Prophylaxis of upper gastrointestinal bleeding in intensive care units: a meta-analysis

A Review of Stress Ulcer Prophylaxis

Stress-related mucosal damage (SRMD) is an erosive process of the gastroduodenum that occurs frequently in critically ill patients. Symptomatic lesions may range from overt bleeding (by hematemesis, melena, bloody or coffee ground aspirates, or hematochezia) to clinically significant hemorrhage (hypotension, tachycardia, or acute anemia requiring transfusion). SRMD is caused by mucosal ischemia that produces an imbalance between injurious factors and the protective mechanisms. Common patient risk factors include mechanical ventilation, coagulopathy, shock, hepatic dysfunction, renal dysfunction, thermal injury, trauma, kidney or liver transplant, head injury or spinal cord injury, recent gastrointestinal hemorrhage, and pharmacologic interventions. Stress ulcer prophylaxis may be provided by administering one of the following pharmacologic agents: an antacid, a histamine2 receptor antagonist, sucralfate, or a proton pump inhibitor. All agents possess equal efficacies but differ in their mechanisms of action, adverse event profile, drug interactions, monitoring requirements, costs, and personnel requirements for preparation and administration. Implementation of institution-specific protocols for stress ulcer prophylaxis provides cost minimization by maximizing appropriate drug usage.

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.

Gastrointestinal prophylaxis in neurocritical care

The aim of this study is to review and summarize the relevant literature regarding pharmacologic and non-pharmacologic methods of prophylaxis against gastrointestinal (GI) stress ulceration, and upper gastrointestinal bleeding in critically ill patients. Stress ulcers are a known complication of a variety of critical illnesses. The literature regarding epidemiology and management of stress ulcers and complications thereof, is vast and mostly encompasses patients in medical and surgical intensive care units. This article aims to extrapolate meaningful data for use with a population of critically ill neurologic and neurosurgical patients in the neurological intensive care unit setting. Studies were identified from the Cochrane Central Register of controlled trials and NLM PubMed for English articles dealing with an adult population. We also scanned bibliographies of relevant studies. The results show that H(2)A, sucralfate, and PPI all reduce the incidence of UGIB in neurocritically ill patients, but H(2)A blockers may cause encephalopathy and interact with anticonvulsant drugs, and have been associated with higher rates of nosocomial pneumonias, but causation remains unproven and controversial. For these reasons, we advocate against routine use of H(2)A for GI prophylaxis in neurocritical patients. There is a paucity of high-level evidence studies that apply to the neurocritical care population. From this study, it is concluded that stress ulcer prophylaxis among critically ill neurologic and neurosurgical patients is important in preventing ulcer-related GI hemorrhage that contributes to both morbidity and mortality. Further, prospective trials are needed to elucidate which methods of prophylaxis are most appropriate and efficacious for specific illnesses in this population.

Proton pump inhibitor prophylaxis increases the risk of nosocomial pneumonia in patients with an intracerebral hemorrhagic stroke

BACKGROUND

Stress-related mucosal damage is an erosive process of the gastric lining resulting from abnormally high physiologic demands. To avoid the morbidity and mortality associated with significant bleeding from the damage, prophylaxis with an acid suppression medication is given. This is especially common in stroke victims. Recent studies have suggested a link between acid suppression therapy and nosocomial pneumonia, specifically implicating proton pump inhibitors (PPI), a potent acid suppression medication, as the culprit. In this retrospective study, we reviewed the medical records of admitted intracerebral hemorrhage (ICH) patients and determined if there is a link between PPI prophylaxis and nosocomial pneumonia in our ICH population.

MATERIALS AND METHODS

Medical records of 200 ICH patients admitted to the First Affiliated Hospital of Chongqing Medical University were reviewed from January 1, 2008 to October 31, 2009. PPIs were the only accepted form of acid suppression therapy. In all, 95 patients were given PPI prophylaxis, whereas 105 patients did not receive any form of acid suppression.

RESULTS

The unadjusted incidence rate of pneumonia in the PPI prophylactic group was 23.2%, and 10.5% in patients not having received prophylaxis. Additionally, patients treated with PPI prophylaxis were more likely to be critically ill, defined by an increase in conscious disturbance and dependency on mechanical ventilation and/or a nasogastric tube.

CONCLUSION

The use of a PPI as a prophylactic treatment against stress-related mucosal damage was associated with a higher occurrence of nosocomial pneumonia in our ICH population. This study suggests the need for further research investigating the use of PPI prophylaxis in ICH patients and the possibility of using alternate acid suppression therapeutic modalities.

Cautionary tales in the interpretation of systematic reviews of therapy trials

This is the second in a series of articles emphasizing the cautions in the interpretation of health-care studies. Systematic reviews are presented as comprehensive, unbiased summaries of evidence and are often referred to by clinicians, guideline developers and health policy-makers. Their strengths and limitations, and how their results can be subject to bias and misinterpretation, are discussed.

Impact of stress ulcer prophylaxis algorithm study

BACKGROUND

In the intensive care unit at Royal Victoria Hospital, we noted that drugs prescribed for stress ulcer prophylaxis were not always indicated or optimal. Accordingly, we implemented an algorithm for stress ulcer prophylaxis to guide the medical team in their decisions. The agents selected for the algorithm were intravenous famotidine and omeprazole suspension or tablets, depending on the available administration route.

OBJECTIVE

To evaluate the impact of a treatment algorithm on the appropriateness of prescriptions for stress ulcer prophylaxis.

METHODS

A quasi-experimental-type evaluative study was conducted based on a pre-/post-intervention design without a concurrent control group. A total of 555 complete admissions met the selection criteria; 303 patients formed the pre-intervention group, and 252 made up the post-intervention group (exposed to the treatment algorithm).

