Dexamethasone for Preventing Nausea and Vomiting Associated with Epidural Morphine: A Dose-Ranging Study

Comparison of Low-Dose Promethazine and Dexamethasone against Ondansetron Monotherapy Given as Antiemetic Prophylaxis during Myomectomy Under Spinal Anesthesia: A Randomized Clinical Trial

Background. Postoperative nausea and vomiting (PONV) prophylaxis is still inadequate for a significant proportion of women undergoing myomectomy under spinal anesthesia; and it substantially decreases patient’s quality of postoperative recovery. Current protocol and practice favor the use of combination therapy like promethazine/dexamethasone for PONV prophylaxis with minimal side effects and cost advantages in low-resource climes. Methodology. Seventy American Society of Anesthesiologist (ASA) class I or II women aged 21–65 years scheduled for myomectomy were recruited and randomized into group A (promethazine/dexamethasone group) and group B (ondansetron group). Myomectomy was performed on each patient using spinal anesthesia. After induction of spinal anesthesia, patients in group A received intravenous promethazine 12.5 mg and dexamethasone 8 mg while group B received intravenous ondansetron 8 mg. Early (0–3 h) and late (4–24 h) PONV was assessed using the numerical scoring scale. Results. Data analysis was done using SPSS version 20. Postoperatively, there was no significant difference in the incidence of early ansd late PONV ( $p$ value >0.05) despite the higher incidents in the ondansetron group. The proportion of patients who required rescue antiemetics was more in the ondansetron group when compared with the promethazine/dexamethasone, with minimal and statistically insignificant side effects in both groups. There was significant patient satisfaction in both groups. Conclusion. The study shows that the combination of low-dose promethazine and dexamethasone is comparable to ondansetron when used as prophylaxis for PONV with cost benefits in low-resource environments.

Adverse side effects of dexamethasone in surgical patients

BACKGROUND

In the perioperative period, dexamethasone is widely and effectively used for prophylaxis of postoperative nausea and vomiting (PONV), for pain management, and to facilitate early discharge after ambulatory surgery.Long-term treatment with steroids has many side effects, such as adrenal insufficiency, increased infection risk, hyperglycaemia, high blood pressure, osteoporosis, and development of diabetes mellitus. However, whether a single steroid load during surgery has negative effects during the postoperative period has not yet been studied.

OBJECTIVES

To assess the effects of a steroid load of dexamethasone on postoperative systemic or wound infection, delayed wound healing, and blood glucose change in adult surgical patients (with planned subgroup analysis of patients with and without diabetes).

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, and the Web of Science for relevant articles on 29 January 2018. We searched without language or date restriction two clinical trial registries to identify ongoing studies, and we handsearched the reference lists of relevant publications to identify all eligible trials.

SELECTION CRITERIA

We searched for randomized controlled trials comparing an incidental steroid load of dexamethasone versus a control intervention for adult patients undergoing surgery. We required that studies include a follow-up of 30 days for proper assessment of the number of postoperative infections, delayed wound healing, and the glycaemic response.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for eligibility, extracted data from relevant studies, and assessed all included studies for bias. We resolved differences by discussion and pooled included studies in a meta-analysis. We calculated Peto odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. Our primary outcomes were postoperative systemic or wound infection, delayed wound healing, and glycaemic response within 24 hours. We created a funnel plot for the primary outcome postoperative (wound or systemic) infection. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included in the meta-analysis 37 studies that included adults undergoing a large variety of surgical procedures (i.e. abdominal surgery, cardiac surgery, neurosurgery, and orthopaedic surgery). We excluded one previously included study, as this study was recently retracted. Age range of participants was 18 to 80 years. There is probably little or no difference in the risk of postoperative (wound or systemic) infection with dexamethasone compared with no treatment, placebo, or active control (ramosetron, ondansetron, or tropisetron) (Peto OR 1.01, 95% confidence interval (CI) 0.80 to 1.27; 4603 participants, 26 studies; I² = 32%; moderate-quality evidence). The effects of dexamethasone on delayed wound healing are unclear because the wide confidence interval includes both meaningful benefit and harm (Peto OR 0.99, 95% CI 0.28 to 3.43; 1072 participants, eight studies; I² = 0%; low-quality evidence). Dexamethasone may produce a mild increase in glucose levels among participants without diabetes during the first 12 hours after surgery (MD 13 mg/dL, 95% CI 6 to 21; 10 studies; 595 participants; I² = 50%; low-quality evidence). We identified two studies reporting on glycaemic response after dexamethasone in participants with diabetes within 24 hours after surgery (MD 32 mg/dL, 95% CI 15 to 49; 74 participants; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

