***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 performed a r and omized , prospect i ve clinical trial comparing intratracheal administration of human surfactant with conventional treatment with intermittent m and atory mechanical ventilation alone for treatment of severe respiratory distress syndrome in preterm infants of less than 30 weeks gestation . Twenty-two infants ( mean gestational age 27.0 weeks , mean birth weight 987 gm ) were given surfactant , and 23 infants ( mean gestational age 27.2 week , mean birth weight 1055 gm ) received intermittent m and atory ventilation . Infants given surfactant required less FiO2 during the first week , had lower mean airway pressure during the first 48 hours , and had improved ventilatory index and a/A PO2 ratio . Death or the occurrence of bronchopulmonary dysplasia was significantly less among infants given surfactant ( P = 0.019 ) . Pneumothorax , pulmonary interstitial emphysema , and need for FiO2 greater than or equal to 0.3 for greater than 30 days was significantly less in the surfactant group . This trial confirms the efficacy of treatment with human surfactant in preterm infants with severe respiratory distress syndrome We carried out a multicenter r and omized , placebo-controlled trial to evaluate the efficacy and safety of surfactant in the treatment of respiratory distress syndrome . The study population was made up of newborn infants weighing 750 to 1750 g who were receiving assisted ventilation with 40 percent or more oxygen . The eligible infants received a single dose of either surfactant ( 100 mg of phospholipid per kilogram of body weight [ 4 ml per kilogram ] ) or an air placebo ( 4 ml per kilogram ) , administered into the trachea within eight hours of birth by an investigator not involved in the clinical care of the infant . When compared with the infants who received the placebo ( n = 81 ) , the infants who were treated with surfactant ( n = 78 ) had a 0.12 greater average increase in the ratio of arterial to alveolar oxygen tension ( P less than 0.0001 ) , a 0.20 greater average decrease in the fractional inspiratory oxygen concentration ( P less than 0.0001 ) , and a 0.26-kPa greater average decrease in the mean airway pressure ( P less than 0.0001 ) during the 72 hours after treatment . Pneumothorax was less frequent among the infants treated with surfactant than in the control group ( 13 percent vs. 37 percent ; P = 0.0005 ) . There were no statistically significant differences between the groups in the proportion of infants in each of five ordered clinical -status categories on day 7 ( P = 0.08 ) or day 28 ( P = 0.75 ) after treatment . There were also no significant differences between the groups in the frequency of bronchopulmonary dysplasia , patent ductus arteriosus , necrotizing enterocolitis , or periventricular-intraventricular hemorrhage . In each group , 17 percent of the infants died by day 28 . We conclude that treatment with the single-dose surfactant regimen used in this study reduces the severity of respiratory distress during the 72 hours after treatment and decreases the frequency of pneumothorax , but that it does not significantly improve clinical status later in the neonatal period and does not reduce neonatal mortality . Further study of different surfactant regimens and patient- selection criteria will be required to determine whether this initial improvement can be translated into reductions in mortality or serious morbidity In a double-blind clinical trial the effects of a single dose of reconstituted bovine surfactant ( ' Surfactant TA ' ) were assessed in 30 premature infants ( birthweight 751 - 1750 g ) with severe hyaline membrane disease . 17 infants had a sonicated saline suspension of 100 mg/kg surfactant phospholipid instilled into the trachea at 5.0 ( SD 0.7 ) hours of age and 13 infants received saline by the same route at 4.3 ( 1.1 ) hours of age . In the surfactant-treated group there was early improvement in oxygenation and ventilation . Haemodynamically significant patent ductus arteriosus occurred more often in the surfactant group ; pneumothorax and pulmonary interstitial emphysema occurred less often . The combined incidence of death and severe bronchopulmonary dysplasia was significantly lower in the surfactant group ( 3/17 ) than in the placebo group ( 9/13 ) The postnatal growth , respiratory status and neurodevelopmental outcome of surviving babies enrolled in the first European multicentre trial of porcine surfactant ( Curosurf ) replacement for severe neonatal respiratory distress syndrome , were assessed at corrected ages of 