Background and objective This study compares the effect of oral clonidine vs. hydroxyzine on the haemodynamic and catecholamine responses to microlaryngoscopy.

Methods Thirty-five ASA II-III patients were included in this double-blind randomized trial. The patients received either hydroxyzine 1 mg kg−1 (n=18) or clonidine 3 μg kg−1 (n = 17) for their oral premedication 100 min before an intravenous induction of anaesthesia using propofol (2–3 mg kg−1) and fentanyl (2 μg kg−1). Arterial pressure and heart rate were measured before premedication, and throughout the procedure and recovery. Plasma catecholamine levels were determined before premedication, after induction, and 1.5, 30 and 120 min after laryngoscopy.

Results Mean arterial pressure was significantly lower after clonidine, whereas there was no difference in heart rate and plasma catecholamine levels between the two groups.

Conclusions Clonidine for premedication significantly decreased mean arterial pressure during microlaryngoscopy and the following recovery phase but did not modify the overall haemodynamic response to the suspension microlaryngoscopic nociceptive stimulus.

Alpha-adrenergic agonists produce pain relief through an opioid independent mechanism and may be alternatives to opioids for combination with local anaesthetics for analgesia during labour. We studied 41 pregnant women. Epidural block was performed with 75 μg clonidine (n=20) or 50 μg fentanyl (n=21) combined with 0.125% bupivacaine (10 mL). Maternal vital parameters were measured. Analgesia was evaluated using a visual analogue scale (VAS); sedation was scored using a five-point scale. There were no differences in maternal vital parameters, fetal heart rate (FHR) or Apgar scores between the groups. Analgesia lasted longer in the bupivacaine-clonidine group (139.4±31 min) compared with the bupivacaine–fentanyl group (127.9±48 min) (P=0.42). Additional analgesic requirement was more often in the fentany–bupivacaine group and total bupivacaine requirement was less in the clonidine–bupivacaine group (22.5±12.5mg vs. 30.9±12.8 mg) (P=0.04). This small study confirms that this combination of bupivacaine and clonidine provides satisfactory analgesia for first-stage labour, and of longer duration than bupivacaine–fentanyl.

The aim of this study was to evaluate whether the addition of clonidine, or sufentanil, or both, to a bupivacaine solution for a caudal block prolonged the period of analgesia after operation in children. Sixty ASA class I or II boys, aged between 8 months and 13 years, admitted for hypospadias repair were enrolled into a prospective randomised study. After induction of general anaesthesia and endotracheal intubation the children were allocated into four groups. Group I received 0.5 mL kg−1 bupivacaine 0.25% caudally, in addition group II received 1 mg kg−1 clonidine, group III 0.5 mg kg−1 sufentanil and group IV 0.5 mg kg−1 clonidine and 0.25 mg kg−1 sufentanil. The concentrations of clonidine and sufentanil in group IV were halved to reduce possible side-effects with higher dosages. Analgesia and side-effects were assessed 2, 4, 6, 8 and 12 h after operation. No significant differences were found among the four groups for the pain scores at 2, 4, 6, 8 and 12 h. All groups had a similar frequency of vomiting and a comparable appetite and quality of night rest during the first 24 h following the operation. There was no signficant difference in the requirement for additional doses of analgesics. The addition of sufentanil, or clonidine, or both, to bupivacaine for caudal administration provides no additional clinical benefit over bupivacaine alone.