***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: CONTEXT The use of acid-suppressive medication has been steadily increasing , particularly in the inpatient setting , despite lack of an accepted indication in the majority of these patients . OBJECTIVE To examine the association between acid-suppressive medication and  hospital-acquired pneumonia . DESIGN , SETTING , AND PATIENTS Prospect i ve pharmacoepidemiologic cohort study . All patients who were admitted to a large , urban , academic medical center in Boston , Massachusetts , from January 2004 through December 2007 ; at least 18 years of age ; and hospitalized for 3 or more days were eligible for inclusion . Admissions with time spent in the intensive care unit were excluded . Acid-suppressive medication use was defined as any order for a proton-pump inhibitor or histamine(2 ) receptor antagonist . Traditional and propensity-matched multivariable logistic regression were used to control for confounders . MAIN OUTCOME MEASURE Incidence of hospital-acquired pneumonia , defined via codes from the International Classification of Diseases , Ninth Revision , Clinical Modification ( ICD-9-CM ) , in patients exposed and unexposed to acid-suppressive medication . RESULTS The final cohort comprised 63 878 admissions .  Acid-suppressive medication was ordered in 52 % of admissions and hospital-acquired pneumonia occurred in 2219 admissions ( 3.5 % ) . The unadjusted incidence of hospital-acquired pneumonia was higher in the group exposed to acid-suppressive medication than in the unexposed group ( 4.9 % vs 2.0 % ; odds ratio [ OR ] , 2.6 ; 95 % confidence interval [ CI ] , 2.3 - 2.8 ) . Using multivariable logistic regression , the adjusted OR of hospital-acquired pneumonia in the group exposed to acid-suppressive medication was 1.3 ( 95 % CI , 1.1 - 1.4 ) . The matched propensity-score analyses yielded identical results . The association was significant for proton-pump inhibitors ( OR , 1.3 ; 95 % CI , 1.1 - 1.4 ) but not for histamine(2 ) receptor antagonists ( OR , 1.2 ; 95 % CI , 0.98 - 1.4 ) . CONCLUSIONS In this large , hospital-based pharmacoepidemiologic cohort , acid-suppressive medication use was associated with 30 % increased odds of hospital-acquired pneumonia . In subset analyses , statistically significant risk was demonstrated only for proton-pump inhibitor use BACKGROUND Critically ill patients who require mechanical ventilation are at increased risk for gastrointestinal bleeding from stress ulcers . There are conflicting data on the effect of histamine H2-receptor antagonists and the cytoprotective agent sucralfate on rates of gastrointestinal bleeding , ventilator-associated pneumonia , and mortality . METHODS In a multicenter , r and omized , blinded , placebo-controlled trial , we compared sucralfate with the H2-receptor antagonist ranitidine for the prevention of upper gastrointestinal bleeding in 1200 patients who required mechanical ventilation . Patients received either nasogastric sucralfate suspension ( 1 g every six hours ) and an intravenous placebo or intravenous ranitidine ( 50 mg every eight hours ) and a nasogastric placebo . RESULTS The patients in the two groups had similar base-line characteristics . Clinical ly important gastrointestinal bleeding developed in 10 of 596 ( 1.7 percent ) of the patients receiving ranitidine , as compared with 23 of 604 ( 3.8 percent ) of those receiving sucralfate ( relative risk , 0.44 ; 95 percent confidence interval , 0.21 to 0.92 ; P=0.02 ) . In the ranitidine group , 114 of 596 patients ( 19.1 percent ) had ventilator-associated pneumonia , as compared with 98 of 604 ( 16.2 percent ) in the sucralfate group ( relative risk , 1.18 ; 95 percent confidence interval , 0.92 to 1.51 ; P=0.19 ) . There was no significant difference between the groups in mortality in the intensive care unit ( ICU ) ( 23.5 percent in the ranitidine group and 22.9 percent in the sucralfate group ) or the duration of the stay in the ICU ( median , nine days in both groups ) . CONCLUSIONS Among critically ill patients requiring mechanical ventilation , those receiving ranitidine had a significantly lower rate of clinical ly important gastrointestinal bleeding than those treated with sucralfate . There were no significant