1 and 2 years . Follow up rates of survivors were 93 % at 1 year and 89 % at 2 years . Treated and control groups were similar at both 1 and 2 years in terms of physical growth , the prevalence of persistent respiratory symptoms and the occurrence of major and minor disability . Serum antibodies recognising Curosurf and surfactant-anti-surfactant immune complexes were detected in both treated and control babies , the titres showing no difference between groups . Examination of histological lung sections from non-survivors revealed a higher incidence of severe pulmonary interstitial emphysema in control babies than in those treated with surfactant . Surfactant treatment for severe respiratory distress syndrome reduces neonatal mortality and air leaks and is not associated with an increase in disability 2 years later Treatment with bovine surfactant ( SF-RI 1 ) was shown to be efficacious in improving pulmonary function and in increasing survival rate without BPD in very premature infants .  Surfactant therapy did not affect the risk of major complications of prematurity We conducted a prospect i ve , r and omized , unblinded , controlled trial of exogenous bovine surfactant ( surfactant TA ) in premature infants requiring ventilator support for the treatment of severe hyaline membrane disease . Forty-one low birth weight infants with severe hyaline membrane disease were r and omly assigned to saline or surfactant therapy and treated within eight hours of birth . Significant improvements in oxygenation ( increased arterial/alveolar PO2 ) and respiratory support ( decreased mean airway pressure ) were seen in the group receiving surfactant within four hours after treatment . These improvements were maintained in the surfactant-treated infants , who also had fewer pneumothoraces and fewer number of days in environments of fractional inspiratory oxygen greater than 0.4 mm Hg . No problems were associated with administration of surfactant , and no acute side effects were detected . We conclude that exogenous surfactant , administered early in the course of severe hyaline membrane disease , is an effective therapy that can diminish the amount of respiratory support required during the first 48 hours of life The results obtained with porcine surfactant ( Curosurf ) administration for the treatment of hyaline membrane disease ( HMD ) are reported . Thirty premature infants weighing 700 to 2,000 g with severe HMD ( mechanical ventilation and oxygen requirement ( FiO2 ) greater than 60 % were r and omly allocated at 2 to 15 hours postnatal age . Eight of the 30 patients included in this group participated in a multicenter european trial . The fifteen infants with mean gestational age ( GA ) of 29.5 weeks included in the treatment group ( T ) , were treated at 8.6 hours of life with a single dose of 200 mg/kg Curosurf given intratracheally while 15 infants of mean GA 30 weeks formed the control group ( C ) . Infants in the T group showed an immediate , dramatic and sustained improvement of oxygenation as reflected by increased PaO2/FiO2 and arterial to alveolar PO2 ratios within 1 hour . This significant improvement in favor of T group ( p less than 0.005 ) persisted for 2 days when control infants began to recover . This improvement in oxygenation allowed a significant decrease of FiO2 ( p less than 0.005 ) and mean airway pressure ( p less than 0.01 ) in the T group within 1 hour and up till the second day . Despite this early improvement obtained with Curosurf the survival rate at 28 days of life and the incidence of associated HMD complications were not significantly modified . However the tendency was towards decreased respiratory morbidity . The discussion will consider the value of multiple doses We investigated the clinical efficacy of a new surfactant product , Curosurf , isolated from porcine lungs by liquid-gel chromatography . Ten premature newborn infants ( birth weight 850 - 1850 g ) , all ventilated artificially for severe hyaline membrane disease categorized radiologically as stage III-IV , received a single dose of Curosurf ( 200 mg/kg ) via the tracheal tube . This treatment result ed in a rapid improvement of oxygenation , similar to that observed by other teams collaborating in the study and , in an astonishingly fast resolution of the radiological changes . In comparison with a control group of 8 infants , the surfactant-treated babies also had a lower incidence of acute and chronic complications In a r and omized , controlled study , human surfactant derived from amniotic fluid was administered within 12 hours of birth to infants with severe