Despite availability of advanced monitoring tools, most neonatologists still primarily rely on nursing documentation of desaturation and bradycardia events to assess the respiratory status of very low birth weight (VLBW) premature infants. We aimed to compare oxygenation instability as recorded in nursing charts versus SpO2 histograms in VLBW infants during their first weeks of life.

An observational study including VLBW premature infants who required respiratory support on day 1 of life. We recorded the daily number of desaturation events <90% from nursing charts and the cumulative duration of SpO2 <90% from 24 hours SpO2 histograms. Data were collected from birth until respiratory support was discontinued.

Data from 1,749 chart days of 77 VLBW infants (mean ± SD birth weight 1,040 ± 243 g; gestational age: 28.5 ± 2.1weeks) were analyzed. A strong Pearson correlation was found between the number of desaturation events and total time in SpO2 <90% (r = 0.8). However, similar event counts often reflected different hypoxemia burden. Eight or more daily desaturation events predict an unstable SpO2 histogram (sensitivity: 90.3%, specificity: 76.1%).

Nursing charts and SpO2 histograms strongly correlate but offer unique insights—charts capture the frequency and distribution of desaturation events, while histograms quantify overall hypoxemic exposure. Used together, they provide a more comprehensive assessment of respiratory status in VLBW infants.

Oxygenation instability is common among VLBW premature infants.

We compared oxygenation instability documentation in the NICU by nursing charts versus SpO2 histograms.

Strong Pearson correlation was found between documented desaturation events and time with SpO2 <90%.

However, for a given number of desaturation events, the time in SpO2 <90% varied significantly.

Combining charts and SpO2 histograms gives a more complete respiratory assessment in VLBW infants.

‡These authors contributed equally to this article.

Received: 10 September 2025

Accepted: 11 December 2025

Article published online:
31 December 2025

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