differences in the rates of ventilator-associated pneumonia , the duration of the stay in the ICU , or mortality BACKGROUND / AIMS Critically ill patients especially who require mechanical ventilation or have coagulopathy are at increased risk for stress-related gastrointestinal hemorrhage . There are conflicting data on the efficacy and complication rates of various prophylactic regimens . METHODOLOGY Our single-center r and omized , placebo-controlled study included 287 patients with high risk for stress-related upper gastrointestinal hemorrhage ( > 48 h mechanical ventilation , coagulopathy ) . We compared 3 prophylactic regimens ( proton pump inhibitor -- omeprazole 40 mg i.v . once daily , n=72 ; H2 antagonists -- famotidine 40 mg twice a day , n=71 ; and sucralfate 1 g every 6 hours , n=69 ) with placebo ( n=75 ) in patients with trauma or after major surgery . RESULTS Of 287 assessable patients , clinical ly significant stress-related upper gastrointestinal bleeding was observed in 1 % , 3 % , 4 % , and 1 % of patients assigned to receive omeprazole , famotidine , sucralfate , and placebo , respectively ( p>0.28 ) . Bleeding developed significantly more often in patients with coagulopathy compared with the others ( 10 % vs. 2 % ; p=0.006 ) . The gastric pH ( p>0.001 ) and gastric colonization ( p<0.05 ) was significantly higher in the patients who received pH increasing substances when compared with the other 2 groups . Nosocomial pneumonia occurred in 11 % of patients receiving omeprazole , in 10 % of famotidine patients , in 9 % of sucralfate patients and in 7 % of controls ( p>0.34 ) . No statistically significant differences were found for days on ventilator , length of ICU stay , or mortality among all the 4 groups . CONCLUSIONS We could not show that omeprazole , famotidine , or sucralfate prophylaxis can affect already very low incidence of clinical ly important stress-related bleeding in high-risk surgical intensive care unit patients . Furthermore , our data suggested that especially gastric pH increasing medication could increase the risk for nosocomial pneumonia . Routine prophylaxis for stress-related bleeding even in high-risk patients seems not to be justified Thirty-two long-term ventilated patients were r and omly selected for a study of the efficacy of sucralfate ( 1 g six times per day via gastric tube ) versus ranitidine ( six 50-mg to six 100-mg doses per day intravenously ) for the prevention of upper gastrointestinal bleeding .  The patients of the two treatment groups ( each 16 ) were comparable with respect to diseases precipitating acute respiratory failure and risk factors of bleeding , e.g. , renal failure , thrombopenia , coagulopathy , and anticoagulant treatment . Mean duration of mechanical ventilation was 7.4 in sucralfate- and 7.7 days in  ranitidine-treated patients . During mechanical ventilation , macroscopically visible bleeding developed in three of the sucralfate-treated ( 18.7 percent ) and seven of the ranitidine-treated ( 43.7 percent ) patients . Until the end of the study , only three of the  sucralfate-treated  but nine of the ranitidine-treated ( 56.2 percent ) patients bled ; the difference between the two treatment groups was at all times significant ( p less than 0.05 ) . Packed red blood cells had to be administered to the three bleeding patients in the sucralfate group and to seven bleeding in the ranitidine group . Therefore it seems that sucralfate prevented mostly minor bleeding . The high bleeding rate during ranitidine treatment was presumably due to the high number of pH-nonresponders , as almost 30 percent of the gastric aspirates of this group had a pH less than 5 . During treatment no difference was found in positive blood culture specimens and bronchial secretions between the two groups . However , nosocomial pneumonia developed in two ranitidine-treated patients , whereas that complication developed in none of the sucralfate-treated patients . In long-term ventilated patients , sucralfate prevented minor upper gastrointestinal bleeding significantly better than ranitidine . However , this does not imply that major upper gastrointestinal bleeding can be prevented by either sucralfate or ranitidine in these patients Objectives To determine whether