A single dose of dexamethasone probably does not increase the risk for postoperative infection. It is uncertain whether dexamethasone has an effect on delayed wound healing in the general surgical population owing to imprecision in trial results. Participants with increased risk for delayed wound healing (e.g. participants with diabetes, those taking immunosuppressive drugs) were not included in the randomized studies reporting on delayed wound healing included in this meta-analysis; therefore our findings should be extrapolated to the clinical setting with caution. Furthermore, one has to keep in mind that dexamethasone induces a mild increase in glucose. For patients with diabetes, very limited evidence suggests a more pronounced increase in glucose. Whether this influences wound healing in a clinically relevant way remains to be established. Once assessed, the two studies awaiting classification and three that are ongoing may alter the conclusions of this review.

Adverse side effects of dexamethasone in surgical patients

BACKGROUND

In the perioperative period, dexamethasone is widely and effectively used for prophylaxis of postoperative nausea and vomiting (PONV), for pain management, and to facilitate early discharge after ambulatory surgery.Long-term treatment with steroids has many side effects, such as adrenal insufficiency, increased infection risk, hyperglycaemia, high blood pressure, osteoporosis, and development of diabetes mellitus. However, whether a single steroid load during surgery has negative effects during the postoperative period has not yet been studied.

OBJECTIVES

To assess the effects of a steroid load of dexamethasone on postoperative systemic or wound infection, delayed wound healing, and blood glucose change in adult surgical patients (with planned subgroup analysis of patients with and without diabetes).

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, and the Web of Science for relevant articles on 29 January 2018. We searched without language or date restriction two clinical trial registries to identify ongoing studies, and we handsearched the reference lists of relevant publications to identify all eligible trials.

SELECTION CRITERIA

We searched for randomized controlled trials comparing an incidental steroid load of dexamethasone versus a control intervention for adult patients undergoing surgery. We required that studies include a follow-up of 30 days for proper assessment of the number of postoperative infections, delayed wound healing, and the glycaemic response.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for eligibility, extracted data from relevant studies, and assessed all included studies for bias. We resolved differences by discussion and pooled included studies in a meta-analysis. We calculated Peto odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. Our primary outcomes were postoperative systemic or wound infection, delayed wound healing, and glycaemic response within 24 hours. We created a funnel plot for the primary outcome postoperative (wound or systemic) infection. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included in the meta-analysis 38 studies that included adults undergoing a large variety of surgical procedures (i.e. abdominal surgery, cardiac surgery, neurosurgery, and orthopaedic surgery). Age range of participants was 18 to 80 years. There is probably little or no difference in the risk of postoperative (wound or systemic) infection with dexamethasone compared with no treatment, placebo, or active control (ramosetron, ondansetron, or tropisetron) (Peto OR 1.01, 95% confidence interval (CI) 0.80 to 1.27; 4931 participants, 27 studies; I² = 27%; moderate-quality evidence). The effects of dexamethasone on delayed wound healing are unclear because the wide confidence interval includes both meaningful benefit and harm (Peto OR 0.99, 95% CI 0.28 to 3.43; 1072 participants, eight studies; I² = 0%; low-quality evidence). Dexamethasone may produce a mild increase in glucose levels among participants without diabetes during the first 12 hours after surgery (MD 13 mg/dL, 95% CI 6 to 21; 10 studies; 595 participants; I² = 50%; low-quality evidence). We identified two studies reporting on glycaemic response after dexamethasone in participants with diabetes within 24 hours after surgery (MD 32 mg/dL, 95% CI 15 to 49; 74 participants; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

