Comparison of metoclopramide and ondansetron for the prevention of nausea and vomiting after intrathecal morphine.

Nausea and vomiting remain unpleasant side effects of intrathecal (i.t.) morphine and of the numerous therapies tried, only prophylactic intravenous (i.v.) metoclopramide has been reported to be promising. Seventy-three patients, scheduled for orthopaedic prosthesis surgery of the hip or knee were studied. They received 4 mL of plain bupivacaine and 0.3 mg of preservative-free morphine i.t. for anaesthesia. The test drugs given in a double-blind and randomized fashion, were either metoclopramide 20 mg, three times, at 6 h intervals (23 patients), ondansetron, 8 mg, twice, at 12 h intervals (25 patients), or 0.9% saline three times, at 6 h intervals (25 patients). The occurrence of nausea, vomiting and pain was followed for 24 h. The incidences of nausea and vomiting were 60% (15/25) and 56% (14/25) in the saline group, 52% (12/23) and 48% (11/23) in the metoclopramide group, and 52% (13/25) and 40% (10/25) in the ondansetron group. Incidences of severe vomiting were 24, 35 and 12% respectively. Eight patients in the saline group, seven in the metoclopramide and 10 in the ondansetron group did not need additional opioids for post-operative pain relief. We conclude that, metoclopramide and ondansetron were not better than saline in the prevention of post-operative emesis induced by intrathecal morphine.

Effect of tropisetron, a 5-HT3 receptor antagonist, on analgesia and nausea after intrathecal morphine.

We have studied the effect of tropisetron, a 5-HT3-receptor antagonist, on postoperative nausea, vomiting and pain in 54 patients, aged 50-83 yr, after major hip or knee surgery. The patients were given subarachnoid injection of plain 0.5% bupivacaine, mixed with preservative-free morphine 0.3 mg, for surgical and postoperative analgesia. In a double-blind fashion, either tropisetron 5 mg (1 mg ml-1) or saline 5 ml was injected i.v. 30 min after spinal administration of bupivacaine and morphine. The number of patients needing i.m. oxycodone for pain relief, the total number of oxycodone doses or the mean time to the first i.m. oxycodone administration did not differ significantly between the two groups. The number of patients who became nauseated or vomited during the observation period did not differ significantly between groups. Seventeen patients had nausea and 11 vomited in the tropisetron group, compared with 20 and 13, respectively, in the control group during the first 24 h.

Comparison of intrathecal fentanyl infusion with intrathecal morphine infusion or bolus for postoperative pain relief after hip arthroplasty.

The purpose of this study was to compare an intrathecal fentanyl infusion with intrathecal morphine infusion or bolus for postoperative pain relief after hip arthroplasty. Sixty patients scheduled to undergo hip joint replacement were studied. A 28-gauge (n = 12) or a 22-gauge (n = 48) spinal catheter was introduced through the L3-4 interspace, 3-4 cm into the subarachnoid space. Spinal anesthesia was induced with 2 mL of plain 0.5% bupivacaine; additional bupivacaine was given in 0.5-mL increments, as required. Patients were given in a random and double-blind fashion either 0.5 mL of saline as a single bolus, followed by an infusion of 120 micrograms of fentanyl in 24 h (Group I, n = 20), 0.5 mL of saline, followed by an infusion of 200 micrograms of morphine in 24 h (Group II, n = 20), or 200 micrograms of morphine as a single bolus, followed by an infusion of 3 mL of saline in 24 h (Group III, n = 20) through the intrathecal catheter. In Group I, supplementary intramuscular (IM) opioid was required more often (46 doses) than in Group II (18 doses) in 24 h (P < 0.01). The number of patients given IM administered opioid was larger in Group I (18 patients) than in Group II (8 patients) (P < 0.01). The IM opioid was requested sooner in Group I (18 patients, mean 480 min) after the intrathecal injection than in Group III (13 patients, mean 786 min) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Fentanyl-prilocaine mixture for intravenous regional anaesthesia in patients undergoing surgery.

The effect of the addition of 0.1 mg or 0.2 mg fentanyl to 40 ml 0.5% prilocaine in intravenous regional anaesthesia of the arm was investigated in 37 patients in a randomised, double-blind study. The characteristics of the sensory and motor block were studied. There was no difference in the speed of onset of analgesia in the groups (mean latency approximately 4 min in each group). However, significantly more patients in the fentanyl 0.2 mg group (7/12) had complete anaesthesia at 15 min than in the fentanyl 0.1 mg group (1/13) and the control group (2/12) (p less than 0.05). There were no differences in the incidence of tourniquet pain immediately before cuff deflation (tourniquet time 45-87 min). After cuff deflation, in those patients who complained of wound pain within 30 min, on average the pain appeared later in the fentanyl 0.2 mg group (six patients, mean 14.3 min) than in the control group (eight patients, mean 9.4 min) (ns). In the fentanyl groups, the incidence of central nervous system side effects was greater than in the control group (fentanyl 0.1 mg 7/13 patients, fentanyl 0.2 mg 6/12 patients, control 1/12 patients) (p less than 0.05). The plasma concentrations of prilocaine after cuff deflation were higher, in a dose-dependent fashion, in the fentanyl groups than in the control group, but the concentrations of prilocaine and fentanyl did not correlate with the symptoms. Postoperative nausea occurred only in the patients who had received fentanyl.

