Ondansetron for treatment of intrathecal morphine-induced pruritus after cesarean delivery

BACKGROUND AND OBJECTIVES: Pruritus induced by intrathecal morphine is a concern in many obstetric patients after cesarean delivery and may detract from the benefit of postoperative pain relief. This study was performed to investigate the efficacy of ondansetron (5-HT3 receptor antagonist) in treatment of pruritus following intrathecal morphine. METHODS: Eighty parturients developing moderate to severe pruritus following intrathecal morphine were randomly allocated into 2 groups. One group received 4 mg ondansetron while the other group received placebo (normal saline). The improvement of pruritus and other adverse effects such as pain scores, nausea, vomiting, sedation, hallucination, and respiratory depression were determined at 30 minutes after study drugs' administration. RESULTS: The treatment success rate was higher in the ondansetron group than in the placebo group (80% v 36%, P < .001). Among the successfully treated patients, the recurrence rates of moderate to severe pruritus within 4 hours after administration of ondansetron and placebo were 12% and 70%, respectively (P < .001). The number of patients with decreased nausea and vomiting score was also higher in the ondansetron group (11 v 1, P < .006). CONCLUSION: Ondansetron treats intrathecal morphine-induced pruritus after cesarean delivery, particularly in patients suffering from both nausea/vomiting and pruritus.     

Ondansetron, orally disintegrating tablets versus intravenous injection for prevention of intrathecal morphine-induced nausea, vomiting, and pruritus in young males

In this study we compared the efficacy of orally disintegrating tablets (ODT) and IV ondansetron for preventing spinal morphine-induced pruritus and postoperative nausea and vomiting (PONV) in healthy young male patients. Patients who received bupivacaine with 0.20 mg morphine for spinal anesthesia were randomly assigned to the ODT group (ODT ondansetron 8 mg, n = 50), the IV group (4 mg ondansetron IV, n = 50), or the placebo group (n = 50). Each individual was assessed for pruritus, postoperative nausea and vomiting, and pain at 0, 2, 6, 12, 18, and 24 h after surgery using three distinct visual analog scales. The frequencies of postoperative nausea and vomiting and frequencies of requirement for rescue antiemetic and antipruritic were recorded. There were no significant differences among the three groups with respect to incidence or severity of PONV or postoperative pain visual analog scale scores. The incidences of pruritus in the ODT (56%) and IV (66%) groups were significantly different from that in the placebo group (86%) (P < 0.02 for both). Only the ODT group had significantly lower mean pruritus visual analog scale scores at 0, 2, 6, and 12 h postsurgery than the placebo group (P < 0.023 for all). The frequency of requirement for rescue antipruritic was significantly less in the ODT group than the placebo group (P = 0.013). Both ODT ondansetron 8 mg and IV ondansetron 4 mg are more effective than placebo for preventing spinal morphine-induced pruritus, but neither form of this agent reduces spinal morphine-induced postoperative nausea and vomiting in this patient group.     

Prophylactic ondansetron is effective in the treatment of nausea and vomiting but not on pruritus after cesarean delivery with intrathecal sufentanil-morphine

STUDY OBJECTIVES: To assess the safety and efficacy of ondansetron for prevention of pruritus, nausea and vomiting after cesarean delivery with intrathecal sufentanil-morphine. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Referral center, institutional practice. PATIENTS: 100 nonbreastfeeding women undergoing elective cesarean delivery with sufentanil-morphine-bupivacaine anesthesia. INTERVENTIONS: After the umbilical cord was clamped, patients in Group 1 received ondansetron 8 mg intravenously (IV) and patients in Group 2 received placebo. MEASUREMENTS: Frequency and severity of postoperative (24-hour) pruritus, nausea and vomiting, surgical pain, and side effects related to ondansetron were recorded. MAIN RESULTS: In the ondansetron group, 38 patients had pruritus (16 mild and 22 severe) and 9 patients had nausea and vomiting (5 mild and 4 severe). In the placebo group, 41 patients had pruritus (21 mild and 20 severe) and 29 patients had nausea and vomiting (9 mild and 15 severe). The frequency and severity of the nausea and vomiting episodes were significantly reduced in the ondansetron group. Pain scores were comparable between groups. No side effects related to ondansetron were reported. CONCLUSIONS: Prophylactic IV ondansetron 8 mg is safe and effective in reducing the frequency and the severity of nausea and vomiting, but not pruritus, following cesarean delivery with intrathecal sufentanil-morphine.     

