in the long-term prevention of recurrent peptic ulcer bleeding.

Gastrointestinal bleeding after hepatic transcatheter arterial embolization in patients with hepatocellular carcinoma

BACKGROUND

Transcatheter arterial embolization is a popular palliative treatment for patients with hepatocellular carcinoma, but the incidence of post-treatment gastrointestinal bleeding is not well-defined.

METHODS

We retrospectively analyzed 206 patients with hepatocellular carcinoma who received transcatheter arterial embolization and compared them with 193 patients with hepatocellular carcinoma who underwent angiography along.

RESULTS

Twenty-three episodes (8.5%) of gastrointestinal bleeding occurred within 3 months of hepatic transcatheter arterial embolization following 269 procedures involving 206 patients with hepatocellular carcinoma. Eight episodes (3.0%) of esophageal variceal bleeding and 15 episodes (5.5%) of nonvariceal bleeding were found. The sites of the nonvariceal bleeding episodes were the stomach (n = 7), duodenum (n = 5), and colon (n = 3). When compared with other sources, bleeding from esophageal varices took place earlier, required intensive treatment, and led to a higher mortality. Among another 193 patients with hepatocellular carcinoma who received angiography only, 6 patients developed gastrointestinal bleeding within 3 months (3.1%), and all bled from esophageal varices.

CONCLUSIONS

This study suggests that esophageal variceal bleeding may occur after both angiography and transcatheter arterial embolization. Nonvariceal bleeding episodes, which were usually milder than episodes of variceal bleeding, may be related to the embolization procedure itself.

Intravenous omeprazole/amoxicillin and omeprazole pretreatment in Helicobacter pylori-positive acute peptide ulcer bleeding. A pilot study

BACKGROUND

The aims of this study were to evaluate a Helicobacter pylori eradication schedule for H. pylori-positive gastroduodenal ulcer bleeding, which could be commenced intravenously after endoscopic diagnosis, and to assess the effect of omeprazole pretreatment on bacterial eradication.

METHODS

In a prospective study 20 consecutive patients with H. pylori-positive acute peptide ulcer bleeding, who were managed conservatively including endoscopic injection therapy, were treated with a 2-week regimen consisting of either 40 mg omeprazole three times daily (with the exception of the loading dose of 80 mg) and 2 g amoxicillin three times daily intravenously for 3 days and 20 mg omeprazole twice daily and 1 g amoxicillin twice daily orally for 11 days (n = 10) or only with 40 mg omeprazole three times daily (with the exception of the loading dose of 80 mg) intravenously for 3 days and 20 mg omeprazole twice daily and 1 g amoxicillin twice daily orally for 11 days (n = 10). Subsequently, both groups received 20 mg omeprazole twice daily orally for 4 weeks.

RESULTS

H. pylori eradication, defined as negative bacterial findings in urease test, culture and histology, or 13C-urea breath test at least 4 weeks after cessation of omeprazole medication, was achieved in 100% (10/10) of patients in the first group but only in 30% (3/10) of patients in the second group (p < 0.01). Ulcer healing was endoscopically confirmed in all but one patient in the second group.

CONCLUSIONS

For the first time a promising concept for H. pylori eradication in H. pylori-positive ulcer bleeding is available by using a combined intravenous and oral omeprazole/amoxicillin therapy, which can be started intravenously immediately after an emergency upper GI endoscopy. In addition, these data imply that omeprazole pretreatment may not be wise when H. pylori eradication is attempted.

