***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: OBJECTIVE To assess the therapeutic effects of breathing a low-density gas mixture ( heliox : 70 % helium and 30 % oxygen ) in infants with bronchiolitis . DESIGN Prospect i ve , interventional , comparative study . SETTING A pediatric intensive care unit ( PICU ) in a tertiary care , teaching hospital . PATIENTS Thirty-eight infants , 1 month to 2 years old , consecutively admitted to the PICU for treatment of moderate-to-severe acute respiratory syncytial virus bronchiolitis . INTERVENTIONS The first 19 patients were enrolled as the control group and received supportive care and nebulized epinephrine . In the next 19 patients , heliox therapy was added through a nonrebreather reservoir face mask . Measurements and Outcomes . Respiratory distress score , respiratory rate , heart rate , end-tidal CO(2 ) ( etCO(2 ) ) , and pulse oximetry oxygen saturation ( satO(2 ) ) values were recorded at baseline and at regular intervals . Data obtained during the first 4 hours were analyzed for comparison purpose s. Demographic data , age , time elapsed from the start of the symptoms to the admission to PICU , length of stay in PICU ( PICU-LOS ) , and duration of heliox therapy  were also collected for each patient . Reductions in clinical scores and PICU-LOS were considered primary outcomes . Main Results . At baseline , the heliox and control groups had similar age ( 5.5 + /- 3.1 vs 5.9 + /- 3 months ) , previous length of course ( 47.3 + /- 19.3 vs 45.4 + /- 18.6 hours ) , clinical score ( 6.7 + /- 1.1 vs 6.6 + /- 1 ) , heart rate ( 160 + /- 24 vs 165 + /- 20 beats per minute ) , respiratory rate ( 64 + /- 7 vs 61 + /- 7 respirations per minute ) , satO(2 ) ( 91 + /- 2.3 vs 91 + /- 2.5 % ) , and etCO(2 ) ( 34 + /- 7 vs 33 + /- 6 mm Hg ) . Clinical score , heart rate , respiratory rate , and satO(2 ) improved during the study in both groups . After 1 hour , the improvement in clinical score was significantly higher in the heliox group than in the control group ( 3.6 + /- 1.16 vs 5.5 + /- 0.89 ) , and these differences continued to be significant at the end of the observation period ( 2.39 + /- 0.69 and 4.07 + /- 0.96 , respectively ) , with a total average decrease in the score of 4.2 points in the heliox group versus 2.5 points in the control group . Heart and respiratory rates were also significantly lower in the heliox group compared with the control group after 1 hour and stayed lower throughout the rest of the study period . No changes were noted either in satO(2 ) between groups or in etCO(2 ) within or between groups throughout the study . Mean duration of heliox administration was 53 + /- 24 hours ( range : 24 - 112 hours ) and no adverse effects were detected . PICU-LOS was significantly shorter in the heliox group ( 3.5 + /- 1.1 days ) than in the control group ( 5.4 + /- 1.6 days ) . CONCLUSIONS In infants with moderate-to-severe respiratory syncytial virus bronchiolitis , heliox therapy enhanced their clinical respiratory status , according to the marked improvement in their clinical scores and the reduction of the accompanying tachycardia and tachypnea . This beneficial response occurred within the first hour of its administration and was maintained as long as heliox therapy continued . In addition , PICU-LOS was reduced in heliox-treated patients . Long-term prospect i ve studies are required to corroborate these findings and to establish the proper place of heliox in the therapeutic schedule of bronchiolitis Introduction : Although acute respiratory illnesses ( ARI ) are major causes of morbidity and mortality in early childhood worldwide , little progress has been made in their control and prophylaxis . Most studies have focused on hospitalized children or children from closed population s. It is essential that the viral etiology of these clinical diseases be accurately defined in the development of antiviral drugs . Objective : To investigate the role of all common respiratory viruses as upper and lower respiratory tract pathogens in the first year of life . Study Design : This community-based birth cohort study prospect ively collected detailed information on all ARI contracted by 263 infants from birth until 1 year of age .  