Ondansetron and tropisetron do not prevent intraspinal morphine- and fentanyl-induced pruritus in elective cesarean delivery

BACKGROUND: Although intraspinal morphine has been shown to be effective in providing analgesia after cesarean delivery, pruritus as a side-effect remains a common cause of dissatisfaction. The role of ondansetron has been studied in preventing pruritus but the results have been contradictory. METHODS: We randomized 98 parturients undergoing elective cesarean section using combined spinal-epidural anesthesia into a double-blinded trial to receive tropisetron 5 mg (T group) or ondansetron 8 mg (O group) or placebo (NaCl group) after delivery, when intrathecal morphine 160 microg and fentanyl 15 microg were used for post-operative pain control. The patients additionally received ketoprofen 300 mg per day. Post-operative itching, nausea and vomiting, sedation and need for rescue analgesics were registered every 3 h up to 24 h, and all patients were interviewed on the first post-operative day. RESULTS: Seventy-six percent of the parturients in the placebo group, 87% in the ondansetron, and 79% in the tropisetron group had itching. The incidence of post-operative nausea and vomiting was 21%, 20% and 11% of the patients in the placebo, ondansetron and tropisetron groups, respectively. Medication for pruritus was needed by 31%, 23% and 39% of the patients in the placebo, ondansetron and tropisetron groups, respectively. In the post-operative questionnaire, the patients reported less post-operative nausea in the tropisetron group than in the placebo group (P < 0.01). CONCLUSION: Neither ondansetron nor tropisetron prevent itching caused by intrathecal morphine with fentanyl. However, tropisetron reduced post-operative nausea.     

Comparison of ondansetron, metoclopramide and placebo as premedicants to reduce nausea and vomiting after major surgery

In a randomised, double-blind study, we have compared the incidence of postoperative nausea and vomiting in 124 patients undergoing major lower limb orthopaedic surgery following oral premedication with temazapam and ondansetron 8 mg, metoclopramide 10 mg or placebo. They received a standardised epidural and general anaesthetic. An epidural mixture containing bupivacaine 0.1% and fentanyl 10 mg.ml⁻¹ was infused postoperatively. The occurrence of nausea and vomiting was assessed every 4 h for 24 h. The incidence of vomiting significantly decreased from 55% and 43% in the placebo and metoclopramide groups, respectively, to 26% in the ondansetron group (p = 0.03). The incidence of nausea and vomiting in patients who had previously suffered was also significantly reduced from 67% and 68% in the placebo and metoclopramide groups, respectively, to 29% in the ondansetron group (p = 0.035). We conclude that oral premedication with ondansetron 8 mg was superior to metoclopramide 10 mg and placebo in preventing postoperative nausea and vomiting following major orthopaedic surgery in patients given epidural opioid analgesia.     

Dexamethasone decreases epidural morphine-related nausea and vomiting.

The aim of our study was to compare the antiemetic effect of IV dexamethasone with saline control in preventing epidural morphine-related nausea and vomiting. Eighty patients requiring epidural anesthesia for abdominal total hysterectomy were enrolled in a randomized, double-blinded, and placebo-controlled study. At the end of surgery, all patients received epidural morphine 3 mg for relief of postoperative pain. Before the morphine injection, the dexamethasone group (n = 40) received IV dexamethasone 8 mg, whereas the saline group (n = 40) received IV saline. We found that the incidence of postoperative vomiting was 5% in the dexamethasone group and 25% in the saline group (P<0.05). The total incidence of nausea and vomiting was 16% in the dexamethasone group and 56% in the saline group (P<0.001). IV dexamethasone 8 mg significantly decreases the incidence of epidural morphine-related nausea and vomiting. IMPLICATIONS: We evaluated IV dexamethasone versus saline control in preventing epidural morphine-related nausea and vomiting in patients receiving epidural morphine for postoperative pain control. We found that IV dexamethasone significantly decreased the total incidence of nausea and vomiting after epidural morphine. IV dexamethasone may be a valuable treatment for preventing epidural morphine-related nausea and vomiting.     

