Olanzapine as an add-on, pre-operative anti-emetic drug for postoperative nausea or vomiting: a randomised controlled trial.

Postoperative nausea or vomiting occurs in up to 40% in patients with multiple risk factors, despite prophylaxis. Olanzapine is an antipsychotic drug that is used to prevent nausea and vomiting in palliative care and to treat chemotherapy-induced nausea and vomiting. This study aimed to examine whether pre-operative olanzapine, as a prophylactic anti-emetic added to intra-operative dexamethasone, ondansetron and total intravenous anaesthesia, reduced the incidence of postoperative nausea or vomiting. We performed a multiply-blinded randomised controlled trial in patients aged 18-60 years with cancer at high risk of postoperative nausea or vomiting (three or four risk factors according to the Apfel criteria) plus a previous history of chemotherapy-induced nausea and vomiting. Patients were allocated at random to receive 10 mg olanzapine or placebo orally 1 h before surgery in addition to a two-drug regimen (dexamethasone and ondansetron) and propofol anaesthesia to prevent postoperative nausea or vomiting. The primary outcome was the incidence of postoperative nausea or vomiting in the first 24 h after surgery. In total, 100 patients were enrolled; 47 in the olanzapine group and 49 in the control group completed the study. The baseline characteristics of the groups were similar. The incidence of postoperative nausea or vomiting in the first 24 h after surgery was lower in the olanzapine group (12/47, 26%) than in the control group (31/49, 63%) (p = 0.008, RR 0.40 (95%CI 0.21-0.79)). Adding pre-operative oral olanzapine to intra-operative dexamethasone and ondansetron was highly effective in reducing the risk of postoperative nausea or vomiting in the first 24 hours after surgery in patients with a previous history of chemotherapy-induced nausea and vomiting and at least three Apfel risk factors for postoperative nausea or vomiting.

Does previous chemotherapy-induced nausea and vomiting predict postoperative nausea and vomiting?

BACKGROUND: Postoperative nausea and vomiting (PONV) remains a problem in the postoperative period. Previous PONV in oncology patients has recently been associated with chemotherapy-induced nausea and vomiting (CINV). We assessed if CINV could improve Apfel's heuristic for predicting PONV. METHODS: We conducted a retrospective study of 1500 consecutive patients undergoing intermediate or major cancer surgery between April and July 2011. PONV was assessed in the first postoperative day during post-anaesthesia care. The assigned anaesthetist completed an electronic medical record with all of the studied variables. Multiple logistic regression analyses were performed to assess whether any of the variables could add predictive ability to Apfel's tallying heuristic, and receiver operating characteristic (ROC) curves were modelled. The areas under the curve (AUC) were used to compare the model's discriminating ability for predicting patients who vomited from those who did not vomit. RESULTS: The overall incidence of PONV was 26%. Multiple logistic regressions identified two independent predictors for PONV (odds ratio; 95% CI), Apfel's score (1.78; 1.23-2.63) and previous chemotherapy-induced vomiting (3.15; 1.71-5.9), Hosmer-Lemeshow's P < 0.0001. Previous CINV was the most significant predictor to be added to Apfel's heuristic in this population. CONCLUSIONS: A history of chemotherapy-induced nausea vomiting was a strong predictor for PONV and should be investigated as an added risk factor for PONV in the preoperative period of oncology surgery in prospective studies.

Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2 percent lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2 percent lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

Postoperative analgesic effect of intrathecal neostigmine and its influence on spinal anaesthesia.

A clinical trial was conducted to evaluate the postoperative analgesic efficacy and the safety of intrathecal neostigmine in patients undergoing anterior and posterior vaginoplasty under spinal anaesthesia. Thirty-six patients were randomly divided into three groups to receive: normal saline (1 ml), morphine (100 micrograms in 1 ml of saline) or neostigmine (100 micrograms in 1 ml of saline) intrathecally just before a spinal injection of hyperbaric bupivacaine (0.5%, 4 ml). The mean [SD] time to the first analgesic (nonsteroidal anti-inflammatory drug) administration was significantly prolonged by intrathecal neostigmine (10.7 [4.3] h) and morphine (15.3 [3.0] h) compared with saline (4.5 [1.0] h). The three groups also differed in the number of patients requiring subcutaneous morphine to complement the analgesia provided by the intramuscular nonsteroidal anti-inflammatory drugs and the mean [SD] times for their administration: eight patients in the saline group (8.0 [3.8] h), one patient in the morphine group (18 h) and two patients in the neostigmine group (8 and 12.9 h). The morphine and neostigmine groups showed similar analgesic effectiveness. The characteristics of spinal anaesthesia were not modified by intrathecal morphine or neostigmine. Severe nausea and vomiting, sweating and distress during surgery were the most obvious adverse effects of intrathecal neostigmine. On the other hand, less hypotension was observed in the neostigmine group. The usefulness of intrathecal neostigmine as the sole postoperative analgesic may be restricted by the severity of its adverse effects.