A single dose of dexamethasone probably does not increase the risk for postoperative infection. It is uncertain whether dexamethasone has an effect on delayed wound healing in the general surgical population owing to imprecision in trial results. Participants with increased risk for delayed wound healing (e.g. participants with diabetes, those taking immunosuppressive drugs) were not included in the randomized studies reporting on delayed wound healing included in this meta-analysis; therefore our findings should be extrapolated to the clinical setting with caution. Furthermore, one has to keep in mind that dexamethasone induces a mild increase in glucose. For patients with diabetes, very limited evidence suggests a more pronounced increase in glucose. Whether this influences wound healing in a clinically relevant way remains to be established. Once assessed, the three studies awaiting classification and two that are ongoing may alter the conclusions of this review.

WITHDRAWN: Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

A comparison of palonosetron and dexamethasone for postoperative nausea and vomiting in orthopedic patients receiving patient-controlled epidural analgesia

Background

Postoperative nausea and vomiting (PONV) is one of the major concerns after anesthesia and surgery, and it may be more frequent in orthopedic patients receiving patient-controlled epidural analgesia (PCEA). The purpose of this study was to compare the effect of palonosetron and dexamethasone on the prevention of PONV in patients undergoing total joint arthroplasty and receiving PCEA.

Methods

Patients scheduled for total hip or knee arthroplasty under spinal anesthesia/PCEA were randomly allocated to receive either intravenous palonosetron (0.075 mg, n = 50) or dexamethasone (5 mg, n = 50). Treatments were administered intravenously to the patients 30 min before the beginning of surgery. The total incidence of PONV and incidence in each time period, severity of nausea, need for rescue anti-emetics, pain score, and adverse effects during the first 48 h postoperatively were evaluated.

Results

The total incidence of PONV was lower in the palonosetron group compared with the dexamethasone group (18.4% vs. 36.7%, P = 0.042), but there were no statistically significant differences in incidence between the groups at all time points. No significant intergroup differences were observed in the severity of nausea, use of rescue anti-emetics, pain score, and adverse effects.

Conclusions

Although there were no significant differences in the incidence of PONV between the treatment groups at all time points, intravenous palonosetron reduced the total incidence of PONV in orthopedic patients receiving PCEA compared with dexamethasone.

Practice guidelines for postanesthetic care: an updated report by the American Society of Anesthesiologists Task Force on Postanesthetic Care

Supplemental Digital Content is available in the text.

Dexamethasone to prevent postoperative nausea and vomiting: an updated meta-analysis of randomized controlled trials

BACKGROUND

Dexamethasone has an established role in decreasing postoperative nausea and vomiting (PONV); however, the optimal dexamethasone dose for reducing PONV when it is used as a single or combination prophylactic strategy has not been clearly defined. In this study, we evaluated the use of 4 mg to 5 mg and 8 mg to 10 mg IV doses of dexamethasone to prevent PONV when used as a single drug or as part of a combination preventive therapy.

METHODS

A wide search was performed to identify randomized clinical trials that evaluated systemic dexamethasone as a prophylactic drug to reduce postoperative nausea and/or vomiting. The effects of dexamethasone dose were evaluated by pooling studies into 2 groups: 4 mg to 5 mg and 8 mg to 10 mg. The first group represents the suggested dexamethasone dose to prevent PONV by the Society for Ambulatory Anesthesia (SAMBA) guidelines, and the second group represents twice the dose range recommended by the guidelines. The SAMBA guidelines were developed in response to studies, which have been performed to examine different dosages of dexamethasone.