Bleeding duodenal ulcer. Role of gastric acid hypersecretion

Basal gastric acid output was analyzed prospectively in 110 patients with endoscopically documented duodenal ulcer disease to determine the frequency of gastric acid hypersecretion in patients with bleeding versus nonbleeding ulcers. Thirty-eight patients with stigmata of an actively or recently bleeding duodenal ulcer had a mean basal output of 12.6 +/- 8.9 meq/hr. In comparison, 72 patients with nonbleeding duodenal ulcers (and no history of prior bleeding) had a significantly lower mean basal acid output of 8.7 +/- 7.5 meq/hr (P < 0.05). Twenty-four of the 38 patients (63%) with bleeding and 28 of the 72 (39%) with nonbleeding duodenal ulcers had gastric acid hypersecretion, defined as a basal acid output of greater than 10.0 meq/hr. There was a statistically significant association between bleeding duodenal ulcer and acid hypersecretion (P = 0.01). All 110 patients were treated with standard doses of H2-receptor antagonists for eight weeks. In that time, 87 patients healed and 23 patients (14 with prior bleeding and nine with nonbleeding duodenal ulcers) remained unhealed. Significantly more patients who had bled had nonhealing duodenal ulcers (P = 0.004). Irrespective of bleeding history, all 23 patients with nonhealing duodenal ulcers at eight weeks had basal acid outputs of greater than 10.0 meq/hr (range 10.1-49.1 meq/hr). These 23 patients with nonhealing duodenal ulcers were treated with increased doses of ranitidine (mean 690 mg/day, range 600-1200 mg/day) for up to eight additional weeks. All were observed to have complete endoscopic healing documented within that period.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous intravenous famotidine for haemorrhage from peptic ulcer

Peptic ulcer bleeding often stops spontaneously but rebleeding may be catastrophic. Emergency surgery carries risks so safe medical therapies are needed. Since platelet function and plasma coagulation are both pH sensitive and since pepsin lyses clot at low pH the maintenance of gastric pH close to neutrality might influence rebleeding rates. Previous trials with H2 antagonists have been inadequate although a 1985 meta-analysis did support an important clinical effect. We report here a large multicentre trial of famotidine in ulcer bleeding. 1005 patients admitted to one of sixty-seven hospitals in the UK or Eire with haemorrhage from peptic ulcer with endoscopic signs of oozing, black slough, fresh clot or visible vessel were randomly allocated to famotidine (10 mg bolus followed by 3.2 mg/h intravenously) or matching placebo for 72 h. This famotidine regimen had previously been shown to maintain pH near 7 in such patients. 497 patients received famotidine and 508 placebo. The treatment groups were similar in respect of age, sex, ulcer site, and signs and severity of bleeding. Case fatality (6.2% famotidine vs 5.0% placebo), rebleeding (23.9% vs 25.5% placebo), and surgery (15.5% vs 17.1% placebo) rates were not significantly different between the two groups. This trial suggests that potent inhibition of gastric secretion does not influence the natural history of peptic ulcer haemorrhage.

Conservative treatment of stress ulcer bleeding: a new approach

Stress ulcer prophylaxis diminishes but does not eliminate the risk of severe bleeding from this complication. In 70-80% of the cases the source of bleeding is hemorrhagic gastritis. No controlled studies exist which have in particular investigated conservative therapy in patients with stress-induced hemorrhage. Even effective measures to suppress gastric acid secretion or to reduce splanchnic blood flow are ineffective in 10-40% of intensive care unit patients with stress-induced bleeding. In these cases total gastrectomy has so far often been the only therapeutic approach. We report our experience with a new approach in treating severe stress-induced hemorrhagic gastritis after ineffective primary treatment with H2-receptor antagonists, pirenzepine and somatostatin. Continuous gastric lavage with 5-10 l ice-cold Ringer's solution was used until complete cessation of bleeding, as evident from clear lavage. Repeated administration of 12 g sucralfate (60 ml) at 2-h intervals for 24 h through a gastric tube was used to prevent recurrence of bleeding and to promote healing. Sucralfate was reduced on the 2nd and 3rd day to 20 ml 2-hourly and later to 10 ml 4-hourly. In four patients this treatment was used as an ultima ratio when the patients were already scheduled for total gastrectomy. A total of 23 patients were treated during a 7-year period; all of them responded successfully, and no patient required surgery.

Acute upper gastrointestinal bleeding in elderly persons

We have seen that UGI bleeding is a serious and apparently growing problem for seniors. Of special concern in the older patient are the frequency with which serious peptic disease presents silently, the limitation frequently imposed on adequate pain relief from NSAIDs, and the higher complication rates from most of the causes of UGI bleeding. Care of the elderly would be enhanced by research focused on defining those older patients most at risk of experiencing NSAID-induced peptic complications, improved methods for preventing or treating NSAID-induced ulceration that are well tolerated and cost-effective, and better regimens for preventing the recurrence of ulcers and UGI bleeding in these patients. In regard to the last, future investigation of the role of H. pylori, methods for successfully eliminating the organism, and the effect of eradication on patients' subsequent course may be particularly helpful.