Nasopharyngeal aspirates were collected for each ARI episode , and all common respiratory viruses were detected by polymerase chain reaction . Episodes were classified as upper respiratory illnesses or lower respiratory illnesses ( LRI ) , with or without wheeze . Results : The majority reported 2–5 episodes of ARI in the first year ( range , 0–11 episodes ; mean , 4.1 ) . One-third were LRI , and 29 % of these were associated with wheeze . Viruses were detected in 69 % of ARI ; most common were rhinoviruses ( 48.5 % ) and respiratory syncytial virus ( RSV ) ( 10.9 % ) . Compared with RSV , > 10 times the number of upper respiratory illnesses and > 3 times the number of both LRI and wheezing LRI were attributed to rhinoviruses . Conclusion : Rhinoviruses are the major upper and lower respiratory pathogens in the first year of life . Although RSV is strongly associated with severe LRI requiring hospitalization , the role of rhinoviruses as the major lower respiratory pathogens in infants has not previously been recognized OBJECTIVES . Although bronchiolitis is the leading cause of hospitalization for infants , there are limited data describing the epidemiology of bronchiolitis hospitalizations , and the associated cost is unknown . Our objective was to determine nationally representative estimates of the frequency of bronchiolitis hospitalizations and its associated costs . PATIENTS AND METHODS . We analyzed the 2002 Health Care Utilization Project-National Inpatient Sample , a federal , stratified r and om survey of hospital discharges . For admissions age < 2 years with a discharge diagnosis of bronchiolitis ( International Classification of Diseases , Ninth Revision , Clinical Modification , code 466.1 ) , we used nationally representative weighted estimates to determine frequency and total hospital charges . Costs were estimated from reported charges by applying hospital-specific cost/charge ratios based on all-payer inpatient cost . RESULTS . In 2002 , an estimated 149000 patients were hospitalized with bronchiolitis .  Frequency of hospitalizations was higher among children age < 1 year of age , male gender , and nonwhite race .  Mean length of stay was 3.3 days . Total annual costs for bronchiolitis-related hospitalizations were $ 543 million , with a mean cost of $ 3799 per hospitalization . Mean cost of bronchiolitis with a codiagnosis of pneumonia was $ 6191 . In a multivariate analysis controlling for 3 confounding factors ( including length of stay ) , cost per hospitalization was higher for children ≥1 year and lower for those in the South versus Northeast . CONCLUSIONS . Bronchiolitis admissions cost more than $ 500 million annually . A codiagnosis of bronchiolitis and pneumonia almost doubles the cost of the hospitalization . Inpatient health care costs of bronchiolitis are higher than estimated previously and highlight the need for initiatives to safely reduce bronchiolitis hospitalizations and thereby decrease health care costs A prospect i ve r and omised controlled pilot study was performed comparing home oxygen therapy with traditional inpatient hospitalisation for children with acute bronchiolitis . Children aged 3–24 months with acute bronchiolitis , still requiring oxygen supplementation 24 h after admission to hospital , were r and omly assigned to receive oxygen supplementation at home with support from “ hospital in the home ” ( HiTH ) or to continue oxygen supplementation in hospital .  44 children ( 26 male , mean age 9.2 months ) were recruited ( HiTH n = 22 ) between 1 August and 30 November 2007 . Only one child from each group was readmitted to hospital and there were no serious complications . Children in the HiTH group spent almost 2 days less in a hospital bed than those managed as traditional in patients : HiTH 55.2 h ( interquartile range ( IQR ) 40.3–88.9 ) versus in hospital 96.9 h ( IQR 71.2–147.2 ) p = 0.001 .  