Oxygen saturation histogram classification system to evaluate response to doxapram treatment in preterm infants

Background An oxygen saturation (SpO(2)) histogram classification system has been shown to enable quantification of SpO(2) instability into five types, based on histogram distribution and time spent at SpO(2) <= 80%. We aimed to investigate this classification system as a tool to describe response to doxapram treatment in infants with severe apnea of prematurity. Methods This retrospective study included 61 very-low-birth-weight infants who received doxapram. SpO(2) histograms were generated over the 24-h before and after doxapram start. Therapy response was defined as a decrease of >= 1 histogram types after therapy start. Results The median (IQR) histogram type decreased from 4 (3-4) before to 3 (2-3) after therapy start (p < 0.001). The median (IQR) FiO(2) remained constant before (27% [24-35%]) and after (26% [22-35%]) therapy. Thirty-six infants (59%) responded to therapy within 24 h. In 34/36 (94%) of the responders, invasive mechanical ventilation (IMV) was not required during the first 72 h of therapy, compared to 15/25 (60%) of non-responders (p = 0.002). Positive and negative predictive values of the 24-h response for no IMV requirement within 72 h were 0.46 and 0.94, respectively. Conclusions Classification of SpO(2) histograms provides an objective bedside measure to assess response to doxapram therapy and can serve as a tool to detect changes in oxygenation status around respiratory interventions. Impact The SpO2 histogram classification system provides a tool for quantifying response to doxapram therapy. The classification system allowed estimation of the probability of invasive mechanical ventilation requirement, already within a few hours of treatment. The SpO2 histogram classification system allows an objective bedside assessment of the oxygenation status of the preterm infant, making it possible to assess the changes in oxygenation status in response to respiratory interventions.

Automated summary

The study showed that the SpO(2) histogram classification system provides an objective measure of response to doxapram therapy in preterm infants. Infants who responded to treatment within 24 hours were less likely to require invasive mechanical ventilation. The classification system allows for bedside assessment of oxygenation status changes in response to respiratory interventions within a few hours.