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