地塞米松减少手术后硬膜外吗啡镇痛引起的恶心呕吐

目的　观察静脉注射地塞米松 (Dex)对减少手术后与硬膜外吗啡镇痛有关的恶心呕吐发生率的作用。方法　随机双盲选择 87例在硬膜外麻醉下行腹部手术的女性病人进行观察。所有病人在手术后均接受硬膜外吗啡镇痛。Dex组病人 (n =41)在手术后静注Dex 8mg ,对照组病人 (n=46 )则给予等量生理盐水。结果　在手术后 2 4小时内 ,Dex组病人手术后总的恶心呕吐发生率为2 6 8% ,明显低于对照组病人的 43 5 % (P <0 0 1)。两组病人之间手术后皮肤瘙痒的发生率无明显差异 ,Dex也不影响手术后硬膜外吗啡的镇痛作用。结论　预防性静脉注射Dex是一种减少与硬膜外吗啡镇痛有关的恶心呕吐并发症的有效方法     

Continuous epidural, not intravenous, droperidol inhibits pruritus, nausea, and vomiting during epidural morphine analgesia

PURPOSE: To investigate whether continuous epidural droperidol and intravenous (IV) intraoperative droperidol inhibit pruritus and postoperative nausea and vomiting (PONV) during epidural morphine analgesia. DESIGN: Randomized, double-blinded, controlled study. SETTING: Metropolitan cancer center. PATIENTS: 120 ASA physical status I and II patients undergoing thoracic or abdominal surgery with general anesthesia combined with epidural anesthesia. INTERVENTIONS: Patients received an intraoperative epidural injection of 2 mg morphine hydrochloride, followed postoperatively by a continuous epidural infusion of morphine hydrochloride 4 mg/day for 4 days. Patients were randomly allocated to four groups: Group A = control group, Group B = intraoperative single IV injection of droperidol (2.5 mg), Group C = postoperative continuous epidural droperidol infusion (2.5 mg/day), and Group D = intraoperative IV injection of droperidol (2.5 mg) and postoperative continuous epidural droperidol infusion (2.5 mg/day). MEASUREMENTS AND MAIN RESULTS: The frequency and severity of pruritus and PONV in each group were evaluated during the postoperative period. Continuous epidural infusion of droperidol significantly reduced the frequency and severity of pruritus and PONV induced by epidural morphine without causing significant side effects. Intraoperative single IV injection of droperidol was effective for PONV (p < 0.05) but not for pruritus. CONCLUSION: Postoperative epidural droperidol infusion significantly decreased both the frequency and severity of pruritus and PONV during postoperative continuous epidural morphine analgesia. IV intraoperative droperidol significantly reduced the frequency and the severity of PONV but not pruritus.     

Ondansetron Is Effective to Treat Spinal or Epidural Morphine-induced Pruritus

Background: Spinally and epidurally administered morphine is frequently associated with pruritus. Isolated case reports indicate that ondansetron may be effective in this context. This study aims to investigate the effectiveness of ondansetron to treat this side effect.

Methods: In a prospective, randomized, double-blind, placebo-controlled study, 100 patients with pruritus (> 4 on a visual analog scale, on which 0 represents no pruritus and 10 represents worst pruritus imaginable) after spinal or epidural administration of morphine, received either 8 mg ondansetron intravenously (ondansetron group) in 100 ml NaCl 0.9% or vehicle (placebo group). A decrease of more than 4 points on the visual analog scale 60 min after treatment was considered a success. Changes in levels of pain and sedation, hemodynamic values, and other side effects were checked regularly. The presence or absence of pruritus was assessed for the last time 24 h later.

Results: The two groups were similar for demographic characteristics, the route of administration of morphine, and severity of pruritus at the beginning of the study. The ondansetron group showed a success rate of 70% versus 30% for the placebo group (P > 0.05). Among the successfully treated patients, three (9%) in the ondansetron group and six (40%) in the placebo group reported the recurrence of pruritus (P < 0.05). Among the successfully treated patients, none complained of residual pruritus 24 h later. No changes in pain or sedation levels were noted. Hemodynamic values remained stable, hemoglobin oxygen saturation did not decrease, and no other side effects were observed.     

