***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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    ***EXAMPLES*** 
    Input: Objective To determine the attributable cost of ventilator-associated pneumonia from a hospital-based cost perspective , after adjusting for potential confounders . Design Patients admitted between January 19 , 1998 , and December 31 , 1999 , were followed prospect ively for the occurrence of ventilator-associated pneumonia . Hospital costs were defined by using the hospital cost accounting data base . Setting The medical and surgical intensive care units at a suburban , tertiary care hospital . Patients Patients requiring > 24 hrs of mechanical ventilation . Interventions None . Measurements and Main Results We measured occurrence of ventilator-associated pneumonia , in-hospital mortality rate , total intensive care unit ( ICU ) and hospital lengths of stay ( LOS ) , and total hospital cost per patient . Ventilator-associated pneumonia occurred in 127 of 819 patients ( 15.5 % ) . Compared with uninfected , ventilated patients , patients with ventilator-associated pneumonia had a higher Acute Physiology and Chronic Health Evaluation II score on admission ( p < .001 ) and were more likely to require multiple intubations ( p < .001 ) , hemodialysis ( p < .001 ) , tracheostomy ( p < .001 ) , central venous catheters ( p < .001 ) , and corticosteroids ( p < .001 ) . Patients with ventilator-associated pneumonia were more likely to be bacteremic during their ICU stay ( 36 [ 28 % ] vs. 22 [3%];p < .001 ) . Patients with ventilator-associated pneumonia had significantly higher unadjusted ICU LOS ( 26 vs. 4 days;p < .001 ) , hospital LOS ( 38 vs. 13 days;p < .001 ) , mortality rate ( 64 [ 50 % ] vs. 237 [34%];p < .001 ) , and hospital costs ( $ 70,568 vs. $ 21,620 , p < .001 ) . Multiple linear regression , controlling for other factors that may affect costs , estimated the attributable cost of ventilator-associated pneumonia to be $ 11,897 ( 95 % confidence interval = $ 5,265–$26,214;p < .001 ) . Conclusions Patients with ventilator-associated pneumonia had significantly longer ICU and hospital LOS , with higher crude hospital cost and mortality rate compared with uninfected patients . After we adjusted for underlying severity of illness , the attributable cost of ventilator-associated pneumonia was approximately $ 11,897 Objective : To evaluate the effect of a method of Selective Decontamination of the Digestive Tract ( SDD ) on colonization , nosocomial infection ( NI ) , bacterial resistance , mortality and economic costs . Design : R and omized , double blind , placebo controlled study . Setting : Polyvalent intensive care unit ( ICU ) of a tertiary care hospital with 27 beds . Patients : 101 patients with > 3 days of mechanical ventilation and > 5 days of stay , without infection at the start of the study . 47 belonged to the Treated Group ( TG ) and 54 to the Placebo Group ( PG ) . Interventions : The TG was given Cefotaxime i.v . ( 6 g/day ) for the first four days and an association of Polymyxin E , Tobramycin and Amphothericin B at the oropharyngeal and gastrointestinal level throughout the whole stay . Results : In the TG , colonization by gram-negative agents at oropharyngeal , tracheal and gastrointestinal level fell significantly . There was a significant drop in the overall , respiratory and urinary NI ( 26 % vs 63%,p<0.001 ; 15 % vs 46%,p<0.001 ; 9 % vs 31%,p<0.01 ) . The overall mortality and NI related mortality was less in the TG ( 21 % vs 44%,p<0.05 ; 2 % vs 20%,p<0.01 ) . The economic costs , mechanical ventilation time and length of stay were similar . The percentage of bacterial isolations resistant to Cefotaxime and Tobramycin was greater in the TG ( 38 % vs 15 % and 38 % vs 9%,p<0.001 ) . Conclusions : colonization by gram-negative bacilli , NI and the mortality related to it can be modified by SDD . Continuous bacteriological surveillance is necessary BACKGROUND The purpose of this study was to compare the performance of heat and moisture exchanger filters with heated humidifying systems in the mechanical ventilator circuit on the incidence of ventilator-associated pneumonia ( VAP ) and bacterial colonization . METHOD