RESULTS

After implementation of the algorithm, the proportion of inappropriate prophylaxis was decreased (95.7% vs 88.2%; p = 0.033). The number of days of inappropriate prophylaxis was also reduced significantly (p = 0.013), as was the cost per patient (p = 0.003) for all admissions. However, no difference was observed when the subgroup of patients who received prophylaxis alone was studied (p = 0.098 and p = 0.918). The presence of bleeding was similar in both groups.

CONCLUSIONS

Introduction by pharmacists of a treatment algorithm for stress ulcer prophylaxis in intensive care units allows a reduction of inappropriate prescriptions and thus a reduction in the cost of drugs. The use of omeprazole suspension seems to be an alternative to intravenous histamine2-inhibitors; however, a large-scale study is necessary to confirm the efficacy and safety of proton-pump inhibitors administered by an enteral tube.

Other supportive therapies in sepsis: an evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for other supportive therapies in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSION

Patients with severe sepsis should be treated with deep-vein thrombosis prophylaxis. Low-dose unfractionated heparin or low molecular weight heparin is preferred. Use of graduated compression devices is recommended in septic patients with contraindication to the use of heparin or combined with heparin in very high-risk patients. Stress ulcer prophylaxis should be given to all patients with severe sepsis. Histamine-2 receptor antagonists are more effective than sucralfate in decreasing bleeding risk and transfusion requirements. Proton pump inhibitors have not been assessed in a direct comparison with histamine-2 receptor antagonists but do demonstrate equivalency and ability to increase gastric pH.

Clinically significant gastrointestinal bleeding in critically ill patients with and without stress-ulcer prophylaxis

OBJECTIVE

To compare the rates of clinically significant gastrointestinal bleeding and the number of blood units and endoscopies required for gastrointestinal hemorrhage between patients receiving or not receiving stress-ulcer prophylaxis.

DESIGN

Historical observational study comparing two consecutive periods: with (phase 1) and without stress-ulcer prophylaxis (phase 2).

DESIGN AND SETTING

A 17-bed intensive care unit in a university teaching hospital. PATIENTS. In phase 1 there were 736 patients and in phase 2737. Those in the two phases were comparable in age and reason for admission; clinically significant gastrointestinal bleeding rates did not differ between the two phases, but patients in phase 2 were more severely ill.

MEASUREMENTS AND RESULTS

Comparable numbers of blood units were transfused per bleeding patient in the two phases, especially for patients with significant gastrointestinal bleeding. During each phase 19 fibroscopies were performed for significant bleeding, and two patients required surgery. The clinically significant gastrointestinal bleeding rate and outcome did not differ in patients with at least one risk factor. Total expenditures directly related to gastrointestinal bleeding were similar during the two phases; the total cost incurred by stress-ulcer prophylaxis was estimated at <euro>6700.

CONCLUSIONS

Our results suggest that stress-ulcer prophylaxis does not influence the clinically significant gastrointestinal bleeding rate in intensive care unit patients or the cost of its management.

A cost-effectiveness analysis of stress ulcer prophylaxis

OBJECTIVE

To evaluate the efficacy, safety, and cost of using cimetidine, famotidine, and lansoprazole for stress ulcer prophylaxis (SUP) at our institution and determine which agent was most cost-effective.

METHODS

An observational study of adults admitted to the medical, surgical, or cardiovascular intensive care unit was conducted to compare the cost and effectiveness of cimetidine, famotidine, and lansoprazole for SUP. Patients were identified for inclusion during three 2-week periods in 2000. Medical record reviews were conducted to gather data regarding the costs associated with the administration of SUP drugs and the treatment of any adverse events or therapeutic failures. Decision analysis was used to determine the average cost per patient for each treatment arm. A cost-effectiveness analysis was then conducted to determine which of the SUP agents was associated with the least cost without adversely affecting patient outcomes. A sensitivity analysis was applied to determine the robustness of the data.

RESULTS

Eighty-eight patients were included in the analysis. Five of the patients started on cimetidine experienced therapeutic failure, whereas no patients receiving lansoprazole experienced therapeutic failure. For these reasons, and because lansoprazole is an oral agent, the average costs associated with lansoprazole use were lower than with the use of cimetidine. Lansoprazole was found to be the most cost-effective therapy.

CONCLUSIONS

This study showed that lansoprazole is a cost-effective agent for the use of SUP at our institution. However, due to the higher cost of intravenous pantoprazole, the model demonstrates that, assuming equal effectiveness, intravenous pantoprazole would not be cost-effective when compared with cimetidine.

Proton-pump inhibitors for stress ulcer prophylaxis in critically ill patients

OBJECTIVE

To evaluate the use of proton-pump inhibitors (PPIs) for stress ulcer prophylaxis in critically ill adults.

DATA SOURCES

Computerized biomedical literature search of MEDLINE (1966-June 2002) was conducted using the MeSH headings proton-pump inhibitor, ulcer, critical care, and acid. References of selected articles were reviewed. A manual search of critical care, surgery, trauma, gastrointestinal, and pharmacy journals was conducted to identify relevant abstracts.

DATA SYNTHESIS

Traditional medications used for stress ulcer prophylaxis include antacids, histamine(2) receptor antagonists (H(2)RAs), and sucralfate. Few studies have evaluated PPIs for stress ulcer prophylaxis. The majority of studies have demonstrated that enteral or intravenous administration of PPIs to critically ill patients elevates intragastric pH and consistently maintains pH > or =4.0. PPIs are safe and seem to be as efficacious as H(2)RAs or sucralfate for prevention of bleeding from stress-related mucosal damage (SRMD) and they may provide cost minimization. The small patient populations limit the results of comparative studies.

CONCLUSIONS

Available data indicate that PPIs are safe and efficacious for elevating intragastric pH in critically ill patients. PPIs should be used only as an alternative to H(2)RAs or sucralfate since the superiority of PPIs over these agents for preventing SRMD-associated gastrointestinal bleeding has not been established. Additional comparative studies with adequate patient numbers and pharmacoeconomic analyses are needed before PPIs are considered the agents of choice for stress ulcer prophylaxis.

