Randomization and concealment of group
blindness
BLINDNESS
Parturients were randomly divided into the conventional PIEB group (CON, n = 34) or the intranasal dexmedetomidine before PIEB group (IND, n = 33) through a computer-generated random number sequence using SPSS version 22.0 (IBM Corp, USA). To maintain the blindness of the study, two anesthesia personnel were involved. The anesthesiologist prepared the drug and placebo and administered them 15 min before the analgesia procedure. The anesthesia nurse was responsible for the management of labor analgesia and the assessment and recording of the data. The parturients and the outcome assessor (the anesthesia nurse) were blinded to the group allocations. A senior anesthesiologist-in-charge who had previously completed over 1000 neuraxial punctures conducted the analgesia procedures.