Effect of maternal oxygen supplementation for parturient undergoing elective cesarean section by high-flow nasal oxygen compared with room air on fetal acidemia: study protocol for a randomized controlled trial.

BACKGROUND: Maternal oxygen supplementation is usually used as an intrauterine resuscitation technique to prevent fetal hypoxia and acidemia during delivery. However, there has been a great deal of controversy regarding the effects of prophylactic maternal oxygen during cesarean section, during which the incidence of fetal acidemia seems to be higher compared with that during labor. High-flow nasal oxygen (HFNO) can improve oxygenation better in patients with high-flow oxygen airflow. The purpose of this study is to determine whether maternal oxygen supplementation with HFNO has a positive effect on fetal acidemia during cesarean section through umbilical arterial blood gas analysis. METHOD: This prospective, single-center, randomized, double-blinded trial will enroll 120 patients undergoing cesarean section. Participants will be randomly assigned to the HFNO group or air group at a 1:1 ratio. For parturients in the HFNO group, the flow rate is 40L/min, and the oxygen is heated to 37℃ with humidity 100% oxygen concentration through the Optiflow high-flow nasal oxygen system. And for the air group, the flow rate is 2 L/min with an air pattern through the same device. The primary outcome was umbilical artery (UA) lactate. Secondary outcomes include UA pH, PO2, PCO2, BE, the incidence of pH < 7.20 and pH < 7.10, Apgar scores at 1 and 5 min, and neonatal adverse outcomes. DISCUSSION: Our study is the first trial investigating whether maternal oxygen supplementation with HFNO can reduce the umbilical artery lactate levels and the incidence of fetal acidemia in cesarean section under combined spinal-epidural anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov NCT05921955. Registered on 27 June 2023.

[Expression of cyclin D1 and p16 protein in vulvar white lesion].

OBJECTIVE: To investigate the relationship between cell cycle protein (cyclin D1 and p16) expression and vulvar white lesion. METHODS: Biopsies from 34 cases with vulvar white lesion, including 12 cases with lichen sclerosus (LS), 18 with squamous hyperplasia (SH) and 4 SH accompanied with LS, were examined for protein expression of cyclin D1 and p16 using immunohistochemical techniques. Normal vulvar tissues from 11 patients with other benign gynecologic diseases were used as control. RESULTS: Fifty-six percent of patients with vulvar white lesion were immunopositive for cyclin D1 protein, which was significantly higher than that of control group (9%, P < 0.05); but there was no significant difference between LS (58%) and SH patients (50%, P > 0.05) in expression of cyclin D1 protein. Immunopositive expression of p16 protein in patients was 6%, with no significant difference from the control group (0, P > 0.05). CONCLUSIONS: Cyclin D1 and p16 are important factors modulating cell cycle. The interrupt of balance between these two factors derived from abnormal expression of cyclin D1 may be one of the causes of vulvar white lesion.