effect of nasal cpap versus nippv on diaphragm electrical activity (edi) in vlbw preterm infants

Conditions: Preterm Birth; Premature Lungs; Respiratory Distress Syndrome in Premature Infant

Summary: background: in premature babies, many organ systems are not fully grown and developed, including the lungs and respiratory muscles, so they will need breathing support to help them to breathe by preventing their tiny air sacs to collapse. this support commonly done by cpap and non-invasive positive pressure ventilation (nippv) therapy by giving some pressure and oxygen to their lungs through an interface placed on their noses. both (cpap and nippv) can be used as a support modality for respiratory distress syndrome, apnea of prematurity, and providing breathing support after extubation from the full mechanical breathing support. the cpap supports the baby's immature lungs by delivering constant pressure to keep their lungs and breathing well supported. whereas the nippv will use constant pressure in the background (similar to cpap), and on top, it will give extra intermittent puffs at regular intervals to support the baby's breathing. the nippv is the most common choice by the clinicians when the traditional cpap is no longer effective, to avoid the full mechanical breathing support and to protect the developing lungs. studies suggested that nippv is better than the traditional cpap in reducing the need of the baby to need full mechanical breathing support. this might be because the investigators tend to use lower pressures with cpap (5-8 cmh2o) compared to relatively higher pressures with nippv. more recently, clinicians showed the safety of using equivalent higher cpap pressures (\>9 cmh2o) to what the investigators use in the nippv in preterm babies. one way to measure the support that the investigators are giving to the patient with the different devices is to measure the diaphragm activity, which the investigators call the edi signal, using a special feeding catheter and a specific machine to measure it. the catheter is placed and used as a routine feeding tube but has sensors at the end to measure this edi signal. one opening of the tube will be connected to a computer to record the edi signals. the other opening of the tube will be used for feeding.

our main goal in this study: to measure and compare the edi in preterm babies requiring breathing support with cpap or nippv. inclusion criteria (potential candidates): this study involves stable babies who were born with a birth weight of less than 1500 grams and require cpap. the steps of the study: the baby will be assigned to first go on traditional cpap, nippv, or high cpap, stay for 2 hours, switch to one of the other methods for 2 hours and then spend 2 hours supported by the remaining method. the investigators will continue to record the edi signals during the 3 methods. study duration will be 6 hours from the time of catheter insertion to fit into feeding and handling plans. upon completion or termination of the study protocol, the participant's baby will be put back to the originally prescribed breathing support. routine monitoring for oxygen saturation, heart rate, and respiratory rate will be continued as per the standard of practice in the nicu.

Eligibility criteria:
inclusion criteria: * clinically stable preterm infants (defined as cardiovascular stability with normal blood pressure and heart rate for gestational age and no recent increase in apneic episodes or spells and confirmed by the attending neonatologist) * birth weight less than 1500 grams * admitted to the nicu at sunnybrook health sciences centre on nasal cpap of 5 to 8 cmh2o support, for at least 48 hours and requiring less than 35% of oxygen exclusion criteria: * congenital anomalies of the gastrointestinal tract * phrenic nerve damage * diaphragmatic paralysis * esophageal perforation * congenital or acquired neurological deficit (including significant intraventricular hemorrhage greater than grade ii) or neonatal seizure * significant congenital heart disease (including symptomatic pda) * congenital anomalies of the diaphragm * congenital anomalies of the respiratory tracts (e.g., congenital cystic adenomatoid malformation 'ccam') * ongoing treatment for sepsis * ongoing treatment for necrotizing enterocolitis (nec) * ongoing treatment for lung infections * narcotic analgesics * gastric motility agents * infants on nasal cpap and requiring more than 35% oxygen * infants with significant gastric residuals and vomiting * infants with facial anomalies * infants with pneumothorax or pneumomediastinum * infants in the immediate postoperative period