Use of continuous infusion of histamine2-receptor antagonists in critically ill patients

Certain clinical situations require the use of a histamine2 (H2)-receptor antagonist to reduce gastric-acid volume and concentration or an antacid to act as a buffering agent. Presently, there are three H2-receptor antagonists available for iv use: cimetidine, ranitidine, and famotidine. Conventional therapy dictates that the H2-receptor antagonist be given by intermittent intravenous infusion, resulting in peaks and valleys of acid secretory control. Antacids, although capable of providing adequate gastric acidity control, must be administered frequently, often hourly, and thus require excessive nursing time. Presented here is a review of the rationale for the use of an H2-receptor antagonist by continuous infusion.

Considerations for selection of parenteral histamine (H2)-receptor antagonists

Parenteral histamine (H2)-receptor antagonists are safe and effective therapy for the prophylaxis of stress-related erosive syndrome. Of the three agents available, parenteral cimetidine is the most widely studied; parenteral formulations of ranitidine and famotidine have not been investigated as extensively. Parenteral cimetidine appears to be effective in reducing incidence and complications associated with gastrointestinal hemorrhage caused by stress-related erosive syndrome, although its effects on bleeding that has already begun are not clear. Antacids are also effective in decreasing the incidence of stress-related gastrointestinal hemorrhage, but they are inconvenient and expensive to administer. Primed continuous of stress-related erosive syndrome in critically ill patients; the evidence available on the efficacy of continuous infusions of ranitidine is inconsistent, and very few data are available on the value of famotidine. Direct comparative clinical trials are needed to assess definitively the efficacy of primed continuous infusions of cimetidine or other H2-receptor antagonists versus that of antacid therapy.

Recognition and management of upper gastrointestinal hemorrhage

Upper gastrointestinal hemorrhage is a frequent and severe problem in the intensive care unit. Such bleeding results from diverse gastroenterologic causes. Diagnosis and assessment of the severity of bleeding is accomplished primarily through the physical examination; endoscopy is the most sensitive means of establishing a specific site of hemorrhage. Medical management of gastrointestinal hemorrhage includes treatment with the histamine (H2)-receptor antagonists, antacids, or both. Recent studies suggest that continuous infusion of H2-receptor antagonists may be more efficacious than fixed-bolus dosing in prophylaxis of upper gastrointestinal bleeding. It is not known as yet if the continuous infusion regimen will be effective in stopping gastrointestinal bleeding that has already begun.

Antacids, pepsin inhibitors, and gastric cooling in the management of massive upper gastrointestinal haemorrhage

On the basis of the clinical evidence available there is no indication for treating acute upper gastrointestinal bleeding with antacids, pepsin inhibitors, or gastric cooling. Intensive treatment with continuously administered antacids, water-soluble pepsin inhibitors, or ice-water lavage, however, has not yet been evaluated in controlled clinical trials.

Acute gastrointestinal bleeding

Acute gastrointestinal bleeding remains a major cause of morbidity and mortality. Recent diagnostic and therapeutic advances may play a significant role in the care of the bleeding patient.

Why have controlled trials failed to demonstrate a benefit of esophagogastroduodenoscopy in acute upper gastrointestinal bleeding? A probability model analysis

Numerous prospective randomized trials have failed to demonstrate a benefit attributable to early diagnostic esophagogastroduodenoscopy (EGD) in acute upper gastrointestinal bleeding (UGIB). The clinical implications of these studies have received extensive editorial comment and analysis. We have employed a probability model to further analyze the reasons why these studies have failed to demonstrate an impact of EGD on UGIB. The clinical course of each bleeding lesion can be predicted from the literature. For each lesion, the mortality associated with early specific intervention afforded by an early specific diagnosis can be compared with the mortality of intervention delayed by applying EGD only to those patients who have a complicated course marked by continued bleeding or rebleeding. Using optimistic assumptions that would tend to overstate the impact of EGD, this analysis estimates the maximum decrease in overall mortality in any of these trials afforded by early diagnostic EGD to be 1.2% which would require randomization of over 5000 patients to demonstrate this benefit in a prospective trial.

