***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: We tested the hypothesis that active and passive airway humidification minimize hypothermia in infants , but that maintaining normothermia does not decrease the duration of postoperative recovery . A circle system was used to ventilate the lungs of anesthetized , intubated infants who were r and omly assigned to active airway humidification and warming with use of an MR450 Servo airway heater and humidifier set at 37 ° C ( n = 10 ) , passive airway humidification with use of the Humid-Vent Mini heat and moisture exchanger placed between the Y-piece of the circle and the endotracheal tube ( n = 10 ) , or no airway humidification and heating ( control , n = 10 ) . Anesthesia was induced with thiopental and maintained with isoflurane and nitrous oxide in oxygen .  The relative humidity of inspired respiratory gases was ∼35 % in the control group and ∼90 % in the group undergoing active airway humidification . Initial inspired humidity in the passive humidification group ( 45 % ) increased to ∼80 % after 1 h of anesthesia . Humidity differed significantly across groups at all times ( P ≤ 0.05 ) . Steady-state rectal temperatures ( 100 - -120 min after induction ) were 36.2 ± 0.7 ° C in patients given active humidification and heating , 35.7 ± 0.9 ° C in the passively humidified group , and 35.2 ± 0.4 ° C in the control group ( P ≤ 0.05 between each group ) . Recovery from general anesthesia was rapid in all patients and did not correlate with central temperature changes or type of humidification ( P = NS ) . We conclude that heat and moisture exchangers are less effective than active heating and humidification , but significantly better than no humidification 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 Determine the utility of a proposed algorithm in allowing safe , efficient humidification in mechanically ventilated patients using both a hygroscopic condenser humidifier ( HCH ) and heated humidifier ( HH ) . DESIGN A prospect i ve study using an algorithm to chose humidification devices based on physical examination and sputum characteristics . SETTING All patients admitted to the surgical ICU . PATIENTS One hundred twenty consecutive patients requiring mechanical ventilation ( MV ) were studied . INTERVENTIONS Patients were examined by the attending respiratory care practitioner and given either an HCH or HH . If patients demonstrated any of the following -- thick or tenacious secretions , core temperature < 32 degrees C , or bloody secretions -- they were given an HH . All others used an HCH . If any of the above conditions occurred during HCH use , the patient was given an HH . MEASUREMENTS AND RESULTS Duration of ventilation , incidence of nosocomial pneumonia , ventilator circuit colonization , and mortality were determined for patients in each group . Cost of humidification devices , number of suctioning procedures per day , and volume of saline solution instilled were also recorded . Initially , 27 percent ( 32/120 ) of patients used an HH and 73 percent ( 88/120 ) used an HCH . During the study , ten patients required changing to an HH during HCH use . Patients in the HH group were more likely to have preexisting lung disease and had a longer duration of ventilation ( 83 + /- 21 h ) and higher mortality ( 21 percent ) . Patients in the HCH group were more likely to be postoperative , had shorter duration s of ventilation ( 38 + /- 14 h ) , and lower mortality ( 9 percent ) . There was no difference in the incidence of nosocomial pneumonia between the two groups ( 9 percent vs 6 percent ) and endotracheal tube occlusion did not occur in either group . Circuit colonization was common in the HH group ( 64 percent ) but rate in the HCH group ( 5 percent ) . Cost per day was significantly less for the HCH group ( $ 4 vs $ 19.80 ) . Patients who required a change from HCH to HH did so at a mean of 5 days . CONCLUSION The proposed algorithm result ed in cost-efficient and safe application of humidification devices in patients in the surgical ICU Critically ill patients in the intensive care unit ( ICU ) are at high risk for infections associated with increased morbidity , mortality , and health care costs ( 1 - 3 ) . The overall infection rate in critically ill patients approaches 40 % and may be as high as 50 % or 60 % in patients who remain in the ICU for more than 5 days ( 4 , 5 ) . Respiratory tract infections account for 30 % to 60 % of all such infections . The incidence of pneumonia acquired in the ICU ranges from 10 % to 65 % ( 6 - 11 ) . Among patients at high risk for ventilator-associated pneumonia ( VAP ) are those who have chronic obstructive pulmonary disease , burns , neurosurgical conditions , the acute respiratory distress syndrome , and witnessed aspiration ; those who are reintubated ; and those who receive paralytic agents or enteral nutrition ( 12 , 13 ) . The attributable morbidity and mortality of VAP are clinical ly important . In a prospect i ve , matched cohort study , patients with VAP remained in the ICU 4.3 days ( 95 % CI , 1.5 to 7.0 days ) longer than patients who did not have VAP and had a trend toward an increased risk for death ( absolute risk increase , 5.8 % [ CI , 2.4 % to 14.0 % ] ) ( 14 ) . Six other studies using a matching strategy found a prolonged length of ICU stay associated with VAP ( range , 5 to 13 days ) and attributable mortality ranging from an absolute risk increase of 0 % to 50 % ( 15 - 20 ) . Therefore , strategies to decrease the incidence of VAP could decrease morbidity , mortality , and health care costs and improve patient safety . A survey of the use of VAP prevention strategies identified differences across countries ( 21 ) . For example , changing the ventilator circuit for each new patient was reported more frequently by French ICU directors than those in Canada ( 21 ) . This survey also showed that some effective strategies were used infrequently , suggesting inadequate translation of r and omized trial results into practice . One potential catalyst for knowledge translation is an evidence -based clinical practice guideline . Therefore , a Joint Planning Group of the Canadian Critical Care Society and Canadian Critical Care Trials Group commissioned the development of an evidence -based clinical practice guideline for the prevention of VAP . In this paper , we describe the methods used to create the guideline and the recommendations generated . Methods The Joint Planning Group selected an 11-member VAP Prevention Guideline Panel made up of 9 intensivists from university-affiliated and community hospitals , an ICU nurse , and an ICU respiratory therapist . Panel members were experts in critical care medicine ( n= 9 ) , VAP ( n= 4 ) , evidence -based medicine ( n= 4 ) , and guideline development ( n= 3 ) . The context was