Home oxygen therapy appears to be a feasible alternative to traditional hospital oxygen therapy  in selected children with acute bronchiolitis OBJECTIVES To conduct an in vitro evaluation of a humidified high-flow nasal cannula ( HFNC ) system at different flows , cannula sizes , and air leaks and also an in vivo analysis of mean end-expiratory esophageal pressure ( EEEP ) from nasal continuous positive airway pressure at 6 cm H(2)O ( NCPAP+6 ) versus HFNC . STUDY DESIGN In the in vitro study , we measured HFNC system pressure and flow , with varying degrees of leak and with and without the use of a pressure-limiting valve . In the in vivo study , we measured  EEEP  in 15 newborns on NCPAP+6 and then on HFNC at 6 L/minute , with flow decreased by 1 L/minute every 30 minutes . Heart rate , respiratory rate , fraction of inspired oxygen , arterial oxygen saturation , respiratory distress syndrome score , and EEEP were recorded for each intervention . Data analysis was done using repeated- measures analysis of variance and linear regression . RESULTS In the in vitro study , in the absence of leaks , the pressures were limited by the pressure-limiting valve only at flows > or = 2 L/minute . With leaks of 30 % and 50 % , delivered pressures were always < 3 cm H(2)O. In the in vivo study , respiratory rate increased from baseline ( NCPAP+6 ) as flow decreased ( P < .02 ) . Intrapatient and interpatient coefficients of variation were always high . CONCLUSIONS A pressure-limiting valve is necessary in a HFNC system . Although mean EEEP levels were similar in NCPAP+6 and HFNC , tachypnea developed as flow diminished . This system apparently can not predict EEEP , because of interpatient and intrapatient variation Purpose The high flow nasal cannula ( HFNC ) has recently been proposed to support infants with respiratory syncytial virus (RSV)-related respiratory distress . However , in this disease , no physiologic data are currently available on the effects of this device . We assessed the capacity of HFNC to generate positive airway pressure , as well as the result ing effects on breathing pattern and respiratory effort . Methods Twenty-one infants less than 6 months old with acute RSV bronchiolitis were studied prospect ively in the pediatric intensive care unit of a university hospital .  Pharyngeal pressure ( PP ) and esophageal pressure ( Pes ) were measured simultaneously at four increasing flows of 1 , 4 , 6 and 7 L/min delivered through HFNC . Results The PP was correlated with flow rate ( r = 0.65 , p ≤ 0.0001 ) , reaching mean and end-expiratory values of , respectively , 4 ( 95 % CI 3–5 ) cmH2O and 6.5 ( 95 % CI 5–8 ) cmH2O at 7 L/min . A flow ≥2 L/kg/min was associated with the generation of a mean pharyngeal pressure ≥4 cmH2O with a sensitivity of 67 % , a specificity of 96 % , a positive predictive value of 75 % , and a negative predictive value of 94.5 % . Only flows ≥6 L/min provided positive PP throughout the respiratory cycle . From baseline to maximal flow rate , breathing frequency ( p < 0.01 ) , Ti/Ttot ( p < 0.05 ) , Pes swing ( p < 0.05 ) and PTPesinsp/min ( p < 0.01 ) , an index of respiratory effort , were reduced . Conclusions HFNC with a flow rate equal to or above 2 L/kg/min generated a clinical ly relevant PP , with improved breathing pattern and rapid unloading of respiratory muscles , in young infants with acute RSV bronchiolitis OBJECTIVE . Hypoxia is a common reason for hospital admission in infants and children with acute bronchiolitis . No study has evaluated discharge from the emergency department ( ED ) on home oxygen . This study evaluated the feasibility and safety of ED discharge on home  oxygen in the treatment of acute bronchiolitis . METHODS . This was a prospect i ve , r and omized trial of infants and children with acute bronchiolitis and hypoxia ( room-air saturations of ≤87 % ) aged 2 to 24 months presenting to an urban , academic , tertiary care children 's hospital ED from December 1998 to April 2001 . Subjects received inpatient admission or home oxygen after an 8-hour observation period in the ED . We measured the failure to meet discharge criteria during the observation period , return for hospital admission , and incidence of serious complications . RESULTS . Ninety-two patients were enrolled . Fifty three ( 58 % ) were r and omly assigned to home and 39 ( 42 % ) to inpatient admission . There were no differences between the groups in age , 
    Output:
    
There was no clear evidence of a difference in total duration of oxygen therapy , time to discharge or total length of stay between groups .
There is insufficient evidence to determine the effectiveness of HFNC therapy for treating infants with bronchiolitis .
The included study provides some indication that  HFNC therapy is feasible and well tolerated .