Exploration of the optimal pulse oximetry-derived oxygen saturation target for critically ill AECOPD patients: a retrospective cohort study

Background: Appropriate levels of blood oxygen are crucial for critically ill patients. However, the optimal oxygen saturation has not been confirmed for AECOPD patients during their ICU stays. The purpose of this study was to determine the optimal oxygen saturation range target to reduce mortality for those individuals. Methods Data of 533 critically ill AECOPD patients with hypercapnic respiratory failure from the MIMIC-IV database were extracted. The association between median SpO2 value during ICU stay and 30days mortality was analyzed by LOWESS curve, and an optimal range of SpO2(92–96%) platform was observed. Comparisons between subgroups and linear analyses of the percentage of SpO2 in 92–96% and 30days or 180 days mortality were performed to support our view further. Methods Although patients with 92–96% SpO2 had a higher rate of invasive ventilator than those with 88–92%, there was no significant increase in the adjusted ICU stay duration, non-invasive ventilator duration, or invasive ventilator duration while leading to lower 30days and 180days mortality in the subgroup with 92–96%. In addition, the percentage of SpO2 in 92–96% was associated with decreased hospital mortality. Conclusion In conclusion, SpO2 within 92–96% could lead to lower mortality than 88–92% and > 96% for AECOPD patients during their ICU stay.