Prophylactic intravenous ondansetron reduces the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery

Pruritus is a common side effect of intrathecal morphine injection for postoperative pain control. Its incidence is especially high in patients undergoing cesarean delivery. We investigated the effectiveness of ondansetron in preventing intrathecal morphine-induced pruritus in such patients. We included 60 consecutive nonbreastfeeding women who were scheduled for elective cesarean delivery. After the administration of spinal anesthesia with bupivacaine and intrathecal morphine 0.15 mg injection, the patients were randomly divided into three groups. Group 1 received placebo (normal saline) IV injection, Group 2 diphenhydramine 30 mg IV injection, and Group 3 ondansetron 0.1 mg/kg IV injection. The incidence of pruritus was significantly lower in the ondansetron group (25%) when compared with that in the placebo group (85%) and in the diphenhydramine group (80%) (both P < 0.05). The postoperative pain score and time to flatus passage were not significantly different among the three groups. There were no headache or extrapyramidal signs associated with ondansetron use. In conclusion, ondansetron prophylaxis significantly reduced the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery. IMPLICATIONS: Ondansetron prophylaxis significantly decreases the incidence of pruritus, a common side effect of intrathecal morphine used to treat postcesarean delivery pain.     

Antiemetic effect of ondansetron 0.2 mg mL-1 in PCA morphine solution

BACKGROUND AND OBJECTIVES: To study the effect of 0.2 mg mL-1 of ondansetron added to morphine patient-controlled analgesia solution after a 4 mg loading dose on the incidence and severity of postoperative nausea and vomiting. METHODS: One hundred and sixty patients scheduled for elective surgery, between 18 and 65 yr old, were studied. Patients who smoked, received antiemetics and hormonal therapy, had a history of motion sickness or gastrointestinal disease, a body mass index >35 or menstruation at the time of the study were excluded. Patients were assigned to the ondansetron and control groups by block randomization. At the end of anaesthesia, all patients received 4 mg of ondansetron intravenously and the same patient-controlled analgesia regimen of morphine. The ondansetron group (n = 80) received 0.2 mg of ondansetron per 1 mg of morphine. The nausea score, vomiting score and the requested ondansetron dose were evaluated at 1, 2, 6, 12 and 24 h. Patient-satisfaction for nausea/vomiting was recorded at the end of the study. RESULTS: Patient characteristics and cumulative morphine consumption were similar but ondansetron group had higher pain scores (P = 0.006). The ondansetron group had a lower nausea and vomiting scores, and more patients were free from nausea and vomiting than the control group (41 vs. 26, respectively, P = 0.025). The ondansetron group had fewer cumulative ondansetron doses than the control group and better patient satisfaction than the control group (P < 0.05).CONCLUSION(S): Ondansetron 4 mg plus 0.2 mg mL-1 given with PCA morphine can reduce nausea and vomiting thus improving patient satisfaction.     

Antipruritic and antiemetic effect of epidural droperidol: comparative study between single and continuous epidural injection

BACKGROUND AND OBJECTIVES: This study was designed to investigate whether single epidural droperidol or continuous epidural droperidol inhibit pruritus and postoperative nausea and vomiting induced by postoperative continuous epidural fentanyl administration, and to identify the optimal method of administering epidural droperidol. METHODS: 120 ASA I-II patients undergoing subtotal gastrectomy with general anaesthesia combined with epidural anaesthesia were randomly allocated into three groups: control (no droperidol), single injection (droperidol 2.5 mg) and continuous group (droperidol 2.5 mg 2 day(-1)). Postoperatively the frequency and severity of pruritus and postoperative nausea and vomiting in all groups were compared during 48 h. RESULTS: The frequency and severity of pruritus was significantly lower in both single injection and continuous groups than control group after epidural fentanyl administration (P < 0.05). The frequency and severity of postoperative nausea and vomiting was significantly lower in single injection group than control group after epidural fentanyl administration (P < 0.05). CONCLUSION: Epidural continuous droperidol is effective for reducing pruritus, and single epidural droperidol injection is effective for reducing pruritus and postoperative nausea and vomiting induced by postoperative continuous epidural fentanyl analgesia.     