Evidence-based medicine as it applies to acid suppression in the hospitalized patient

An evidence-based-medicine approach may be applied to studies in the medical literature to help physicians make sound judgments about efficacy and safety data and to improve clinical decision making. To assess the role of gastric acid suppression in the prevention of stress ulcer bleeding and in the management of upper gastrointestinal bleeding after successful hemostasis of bleeding peptic ulcer disease, the following questions should be addressed: Is it possible to identify risk factors for clinically important bleeding in critically ill patients? Can intravenous acid suppression prevent stress ulcer-related bleeding or prevent rebleeding in peptic ulcers after successful hemostasis? What is the most effective method of acid suppression for these disorders? An evidence-based-medicine review of published trials yields sufficient evidence to support the use of prophylactic acid suppression in critically ill patients with coagulopathy or in those who are receiving prolonged mechanical ventilation. Not enough data have accumulated to prove the superiority of intravenous proton pump inhibitors to intravenous histamine-2-receptor antagonists for prophylaxis of clinically important stress ulcer bleeding. With respect to acute gastrointestinal bleeding, however, two well-conducted trials indicate that an intravenous proton pump inhibitor is significantly more effective than an intravenous histamine-2-receptor antagonist or placebo in reducing the rate of rebleeding after hemostasis in patients with bleeding peptic ulcer. Analysis of the data from both trials shows that only five to six patients would need to receive an intravenous proton pump inhibitor to avoid one episode of rebleeding.

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.

National survey of stress ulcer prophylaxis

OBJECTIVE

To determine the rationale for using stress ulcer prophylaxis (SUP) among clinicians; to assess criteria used to define failure of SUP; and to evaluate the decision-making process in the selection of a prophylactic agent.

DESIGN

A cross-sectional national mail survey.

SETTING

Random sample of the members of the Society of Critical Care Medicine who identified anesthesiology, surgery, or internal medicine as their primary specialty area.

PATIENTS

None.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Questionnaires consisting of multiple-choice and short-answer questions were sent to a simple random sample of 1,268 physicians to assess the current practice of SUP. A total of 328 usable questions were returned, resulting in a response rate of 26%. All percentages reported in the results are based on the total number of responses. The risk factors for SUP that were most commonly identified were burns (91%), shock (90%), and sepsis (88%). These were also risk factors for which the respondents most commonly started SUP. Histamine-2-receptor (H2)-antagonists as a class, were the most commonly used prophylactic agents (67%). The most commonly used agents for SUP were ranitidine (31%), famotidine (24%), sucralfate (24%), and cimetidine (12%). Most respondents selected ranitidine for ease of administration, famotidine because of formulary availability, sucralfate for a better side effects profile, and cimetidine for cost-effectiveness. Eighty-two percent of respondents considered the presence of bright red blood in the nasogastric tube as failure of SUP. In cases where SUP failed, most respondents would add a second agent from a different therapeutic class. Of those respondents who used an H2-antagonist initially, 48% would add sucralfate, 36% would add antacid, and 13% would add omeprazole. Of those respondents who used sucralfate, 77% would add an H2-antagonist when SUP failed. For those respondents who would switch to another agent when the H2-antagonist failed, 52% would change to omeprazole, whereas 67% would change to an H2-antagonist when sucralfate failed. Only eight respondents would discontinue SUP when risk factors were resolved. Most respondents would discontinue SUP when the patient was no longer in the "nothing by mouth" status (28%), started on enteral feeding (23%), or discharged from the intensive care unit (21%). The mean duration of SUP was 6.3+/-4.5 (SD) days.

CONCLUSIONS

This survey highlighted the lack of consensus in the use of SUP. Many patients receive SUP for an extended period, without clear-cut indications or documented benefit. The cost of unwarranted SUP in patients with low risk of stress ulcer gastrointestinal bleeding is prohibitive. Treatment algorithms or protocols for SUP based on prescribing patterns, hospital formulary restrictions, and cost-analysis should be considered for each institution to guide critical care physicians on the proper use of SUP therapies.

Risk reduction in the intensive care unit

Many potentially preventable complications occur in patients who receive intensive care. We have reviewed the epidemiology of three important complications (venous thromboembolism, stress-related upper gastrointestinal bleeding, and vascular catheter-related infection) and evaluated common preventive treatments to provide evidence-based recommendations for prevention. We used English language articles located by MEDLINE or cross-citation, giving preference to articles published in the last 10 years, meta-analyses, and clinical trials that were randomized, double-blinded, and used intention-to-treat analysis. We recommend prophylaxis against venous thromboembolism in most patients, whereas those without respiratory failure or coagulopathy may not require prophylaxis against stress-related upper gastrointestinal hemorrhage. Chlorhexidine gluconate is the preferred antiseptic for disinfecting the skin prior to and during intravascular catheterization. Central venous catheters impregnated with antibacterial or antiseptic agents should be considered in patients at high risk for vascular catheter-related infection. Finally, central venous, pulmonary arterial, and systemic arterial catheters should be changed only when clinically indicated.

