Metoclopramide decreases emesis but increases sedation in tramadol patient-controlled analgesia.

PURPOSE: To evaluate the clinical benefits and disadvantages of adding metoclopramide to tramadol for patient-controlled analgesia (PCA). METHODS: Forty adult patients, undergoing elective arthroplasties, were recruited into this prospective, randomized, double-blind study. During general anesthesia all patients received 2.5 mg x kg(-1) of tramadol as a loading dose at the beginning of wound closure. In the postanesthesia care unit (PACU) patients were randomly allocated to receive PCA containing either 20 mg tramadol + 1 mg metoclopramide per millilitre (n = 20, Group T+M) or tramadol 20 mg per millilitre (n = 20, Group T). The PCA setup was 1 mL/bolus with a lockout interval of five minutes. A blinded investigator assessed the vital signs, visual analogue scale, and severity of postoperative nausea and/or vomiting in the PACU. The PCA demand and delivery, overall satisfaction rate and adverse effects were recorded in the PACU and on postoperative days one and two. RESULTS: Nausea/vomiting scores were more severe (1.7 +/- 1.0 vs 0.2 +/- 0.5, 2.3 +/- 1.2 vs 0.6 +/- 0.6, 1.9 +/- 0.9 vs 0.2 +/- 0.5, at 12 hr, 18 hr, 24 hr, respectively, P < 0.05) and more frequent (7/20 vs 1/20, 5/20 vs 0/20 for nausea and vomiting respectively, P < 0.05) on postoperative day one in Group T compared to Group T+M. However, the incidence of sedation was higher in Group T+M (7/20 vs 1/20, P < 0.05). CONCLUSIONS: The incidence and severity of nausea/vomiting decreased if metoclopramide was added to tramadol for PCA. An increased incidence of sedation was noticed with this drug combination.

Can neostigmine reduce propofol injection pain?

BACKGROUND: Neostigmine has been found to cause peripheral analgesia. We used venous retention technique to evaluate whether neostigmine displayed peripheral analgesic effect in reducing propofol injection pain. METHODS: In a double blind fashion, 105 patients were randomly allocated to receive either 1 ml 0.5 mg neostigmine (Group N, n = 35), 1 ml 2% lidocaine (Group L, n = 35), or 1 ml normal saline (Group C, n = 35) as pretreatment to reduce pain on propofol injection. A pediatric T-connector linking with the i.v. catheter port was used for injection. Venous occlusion was made possible with a tourniquet before the intravenous administration of one of the three drugs. The tested drug was allowed to retain for one minute and then the tourniquet was released for propofol injection. Pain and side effect assessments were made after propofol injection. RESULTS: The incidence of propofol injection pain was 85% in normal saline group, 46% in neostigmine group and 6% in lidocaine group (P < 0.05 among groups). The tested drugs arrayed in order of increasing magnitude of intensity of pain upon propofol injection were lidocaine (mean rank 34.20), neostigmine (mean rank 50.42) and normal saline (mean rank 76.81) in sequence (P < 0.05 among groups). CONCLUSIONS: With one-minute venous retention, 0.5 mg neostigmine (1 ml) could produce peripheral analgesia to some degree in reducing propofol injection pain. However, its analgesic effect was inferior to 1 ml of 2% lidocaine.