Fig. 2From: Optimal dose of pretreated-dexmedetomidine in fentanyl-induced cough suppression: a prospective randomized controlled trialEffects of pretreatments on HR in the four groups. HR: heart rate; bpm: beats/min. T0: at the beginning of pretreatment; T1: 3 min after the beginning of pretreatment; T2: 6 min after the beginning of pretreatment; T3: 9 min after the beginning of pretreatment; T4: 12 min after the beginning of pretreatment. a P < 0.05, b P < 0.01, compared to T0Back to article page