Automatic Oxygen Control (SPOC) in Preterm Infants

Study Overview
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Brief Summary
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Single-center, randomised controlled, cross-over clinical trial in preterm infants born at gestational age below 34+1/7 weeks receiving supplemental oxygen and respiratory support (continous positive airway pressure (CPAP) or non-invasive ventilation (NIV) or invasive ventilation (IV)). Routine manual control (RMC) of the fraction of inspired oxygen (FiO2) will be tested against RMC supported by automatic control (SPOC) with old-algorithm and RMC supported by CLAC with new-algorithm. The first primary hypothesis is, that the use of the new algorithm results in more time within arterial oxygen saturation (SpO2) target range compared to RMC only. The a-priori subordinate hypothesis is, that the new algorithm results in more time within SpO2 target range compared to SPOCold. The second primary hypothesis is, that the use of 2 seconds averaging time of the SpO2 Signal results in more time within arterial oxygen saturation (SpO2) target range compared to the use of 8 seconds averaging interval of the SpO2 signal.

Detailed Description
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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 (SPOC) of the FiO2. The objective of this study is to test a revised, new algorithm with 3 adaptions against the former old algorithm and against RMC. The 3 adaptions are: Faster re-adjustment to baseline-FiO2 (baseline FiO2: mean FiO2 during the previous 5min) Delayed reduction of FiO2 below baseline FiO2 Maximum FiO2 adjustable by user The first primary hypothesis is, that the application of SPOCnew 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 revised algorithm is more effective as the old algorithm to maintain the SpO2 in the target range. The second primary hypothesis is, that the shortening of averaging time used for the SpO2 Signal from 8 seconds to 2 seconds results in more time within SpO2 target range for both, SPOCnew and SPOCold. Further hypotheses for exploratory testing are, that the SPOC new algorithm will achieve a lower proportion of time with SpO2 above and below the target range, hyper- and hypoxia and an improved stability of cerebral oxygenation (measured as rcStO2 and rcFtO2E determined by Near-infrared spectroscopy) compared with SPOCold and RMC. Reduction of staff workload (estimated by number of manual adjustments per hour) by SPOC. Validation of a clinical scoring tool to monitor severity of apnea of prematurity. STUDY DESIGN The Study is designed as a single-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 30-hour period the investigators will compare 6 hours of RMC with 12-hour periods of RMC supported by SPOCnew algorithm or SPOCold algorithm, respectively. During intervals with SPOC control the SpO2 Signal averaging time will be 2 second or 8seconds , respectively, for 6 hours each.

Official Title
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Automatic Oxygen Control (SPOC) in Preterm Infants - Evaluation of a Revised Algorithm and Effect of Averaging Time of Pulse Oximetry Signal

Conditions
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Infantile Respiratory Distress Syndrome, Ventilator Lung; Newborn

Intervention / Treatment
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* Device: SPOCnew
* Device: 8s SpO2 averaging
* Device: SPOCold
* Device: 2s SpO2 averaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: gestational age at birth <34+1/7weeks and invasive mechanical ventilation OR noninvasive ventilation OR continous positive airway pressure support and Fraction of inspired oxygen above 0.21 before inclusion and more than 2 hypoxaemic events (arterial oxygen saturation below 80%) within 8 hours before inclusion and parental written informed consent Exclusion Criteria (any of the following): congenital pulmonary anomalies congenital heart defects influencing SpO2 (i.e. cyanotic heart defects) right-to -left shunt through a PDA Severe neonatal complications during study period (sepsis, necrotising enterocolitis) diaphragmatic hernia or other diaphragmatic disorders

Ages Eligible for Study
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Maximum Age: 34 Weeks

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: RMC only<br>routine manual control (RMC) of the fraction of inspired oxygen (FIO2) | |
| Experimental: SPOCnew and 2s SpO2 averaging<br>routine manual control (RMC) + automatic oxygen control (SPOC) with new algorithm of the fraction of inspired oxygen (FIO2). The SpO2 signal averaging time is 2s. | Device: SPOCnew<br>* SPOC is an automated, algorithm based adjustment of the fraction of inspired oxygen in relation to arterial saturation (SPO2). The revised new algorithm is turned on.<br>Device: 2s SpO2 averaging<br>* The arterial saturation (SPO2) will be averaged over 2s.<br>|
| Experimental: SPOCnew and 8s SpO2 averaging<br>routine manual control (RMC) + automatic oxygen control (SPOC) with new algorithm of the fraction of inspired oxygen (FIO2). The SpO2 signal averaging time is 8s. | Device: SPOCnew<br>* SPOC is an automated, algorithm based adjustment of the fraction of inspired oxygen in relation to arterial saturation (SPO2). The revised new algorithm is turned on.<br>Device: 8s SpO2 averaging<br>* The arterial saturation (SPO2) will be averaged over 8s.<br>|
| Active Comparator: SPOCold and 2s SpO2 averaging<br>routine manual control (RMC) + automatic oxygen control (SPOC) with old algorithm of the fraction of inspired oxygen (FIO2). The SpO2 signal averaging time is 2s. | Device: SPOCold<br>* SPOC is an automated, algorithm based adjustment of the fraction of inspired oxygen in relation to arterial saturation (SPO2). The former old algorithm is turned on.<br>Device: 2s SpO2 averaging<br>* The arterial saturation (SPO2) will be averaged over 2s.<br>|
| Active Comparator: SPOCold and 8s SpO2 averaging<br>routine manual control (RMC) + automatic oxygen control (SPOC) with old algorithm of the fraction of inspired oxygen (FIO2). The SpO2 signal averaging time is 8s. | Device: 8s SpO2 averaging<br>* The arterial saturation (SPO2) will be averaged over 8s.<br>Device: SPOCold<br>* SPOC is an automated, algorithm based adjustment of the fraction of inspired oxygen in relation to arterial saturation (SPO2). The former old algorithm is turned on.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of time with SpO2 within target range | Comparison of proportion of time with SpO2 within target range and time above target range if no supplemental oxygen was administered at that time and within the preceding 30sec between the five treatment modalities | 30 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of Time with SpO2 above target range | Comparison of proportion of time with SpO2 above target range if supplemental oxygen was administered at that time or within the preceding 30sec . | 30 hours | 
| Proportion of Time with SpO2 below target range | Comparison of proportion of time with SpO2 below target range. | 30 hours | 
| Proportion of Time with Hypoxia | Comparison of proportion of time with SpO2 below 80%. | 30 hours | 
| Proportion of Time with Hyperoxia | Comparison of proportion of time with SpO2 above 97% if supplemental oxygen was administered at that time or at anytime during the previous 30 seconds. | 30 hours | 
| Stability of cerebral oxygenation | Area under the curve of cerebral tissue saturation or fraction of tissue oxygen extraction outside of the infants Median +- 5% or outside of the safe interval of 55-80% rcStO2. | 30 hours | 
| Severe hypoxemic episodes | Rate of episodes with SpO2 <80% for at least 60seconds | 30 hours |