Two hundred and forty-three consecutive patients who required mechanical ventilation for 48 hours or more in the adult intensive care unit were r and omized to either a heat and moisture exchanger ( HME ) or a heated humidifying breathing circuit . RESULTS The VAP rate among the group with HME was 11.4 % ; the rate among the group with heated humidifying system ( HHS ) was 15.8 % . The difference was not statistically significant . Approximately 68 % of the patients in the HME group had no pathogen isolated compared with 50 % of the patients in the HHS group . This difference was statistically significant ( P = .006 ) . However , the distribution of the pathogens among those patients who had the isolated pathogens was mostly identical in the 2 groups . CONCLUSION Even though the study did not find HME to be significantly advantageous over the HHS , in as much as VAP rate is concerned , other advantages such as reduced nurses workload , reduced financial cost , and better safety made HME a more favorable device for use in our adult intensive care unit STUDY OBJECTIVE To determine the cost-effectiveness of continuous subglottic suctioning ( CSS ) as a strategy to decrease the incidence of  ventilator-associated pneumonia ( VAP ) .  DESIGN Decision-model analysis of the cost and efficacy of endotracheal tubes that allow CSS at preventing VAP . The primary outcome was cases of VAP averted . Model estimates were based on data from published prospect i ve trials of CSS and other prospect i ve studies of the incidence of VAP . SETTING AND PATIENTS Hypothetical cohort of 100 patients requiring nonelective endotracheal intubation and management in an ICU . INTERVENTIONS In the model , patients were managed with either traditional endotracheal tubes ( ETs ) or ETs capable of CSS . MEASUREMENTS AND MAIN RESULTS The marginal cost-effectiveness of CSS  was calculated as the savings result ing from cases of VAP averted minus the additional costs of CSS-ETs , and expressed as cost ( or savings ) per episode of VAP prevented . Sensitivity analysis of the impact of the major clinical inputs on the cost-effectiveness was performed . The base case assumed that the incidence of VAP in patients requiring > 72 h of mechanical ventilation ( MV ) was 25 % , that CSS-ETs had no impact on patients requiring MV for < 72 h , and that CSS-ETs result ed in a relative risk reduction of VAP of 30 % . Despite the higher costs of ETs capable of CSS , this tactic yielded a net savings of $ 4,992 per case of VAP prevented . For sensitivity analysis , model inputs were adjusted by 50 % individually and then simultaneously . This demonstrated the model to be only moderately sensitive to the calculated cost of VAP . With the relative risk reduction at 50 % of the base-case estimate , CSS result ed in $ 1,924 saved per case of VAP prevented . When all variables were skewed against CSS , total outlays were trivial ( approximately $ 14 per patient in the cohort ) . CONCLUSIONS CSS represents a strategy for the prevention of VAP that may result in savings . Further studies are warranted to confirm the efficacy of CSS Risk factors for the development of ventilator-associated pneumonia ( VAP ) , as identified in epidemiological studies , have provided a basis for testable interventions in r and omized trials . We describe how these results have influenced patient treatment . Single interventions in patients undergoing intubation  have focused on either reducing aspiration of oropharyngeal secretions , modulation of colonization ( in either the oropharynx , the stomach , or the whole digestive tract ) , use of systemic antimicrobial prophylaxis , or ventilator circuit changes . More recently , multiple simultaneously implemented interventions have been used . In general , routine measures to decrease oropharyngeal aspiration and antibiotic-containing prevention strategies appear to be the most effective , and the latter were associated with improved rates of patient survival in recent trials . These benefits must be balanced against the widespread fear of emergence of antibiotic resistance . In hospital setting s with low baseline levels of antibiotic resistance , however , the benefits to patient outcome may