Epidural analgesia procedure
labor
DECUBITUS
Upper arm venous access was established via a 22G intravenous indwelling needle. Then, parturients were brought into the labor analgesia room for the epidural analgesia procedure. Noninvasive blood pressure (NIBP), heart rate (HR) and pulse oximetry (SpOIn the IND group, 100 μg/ml dexmedetomidine hydrochloride (You Bi Tuo; Jiangsu Yang Zi Jang Medicine Co., Ltd.) was prepared without further dilution [Epidural puncture was performed at the L2-3 interspace with an 18-gauge epidural needle via the loss-of-resistance-to-saline method. Briefly, parturients were placed in the left decubitus and knee-hugging position, and 2% lidocaine was administered as local anaesthesia. A guide needle was used to penetrate the skin and supraspinous ligament. The epidural needle pierced the skin, supraspinous ligament, and interspinous ligament along the guiding pinhole and was then slowly advanced. When the tip passed through the ligamentum flavum, the loss of resistance to saline or the appearance of negative pressure indicated that the tip entered the epidural space. When no outflow of cerebrospinal fluid or blood return was observed by syringe suction, a small amount of saline was injected without resistance, which proved that the puncture was successful.An epidural catheter was then inserted 4.5 cm cephalad into the epidural space. Five minutes after a test dose of 5 ml of 1% lidocaine, labor analgesia was initiated with 10 mL of 0.083% ropivacaine (AstraZeneca, Sweden) combined with 0.4 μg/mL sufentanil (Yichang HumanWell, China). Seven millilitres of this mixed solution was administered every 30 min for maintenance of labor analgesia with a programmed intermittent epidural bolus (PIEB). The PCEA dose was 7 ml with a lockout time of 30 min.