***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 determine survival and neonatal morbidity for babies born between 22 and 26 weeks ’ gestation in Engl and during 2006 , and to evaluate changes in outcome since 1995 for babies born between 22 and 25 weeks ’ gestation . Design Prospect i ve national cohort studies . Setting Maternity and neonatal units in Engl and . Participants 3133 births between 22 and 26 weeks ’ gestation in 2006 ; 666 admissions to neonatal units in 1995 and 1115 in 2006 of babies born between 22 and 25 weeks ’ gestation . Main outcome measures Survival to discharge from hospital , pregnancy and delivery outcomes , infant morbidity until discharge . Results In 2006 , survival of live born babies was 2 % ( n=3 ) for those born at 22 weeks ’ gestation , 19 % ( n=66 ) at 23 weeks , 40 % ( n=178 ) at 24 weeks , 66 % ( n=346 ) at 25 weeks , and 77 % ( n=448 ) at 26 weeks ( P<0.001 ) . At discharge from hospital , 68 % ( n=705 ) of survivors had bronchopulmonary dysplasia ( receiving supplemental oxygen at 36 weeks postmenstrual age ) , 13 % ( n=135 ) had evidence of serious abnormality on cerebral ultrasonography , and 16 % ( n=166 ) had laser treatment for retinopathy of prematurity . For babies born between 22 and 25 weeks ’ gestation from March to December , the number of admissions for neonatal care increased by 44 % , from 666 in 1995 to 959 in 2006 . By 2006 adherence to evidence based practice associated with improved outcome had significantly increased . Survival increased from 40 % to 53 % ( P<0.001 ) overall and at each week of gestation : by 9.5 % ( confidence interval −0.1 % to 19 % ) at 23 weeks , 12 % ( 4 % to 20 % ) at 24 weeks , and 16 % ( 9 % to 23 % ) at 25 weeks . The proportions of babies surviving in 2006 with bronchopulmonary dysplasia , major cerebral scan abnormality , or weight and /or head circumference < −2 SD were similar to those in 1995 , but the proportion treated for retinopathy of prematurity had increased from 13 % to 22 % ( P=0.006 ) . Predictors of mortality and morbidity were similar in both cohorts . Conclusion Survival of babies born between 22 and 25 weeks ’ gestation has increased since 1995 but the pattern of major neonatal morbidity and the proportion of survivors affected are unchanged . These observations reflect an important increase in the number of preterm survivors at risk of later health problems Objective : Neurally adjusted ventilatory assist ( NAVA ) synchronizes spontaneous respiratory effort with mechanical ventilation . Electrodes detect the electrical activity of the diaphragm ( Edi ) and transmit this information to the ventilator , allowing the patient to determine their own respiratory rate ( RR ) , peak pressures , and inspiratory and expiratory times in synchrony with the ventilator . The objective of this study was to evaluate if premature neonates ventilate as effectively on NAVA as compared to pressure control ventilation ( PCV ) . Study Design : Five ventilated neonates were enrolled ( gestational age 25–29 weeks ) . Each neonate was ventilated on NAVA for 4 h , then switched to PCV for another 4 h. The cycle was repeated three times . Ventilatory parameters were averaged every 30 min to collect eight time points for each ventilatory mode . Data were analyzed using the mixed effects model procedure , utilizing the least-squares means ( P<0.05 ) . Result : When compared to PCV , neonates ventilated with NAVA had lower peak inspiratory pressures ( PIP ) , fraction of inspired oxygen ( FiO2 ) , transcutaneous PCO2 Edi peak and RR . There was an increase in expiratory tidal volume ( TV ) , compliance and Edi minimum . Despite lower PIP and RR , partial pressure of CO2 ( PCO2 ) was lower when ventilated on NAVA . There was no difference in mean airway pressure . Conclusion : Premature neonates ventilated with  NAVA required less PIP , FiO2 and RR to achieve lower PCO2 and better compliance compared with PCV Abstract Neurally adjusted ventilatory assist ( NAVA ) improves patient-ventilator synchrony during invasive ventilation and leads to lower peak inspiratory pressures ( PIP ) and oxygen requirements . The aim of this trial was to compare NAVA with current st and ard ventilation in preterm infants in terms of the duration of invasive ventilation .  