Efficacy of nasal high frequency oscillation ventilation (NHFOV) compared to noninvasive positive-pressure ventilation (NIPPV) in pre-terms with respiratory distress syndrome during the first 7 days of life

Premature neonates (Gestational age 27 wk -34wk) born with respiratory distress syndrome was assigned on intervention group within 6 hours of birth by an attending pediatric registrar not involved in the research in neonatl intensive care unit. intervention group was provided nasal high frequency oscillation ventilation (NHFOV) by a high-frequency ventilator (Medin, Germany) via nasal mask. Initial settings were be a mean airway pressure of 6 cm H2O (range 6–10), which was equivalent to that for the NIPPV group and a frequency of 8 Hz (range 8-12).The amplitude produced by the Medin CNO device was adjusted between 1 and 10, and the initial setting for the amplitude was 7 (range 7–10). An Oro-gastric tube was placed in the stomach to limit the abdominal distention and was intermittently aspirated during the study period in intervention group. Nasal mask as an interface was used in intervention group. Nasal mask that fits the nares without blanching the surrounding skin,based on the diameter of the nares (small , medium ,large size )as per manufacturer’s recommendations was used. Pacifiers was be used to reduce the air leaks from the mouth. Target oxygen saturation (SpO2) from 90 %to 94% in preterm neonates less 30weeks gestational age (GA) and more than 89 % to 94% in neonates more than 30 week gestational age by pulse oximeter. Neonates with moderate to sever Respiratory Distress Syndrome was given Surfactant (curocef, Poractant alfa, Chiesi Pharmaceuticals, Parma, Italy), at a dose of 2.5ml/kg via the INSURE method (intubation, surfactant, and extubation) before initiation of intervention. In the INSURE technique, surfactant was administered via an endotracheal tube and after a brief period of positive pressure ventilation, patients was extubated via the assigned mode. Infants undergoing the INSURE method was not be considered as having received inasive mechanical ventilation (IMV). Second doses of surfactant 1.5ml/kg may be given using the INSURE technique with in 12 hours, if FiO2 requirement more than 0.40 to maintain target SpO2 (89% to 93%) for preterm with less than 30 week (90-94%) for more than 30week gestational age. A caffeine citrate injection (Chiesi Pharmaceuticals, Parma, Italy) was be administered via intravenous site,when infants present with moderate apnea (defined as three or more episodes in 24 h or a single episode requiring resuscitation and bag and mask ventilation). The initial loading dose was 20 mg/kg, and the maintenance dose was 10mg/kg per day till completion of 34 week post-conception gestational age. If baby was failed on intervention group then neonate was intubated as follows. The criteria for intubation and invasive mechanical ventilation (IMV) was : severe respiratory acidosis (PaCO2 more than 65 mmHg with pH <7.20), severe apnea and bradycardia (defined as recurrent apnea with more than 3 episodes per hour associated with heart rate less than 100/min or a single episode of apnea that requires bag and mask ventilation), hypoxemia (FiO2 more than 0.5 with PaO2 less than 50 mmHg from an arterial blood gas sample), severe respiratory distress, pulmonary hemorrhage, and cardiopulmonary arrest needing chest compressions. The criteria for weaning from intervention was: (1) minimal or no signs of respiratory distress, (2) mean airway pressure pressure less than 6 cm H2O, and (3) FiO2 less than 0.25 to achieve target oxygen saturation ( SpO2).