RESULTS

Sixty randomized clinical trials with 6696 subjects were included. The 4-mg to 5-mg dose dexamethasone group experienced reduced 24-hour PONV compared with control, odds ratio (OR, 0.31; 95% confidence interval [CI], 0.23-0.41), and number needed to treat (NNT, 3.7; 95% CI, 3.0-4.7). When used together with a second antiemetic, the 4-mg to 5-mg dexamethasone group also experienced reduced 24-hour PONV compared with control (OR, 0.50; 95% CI, 0.35-0.72; NNT, 6.6; 95% CI, 4.3-12.8). The 8-mg to 10-mg dose dexamethasone group experienced decreased 24-hour PONV compared with control (OR, 0.26; 95% CI, 0.20-0.32; NNT, 3.8; 95% CI, 3.0-4.3). Asymmetric funnel plots were observed in the 8-mg to 10-mg dose analysis, suggesting the possibility of publication bias. When used together with a second antiemetic, the 8-mg to 10-mg dose group also experienced reduced incidence of 24-hour PONV (OR, 0.35; 95% CI, 0.22-0.53; NNT, 6.2; 95% CI, 4.5-10). In studies that provided a direct comparison between groups, there was no clinical advantage of the 8-mg to 10-mg dexamethasone dose compared with the 4-mg to 5-mg dose on the incidence of postoperative nausea and/or vomiting.

CONCLUSIONS

Our results showed that a 4-mg to 5-mg dose of dexamethasone seems to have similar clinical effects in the reduction of PONV as the 8-mg to 10-mg dose when dexamethasone was used as a single drug or as a combination therapy. These findings support the current recommendation of the SAMBA guidelines for PONV, which favors the 4-mg to 5-mg dose regimen of systemic dexamethasone.

Dexamethasone for the prophylaxis of postoperative nausea and vomiting associated with neuraxial morphine administration: a systematic review and meta-analysis

BACKGROUND

We performed a systematic review to assess the efficacy of dexamethasone in reducing postoperative nausea, vomiting (PONV), pruritus, and enhancing postoperative analgesia in patients receiving neuraxial anesthesia with neuraxial morphine.

METHODS

We searched Medline (1966-2011), the Cochrane Central Register of Controlled Trials, EMBASE, and Web of Science for all randomized controlled trials comparing dexamethasone with placebo for the prevention of PONV and/or pruritus in patients receiving neuraxial morphine as part of a neuraxial anesthetic technique. Data were extracted independently by the authors on the incidence of PONV, pruritus, pain scores at 4 and 24 hours, and use of rescue antiemetics, antipruritics, and analgesics.

RESULTS

Eight randomized controlled trials (4 cesarean deliveries, 4 total abdominal hysterectomies) were included. From these trials, 768 patients were analyzed with 473 receiving dexamethasone and 295 receiving placebo. The doses of dexamethasone investigated ranged from 2.5 to 10 mg. Dexamethasone reduced the incidence of postoperative nausea (relative risk, RR [95% confidence interval, CI] = 0.57 [0.45, 0.72]), vomiting (RR [95% CI] = 0.56 [0.43, 0.72]), and the use of rescue antiemetic therapy (RR [95% CI] = 0.47 [0.36, 0.61]) compared with placebo. There was no evidence of dose responsiveness with respect to its antiemetic effect. Dexamethasone also reduced 24-hour visual analog pain scores (measured on an 11-point scale [0-10]) (mean difference [95% CI] = -0.30 [-0.46, -0.13]) and the use of rescue analgesics (RR [95% CI] = 0.72 [0.52, 0.98]). Dexamethasone did not reduce the incidence of pruritus (RR [95% CI] = 0.98 [0.84, 1.15]). Examination of the funnel plots and Egger's test revealed evidence of publication bias in the primary outcomes.

CONCLUSION

Dexamethasone is an effective antiemetic for patients receiving neuraxial morphine for cesarean delivery and abdominal hysterectomy. In addition, the doses used for antiemetic prophylaxis enhanced postoperative analgesia compared with placebo. However, dexamethasone was not effective for the prophylaxis against neuraxial morphine-induced pruritus.