Base variant of human pancreatic secretory trypsin inhibitor in healing of stress-induced gastric lesions in rats

Pancreatic secretory trypsin inhibitor (PSTI) is an inhibitor of serine-proteinases including pancreatic trypsin that prevents excessive digestion of the gastrointestinal mucus, but its role in the mechanism of mucosal defense has been little studied. This study was designed to determine the effect of base variant of human PSTI (R44S-PSTI) on gastric secretion, healing of gastric lesions induced by stress and the expression of PSTI during mucosal recovery from stress lesions. Recombinant R44S-PSTI was obtained using by site-directed mutagenesis due to replacement of arginine by serine that led to longer half life of this peptide than its natural form. Stress ulcerations were induced by exposure of rats to a standard 3.5 h of water immersion and restraint stress with or without pretreatment with vehicle or R44S-PSTI (0.1 mg/kg) applied s.c. 30 min before and immediately after the end of stress. Rats were then sacrificed immediately (time 0) and at 6 h or 12 h after the termination of stress. The gastric blood flow (GBF) was measured by H2-gas clearance technique at each time period and gastric mucosal samples were excised for assessment of PSTI immunohistochemical expression and PSTI messenger RNA by reverse transcriptase polymerase chain reaction (RT-PCR) and Southern hybridization. Stress produced numerous gastric lesions and decreased the GBF by about 30% as compared to the respective value in vehicle-treated non-stressed gastric mucosa. R44S-PSTI given s.c. in graded doses (0.01-1 mg/kg) inhibited dose-dependently gastric acid and pepsin outputs, in rats with gastric fistula and accelerated the healing of stress-induced gastric lesions significantly. The healing effects of R44S-PSTI (0.1 mg/kg s.c.) recorded at 6 h and 12 h after the end of stress were accompanied by a significant rise in the GBF. The expression of PSTI mRNA in the intact mucosa was weak, but following exposure to stress it was significantly augmented to reach the highest observed value at 6 h after the stress. We conclude that (1) base variant of human PSTI accelerates healing of stress-induced gastric lesions probably due to its antisecretory activity and enhancement of mucosal blood flow and (2) the expression of genes for PSTI plays an important role in the mechanism of mucosal recovery from gastric lesions induced by stress.

Clinically significant upper gastrointestinal bleeding acquired in a pediatric intensive care unit: a prospective study

OBJECTIVES

To determine the incidence, risk factors, and complications associated with or attributable to clinically significant upper gastrointestinal (GI) bleeding acquired in a pediatric intensive care unit (ICU).

METHODS

Prospective, descriptive epidemiologic study in a multidisciplinary pediatric ICU of a tertiary-care university hospital. Upper GI bleeding was considered to be present if hematemesis occurred or blood was present in the gastric tube. An upper GI bleed was qualified as clinically significant if two or three reviewers independently assessed that at least one of the six complications considered for analysis was attributable to the upper GI bleed.

RESULTS

A cohort of 1114 consecutive admissions was enrolled; 108 (9.7%) were excluded mostly (37.0%) because they already had an upper GI bleed at entry to the pediatric ICU. The final sample included 1006 admissions (881 patients); 103 upper GI bleeds (10.2%) were diagnosed, including 16 clinically significant upper GI bleeds (1. 6%). Complications attributed to an upper GI bleed included: decreased hemoglobin concentration (10 cases), transfusion (10), hypotension (3), and surgery (1). Three independent risk factors for clinically significant upper GI bleeding were retained by multivariate analysis: respiratory failure, coagulopathy, and pediatric risk of mortality score >/=10. Nine of the 16 cases (56. 3%) with clinically significant upper GI bleeding had three risk factors, 14 (87.5%) had two, and 1 (6.3%) had none.

CONCLUSIONS

Clinically significant upper GI bleeds are rare in critically ill children. Prophylaxis to prevent them may be limited to patients who present with at least two risk factors.

Implementation of a clinical practice guideline for stress ulcer prophylaxis increases appropriateness and decreases cost of care

OBJECTIVE

To develop, implement and evaluate a practice guideline for stress ulcer prophylaxis.

DESIGN

Before-after study.

SETTING

Ten-bed Intensive Care Unit (ICU) and 4-bed Step-down Unit in a teaching hospital.

PATIENTS AND PARTICIPANTS

Fifty patients admitted during 1 year before and 50 patients admitted 3-6 months after introduction of the guideline.

INTERVENTION

Introduction of the practice guideline by dissemination of pocket cards, seminars and "academic detailing".

MEASUREMENTS AND RESULTS

Appropriateness (defined as proportion of days in which the prophylaxis met the criteria in the guideline), incidence of gastrointestinal bleeding and of ventilator-associated pneumonia, length of stay in ICU and in hospital, ventilator days. ICU mortality and medication costs for stress ulcer prophylaxis. After the introduction of the guideline, appropriateness increased from 75.8% to 91.1%, and medication costs decreased from C $2.50/day to C $1.30/day. There were no differences in any clinical outcomes. Predictors of appropriate use or the withholding of prophylaxis were the introduction of the guideline, lack of an indication for prophylaxis and number of days studied.

CONCLUSIONS

Introduction of this guideline was associated with an increase in appropriateness of prophylaxis and a decrease in medication costs.

A review of stress ulcer prophylaxis in the neurosurgical intensive care unit

STRESS ULCERS OCCUR frequently in intensive care unit patients who have intracranial disease. After major physiological stress, endoscopic evidence of mucosal lesions of the gastrointestinal tract appears within 24 hours of injury; 17% of these erosions progress to clinically significant bleeding. Gastrointestinal hemorrhage has been associated with mortality rates of up to 50%. The pathogenesis of stress ulcers may not be completely understood, but gastric acid and pepsin appear to play significant roles. Antacids, H2 antagonists, and sucralfate are effective prophylactic agents in the medical/surgical intensive care unit. Appropriate therapy for neurosurgical patients remains unclear, however. This review summarizes the current literature regarding the pathogenesis and therapy of stress ulcers in neurosurgical patients.

