Pain on injection of propofol: comparison of metoprolol with lidocaine.

BACKGROUND AND OBJECTIVE: Pain is often experienced when propofol is injected, and intravenous lidocaine is often effective in preventing such pain. We decided to determine whether metoprolol, given before the injection of propofol, is as effective as lidocaine in reducing the incidence and severity of the pain. METHODS: Ninety patients scheduled for elective surgery under general anaesthesia were randomly allocated to one of three groups to receive either metoprolol 2 mg, lidocaine 20 mg or saline 2 mL before any propofol was injected. Each patient was given one of these agents intravenously via a 20-G cannula on the dorsum of the hand whilst the venous drainage was occluded manually, at the middle of the forearm, for 45 s. After the occlusion was released, propofol 2.0-2.5 mg kg(-1), at room temperature, was injected at 2 mL (20 mg) every 4 s. Pain was assessed verbally and scored as none (0), mild (1) or severe (2). RESULTS: The incidence of severe pain in the control group (56.7%) was significantly higher than in the metoprolol and lidocaine groups (16.6 and 10%, respectively). The number of patients who were free of pain was significantly higher in those who had been given either metoprolol or lidocaine. CONCLUSIONS: Pretreatment with intravenous metoprolol was equally as effective as lidocaine in reducing the pain associated with propofol injection.

Comparison of bupivacaine 0.2% and ropivacaine 0.2% combined with fentanyl for epidural analgesia during labour.

BACKGROUND AND OBJECTIVE: Recent clinical studies comparing ropivacaine 0.25% with bupivacaine 0.25% reported not only comparable analgesia, but also comparable motor block for epidural analgesia during labour. An opioid can be combined with local anaesthetic to reduce the incidence of side-effects and to improve analgesia for the relief of labour pain. The purpose of the study was to evaluate the effects of epidural bupivacaine 0.2% compared with ropivacaine 0.2% combined with fentanyl for the initiation and maintenance of analgesia during labour and delivery. METHODS: Sixty labouring nulliparous women were randomly allocated to receive either bupivacaine 0.2% with fentanyl 2 microg mL(-1) (B/F), or ropivacaine 0.2% with fentanyl 2 microg mL(-1) (R/F). For the initiation of epidural analgesia, 8 mL of the study solution was administered. Supplemental analgesia was obtained with 4 mL of the study solution according to parturients' needs when their pain was > or = 4 on a visual analogue scale. Analgesia, hourly local anaesthetic use, motor block, patient satisfaction and side-effects between groups were evaluated during labour and at delivery. RESULTS: Sixty patients were enrolled and 53 completed the study. No differences in verbal pain scores, hourly local anaesthetic use or patient satisfaction between groups were observed. However, motor block was observed in 10 patients in the B/F group whereas only two patients had motor block in the R/F group (P < 0.05). The incidence of instrumental delivery was also higher in the B/F group than in the R/F group (P < 0.05). CONCLUSIONS: The results suggest that epidural bupivacaine 0.2% and ropivacaine 0.2% combined with fentanyl produced equivalent analgesia for pain relief during labour and delivery. It is concluded that ropivacaine 0.2% combined with fentanyl 2 microg mL(-1) provided effective analgesia with significantly less motor block and need for an instrumental delivery than a bupivacaine/fentanyl combination at the same concentrations during labour and delivery.