mechanically ventilated adult patients cared for in the ICU . The target audience was ICU clinicians in university-affiliated and community hospitals . To identify potentially relevant evidence , we search ed 3 bibliographic data bases ( MEDLINE , EMBASE , and the Cochrane Data base of Systematic Review s ) to 1 April 2003 for r and omized trials that evaluated interventions influencing VAP ( Appendix ) . We had no language restrictions . We also review ed personal files and practice guidelines on this subject previously published by the Centers for Disease Control and Prevention ( 22 ) and the American Thoracic Society ( 23 ) . We included r and omized trials and systematic review s of r and omized trials that 1 ) studied adult critically ill patients ; 2 ) had VAP as an outcome ; and 3 ) evaluated any of the following interventions : physical strategies ( route of endotracheal intubation , systematic search for maxillary sinusitis , frequency of ventilator circuit changes , type of airway humidification , frequency of humidifier changes , endotracheal suctioning system , subglottic secretion drainage , chest physiotherapy , and tracheostomy timing ) , positional strategies ( kinetic beds , semi-recumbent positioning , and prone positioning ) , and pharmacologic strategies ( stress ulcer prophylaxis and prophylactic antibiotics , including selective decontamination of the digestive tract ) . Since study authors used various definitions of VAP , we used the definitions they provided . The most common definition was a new or persistent radiographic infiltrate plus fever , leukocytosis , change in the volume or color of sputum , or isolation of a pathogen . If available , histologic evidence of pneumonia was also used . A priori , we decided to review only systematic review s of r and omized clinical trials for antibiotic prophylaxis and only r and omized clinical trials for all other topics . We excluded crossover and beforeafter studies . We also excluded r and omized trials of ventilator weaning , including noninvasive mechanical ventilation , and nutritional interventions evaluating VAP because guidelines addressing these topics have recently been published ( 24 , 25 ) . In duplicate and independently , 3 pairs of panel members critically appraised each trial ( 26 , 27 ) and systematic review ( 28 ) . Each member of a pair compared his or her independent appraisal of a given trial or systematic review with that of the other member of the pair . For each r and omized trial , we abstract ed sample , allocation , intervention , co- interventions , exclusions after r and omization , blinding of outcome assessment , definition of VAP , crude VAP events , relative risk for VAP , and other outcomes . For each intervention , we summarized the risk differences and calculated a pooled risk difference . For each systematic review , we abstract ed number of trials , population , intervention , selection criteria , search strategy , validity assessment , method of pooling results , homogeneity assessment , VAP definition , pooled event rates , and other outcomes . Before the panel meeting , each pair of appraisers achieved consensus on the validity and results of the trials they review ed . One month before the panel meeting , panel members received the evidence tables for review prepared by the 3 pairs of appraisers . A priori , panel members agreed to read all circulated documents and evidence tables in advance , to use levels of evidence to generate a status statement for each item , and to abide by the group process and consensus methods . The Canadian Critical Care Society appointed a chair to ensure that the panel achieved its objectives through group process ( 29 ) . At the panel meeting , each member recorded any potential conflicts of interest ( 30 ) . The pair of panel members responsible for critical appraisal of each intervention provided a structured written and oral presentation of the evidence . After the panel discussion , the initial evidence summary was revised if necessary . The panel members assigned levels of evidence , semi-quantitative scores to summarize the evidence and describe the intervention , and a status statement . We classified trials as level 1 if they had all of the following : concealed r and omization , blinded outcome adjudication , an intention-to-treat analysis , and an explicit definition of VAP . Trials were classified as level 2 if any one of these characteristics was unfulfilled and as level 3 if allocation was not strictly r and omized . We used a semi-quantitative score ( 0 , 1 , 2 , or 3 ) to evaluate each intervention with respect to the validity of the r and omized trials ; the effect size of each intervention ; the confidence intervals around the estimate of effect ; the homogeneity of the trial results ; and the safety , feasibility , and economic consequences of the intervention . The language of the status statement for each item was keyed to the levels of evidence and the semi-quantitative scores . We used the term recommended if there were no reservations about endorsing an intervention and the term considered if the evidence supported an intervention but there were minor uncertainties about the benefits , harms , or costs . No recommendation was made if evidence regarding an intervention was inadequate or if there were major uncertainties about the benefits , harms , or costs . After the panel meeting , the chair compiled the summaries and status statements and sent them to all panel members to check accuracy and clarity . In addition , the pairs of evidence appraisers wrote background documents for the interventions they appraised , including the rationale for each intervention , appraisal of r and omized trials and systematic review s , and harms and costs of the interventions . The chair and the writing committee organized the background documents , the evidence summaries , a table of the semi-quantitative scores , and the status statement for each 
    Output:
    
There was no overall effect on artificial airway occlusion , mortality , pneumonia , or respiratory complications ; however , the PaCO(2 ) and minute ventilation were increased when HMEs were compared to HHs and body temperature was lower .
The cost of HMEs  was lower in all studies that reported this outcome .
There was some evidence that hydrophobic HMEs may reduce the risk of pneumonia and that blockages of artificial airways may be increased with the use of HMEs in certain subgroups of patients .
There is little evidence of an overall difference between HMEs and HHs .
However , hydrophobic HMEs may reduce the risk of pneumonia and the use of an HME may increase artificial airway occlusion in certain subgroups of patients .
Therefore , HMEs may not be suitable for patients with limited respiratory reserve or prone to airway blockage .