Comparing the efficacy of prophylactic metoclopramide, ondansetron, and placebo in cesarean section patients given epidural anesthesia

STUDY OBJECTIVE: To compare the relative efficacy of prophylactic metoclopramide, ondansetron, and placebo in nonemergent cesarean section patients given epidural anesthesia intraoperatively and for the first 24-hour period after delivery. DESIGN: Randomized, double blind, placebo-controlled study. SETTING: Inpatient obstetric unit at a university hospital center. PATIENTS: 164 nonemergent cesarean section patients given epidural anesthesia. INTERVENTION: At time of umbilical cord clamp, patients received intravenously (IV) either 4 mg ondansetron (Group O) or 10 mg metoclopramide (Group M) or 10 mL normal saline (Group P). MEASUREMENTS AND MAIN RESULTS: Episodes and severity of nausea and vomiting, rescue antiemetic requirement, patient satisfaction, and side effects were recorded. The frequency of intraoperative nausea were 24%, 43%, and 57% for Group O, Group M, and Group P, respectively (p < 0.03). The frequency of nausea for the 24-hour study period were 26%, 51% and 71% for Groups O, M, and P respectively (p < 0.03). The frequency of intraoperative and postoperative vomiting were similar between Group O and Group M, but significantly higher in Group P (p < 0.05). Overall patient satisfaction was highest in Group O compared with Groups P and M (p < 0.05). Maximum analog sedation score was higher in Group M compared to Groups O and P (p < 0.05). CONCLUSIONS: In cesarean section patients given epidural anesthesia, prophylactic ondansetron, 4 mg IV, is more efficacious and has a higher patient satisfaction than that with metoclopramide, 10 mg IV, or placebo in preventing nausea and achieving complete responses during intraoperative period and the first 24-hour postdelivery period. However, there is no difference between ondansetron and metoclopramide in reducing frequency of vomiting. Prophylactic ondansetron 4 mg IV is more effective in preventing nausea than vomiting.     

Low-dose dexamethasone reduces nausea and vomiting after epidural morphine: a comparison of metoclopramide with saline

STUDY OBJECTIVE: To compare the efficacy of a low dose of dexamethasone (5 mg) with metoclopramide 10 mg and saline in preventing nausea and vomiting after epidural morphine in posthysterectomy analgesia. DESIGN: Randomized, placebo-controlled study. SETTING: Inpatient surgery at Municipal Women's and Children's General Hospital. PATIENTS: 120 ASA physical status I and II women receiving epidural morphine for posthysterectomy analgesia. INTERVENTIONS: All patients received epidural morphine 3 mg for postoperative analgesia. The dexamethasone group (n = 40) received dexamethasone 5 mg, the metoclopramide group (n = 40) received metoclopramide 10 mg, and the saline group (n = 40) received saline. MEASUREMENTS AND MAIN RESULTS: The occurrence of nausea and vomiting appeared more frequently during 6 to 24 hours following the administration of epidural morphine. The total frequency of nausea and vomiting in the dexamethasone group was significantly lower than that of the metoclopramide and saline groups during this period, with reporting frequencies of 21%, 49%, and 53%, respectively (p <.05 each). However, the difference between metoclopramide and saline did not reach statistical significance. CONCLUSIONS: Dexamethasone 5 mg was more effective than metoclopramide or saline in the prevention of nausea and vomiting associated with epidural morphine for postoperative analgesia.     

Postoperative nausea and vomiting in patients undergoing total abdominal hysterectomy under spinal anaesthesia: a randomized study of ondansetron prophylaxis