Perioperative dexamethasone does not affect functional outcome in total hip arthroplasty

Current trends in orthopaedic surgery have explored different forms of adjuvant treatments to minimize postoperative pain and the risk of nausea and vomiting. A small single preoperative dose of dexamethasone, as part of a comprehensive multimodal analgesic regimen in low-risk patients undergoing total hip arthroplasty (THA), provides antiemetic and opioid-sparing effects but the longer-term effects on pain, complications, or function are not known. We therefore asked whether such a routine would affect longer-term pain, complications, or function. Fifty patients undergoing elective primary THA using spinal anesthesia were initially randomized to receive either dexamethasone (40 mg intravenous) or saline placebo. The patients, anesthesiologists, nurses, and research coordinators were blinded to the study arms. The functional outcome was measured using the Harris hip score. Outcomes were assessed 6 weeks and 1 year postoperatively. We observed no difference in resting pain between the two groups at either time period. Both groups had similar functional outcome scores for the total Harris hip score and individual scoring items at each followup interval. There were no wound complications, deep infections, or osteonecrosis in the contralateral hip at 1-year followup. We recommend the addition of a small single preoperative dose of dexamethasone to a comprehensive multimodal analgesic regimen in low-risk patients given its immediate antiemetic and opioid-sparing effects, and absence of subsequent effects.

LEVEL OF EVIDENCE

Level II, therapeutic study (prospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Prevention of postoperative nausea and vomiting after intrathecal morphine for Cesarean section: a randomized comparison of dexamethasone, droperidol, and a combination

BACKGROUND

Intrathecal morphine provides good analgesia after cesarean delivery but the side effects include nausea and vomiting. Low-dose droperidol (0.625 mg) combined with dexamethasone 4 mg is postulated to have an additive antiemetic effect with less side effects. We therefore compared single doses of dexamethasone and droperidol alone with a low-dose combination of the two, to prevent spinal morphine-induced nausea and vomiting after cesarean section.

METHODS

In a double-blind study, 120 women undergoing elective cesarean section under spinal anesthesia (using 0.5% bupivacaine 10 mg and morphine 0.2 mg) were allocated randomly to receive dexamethasone 8 mg, droperidol 1.25 mg, dexamethasone 4 mg and droperidol 0.625 mg, or placebo, before the end of surgery. The incidences of nausea and vomiting, sedative score, pain score, and side effects were recorded.

RESULTS

The incidence of nausea and vomiting within 6 h postoperatively was lower and incidence of no nausea and vomiting for 24 h postoperatively was significantly higher for the combination group compared to the placebo group and the dexamethasone only group. Sedation scores within 3 h postoperatively and incidence of restlessness for the combination group were significantly lower than in the droperidol only group.

CONCLUSION

An additive antiemetic effect and no significant side effects were shown for the combination of dexamethasone 4 mg and droperidol 0.625 mg. This combination was more effective than either dexamethasone 8 mg or droperidol 1.25 mg alone in preventing nausea and vomiting after spinal anesthesia using 0.5% bupivacaine and morphine 0.2 mg.

Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

The role of intrathecal drugs in the treatment of acute pain

Intrathecal opioids are widely used as useful adjuncts in the treatment of acute and chronic pain, and a number of non-opioid drugs show promise as analgesic drugs with spinal selectivity. In this review we examine the historical development and current use of intrathecal opioids and other drugs that show promise for treating pain in the perioperative period. The pharmacology and clinical use of intrathecal morphine and other opioids is reviewed in detail, including dosing guidelines for specific surgical procedures and the incidence and treatment of side effects associated with these drugs. Available data on the use of non-opioid drugs that have been tested intrathecally for use as analgesics are also reviewed. Evidence-based guidelines for dosing of intrathecal drugs for specific surgical procedures and for the treatment of the most common side effects associated with these drugs are presented.

Prevention and treatment of postoperative nausea and vomiting

PURPOSE

The physiology, risk factors, and prevention and treatment of postoperative nausea and vomiting (PONV) are discussed.