The value of early enteral nutrition in the prophylaxis of stress ulceration in the severely burned patient

A retrospective analysis of prospectively collected data was performed to compare the frequency of upper gastrointestinal bleeding (GIB) in seriously burned patients treated with either cimetidine and antacids or enteral nutrition for ulcer prophylaxis. Five hundred and twenty-six seriously burned patients admitted to the burn intensive care unit of the BG Trauma Centre Ludwigshafen during a 4-year period were included into the study. All patients admitted to the burn unit from 1989 to 1991 received i.v. cimetidine (400 mg q4) for ulcer prophylaxis. If the intragastric pH dropped below 3.5, gastric pH was titrated with antacids up to > or = 4 via nasogastric tube. During the second 2-year period (1992-1993) early enteral nutrition alone was regarded to be ulcer protective and no further interventions for ulcer prophylaxis were routinely performed. Signs of overt upper GIB were monitored and documented through the entire study period. The overall occurrence rate of upper GIB in the cimetidine/antacids (C/A) group (n = 253) was 8.3 per cent with six cases of serious bleeding in five patients (1.98 per cent). In the enteral nutrition (EN) group (n = 273) the overall incidence of GIB was 3.3 per cent with two cases of serious bleeding (0.73 per cent). There were no deaths directly related to ulcer haemorrhage. The difference in the overall frequency of overt GIB between the groups studied was statistically significant (< 0.05). In our experience, early enteral nutrition is effective in the prevention of stress haemorrhage in the upper gastrointestinal tract. Additional medicinal prophylaxis is not required in burn patients.

Comparison of omeprazole and ranitidine for stress ulcer prophylaxis

Stress ulcer prophylaxis protects against clinically important gastrointestinal bleeding and has gained widespread use. This study compares the efficacy of omeprazole to ranitidine for this indication. This was a prospective, randomized clinical trial. Sixty-seven high-risk patients were randomized to receive either ranitidine 150 mg (N = 35) intravenously daily or omeprazole 40 mg (N = 32) daily orally or by nasogastric route. Patients were monitored for clinically important bleeding. There was no statistically significant difference between treatment groups in the number of patients enrolled, gender, race, or age. The study groups were comparable in regard to the severity of illness based on their similar APACHE II score, duration of ICU stay, duration of ventilator dependence, and mortality rate. A significant difference was found only in regard to the number of risk factors per patient. The ranitidine-treated group had 2.7 risk factors per patient while the omeprazole-treated group had 1.9 (P < 0.05). Eleven patients (31%) given ranitidine and two patients (6%) given omeprazole developed clinically important bleeding (P < 0.05). Nosocomial pneumonia developed in five patients (14%) receiving ranitidine and one patient (3%) receiving omeprazole (P > 0.05). We conclude that oral omeprazole is safe, effective, and clinically feasible for stress ulcer prophylaxis.

A randomized, controlled study of prophylactic ranitidine in preventing stress-induced gastric mucosal lesions in neonatal intensive care unit patients

OBJECTIVE

To assess endoscopically the effect of prophylactic short-term ranitidine treatment in the prevention of stress-induced gastric lesions in neonatal intensive care unit (ICU) patients.

DESIGN

Prospective, randomized study.

SETTING

Department of Neonatal Intensive Care, University Hospital of Tampere.

PATIENTS

Fifty-three infants were enrolled in a randomized, controlled study. Forty-eight (90%) of these patients underwent endoscopic examination and were evaluated.

INTERVENTIONS

A histamine-2-receptor blocker, ranitidine, was given prophylactically after birth for 4 days to infants mechanically ventilated and treated in the neonatal ICU. The gastric mucosa was both visually and histologically evaluated after 3 to 6 days, and the outcome of the infants was registered.

MEASUREMENTS AND MAIN RESULTS

In the 23 infants prophylactically treated with ranitidine, the gastric mucosa was visually classified as normal in 14 (61%) infants as compared with five (20%) of 25 controls (p < .004). Histologic lesions showed parallel results (57% vs. 16%, p < .004). Eight gastric ulcers were diagnosed endoscopically in the control group vs. none in the treatment group. The ulcers were all clinically "silent" at the time of endoscopy. According to logistic regression modeling, the decreased risk for gastric mucosal lesions in infants receiving prophylactic ranitidine was 0.03 (95% confidence interval 0.003 to 0.178). Surfactant treatment for infant respiratory distress syndrome also decreased the risk for stress-induced gastric mucosal lesions (odds ratio 0.083; 95% confidence interval 0.009 to 0.788), whereas other variables (birth weight, gestational age, Apgar scores, cord blood pH, and duration of intubation) had no significant effect. No side effects could be attributed to the ranitidine treatment.

CONCLUSION

We conclude that short-term prophylactic ranitidine treatment prevents gastric mucosal lesions in newborn infants under stress.

Upper gastrointestinal tract bleeding

Upper GI bleeding is a serious and common emergency. Most upper GI bleeding will stop spontaneously but determining which patients will continue to bleed or rebleed is very difficult in the ED. Resuscitation and stabilization are the primary goals of the emergency physician. Hemorrhage control with pharmacotherapy or balloon tamponade may be necessary until urgent or emergent consultation with a gastroenterologist or surgeon is obtained. Early detection and treatment of H. pylori and the development of safer NSAIDs should alter the future of upper GI bleeding dramatically.

Prophylaxis for stress-related gastrointestinal hemorrhage: a cost effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of prophylaxis for stress-related gastrointestinal hemorrhage in patients admitted to the intensive care unit.

DESIGN

Decision model of the cost and efficacy of sucralfate and cimetidine, two commonly used drugs for prophylaxis of stress-related hemorrhage. Outcome estimates were based on data from published studies. Cost data were based on cost of medications and costs of treatment protocols at our institutions.

MEASUREMENTS AND MAIN RESULTS

The marginal cost-effectiveness of prophylaxis, as compare with no prophylaxis, was calculated separately for sucralfate and cimetidine and expressed as cost per bleeding episode averted. An incremental cost-effectiveness analysis was subsequently employed to compare the two agents. Sensitivity analyses of the effects of the major clinical outcomes on the cost per bleeding episode averted were performed. At the base-case assumptions of 6% risk of developing stress-related hemorrhage and 50% risk-reduction due to prophylaxis, the cost of sucralfate was $1,144 per bleeding episode averted. The cost per bleeding episode averted was highly dependent on the risk of hemorrhage and, to a lesser degree, on the efficacy of sucralfate prophylaxis, ranging from a cost per bleeding episode averted of $103,725 for low-risk patients to cost savings for very high-risk patients. The cost per bleeding episode averted increased significantly if the risk of nosocomial pneumonia was included in the analysis. The effect of pneumonia was greater for populations at low risk of hemorrhage. Assuming equal efficacy, the cost per bleeding episode averted of cimetidine was 6.5-fold greater than the cost per bleeding episode averted of sucralfate.

