Closed-loop Automatic Oxygen Control (CLAC-4) in Preterm Infants: a Randomized Controlled Trial of a Revised Algorithm

BACKGROUND AND OBJECTIVE In preterm infants receiving supplemental oxygen, routine manual control (RMC) of the fraction of inspired oxygen (FiO2) is often difficult and time consuming. The investigators developed a system for closed-loop automatic control (CLAC) of the FiO2 and demonstrated its safety and efficacy in a multi-center study. The objective of this study is to test a revised, "faster" algorithm with a shorter WAIT-interval of 30sec (= time between FiO2 changes) against the previously tested algorithm (WAIT of 180sec) and against RMC. The primary hypothesis is, that the application of CLAC with the "faster" algorithm in addition to RMC results in more time within arterial oxygen saturation (SpO2) target range compared to RMC only. The a-priori subordinate hypothesis is, that the faster algorithm is equally effective as the slower algorithm to maintain the SpO2 in the target range.

Further hypotheses for exploratory testing are, that the "fast" algorithm will achieve a higher proportion of time with SpO2 within target range and an improved stability of cerebral oxygenation (measured as rcStO2 and rcFtO2E determined by Near-infrared spectroscopy) compared with the slow algorithm.

STUDY DESIGN The Study is designed as a two-center, randomized controlled, cross-over clinical trial in preterm infants receiving mechanical ventilation or nasal continuous positive airway pressure or non-invasive ventilation and supplemental oxygen (FiO2 above 0.21). Within a twenty-four-hour period the investigators will compare 8 hours of RMC with 8-hour periods of RMC supported by CLAC "slow" algorithm or "fast" algorithm, respectively.