An Exploratory Investigation of Some Statistical Summaries of Oximeter Oxygen Saturation Data from Preterm Babies

Abstract

Aim. To explore the potential usefulness of the mean, standard deviation (SD), and coefficient of variation (CV = SD/mean) of oximeter oxygen saturations in the clinical care of preterm babies. Methods. This was an exploratory investigation involving 31 preterm babies at 36 weeks postmenstrual age. All babies were healthy, but two were considered to be clinically unstable and required greater attention. Each baby's oxygen saturations were recorded using an oximeter and summarized by the mean, SD, and CV. The potential usefulness of each measure was assessed by its ability to distinguish the two unstable babies from the others. This was achieved using box plots and hierarchical clustering together with the Calinski-Harabasz (CH) index to quantify clustering performance (higher CH index indicates stronger clustering outcome). Results. The box plots flagged both unstable babies as outliers and none of the other babies. Successful clustering of the stable and unstable babies was achieved using the CV (CH = 72.8) and SD (CH = 63.3) but not with the mean. Conclusion. Taking the box plots and clustering results together, it seems plausible that variability might be more effective than mean level for detecting instability in oxygen saturation in preterm babies and that the combination of variability and level through the CV might be even better.

Predicting 2-y outcome in preterm infants using early multimodal physiological monitoring

“…Sepsis is the main cause of preterm infant death during the first week of life and can also increase vulnerability of the brain due to inflammation and white matter damage (20). Low SpO2 to the point of hypoxia, can cause tissue damage of the brain which may result in neurological compromise and neurodevelopmental delay (21). The clinical course score had a higher sensitivity (88%) and similar specificity (70%) to the HR feature.…”

“…One hour epochs of HR and SpO 2 were extracted at the two timepoints, 12 and 24 h. Two features were used to summarize SpO 2 for the 1 h segments: mean SpO 2 and percentage of time <85%, which quantifies hypoxia (21,33). Four features summarized the HR signal over the 1 h segments: mean, SD, skewness, and kurtosis (34).…”

24‐hour oxygen saturation recordings in preterm infants: editing artefact

“…There are to our knowledge no guidelines outlining how to define artefact from neonatal oximetry data, and clinical experience suggests it is often done by informed guesswork. In a review of studies reporting normal values for preterm and term oximetry recorded for 4 hours or longer, no consistency was found in regard to data editing, and in three reports, no editing process was documented .…”

Comparison of 12‐hour and 24‐hour oximetry recordings in preterm infants

“…Positive correlations were found between the apnoea indices derived from a 2–3‐h polysomnography recording and 24‐h oximetry desaturation indices. While 24‐h recording of pulse oximetry is usual for clinical monitoring of infants still in the NICU, research studies in preterm and term infants have tended to focus on oximetry recordings of 12 h or less, with time of day not always specified . There have been no previous studies comparing 12‐ and 24‐h recordings in preterm infants.…”