BACKGROUND AND OBJECTIVE: Patients undergoing total abdominal hysterectomy under general anaesthesia have a high risk of developing postoperative nausea and vomiting (PONV). The aim of this study was to evaluate the incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with intravenous patient-controlled analgesia (PCA) using morphine and to compare its incidence with and without antiemetic prophylaxis. METHODS: Thirty-four patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine postoperatively were divided into two groups. The first (n = 17) received ondansetron prophylaxis near the end of surgery while the second (n = 17) received no prophylaxis. Morphine consumption, emetic episodes (on a 3-point scale), patient satisfaction (visual analogue score), sedation and pruritus were evaluated 2, 4, 6, 9, 12, 18 and 24h postoperatively. RESULTS: Patient characteristics, postoperative morphine consumption (43.3 +/- 7.6 vs. 40.3 +/- 12.3 mg) and peristaltic recovery time (16.9 +/- 5 vs. 18.4 +/- 5.2 h) were similar in both groups. Overall nausea and vomiting were significantly lower in the ondansetron prophylaxis group than in the group without prophylaxis (52.9% vs. 88.2%, P < 0.05). Though nausea alone was higher in the prophylaxis group (41.2% vs. 29.4%), nausea with vomiting was significantly lower in the prophylaxis group (11.8% vs. 58.8%, P < 0.01). Patients' satisfaction scores were higher in the ondansetron group at all times and the difference was significant (P < 0.05) 4 h postoperatively. CONCLUSIONS: The incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine is very high (88.2%). Antiemetic prophylaxis with ondansetron is highly recommended in this patients group resulting in a lower incidence of nausea and vomiting, and significantly improves patient' satisfaction and life quality in the early postoperative period.     

Transdermal scopolamine decreases nausea and vomiting following cesarean section in patients receiving epidural morphine

The authors evaluated the antiemetic properties of transdermal scopolamine (TDS) in healthy patients undergoing elective cesarean section and receiving epidural morphine for postoperative analgesia. Prior to administration of anesthesia, 203 patients had either TDS or a placebo study patch applied behind one ear. All patients were hydrated with lactated Ringer's solution iv and given 2.0% lidocaine with 1:200,000 epinephrine epidurally for surgical anesthesia. Following delivery of the infant, 4 mg of morphine sulphate was injected through the epidural catheter. After the operation patients were evaluated by "blinded" observers at 2, 4, 6, 8, 10, 24, and 48 h for nausea, vomiting, retching, pain relief, itching, and adverse effects. In addition, medications received were noted. No differences were found between the groups in terms of severity or incidence of pain, or requests for analgesic or antipruritic medication. Although there was no difference between the groups in the first 2 h, patients with TDS had significantly less nausea, vomiting, and retching than patients in the placebo group in each time interval between 2 and 10 h. Additionally, the TDS group required less antiemetic medication. There was no difference in the frequency of retching or vomiting between groups. Side effects were minimal and equal in both groups. The authors conclude that TDS results in a decreased incidence of nausea and vomiting in patients who have delivered by cesarean section and received epidural morphine. TDS appears safe for continuous antiemetic administration.     

Comparison of intravenous nalbuphine infusion versus naloxone in the prevention of epidural morphine-related side effects

Background and Objectives. Epidural morphine is accepted as an efficient means of postoperative pain management. However, development of side effects such as nausea and vomiting and pruritus has been reported. This study compared the efficacy of intravenous infusions of nalbuphine or naloxone in the prevention of epidural morphine-related side effects. Methods. Seventy-five female patients undergoing epidural anesthesia for total hysterectomy were enrolled in a randomized, double-blind study. At the end of the surgery, all patients received epidural 3 mg morphine (every 12 hours) for postoperative pain. Meanwhile, patients in group 1 received an adjuvant intravenous infusion of nalbuphine 60 μg/kg/h, patients in group 2 received intravenous infusion of naloxone 2 μg/kg/h, and patients in group 3 received intravenous saline infusion only. A rescue analgesic of intramuscular 50 mg meperidine (every 4 hours) was available for each patient. Patients were observed for 24 hours. Results. All patients had adequate postoperative pain relief. However, the proportion of patients requiring rescue analgesia and the total consumption of rescue analgesic were higher in group 2 than in the other two groups. The incidence of nausea and vomiting and pruritus was higher in group 3 than in the other two groups. Conclusions. We found that coadministration of either nalbuphine or naloxone with epidural morphine reduces the incidence of morphine-related side effects. However, unlike naloxone, nalbuphine did not attenuate the analgesic effect of epidural morphine.     