Prevention of recurrent ulcer bleeding, a multicentre study of the effect of ranitidine and trimipramine over one year

Short term studies of the prevention of bleedings from peptic ulcers and erosions have been reported by a number of authors following treatment with antacids (1), H2-receptor blockers, cimetidine (2-15), a combination of cimetidine and tranexamic acid (16), cimetidine and somatostatin (17), cimetidine and sucralfate or secretion (18, 19, 20), cimetidine compared to antacid (21), and cimetidine compared to antacid and pirenzepine (22). The H2-blocker rantitidine has been compared to placebo (24, 25, 26). An uncontrolled study has been performed using proglumide (27), a controlled study with vasopressin (28) and with secretin versus somatostatin (28). In the studies with H2-receptor antagonists conflicting results have been obtained. No report has been published concerning the effect over more than a few days or weeks.

Cimetidine blocks antacid-induced hypergastrinemia

The effects on fasting serum gastrin concentrations of hourly doses of magnesium and aluminum hydroxide antacid, with and without intravenous cimetidine, were determined in 8 patients with duodenal ulcer disease. Gastrin levels rose significantly over 10 h when antacid was given either as a bolus of 30 ml every hour or as a constant infusion of 0.5 ml/min (36 +/- 5 pg/ml and 33 +/- 6 pg/ml to 108 +/- 32 pg/ml and 109 +/- 22 pg/ml, respectively, p less than 0.05). This effect was specific for some component of the antacid and not for neutralization of acid per se, inasmuch as sodium bicarbonate, infused to keep gastric pH at levels at or above those of antacid, produced no significant rise in serum gastrin concentration. When intravenous cimetidine was administered simultaneously with intragastric antacid, gastrin levels did not rise. This occurred even though intragastric pH levels were actually higher with cimetidine plus antacid than with antacid alone. The ability of intravenous cimetidine to block antacid-induced hypergastrinemia was counteracted by infusing simultaneously both hydrochloric acid and antacid into the stomach. Since hydrochloric acid reacts with magnesium and aluminum hydroxide to form ionic magnesium and aluminum chloride, cimetidine most likely blocks antacid-induced hypergastrinemia by reducing acid secretion from the stomach and thereby limiting the generation of ionic magnesium and aluminum.

Treatment with histamine H2 antagonists in acute upper gastrointestinal hemorrhage. Implications of randomized trials

Histamine H2 antagonists are widely used in treating patients with hematemesis and melena, despite the lack of reliable evidence of benefit from any of the randomized trials, considered separately. Examination of the data from all 27 available randomized trials, in which over 2500 patients were entered, suggests that treatment may reduce the rates of rebleeding, surgery, and death by about 10, 20, and 30 per cent, respectively, although these results were only marginally significant for surgery and death. Any benefit appeared to be confined to patients with bleeding gastric ulcers, but since this subgroup analysis was prompted by preliminary examination of the data in some of the individual trials reviewed here, it should be treated with particular caution. The implications of this overview are that treatment with histamine H2 antagonists appears to be moderately promising, but its effects on important end points, such as death, still need to be assessed reliably. Prevention of "only" about 20 per cent of all deaths could well be worthwhile, for the condition is common, and the treatment widely practicable. To detect such a moderate effect reliably, however, might require the randomization of 10,000 patients (or more), which would be possible only in an extremely simple multicenter collaborative trial.

Sustained fasting achlorhydria: a comparison of medical regimens

The effects on fasting gastric pH of eight medical regimens were evaluated during a 10-h period in 8 duodenal ulcer patients. Our goal was to find a regimen that would produce sustained, fasting achlorhydria (pH greater than 7.0) in every patient. The effects of commonly prescribed bolus doses of cimetidine, antacid, or their combination were studied first. Mean gastric pH with cimetidine (300 mg/6 h intravenously), antacid (30 ml/h intragastrically), and their combination was 3.5, 4.6, and 6.8, respectively. Although mean pH with the combination was significantly higher than with either drug alone (p less than 0.05), sustained achlorhydria was not achieved. Next we tested constant-infusion regimens of cimetidine (50 mg/h intravenously), antacid (0.5 ml/min intragastrically), and their combination. Whereas infusions of cimetidine or antacid alone produced mean pH levels of 4.3 and 5.2, respectively, not significantly different from their bolus counterparts, the combination regimen resulted in a mean pH of 7.4. However, sustained achlorhydria was still not produced in each patient. Only when the dose of cimetidine infusion was doubled to 100 mg/h and administered with a constant infusion of antacid was sustained achlorhydria achieved in each patient.