SUMMARY

Factors to consider when determining a patient's risk for PONV include sex, history of PONV, history of motion sickness, smoking status, duration of anesthesia, use of opioids, and type of surgery. Receptors that, when activated, can cause nausea or vomiting or both include dopamine type 2, serotonin type 3, histamine type 1, and muscarinic cholinergic type 1 receptors. Patients at moderate to high risk for PONV benefit from the administration of a prophylactic antiemetic agent that blocks one or more of these receptors. Effective agents include transdermal scopolamine, prochlorperazine, promethazine, droperidol, ondansetron, dolasetron, granisetron, and dexamethasone. In high-risk patients, combining two or more antiemetics with different mechanisms of action has been shown to be more effective than using a single agent. In addition to administering a prophylactic antiemetic, it is important to reduce the patient's risk by considering regional anesthesia, considering inducing and maintaining general anesthesia with propofol, ensuring good intravenous hydration, avoiding hypotension, and providing effective analgesia. If PONV occurs in the immediate postoperative period, it is best treated with an antiemetic agent from a pharmacologic class different from that of the prophylactic agent.

CONCLUSION

Prophylactic antiemetic therapy for PONV is effective, but combinations of agents may be necessary for high-risk patients. Nonpharmacologic strategies are also important.

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.

Epidural oxycodone or morphine following gynaecological surgery †

BACKGROUND

The analgesic action of oxycodone is of rapid onset, in contrast to morphine, and is mediated by kappa-opioid receptors of the spinal cord. We compared analgesia and side-effects of epidural oxycodone with those of morphine after gynaecological surgery.

METHODS

We studied prospectively in 75 women in a double-blind, randomized manner: epidural morphine 6 mg day(-1) (n=25), epidural oxycodone 6 mg day(-1) (n=25) and epidural oxycodone 12 mg day(-1) (n=25). All patients underwent gynaecological surgery under general (isoflurane and nitrous oxide) and epidural anaesthesia. Visual analogue scale (VAS) pain scores at rest and on coughing, verbal descriptive scale (VDS) satisfaction scores, sedation scores, pruritus scores and nausea/vomiting scores were recorded for 3 days after surgery.

RESULTS

VAS pain scores at rest in patients who received oxycodone 6 mg day(-1) were higher than in patients who received morphine 6 mg day(-1) at 6 h and on the first postoperative day and were significantly higher than in patients who received oxycodone 12 mg day(-1) on the first postoperative day. Scores for nausea, vomiting and pruritus in patients who received oxycodone 6 mg day(-1) and 12 mg day(-1) were lower than those in patients who received morphine. No significant differences were seen in VAS at cough and VDS satisfaction scores between the three groups.

CONCLUSION

Epidural oxycodone was as effective as morphine at the doses investigated, with fewer side-effects.

Prophylacticiv ondansetron reduces nausea, vomiting and pruritus following epidural morphine for postoperative pain control

PURPOSE

To evaluate the prophylactic effect of ondansetron on nausea and vomiting following epidural morphine for postoperative pain control.

METHODS

Seventy women (n = 35 in each group) undergoing abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blinded, and placebo-controlled study. At the end of surgery, all patients received epidural morphine 3 mg for postoperative pain relief. Before morphine injection, the ondansetron group received iv ondansetron 4 mg, whereas the placebo group received iv saline.

RESULTS

Patients in the ondansetron group reported a lower frequency of total postoperative nausea and vomiting (22%) and lower frequency of rescue antiemetic request (12%) than those in the placebo group (52% and 39%, respectively; P < 0.05). In addition, ondansetron was associated with a reduced incidence of pruritus following epidural morphine (28% vs 58%; P < 0.05).

CONCLUSION

We conclude that iv ondansetron 4 mg is effective in the prevention of nausea, vomiting, and pruritus following epidural morphine for postoperative pain control.