CONCLUSIONS

The cost of prophylaxis in patients at low risk of stress-related hemorrhage is substantial, and may be prohibitive. Further research is needed to identify patient populations that are at high risk of developing stress-related hemorrhage, and to determine whether prophylaxis increases the risk of nosocomial pneumonia.

Some Recent Controversies in Intensive Care

The ability of dopamine to reverse oliguria has led to its ubiquitous renal protective use in patients at risk of acute renal failure. However, this diuresis is due primarily to inhibition of distal tubular sodium reabsorption and not renal vasodilation. Recent controlled clinical studies have been unable to demonstrate a renal protective effect independent of changes in cardiac output.

Selective decontamination of the digestive tract (SDD) has the appealing theoretical ability to minimize upper gastrointestinal colonization with gram-negative bacteria and fungi, and subsequently reduce nosocomial infection and mortality. Such modification of flora does occur, but the initial studies showing a reduction in lower respiratory tract infections have not been supported by recent large double-blind randomized controlled trials. A reduction in mortality or length of stay of general intensive care patients given SDD has never been demonstrated, and it remains an experimental therapy with possible application for some patient subgroups.

Upper gastrointestinal hemorrhage (UGH) in the critically ill is associated with prolonged ventilatory support and coagulopathy, but clinically important bleeding is now uncommon. Prophylaxis with agents that increase gastric pH is effective in reducing UGH, but may be associated with a higher incidence of nosocomial pneumonia than occurs with alternatives such as sucralfate. Prophylaxis does not alter mortality, and it is now controversial which patients, if any, should routinely receive such treatment.

Stress ulcer prophylaxis: gastrointestinal bleeding and nosocomial pneumonia. Best evidence synthesis

PURPOSE

To examine the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality.

METHODS

Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files and abstract reports. Independent review of 257 articles identified 71 relevant randomized trials for inclusion. We made independent, duplicate assessment of the methodologic quality, population, intervention and outcomes of each trial.

RESULTS

This overview demonstrates that prophylaxis with histamine-2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio 0.29 [95% CI 0.17-0.45]) and clinically important bleeding (odds ratio 0.35 [95% CI 0.15-0.76]). There is a trend to decreased overt bleeding when antacids are compared with no therapy (odds ratio 0.35 [95% CI 0.08-1.33]). Although sucralfate, antacids, and histamine-2-receptor antagonists are equivalent in reducing clinically important bleeding, sucralfate decreases the incidence of nosocomial pneumonia compared with antacids and/or histamine-2-receptor antagonists (odds ratio 0.50 [95% CI 0.21-0.79]). Sucralfate is associated with lower mortality relative to antacids (odds ratio 0.70 [95% CI 0.52-0.94]), and relative to histamine-2-receptor antagonists (odds ratio 0.71 [95% CI 0.49-1.04]).

CONCLUSIONS

All stress ulcer prophylactic agents appear to be effective in decreasing bleeding. Prophylaxis with sucralfate is associated with a lower rate of nosocomial pneumonia and mortality, providing strong evidence for use of this agent in clinical practice.

Changing perspectives of stress gastritis prophylaxis

OBJECTIVE

To present recent advances in stress gastritis prophylaxis in the critically ill and review considerations in selection of a prophylactic agent.

DATA SOURCES

Information was obtained from MEDLINE search, reference lists from articles identified in search, and from review articles.

STUDY SELECTION

Emphasis was placed on controlled trials conducted within the last 5 years.

DATA EXTRACTION

All literature was assessed for methodology, results, and conclusions. Results of prospective, randomized trials, and meta-analyses are summarized.

DATA SYNTHESIS

Histamine2-receptor antagonists, antacids, and sucralfate appear equally effective in preventing stress gastritis in the critically ill. A definitive cause-effect relationship between histamine2-receptor antagonists and increased incidence of nosocomial pneumonia has not yet been established. The indications for using a prophylactic agent and consideration in selecting an agent should include an evaluation of the following: risk factors for gastritis including the type of intensive care patient, comparative efficacy, adverse effects, drug interactions, cost, and ease of administration. The least expensive, safest agent requiring minimal monitoring is sucralfate. Prevention of stress gastritis has never been shown to reduce morbidity or mortality significantly.

CONCLUSIONS

Controversies still exist regarding the need to provide prophylaxis, the choice of an agent, and the relative importance of previously identified risk factors. Further well-designed studies are needed before consensus can be reached.

The virtual absence of stress-ulceration related bleeding in ICU patients receiving prolonged mechanical ventilation without any prophylaxis. A prospective cohort study

OBJECTIVE

To study the incidence of stress-ulcer related bleeding in ICU patients receiving prolonged (> 2 days) mechanical ventilation without any stress ulceration prophylaxis.

DESIGN

A prospective cohort study in 183 patients.

INTERVENTIONS

All patients received clinical treatment including maintenance of adequate tissue perfusion (with low dose inotropes and vasodilators), infection prevention (by selective decontamination of the digestive tract) throughout ICU stay and suppression of generalized inflammatory reaction (by steroids).

SETTING

Medical/surgical ICU of a major teaching hospital in Amsterdam (Onze Lieve Vrouwe Gasthuis).

MEASUREMENTS AND RESULTS

167 patients were evaluated during 2182 treatment days in the ICU and during 1753 days on mechanical ventilation without stress ulceration prophylaxis. The mean total risk score for stress ulceration related bleeding was 38 (Tryba score). Stress ulceration related bleeding developed in 1 patient (0.6%).