a continuous iv infusion of cimetidine , a histamine-2 ( H2 ) receptor antagonist , is needed to prevent upper gastrointestinal ( GI ) hemorrhage when compared with placebo and if that usage is associated with an increased risk of nosocomial pneumonia . Due to the importance of this latter issue , data were collected to examine the occurrence rate of nosocomial pneumonia under the conditions of this study . Design A multicenter , double-blind , placebocontrolled study . Interventions Patients were r and omized to receive cimetidine ( n = 65 ) as an iv infusion of 50 to 100 mg/hr or placebo  ( n = 66 ) . Setting Intensive care units in 20 institutions . Patients Critically ill patients ( n = 131 ) , all of whom had at least one acute stress condition that previously had been associated with the development of upper GI hemorrhage . Measurements and Main Results Sample s of gastric fluid from nasogastric aspirates were collected every 2 hrs for measurement of pH and were examined for the presence of blood . Upper GI hemorrhage was defined as bright red blood or persistent ( continuing for > 8 hrs ) “ coffee ground material ” in the nasogastric aspirate . Baseline chest radiographs were performed and sputum specimens were collected from all patients , and those patients without clear signs of pneumonia ( positive chest radiograph , positive cough , fever ) at baseline were followed prospec-tively for the development of pneumonia while receiving the study medication . Cimetidine-infused patients experienced significantly ( p = .009 ) less upper GI hemorrhage than placebo-infused patients : nine ( 14 % ) of 65 cimetidine vs. 22 ( 33 % ) of 66 placebo patients . Cimetidine patients demonstrated significantly ( p = .0001 ) higher mean intragastric pH ( 5.7 vs. 3.9 ) , and had intragastric pH values at > 4.0 for a significantly ( p = .0001 ) higher mean percentage of time ( 82 % vs. 41 % ) than placebo patients . Differences in pH variables were not found between patients who had upper GI hemorrhage and those patients who did not , although there was no patient in the cimetidine group who bled with a pH < 3.5 compared with 11 such patients in the placebo group . Also , the upper GI hemorrhage rate in patients with one risk factor ( 23 % ) was similar to that rate in patients with two or more risk factors ( 25 % ) . Of the 56 cimetidine-infused patients and 61 placebo-infused patients who did not have pneumonia at baseline , no cimeti-dine-infused patient developed pneumonia while four ( 7 % ) placebo-infused patients developed pneumonia . Conclusions The continuous iv infusion of cimetidine was highly effective in Objective The authors compared the results of sucralfate versus H2 blocker ± antacid as prophylaxis for  stress ulceration in an intensive care unit patient population . Summary Background Data Stress ulceration carries high morbidity and mortality for the patient who is critically ill . Gastric acid neutralization is an effective prophylaxis . The impact of increased gastric colonization with bacterial pathogens on nosocomial pneumonia after acid neutralization is unclear . The efficacy of sucralfate prophylaxis for stress ulceration and its the effect on the nosocomial pneumonia rate is controversial . The financial implication s of sucralfate prophylaxis versus H2 blocker-based acid neutralization therapy has not been studied . Methods Ninety-eight injured patients who were critically ill and who required intubation and intensive care unit ( ICU ) support for at least 72 hours without gastric feeding were r and omized and received either maximal H2 blocker infusion therapy ( continuous infusion of ranitidine at 0.25 mg/kg/hr after a loading dose of 0.5 mg/kg ) plus antacids ( for persistent pH < 4 ) or sucralfate ( 1 g every 6 hours via nasogastric tube ) for stress ulcer prophylaxis . Efficacy in preventing stress ulcer complications was determined . The impact of each therapeutic approach on development of nosocomial pneumonia was evaluated . The charges/cost for each approach was analyzed . Results Heme-positive gastr 
    Output:
    
INTERPRETATION Use of a proton pump inhibitor or histamine(2 ) receptor antagonist may be associated with an increased risk of both community- and hospital-acquired pneumonia .