A prospective study on reproducibility of the spread of spinal anesthesia using plain 0.5% bupivacaine.

This prospective study was carried out to determine whether a spinal block with plain 0.5% bupivacaine spreads similarly when repeated in the same patient. During a 14-month period, 50 patients underwent from two to five spinal anesthesias using identical anesthetic technique, including the same premedication, the same volume of injected plain 0.5% bupivacaine, the same site of injection and the same position of the patient. Plain 0.5% bupivacaine was injected with the patient lying in the lateral horizontal position. Thereafter, the patients were turned to the supine horizontal position. Pinprick analgesia was recorded 60 minutes after the injection. Regression analysis showed that the reproducibility of the maximal analgesic segmental spread of the second anesthesia on the basis of the initial anesthesia was highly significant (p less than 0.0001). The blocking results of the patients who underwent from three to five anesthesias within the study period were in accordance with the spread of the first anesthesia. If a higher or lower spread of anesthesia is desirable, a modification or another local anesthetic for the spinal anesthesia may be preferred.

Cardiovascular responses caused by the combination of lidocaine and vecuronium in the induction of general anaesthesia.

Fentanyl, vecuronium and enflurane may cause bradyarrhythmias during anaesthesia. Lidocaine administered before endotracheal intubation may interact synergistically with these agents. In this randomized and double-blind study, lidocaine 1 mg kg-1 (24 patients) or saline (20 patients) was given, immediately after glycopyrrolate 5 micrograms kg-1, fentanyl 1.5 micrograms ml-1 and thiopentone 3-5 mg kg-1, together with vecuronium 0.1 mg kg-1 as a rapid i.v. injection to healthy (ASA 1) surgical patients. Enflurane 0.8% was included in the inhaled gases 10 min and enflurane 1.6% 25 min after lidocaine administration. The plasma concentrations of lidocaine rose to a mean level of 3.1 micrograms ml-1 (maximum 7.1 micrograms ml-1) which may affect the electrical conduction at various sites in the heart. There were no statistically significant differences in arterial blood pressures or heart rates during anaesthesia between the groups. The incidence of junctional rhythm was 7/24 patients in the lidocaine group and 5/20 patients in the saline group. Three patients in the lidocaine group, and two patients in the control group developed junctional rhythm immediately after intubation. The plasma concentrations of vecuronium were unaffected by lidocaine. The ratio of the unbound lidocaine to plasma protein bound lidocaine was at the expected level and did not differ significantly 2 and 10 min after the injection.

Quality of axillary brachial plexus block. Comparison of success rate using perivascular and nerve stimulator techniques.

A perivascular catheter technique (PVT) and a nerve stimulator technique (NST) for axillary brachial plexus block were compared in terms of quality: complete, incomplete or failed blocks. In a randomised series, 30 PVT blocks and 30 NST blocks were performed by three staff anaesthetists. In the NST group, surgical anaesthesia was always achieved, whereas in the PVT group, four blocks required supplementation with general anaesthesia. In both groups eight patients needed supplementation with additional conduction blocks of 1-3 peripheral nerves. It is concluded that a nerve stimulator technique may increase the success rate of axillary brachial plexus block to some extent.

Evaluation of the myotoxicity of bupivacaine in bier blocks--a biochemical and electron microscopic study.

The possible myotoxic effect of bupivacaine in combination with tourniquet ischemia was evaluated in 11 patients who underwent surgery of an arm under intravenous regional anesthesia. Eleven patients with the same kind of surgery and tourniquet who had general anesthesia served as controls. Venous blood bupivacaine concentrations in the anesthetized arm were high at the end of tourniquet time (27.2-202 micrograms/m1) and varied from 2.3 to 12.3 micrograms/ml 10 min after tourniquet release. Changes in blood-gas tensions and plasma potassium and lactate concentrations before and just after tourniquet release correlated with the ischemia time. Changes in creatine phosphokinase, lactate dehydrogenase and aspartate aminotransferase activities, possible indices of loss of integrity of muscle cell membranes, varied considerably and did not correlate with the ischemia time. There were no significant differences between the two groups in any of the parameters. Electron microscopy revealed no evidence of muscle degeneration 24 hr after the use of tourniquet with either bupivacaine intravenous regional (n = 4) or general anesthesia (n = 3).