CONCLUSIONS

The incidence of SURB was less then 1% in this cohort of ICU patients receiving longterm mechanical ventilation with a high risk for SURB (mean total risk score 38). All patients received agressive shock resuscitation, infection prevention with selective decontamination of the digestive tract (SDD) and suppression of inflammatory response with steroids. Further studies are needed to evaluate the contribution of each of these elements of the integral approach.

Bleeding peptic ulcer occurring in hospitalized patients: analysis of predictive and risk factors and comparison with out-of-hospital onset of hemorrhage

We reviewed 84 consecutive cases of peptic ulcer hemorrhage, which occurred, in an area of 270,000 people, from 1986 to 1988, in patients already hospitalized for other diseases (in-bleeders). These subjects were compared with a prospective series of 386 patients who initially bled as out-patients and were then admitted (out-bleeders). Of 84 hemorrhages in hospitalized patients, 41 followed major surgery, while 43 were associated with other severe conditions. Bleeding site was duodenal in two thirds. Mean age was 67 +/- 15 years versus 59 +/- 15 among out-bleeders. Fifty percent of in-bleeders had recently received nonsteroidal antiinflammatory drugs (NSAIDs), and one third were on anticoagulants and 10% on corticosteroids; in 39 (46%) bleeding was shown to be persistent or recurrent, 5 (5.9%) underwent endoscopic and 18 (21%) surgical therapy; 29 died (34%). The corresponding figures among out-bleeders were: further bleeding 80 (20.7%), endoscopic therapy 12 (3.1%), surgery 25 (6.5%), deaths 17 (4.4%). As regards in-bleeders, only active bleeding and endoscopic stigmata emerged as statistically significant risk factors for further bleeding. The latter was shown to be significantly related to mortality. The most relevant finding was, however, that NSAIDs and anticoagulants, in association with stress and aging, are very frequently involved in peptic ulcer bleeding of hospitalized patients. The fatal outcome of one third, despite all available treatments, highlights the importance of prevention against drug- and stress-related mucosal damage in in-patients suffering from severe diseases.

Do continuous infusions of omeprazole and ranitidine retain their effect with prolonged dosing?

BACKGROUND/AIMS

Prolonged infusions of H2-antagonists are commonly used in intensive care units, although little is known about their antisecretory efficacy beyond the initial 24 hours of dosing. The aim of this study was to assess the antisecretory effects of infusions of ranitidine and omeprazole for a period of 72 hours.

METHODS

Twelve healthy volunteers received individually titrated 72-hour intravenous infusions of omeprazole, ranitidine, or placebo in a double-blind, crossover study. Gastric pH and dosing requirements were compared.

RESULTS

The median percentage of time with pH > 4 (interquartile range) was 93% (88%-95%) on day 1 and 96% (94%-99%) on day 3 with omeprazole and 67% (56%-78%) and 43% (31%-51%), respectively, with ranitidine (both P < 0.001 vs. omeprazole). The mean doses (+/- SD) required on days 1 and 3 for omeprazole were 235.8 +/- 44 mg and 134.0 +/- 37 mg (P < 0.0001), and ranitidine doses were 502.5 +/- 76 mg and 541.8 +/- 25 mg, respectively (P = 0.05).

CONCLUSIONS

Omeprazole infusions consistently maintained gastric pH above 4 over a period of 72 hours with progressively lower doses. Significant tolerance to the antisecretory effect of ranitidine infusion developed in 72 hours, which was not overcome despite individually titrated doses of more than 500 mg/24 hours. Consequently, application of pharmacodynamic results of single-day H2-blocker and proton-pump inhibitor studies to prolonged infusion trials for stress ulcer-related bleeding is inappropriate.

Continuous infusions of nizatidine are safe and effective in the treatment of intensive care unit patients at risk for stress gastritis. The Nizatidine Intensive Care Unit Study Group

This multicentre, randomized, parallel, double-blind study compared the safety and efficacy of nizatidine 20 and 10 mg/h with placebo. The objective was to maintain gastric pH > 4 in seriously ill patients at risk for stress gastritis. Gastric aspirate was obtained at 2-h intervals through a nasogastric tube after beginning study drug, and tested for pH and the presence of blood. Antacid doses (15 ml per dose) were individually adjusted and administered whenever the gastric pH was < 4. Significant gastrointestinal bleeding was assessed clinically by Hemmocult results, presence of frank bleeding from the GI tract, number of transfusions and vital signs. One hundred and twenty-six patients, 43 nizatidine 20 mg/h, 43 nizatidine 10 mg/h and 40 placebo were admitted to the study. For the treatment period, patients treated with either dose of nizatidine required significantly less antacid than placebo treated patients to maintain gastric acid pH > or = 4 (median total: 45 ml versus 180 ml, p < 0.001). Adverse clinical and laboratory events were similar or less frequent in the nizatidine groups compared with placebo. Nosocomial pneumonia occurred with very low frequency in all treatment groups.

Ranitidine: differential effects on gastric bleeding and mucosal damage induced by aspirin

This study investigated the influence of ranitidine on mucosal injury and gastric bleeding in 20 normal volunteers taking 600 mg aspirin q.d.s. This study was a double-blind placebo controlled crossover study comparing ranitidine, as 150 mg b.d., 300 mg q.d.s. and 600 mg b.d. with placebo. Gastric mucosal injury was assessed at unsedated endoscopy by counting haemorrhagic and non-haemorrhagic erosions; bleeding was measured in gastric washings. Aspirin alone increased mucosal injury from 0 to 11.4 erosions (mean, P < 0.01) and bleeding from 1.77 to 9.11 microliters blood/10 min (mean P < 0.001). Ranitidine prophylaxis reduced bleeding to 5.34, 3.18 and 3.47 microliters/10 min with 150 mg b.d., 300 mg q.d.s. and 600 mg b.d. respectively (overall effect of ranitidine P < 0.001) and also reduced haemorrhagic erosions though it had no effect on the total number of erosions. Ranitidine is effective at reducing aspirin-induced gastric bleeding and whilst not reducing aspirin-induced gastric erosions, it does reduce the number that appear haemorrhagic. Ranitidine may have a role in the prophylaxis of aspirin-induced gastric bleeding.