respiratory distress syndrome who were born at 24 to 32 weeks of gestation weighing less than or equal to 1500 gm . A second dose of surfactant was given to patients in the treatment group if they met ventilator requirements indicating relapse or lack of response to the initial dose . No significant improvement was observed in mortality rate ( 9/28 vs 15/31 ) or incidence of bronchopulmonary dysplasia ( 5/28 vs 3/31 ) when surfactant-treated infants were compared with control subjects , although there was a significant reduction in initial respirator and inspired oxygen requirements and the arterial/alveolar oxygen ratio improved . In addition , there was a significant reduction in pulmonary air leak in treated infants ( 10/28 vs 20/31 ; p less than 0.05 ) . Retreatment was associated with an attenuated ventilatory response and with a higher mortality rate ( 7/14 ) than that of infants who did not require a second dose ( 2/14 ; p = 0.05 ) , indicating a more severe form of disease . Multiple discriminant analysis , including eight independent variables , revealed that increasing birth weight , earlier age at surfactant treatment , and female gender were significantly associated with survival . These data suggest that early surfactant treatment may reduce mortality rates in very low birth weight infants with severe respiratory distress syndrome , as well as reduce ventilator requirements and the incidence of pulmonary air leaks To determine if outcomes of low birth weight neonates with respiratory distress syndrome can be improved by the administration of multiple doses of bovine surfactant , we conducted two identical multicenter , controlled trials , and the results were combined for analysis . Seven hundred and ninety-eight neonates weighing 600 to 1750 g at birth who had developed respiratory distress syndrome within 6 hours of birth were assigned r and omly to receive either 100 mg of phospholipid/kg of Survanta , a modified bovine surfactant ( n = 402 ) , or a sham dosing procedure ( n = 396 ) . Neonates whose respiratory distress persisted could be given up to three more doses , with all doses to be given in the first 48 hours after birth . Dosing was performed by investigators not involved in the clinical care of the neonates ; nursery staff were kept blinded as to the treatment assignment . Fewer Survanta-treated neonates died of any cause ( 18.4 % vs 27.3 % , P = .002 ) , died of respiratory distress syndrome ( 9.0 % vs 20.3 % , P less than .001 ) , and either died or developed bronchopulmonary dysplasia due to respiratory distress syndrome ( 51.2 % vs 64.6 % , P less than .001 ) . Neonates who received Survanta also had greater improvement in their oxygenation and ventilatory status from baseline to 72 hours than did control neonates . Survanta-treated neonates were at lowered risk for developing pulmonary interstitial emphysema ( 18.6 % vs 39.3 % , P less than .001 ) and other pulmonary air leaks ( 11.5 % vs 25.9 % , P less than .001 ) . We conclude that multiple doses of Survanta given after diagnosis of respiratory distress syndrome reduce mortality and morbidity We assessed postnatal growth , neurodevelopmental outcome , and occurrence of respiratory illnesses in 46 infants of very low birth weight who were enrolled in a r and omized , controlled , bicenter clinical trial of human surfactant treatment for respiratory distress syndrome . No long-term adverse effects of human surfactant treatment were detected between control and human surfactant-treated infants with respect to growth , neurologic , or developmental outcome .  Infants with chronic lung disease , regardless of treatment group , had poorer growth and were more likely to have neurodevelopmental abnormalities at 12 to 24 months of age Several r and omized clinical trials have shown that surfactant therapy improves the pulmonary status of infants with respiratory distress syndrome and has the potential to reduce morbidity and mortality in these infants . Relatively little is known , however , about the long-term consequences of surfactant treatment . In this report , the results of health and developmental assess 
    Output:
    
The studies demonstrated an initial improvement in respiratory status ( improved oxygenation and decreased need for ventilator support ) .
AUTHORS ' CONCLUSIONS Infants with established respiratory distress syndrome who receive animal derived surfactant extract treatment  have a decreased risk of pneumothorax , a decreased risk of pulmonary interstitial emphysema , a decreased risk of mortality , and a decreased risk of bronchopulmonary dysplasia or death