Epidural versus intrathecal morphine for postoperative analgesia after Caesarean section

BACKGROUND

Perispinal anaesthesia for Caesarean section allows injection of epidural (ED) or intrathecal (i.t.) morphine to provide long-lasting postoperative analgesia. To compare these two routes, a prospective, randomized, double-blinded study of 53 patients undergoing elective Caesarean section was performed.

METHODS

Combined spinal-epidural anaesthesia with 6 mg of i.t. hyperbaric bupivacaine plus sufentanil 5 microg, and additional ED lidocaine was used. Additionally, each patient received either 2 mg (2 ml) of ED morphine plus 1 ml of i.t. normal saline (ED group, n=28), or 0.075 mg (1 ml) of i.t. morphine plus 2 ml of ED normal saline (i.t. group, n=25). Additional postoperative analgesia was given in the form of propacetamol and ketoprofen, plus self-administered i.v. morphine.

RESULTS

No major respiratory depression occurred. Time to first demand of morphine was similar in the ED (307.5 min) and i.t. (310 min) groups, as was the incidence of side-effects such as sedation, pruritus, nausea, and vomiting. During the first 24 postoperative hours, VAS pain scores were greater in the i.t. group (P=0.032), as was additional morphine consumption (4 vs 1.5 mg) (P=0.03).

CONCLUSIONS

The ED protocol was more effective than the i.t. protocol, whilst side-effects were similar.

Prevention of postoperative nausea and vomiting after spinal morphine for Caesarean section: comparison of cyclizine, dexamethasone and placebo

BACKGROUND

Low-dose intrathecal (spinal) morphine (0.1-0.2 mg) for Caesarean section delivers excellent postoperative analgesia but is associated with significant nausea and vomiting. We compared the antiemetic efficacy of cyclizine, dexamethasone, and placebo in this clinical setting.

METHODS

Ninety-nine women undergoing elective Caesarean section under spinal anaesthesia were allocated randomly, in a double-blind study design, to receive either cyclizine 50 mg, dexamethasone 8 mg, or placebo as a single-dose infusion in saline 0.9%, 100 ml on completion of surgery. Spinal anaesthesia consisted of: hyperbaric bupivacaine 0.5%, 2.0 ml; fentanyl 10 micro g; and spinal morphine 0.2 mg. The primary outcome measure was the incidence of nausea.

RESULTS

The incidence of nausea was significantly less in patients receiving cyclizine compared with dexamethasone and placebo (33 vs 60 and 67%, respectively, P<0.05). Severity of nausea and number of vomiting episodes were also less at 3-6 h in cyclizine patients. Overall satisfaction with postoperative care at 24 h, expressed on a 100 mm visual analogue scale, was greater in cyclizine [78 (28)] than either dexamethasone [58 (31), P=0.03] or placebo [51 (28), P=0.008].

CONCLUSION

We conclude that following spinal morphine 0.2 mg and fentanyl 10 micro g analgesia for Caesarean section, cyclizine 50 mg i.v. reduces the incidence of nausea compared with dexamethasone 8 mg i.v. or placebo. It also lessens the severity of nausea and vomiting, and increases maternal satisfaction in the early postoperative period.

Dexamethasone prevents postoperative nausea and vomiting more effectively in women with motion sickness

PURPOSE

To evaluate the antiemetic effect of iv dexamethasone for preventing postoperative nausea and vomiting (PONV) in women with and without a history of motion sickness.

METHODS

This randomized, double-blinded, placebo-controlled study was carried out in 168 female patients with (n = 84) and without (n = 84) a history of motion sickness undergoing gynecological laparoscopy. Patients received 8 mg dexamethasone or saline immediately before induction of anesthesia. Postoperatively patients were assessed for 24 hr for nausea, vomiting, and complete response (no vomiting, no need for rescue antiemetics).

