None listed
Conditions
Brief summary
Apnoea of prematurity (AOP), where an infant stops breathing for more than 20seconds, is found in over half of babies born very prematurely. AOP may be accompanied by slowing of the heart rate as well as drop in the blood oxygen levels. Another form of breathing disorder called periodic breathing, is found primarily in premature infants where there is a repetitive pattern of breathing efforts alternating with pauses. Most preterm infants exhibit periodic breathing and it can continue until the infant reaches 4-6 months of age. Apart from breathing control disorderm preterm babies are also at risk of developing bronchopulmonary dysplasia (BPD) or chronic lung disease of prematurity, where there the injured premature lung develops in an abnormal way. There is still some debate about the best way of classifying this disease with the NICHD in the United States dividing this into three levels (mild, moderate and severe) based on the need for oxygen or respiratory support. Infants with BPD experience periods of low blood oxygen that may be severe, especially during sleep and these infants are thought to be at risk of sudden infant death syndrome (SIDS) or cot death. The major cause of oxygenation problems in BPD is due to the severity of the lung disease. The level of the lung disease will determine how much oxygen gets absorbed into the blood of the baby with every breath. A reliable way of determing the severity is by measuring how much the blood gets "oxygenated", i.e. the less severe the lung disease the better the oxygenation and vice versa. This measure is also called the right-to-left shunting and the ventilation: perfusion (V:Q )ratio. A nonivasive way of measuring the shunt will involve making stepwise reductions in oxygen that the baby breathes while ensuring that the oxygen level (that is constantly monitored) remains within intended range. The aim of this study is to investigate 1) firstly breathing patterns (or disorders) and develop tools for classifying breathing patterns and 2) secondly lung disease severity (right-left shunts) and develop quantitative measures of these in preterm infants with bronchopulmonary dysplasia or chronic lung disease.
Interventions
Change in concentration of inspired oxygen (FiO2). The steps are detail as follows. Stepwise reduction/increase steps in the FiO2 (of 1-2%) separated by 5 minutes will be made while maintaining the oxygen saturation within the unit's oximeter alarm limits of 88-96% for infants >36 weeks PMA. Once the lower/upper alarm limit is reached, we propose to reverse the stepwise change until the upper/lower limit is reached; so that we can determine the FiO2 limits (range setting phase) whereby the infa
Change in concentration of inspired oxygen (FiO2). The steps are detail as follows. Stepwise reduction/increase steps in the FiO2 (of 1-2%) separated by 5 minutes will be made while maintaining the oxygen saturation within the unit's oximeter alarm limits of 88-96% for infants >36 weeks PMA. Once the lower/upper alarm limit is reached, we propose to reverse the stepwise change until the upper/lower limit is reached; so that we can determine the FiO2 limits (range setting phase) whereby the infant can maintain SpO2 within the reference range in his/her current state. Then we proposed to make a discrete change in the FiO2 to the other end of the range and maintain for between 15-30 seconds and then revert to the opposite extreme. After this, the FiO2 will be returned to its original level. The order in which the FiO2 is either increased or decreased will be randomised.
Sponsors
The Ritchie Centre, Monash University
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
36 Weeks to 44 Weeks
Healthy volunteers
No
Inclusion criteria
Preterm infants < 29 weeks gestation. 1. Healthy preterm infant (<29 weeks) without BPD Infants with BPD defined as need for oxygen or respiratory support at 36 weeks completed postmenstrual age (PMA). Infants will be further subdivided into 2. Mild BPD (no need for oxygen or respiratory support at 36 weeks PMA but need for either at 28 days of age). 3. Moderate BPD - need for supplemental oxygen (<30%) at 36 weeks PMA butself-ventilating 4. Severe BPD - need for supplemental oxygen (>30%) at 36 weeks PMA or needing respiratory support. Infants in Group 1, the healthy preterm infant will be the control group while infants in Groups 2 to 4 with mild/moderate/severe BPD will be in the intervention group
Exclusion criteria
Infants with congenital heart disease Infants with major congenital anomalies
Outcome results
None listed