Sixty infants born between 28 + 0 and 36 + 6 weeks of gestation and requiring invasive ventilation due to neonatal respiratory distress syndrome ( RDS ) were r and omized to conventional ventilation or NAVA .  The median duration s of invasive ventilation were 34.7 h ( quartiles 22.8–67.9 h ) and 25.8 h ( 15.6–52.1 h ) in the NAVA and control groups , respectively ( P = 0.21 ) . Lower PIPs were achieved with NAVA ( P = 0.02 ) , and the rapid reduction in PIP after changing the ventilation mode to NAVA made following the predetermined extubation criteria challenging . The other ventilatory and vital parameters did not differ between the groups . Frequent apneas and persistent pulmonary hypertension were conditions that limited the use of NAVA in 17 % of the patients r and omized to the NAVA group . Similar cumulative doses of opiates were used in both groups ( P = 0.71 ) . Conclusions : NAVA was a safe and feasible ventilation mode for the majority of preterm infants suffering from RDS , but the traditional extubation criteria were not clinical ly applicable during NAVA.What is known:• NAVA improves patient-ventilator synchrony during invasive ventilation.• Lower airway pressures and oxygen requirements are achieved with NAVA during invasive ventilation in preterm infants by comparison with conventional ventilation . What is new:• Infants suffering from PPHN did not tolerate NAVA in the acute phase of their illness.• The traditional extubation criteria relying on inspiratory pressures and spontaneous breathing efforts were not clinical ly applicable during NAVA OBJECTIVE To determine whether neurally adjusted ventilatory assist ( NAVA ) , a new method of mechanical ventilation that delivers pressure assistance that is proportional to the electrical activity of the diaphragm ( EAdi ) , could lower the inspiratory pressure and respiratory muscle load in preterm infants supported with ventilators . STUDY DESIGN Twenty-six mechanically ventilated preterm infants were r and omized to crossover ventilation with NAVA and synchronized intermittent m and atory ventilation ( SIMV ) with pressure support ( PS ) for 4 hours each in a r and omized order . A 1-hour interval for washout was provided between the 2 modes of ventilation . The ventilator setting s were adjusted to maintain similar levels of end-tidal partial pressure of CO(2 ) . The ventilator parameters , vital signs , and gas exchange effects under the 2 ventilatory modes were compared . RESULTS Nineteen infants completed the 9-hour crossover comparison protocol . Peak inspiratory pressure ( PIP ) , work of breathing , and peak EAdi with NAVA were lower than those in SIMV with PS .  Calculated tidal volume to peak EAdi ratio and PIP to peak EAdi ratio were higher with NAVA . There were no significant differences in mean airway pressure , inspiratory oxygen fraction , and blood gas values . The measurements of vital signs did not differ significantly between the 2 modes . CONCLUSION NAVA lowered PIP and reduced respiratory muscle load in preterm infants at equivalent inspiratory oxygen fraction and partial pressure of CO(2 ) of capillary blood in comparison with SIMV with PS Objective To test the hypothesis that in very prematurely born infants remaining ventilated beyond the first week , proportional assist ventilation ( PAV ) compared with assist control ventilation ( ACV ) would be associated with reduced work of breathing , increased respiratory muscle strength and less ventilator – infant asynchrony which would be associated with improved oxygenation . Design R and omised crossover study . Setting Tertiary neonatal unit . Patients 12 infants with a median gestational age of 25 ( range 24–26 ) weeks were studied at a median of 43 ( range 8–86 ) days . Interventions Infants were studied for 1 h each on PAV and ACV in r and om order . Main outcome measures At the end of each hour , the work of breathing ( assessed by measuring the diaphragmatic pressure time product ) , thoracoabdominal asynchrony and respiratory muscle strength ( maximal inspiratory pressure , maximal expiratory pressure ( Pemax ) and maximal transdiaphragmatic pressure ( Pdimax ) ) were