None listed
Conditions
Brief summary
Many preterm infants receive supplemental oxygen during their first hospitalisation, with fraction of inspired oxygen (FiO2) titrated to target a preferred oxygen saturation (SpO2) range. Both hypoxia and hyperoxia are known to be associated with adverse outcomes, including mortality, chronic lung disease, retinopathy and necrotizing enterocolitis. SpO2 targeting is, however, fraught with difficulty, with manual oxygen control targeting the desired SpO2 range less than 50% of the time. Automated oxygen control may offer a solution, with existing control algorithms increase time in target range by around 10% in short term studies. We have developed an adaptive and intuitive algorithm (VDL1.1) for automated control of inspired oxygen in the preterm infant, which is to be used in the study outlined in this proposal. A forerunner version of the algorithm (VDL1.0), has been found to be very effective in SpO2 targeting, both in pre-clinical studies using a simulation of oxygenation, and in a 4 hour crossover study in preterm infants. We propose to evaluate the effectiveness of the VDL1.1 algorithm in a 24 hour crossover study under standard clinical conditions. Preterm infants <32 weeks gestation at birth will be eligible if less than 4 months of age, receiving non-invasive respiratory support and showing the need or potential need for supplemental oxygen. In a non-randomised crossover study, a 24 hour period of automated oxygen control will be compared with two flanking 12 hour periods of standard manual control of inspired oxygen (total 24 hours). Additionally, within the 24 hour automated control period the function of the VDL1.1 algorithm with an apnoea-responsive element active or inactive (12 hours each in random order) will be evaluated. Primary outcome for the main study is eupoxia - the proportion of time with oxygen saturation in the desired target range, or above the desired target range when no supplemental oxygen is being administered. Secondary outcomes include i) proportion of time, and episodes of, hypoxia (SpO2 <80%, 80-84%, 85-88%) and hyperoxia (SpO2 >96% and >98%) when in supplemental oxygen; and ii) number of manual FiO2 adjustments per 24 hours. A total of 60 crossover periods will be studied.
Interventions
Automated control of inspired oxygen therapy will be administered using a custom-built device incorporating a novel, adaptive and intuitive control algorithm (VDL1.1). This device receives SpO2 input from an oximeter, compares the value with the midpoint of the desired SpO2 range, and provides an output, which is an updated value for FiO2. Automated control using this device will be used for a 24 hour period in all study subjects, and will be compared with two flanking periods of manual control.
Automated control of inspired oxygen therapy will be administered using a custom-built device incorporating a novel, adaptive and intuitive control algorithm (VDL1.1). This device receives SpO2 input from an oximeter, compares the value with the midpoint of the desired SpO2 range, and provides an output, which is an updated value for FiO2. Automated control using this device will be used for a 24 hour period in all study subjects, and will be compared with two flanking periods of manual control. The schedule of interventions is thus 12 hours manual control, 24 hours automated control and 12 hours manual control. The SpO2 target range will be 90-94% for both manual and automated control. In a sub-study within the 24 hour period of automated control, the effectiveness of activating an apnoea responsive feature in the algorithm will be compared with no apnoea response in two 12 hour periods in random order. When this feature is activated, the algorithm will make a pre-emptive response when respiratory pauses (5-14 sec) or apnoea (15 sec or more) are detected, potentially in advance of a deviation in SpO2.
Sponsors
Menzies Institute for Medical Research, University of Tasmania
Study design
Allocation
Non-randomised trial
Intervention model
Other
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
No minimum to 4 Months
Healthy volunteers
No
Inclusion criteria
i) Preterm birth at <32 weeks gestation ii) Requirement for non-invasive respiratory support, including continuous positive airway pressure (CPAP), or high flow via nasal cannula (HF). iii ) Either a) requirement for supplemental oxygen at the time of commencing the study, or b) in room air but showing a propensity to hypoxic events with or without apnoea. iv) Research team available to commence recording.
Exclusion criteria
Currently ventilated or in imminent need of intubation and ventilation
Outcome results
None listed