outweigh this fear of resistance . In setting s with high levels of antibiotic resistance , combined approaches of non-antibiotic using strategies and education programs might be most beneficial STUDY OBJECTIVE To compare the clinical outcomes of critically ill patients developing early-onset nosocomial pneumonia ( NP ; ie , within 96 h of ICU admission ) and late-onset NP ( ie , occurring after 96 h of ICU admission ) . DESIGN Prospect i ve cohort study . SETTING A medical ICU and a surgical ICU from a university-affiliated urban teaching hospital . PATIENTS Between July 1997 and November 1998 , 3 , 668 patients were prospect ively evaluated . INTERVENTION Prospect i ve patient surveillance and data collection . RESULTS Four hundred twenty patients ( 11.5 % ) developed NP . Early-onset NP was observed in 235 patients ( 56.0 % ) , whereas 185 patients ( 44.0 % ) developed late-onset NP . Among patients with early onset NP , 114 patients ( 48 . 5 % ) spent at least 24 h in the hospital prior to ICU admission , compared to 57 patients ( 30.8 % ) with late-onset NP ( p = 0.001 ) . One hundred eighty-three patients ( 77.9 % ) with early-onset NP received  antibiotics  prior to the development of NP , as compared to 162 patients ( 87.6 % ) with late-onset NP ( p = 0.010 ) . The most common pathogens associated with early-onset NP were Pseudomonas aeruginosa ( 25.1 % ) , oxacillin-sensitive Staphylococcus aureus ( OSSA ; 17.9 % ) , oxacillin-resistant S aureus ( ORSA ; 17.9 % ) , and Enterobacter species ( 10.2 % ) . P aeruginosa ( 38.4 % ) , ORSA ( 21.1 % ) , Stenotrophomonas maltophilia ( 11.4 % ) , OSSA ( 10.8 % ) , and Enterobacter species ( 10.3 % ) were the most common pathogens associated with late-onset NP . The ICU length of stay was significantly longer for patients with early-onset NP ( 10.3 + /- 8.3 days ; p < 0.001 ) and late-onset NP ( 21 . 0 + /- 13.7 days ; p < 0.001 ) , as compared to patients without NP ( 3.5 + /- 3.2 days ) . Hospital mortality was significantly greater for patients with early-onset NP ( 37.9 % ; p = 0.001 ) and late-onset NP ( 41.1 % ; p = 0.001 ) compared to patients without NP ( 13.1 % ) . CONCLUSIONS Both early-onset and late-onset NP are associated with increased hospital mortality rates and prolonged lengths of stay . The pathogens associated with NP were similar for both groups . This may be due , in part , to the prior hospitalization and use of antibiotics in many patients developing early-onset NP . These data suggest that P aeruginosa and ORSA can be important pathogens associated with early-onset NP in the ICU setting . Additionally , clinicians should be aware of the common microorganisms associated with both early-onset NP and late-onset NP in their hospitals in order to avoid the administration of inadequate antimicrobial treatment Nosocomial pneumonia is the leading cause of death among all hospital-acquired infections [ 1 ] . The estimated incidence of nosocomial pneumonia in intensive care units ranges from 10 % to 65 % ; most studies [ 2 - 6 ] show case fatality rates of more than 20 % . Ventilator-associated pneumonia specifically refers to nosocomial pneumonia that develops in a mechanically ventilated patient and that was not present at the time of airway intubation [ 7 ] . Various clinical risk factors have been associated with an increased incidence of ventilator-associated pneumonia , either because they predispose the patient to bacterial colonization of the oropharynx and stomach ( for example , the administration of antacids or histamine-2-receptor antagonists ) or because they facilitate aspiration of contaminated contents from these sites ( for example , supine positioning ) [ 1 , 2 , 8 , 9 ] . Craven and colleagues [ 10 ] first showed that the frequency of ventilator circuit changes also influences the incidence of ventilator-associated pneumonia . They found that changing circuits every 24 rather than every 48 hours was independently associated with the occurrence of nosocomial p 
    Output:
    
CONCLUSIONS Ventilator-associated pneumonia occurs in a considerable proportion of patients undergoing mechanical ventilation and is associated with substantial morbidity , a two-fold mortality rate , and excess cost .