assessed . Blood gas analysis was performed and the oxygenation index ( OI ) calculated . Results After 1 h on PAV compared with 1 h on ACV , the median OI ( 5.55 ( range 5–11 ) vs 10.10 ( range 7–16 ) , p=0.002 ) and PTP levels were lower ( 217 ( range 59–556 ) cm H2O.s/min vs 309 ( range 55–544 ) cm H2O.s/min , p=0.005 ) , while Pdimax ( 44.26 ( range 21–66 ) cm H2O vs 37.9 ( range 19–45 ) cm H2O , p=0.002 ) and Pemax ( 25.6 ( range 6.5–42 ) cm H2O vs 15.9 ( range 3–35 ) cm H2O levels p=0.010 ) were higher . Conclusions These results suggest that PAV compared with ACV may have physiological advantages for prematurely born infants who remain ventilated after the first week after birth In a previous study of preterm infants requiring mechanical ventilation for the respiratory distress syndrome , we demonstrated a striking association of fluctuating cerebral blood-flow velocity in the first day of life with the subsequent occurrence of intraventricular hemorrhage . Because this fluctuating pattern could be eliminated by muscle paralysis , we conducted a prospect i ve study of preterm infants receiving mechanical ventilation for the respiratory distress syndrome in which we evaluated the effect of paralysis and this flow-velocity pattern on the incidence and severity of intraventricular hemorrhage .  Twenty-four infants with the fluctuating pattern in the first hours of life were identified and r and omly selected to serve as controls ( 10 ) or to be subjected to muscle paralysis ( 14 ) . Intraventricular hemorrhage developed in all 10 control infants but in only 5 of the 14 infants subjected to muscle paralysis . Moreover , in 4 of the 5 paralyzed infants in whom hemorrhage developed , it did so after cessation of the paralysis . Seven of the 10 control infants had Grade III hemorrhage , the most severe variety of intraventricular hemorrhage , whereas none of the paralyzed infants had Grade III hemorrhage . We conclude that elimination of fluctuating cerebral blood-flow velocity in preterm infants with respiratory distress syndrome markedly reduces the incidence and severity of intraventricular hemorrhage OBJECTIVE Neurally adjusted ventilatory assist ( NAVA ) is a new ventilator modality with an innovative synchronization technique . Our aim is to verify if NAVA is feasible and safe in terms of physiological and clinical variables in infants recovering from severe acute respiratory distress syndrome ( ARDS ) . DESIGN This is a pilot nested study to help future trial design . SETTING The study was performed in third-level academic pediatric intensive care units . PATIENTS Infants affected by severe ARDS requiring high-frequency ventilation and weaned with NAVA during 2010 were included . Controls ( 2:1 ratio ) were ARDS infants weaned with pressure support ventilation ( PSV ) during 2008 - 2009 matched for age , gas exchange impairment , and weight . MAIN OUTCOME MEASURES The main outcome measures were the physiological and ventilator parameters and the duration of ventilator support in  PSV  or NAVA . RESULTS Ten infants treated with NAVA and 20 with PSV were studied . Heart rate ( P < .001 ) and mean arterial pressure ( P < .001 ) increased less during NAVA than during PSV . Similarly , Pao2/Fio2 ratio decreased less in NAVA than in PSV ( P < .001 ) . Neurally adjusted ventilatory assist also result ed in lower Paco2 ( P < .001 ) and peak pressure ( P = .001 ) , as well as higher minute ventilation ( P = .013 ) . COMFORT score ( P = .004 ) and duration of support were lower in NAVA than in PSV ( P = .011 ) . CONCLUSIONS Neurally adjusted ventilatory assist is safe and suitable in infants recovering from severe ARDS . It could provide better results than PSV and is worth to be investigated in a multicenter r and omized trial Background : Neurally adjusted ventilatory assist ( NAVA ) is a novel mode of ventilation that has been demonstrated to improve infant-ventilator interaction , compared to the conventional modes in retrospective and short-term studies . Objectives : To prospect ively evaluate the physiologic effects of NAVA in 
    Output:
    
This study found no significant difference in duration of mechanical ventilation , nor in rates of BPD , pneumothorax , or IVH .