Determination of the Predictors of Nocturnal Desaturation in Postpartum Women

Overview

The primary aim of the study is to evaluate the effect of the method of delivery (vaginal delivery vs. cesarean section) on oxygen saturation in the first postpartum night. The investigators hypothesize that nocturnal desaturation occurs more frequently in cesarean section compared with vaginal delivery, expressed as either the duration of SpO2 below 90% or the Oxygen Desaturation Index (ODI). The ODI is defined as number of oxygen desaturations by at least 3 % per hour. Furthermore, the investigators expect a higher pulse rate and a lower mean and minimum SpO2 in the cesarean section group compared with the vaginal delivery group. The secondary aim of the study is to investigate how the upper body position during sleep (45 degree elevated vs. non-elevated) affects the oxygen saturation during the first postpartum night. The investigators hypothesize that an upper body elevation to 45 degrees decreases the incidence of desaturation events, expressed as either the duration of SpO2 below 90% or the ODI , compared with a non-elevated body position within each delivery group (vaginal delivery or cesarean section). The third aim of the study is to identify independent predictors of nocturnal desaturation in postpartum women. To that end, the investigators will administer questionnaires and collect demographic and clinical data according to various obstructive sleep apnea screening scores, including the P-SAP, STOP-Bang, and Epworth Sleepiness Scale. The investigators will also ask the patient to rate the pain during the study night on a verbal numerical rating scale.

Sleep-disordered breathing is common in pregnancy, persisting into the early postpartum period. Postpartum airway obstruction is a main cause of anesthesia-related maternal death in North America. Upper airway edema following labor and delivery may impair pharyngeal anatomy, which can lead to increased vulnerability of the airway collapse during sleep. This study evaluates whether the kind of delivery (vaginal birth versus cesarean section) has an effect on nocturnal desaturation in the first night after delivery. Furthermore, the investigators examine if the upper body position during sleep has an effect on the occurrence of oxygen desaturation. In addition, the investigators evaluate if preexisting conditions, as indicated by a high P-SAP or STOP-Bang-score increase the likelihood of nocturnal desaturation.