RESULTS

The complete response for patients with a history of motion sickness was 80.5% and 37.5% for recipients of dexamethasone and saline, respectively [P < 0.001; number needed-to-treat (NNT) = 2.3]; with corresponding incidences of 83.3% and 53.7% when there was no such history (P = 0.009; NNT = 3.4). Calculation of the efficacy of dexamethasone for the different subgroups shows that dexamethasone was 45.3% more effective in patients with motion sickness than in those without it.

CONCLUSIONS

Prophylactic administration of dexamethasone is effective in reducing PONV in patients with and without a history of motion sickness. The results of this study were more favourable in patients with a history of motion sickness, demonstrating a higher effectiveness of dexamethasone for preventing PONV in this subgroup of patients.

A comparison of three antiemetic combinations for the prevention of postoperative nausea and vomiting

In this study we compared the efficacy and safety of three antiemetic combinations in the prevention of postoperative nausea and vomiting (PONV). Ninety ASA status I-II women, aged 18-65 yr, undergoing general anesthesia for major gynecological surgery, were included in a prospective, randomized, double-blinded study. A standardized anesthetic technique and postoperative analgesia (intrathecal morphine plus IV patient-controlled analgesia (PCA) with morphine) were used in all patients. Patients were randomly assigned to receive ondansetron 4 mg plus droperidol 1.25 mg after the induction of anesthesia and droperidol 1.25 mg 12 h later (Group 1, n = 30), dexamethasone 8 mg plus droperidol 1.25 mg after the induction of anesthesia and droperidol 1.25 mg 12 h later (Group 2, n = 30), or ondansetron 4 mg plus dexamethasone 8 mg after the induction of anesthesia and placebo 12 h later (Group 3, n = 30). A complete response, defined as no PONV in 48 h, occurred in 80% of patients in Group 1, 70% in Group 3, and 40% in Group 2 (P = 0.004 versus Groups 1 and 3). The incidences of side effects and other variables that could modify the incidence of PONV were similar among groups. In conclusion, ondansetron, in combination with droperidol or dexamethasone, is more effective than dexamethasone in combination with droperidol in women undergoing general anesthesia for major gynecological surgery with intrathecal morphine plus IV PCA with morphine for postoperative analgesia.

IMPLICATIONS

The combination of ondansetron plus dexamethasone or droperidol was significantly better than the combination of dexamethasone plus droperidol in the prophylaxis of postoperative nausea and vomiting in women undergoing general anesthesia for major gynecological surgery, with intrathecal and IV morphine (patient-controlled analgesia) for management of postoperative pain.

Endogenous opiates and behavior: 2001

This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).

The prophylactic effect of tropisetron on epidural morphine-related nausea and vomiting: a comparison of dexamethasone with saline

Tropisetron is a 5-hydroxytryptamine subtype 3 receptor antagonist that is primarily used in the prevention of chemotherapy-induced nausea and vomiting. We evaluated the prophylactic effect of tropisetron on postoperative nausea and vomiting associated with epidural morphine. Dexamethasone and saline served as controls. One-hundred twenty women (n = 40 in each of three groups) undergoing abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blinded, and placebo-controlled study. At the end of surgery, Group 1 received IV tropisetron 5 mg, whereas Groups 2 and 3 received dexamethasone 5 mg and saline, respectively. We found that tropisetron did not significantly reduce the occurrence of nausea and vomiting associated with epidural morphine. Dexamethasone, however, reduced the total incidence of nausea and vomiting from 59% to 21% (P < 0.01) and the percentage of patients requiring rescue antiemetic from 38% to 13% (P < 0.05). We conclude that IV tropisetron 5 mg did not prevent the occurrence of postoperative nausea and vomiting associated with epidural morphine. IV dexamethasone 5 mg was effective for this purpose.

IMPLICATIONS

We compared the prophylactic IV administration of tropisetron 5 mg to prevent postoperative nausea and vomiting (PONV) associated with epidural morphine with dexamethasone 5 mg and saline in women undergoing hysterectomy. We found that tropisetron 5 mg did not significantly reduce the occurrence of PONV associated with epidural morphine. Dexamethasone 5 mg was effective for this purpose.

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.