Problems in assessing the technology of critical care medicine

Technology assessment is becoming increasingly important in the area of critical care due both to the explosion of technology associated with this discipline and to the realization that future demand for these health care resources will undoubtedly exceed the ability to pay. Technology assessment remains both confusing and controversial to many physicians. This review tries to address some of the confusion by reviewing the basic strategies involved in this process. From there, problems and prospects for the evaluation of critical care as a program are presented, followed by the assessment of components within the area of critical care. Finally, recommendations are made on how technology assessment could proceed in the future to best achieve the efficient provision of this service.

Pharmacokinetics of ranitidine in a homogeneous population of intensive care unit patients during intermittent and continuous administration

The pharmacokinetics of ranitidine during two different modes of intravenous administration was studied in a homogeneous group of postoperative intensive care unit patients (n = 18). Patients at risk of developing stress-related lesions were randomized to receive repeated injections, 50 mg every 6 h (group A), or a continuous infusion, 50-mg bolus followed by 0.125 mg/kg/h (group B). Before treatment all patients received a single 50-mg ranitidine dose. Serum ranitidine concentrations were measured for 12 h after the single dose and during the treatment period, to calculate individual pharmacokinetic variables. From the single-dose study the calculated half-life, volume of distribution, and clearance were 3.14 +/- 0.61 h, 1.45 +/- 0.42 l/kg, and 0.40 +/- 0.14 l/kg/h for group A and 3.33 +/- 1.08 h, 1.16 +/- 0.20 l/kg, and 0.35 +/- 0.21 l/kg/h, for group B, respectively. Ranitidine pharmacokinetics after the single dose was comparable in the two groups. No statistically significant differences could be detected between the ranitidine pharmacokinetics after the first single dose and the multiple dose or continuous infusion.

Management of Stress Gastritis

Management of stress gastritis is primarily directed toward prevention of gastrointestinal bleeding. Antacids and H2 blockers have been the standard agents used for prophylactic therapy in critically ill patients. However, growing evidence that gastric alkalization leads to an increased incidence of nosocomial pneumonias has led to the development of other prophylactic agents that do not decrease gastric acidity. These cytoprotective agents presumably enhance gastric mucosal defenses and stimulate mucosal repair. Approximately 3% of patients bleed despite prophylactic therapy. Bleeding is usually controlled with intensive medical management, and the need for surgical intervention is rare.

Selective decontamination of the digestive tract (SDD) in intensive care patients: a critical evaluation of the clinical, bacteriological and epidemiological benefits

Twenty trials (17 controlled and three observational cohort studies) on selective decontamination of the digestive tract (SDD) have been undertaken to date. SDD is defined as a technique which aims to eradicate carriage of disease-causing microorganisms by means of lethal oropharyngeal and faecal antimicrobial concentrations. The SDD concept and the criteria for the choice of the antimicrobials used in the SDD programme are explained. Abolition of the carrier state is thought to provide clinical, bacteriological and epidemiological benefits. Infection-specific morbidity and mortality, emergence of antibiotic resistance and outbreaks are the main endpoints evaluated in this review. Of the 15 controlled studies that considered carriage, 14 demonstrated a significant reduction of Gram-negative bacillary (GNB) carriage. Severe infections, including pneumonia and septicaemia, caused by enterobacteria and pseudomonads have been virtually eliminated in these trials. Five of the 12 centres that evaluated mortality showed a significant decrease among patients who received SDD. Two recent trials describe the control of an outbreak with a multiresistant Klebsiella by SDD. There are three indications for the use of SDD so far: (i) in trauma patients; (ii) in certain elective surgical procedures including liver transplantation and oesophageal resection; and (iii) in control of outbreaks of ICU infection. Future lines of research may include a properly designed trial with mortality as endpoint and studies on the transfer of SDD from the ICU into the ward as part of prophylaxis in major surgery.

Stress gastritis revisited

In current ICU populations, overt bleeding from stress gastritis occurs in 10% to 20% of patients. Bleeding rates may be reduced to about 3% in patients receiving prophylactic therapy. Although patients with bleeding have higher mortality rates than other critically ill patients, it is not clear that the mortality rate is improved with prophylactic therapy, as most patients die from their underlying disease. As new complications of prophylactic therapy are identified, better definitions of the population at risk to develop complications of stress gastritis will be necessary to select those patients who will benefit most from prophylactic therapy.

A graded combination regimen for maintenance of gastric pH above 3.5 in critically ill patients

Prophylaxis of acute upper gastrointestinal bleeding by control of gastric pH has been widely advocated for intensive care patients. H2-blockers and antacids have been used and demonstrated to be incompletely effective at maintaining gastric pH above 4. A study of 100 patients measured the efficacy of two-hourly gastric pH measurement and titrated therapy consisting of five levels: 1. no therapy 2. ranitidine 50 mg 8 hourly intravenously 3. ranitidine plus Mylanta 30 ml 2 hourly by nasogastric tube 4. ranitidine plus Mylanta 60 ml 2 hourly and 5. ranitidine 100 mg 8 hourly intravenously plus Mylanta II 60 ml 2 hourly. The level of treatment required by proportions of the total study group were (1) 15%, (2) 71%, (3) 96%, (4) 100%. Head-injured and intubated patients generally fell in the more resistant group while patients having had major elective surgery required lower levels of therapy. If control of gastric pH is to be uniformly achieved, a technique of titrated therapy based on gastric pH measurements is supported as cheaper and more effective than other standardised treatment regimens.