A singleiv dose of ondansetron 8 mg prior to induction of anaesthesia reduces postoperative nausea and vomiting in gynaecological patients

The effect of a single intravenous dose of ondansetron in preventing postoperative nausea and emesis (retching and vomiting) (PONV) was investigated in a randomized, double-blind, placebo-controlled, multicentre, international study. Women of ASA class I–III, requiring gynaecological laparotomy, vaginal hysterectomy, or major vaginal surgery were selected for study. Two hundred and thirty-five received placebo, 231 received 1 mg ondansetron, 228 received 8 mg ondansetron and 229 received 16 mg ondansetron, as an infusion over five minutes before the induction of anaesthesia. A standardized balanced anaesthetic technique was employed. This consisted of premedication with either diazepam or temazepam, thiopentone induction, maintenance with nitrous oxide in oxygen supplemented with enflurane or isoflurane, intraoperative analgesia with fentanyl, neuromuscular blockade with any choice of agent and reversal with neostigmine and atropine. Postoperative analgesia was achieved with morphine, and prochlorperazine or metoclopramide were given if a rescue antiemetic was required. A greater percentage of patients in the 8 mg and 16 mg ondansetron groups experienced no postoperative emesis (44% and 39% respectively) than in the placebo and 1 mg ondansetron groups (29% and 28% respectively) for the first 24 hr postoperative period (8 mg vs placebo and 1 mg: P ≤ 0.001; 16 mg vs placebo: P < 0.05; 16 mg vs 1 mg: P < 0.05). Similarly, the percentage of patients who did not experience postoperative nausea were 20%, 26%, 31% and 28% for the placebo, 1 mg, 8 mg and 16 mg ondansetron treatment groups, respectively (8 mg and 16 mg vs placebo P < 0.05). Overall, the incidences of adverse events in the ondansetron and placebo groups were similar. It is concluded that intravenous ondansetron, at doses of 8 mg and 16 mg, is both well tolerated and effective in preventing postoperative nausea and emesis, and no greater benefit was observed with the 16 mg dose in comparison with the 8 mg dose.     

Effects of epidural naloxone on pruritus induced by epidural morphine: a randomized controlled trial

BACKGROUND: Epidural morphine produces prolonged analgesia but has many side effects including pruritus. Naloxone is an antagonist that can reverse the side effects of morphine. METHOD: We studied the effects of continuously administered epidural naloxone mixed with morphine on side effects and analgesia in a randomized, double blind, two-armed study. Fifty-eight pregnant women undergoing cesarean section were enrolled. All patients received a 4-mg epidural bolus of morphine in the post-anesthetic care unit. After this, patients in group M (n=28) received continuous epidural morphine (6 mg over 48 h) in 0.1% bupivacaine; patients in group N (n=30) received an epidural infusion containing naloxone (1.2 mg over 48 h) and morphine (6 mg over 48 h) in 0.1% bupivacaine. The infusion rate was 2 mL/h. RESULTS: The incidence (82% versus 47%) and severity of pruritus were lower in group N than group M (P=0.001). There were no significant differences in pain score or in the incidence of nausea, vomiting or urinary disturbance between groups. CONCLUSION: Continuous epidural infusion of naloxone combined with morphine is effective in reducing the incidence and severity of pruritus induced by epidural morphine.     

Combination of ondansetron and dexamethasone in the prophylaxis of postoperative nausea and vomiting

We studied 100 ASA I-II females undergoing general anaesthesia for major gynaecological surgery, in a prospective, double-blind, placebo- controlled, randomized study. Patients received one of four regimens for the prevention of postoperative nausea and vomiting (PONV): ondansetron 4 mg (n = 25), dexamethasone 8 mg (n = 25), ondansetron with dexamethasone (4 mg and 8 mg, respectively, n = 25) or placebo (saline, n = 25) There were no differences in background factors or factors related to operation and anaesthesia, morphine consumption, pain or side effects between groups. The incidence of nausea and emetic episodes in the ondansetron with dexamethasone group was lower than in the placebo (P < 0.01), ondansetron (P < 0.05) and dexamethasone (P = 0.057) groups. There were no differences between ondansetron and dexamethasone, and both were more effective than placebo (P < 0.05 and P < 0.01, respectively). Dexamethasone appeared to be preferable in preventing nausea than emetic episodes. Fewer patients in the ondansetron with dexamethasone group needed antimetic rescue (P < 0.01 vs placebo and P < 0.05 vs ondansetron). We conclude that prophylactic administration of combined ondansetron and dexamethasone is effective in preventing PONV.