RETRACTED: Reduction of emetic symptoms during cesarean delivery with antiemetics: propofol at subhypnotic dose versus traditional antiemetics

The Effect of Nicotine Patch on Reducing Nausea, Vomiting, and Pain Following Laparoscopic Cholecystectomy: A Randomized Clinical Trial

BACKGROUND

The effect of nicotine on nausea, vomiting, and postoperative pain has been investigated in studies on animals and humans. This study aimed to evaluate the effect of nicotine patch on decreasing nausea, vomiting, and pain in laparoscopic cholecystectomy.

METHODS

The study sample consisted of 100 non-smoking patients undergoing laparoscopic cholecystectomy under general anesthesia in a triple-blind clinical trial. One hour after the start of surgery, patients were randomly assigned to receive 17.5-mg nicotine or placebo patches. The patches located on the right arm were left for 24 hours. The visual analogue scale (VAS) for pain and N/V score for the severity of nausea and vomiting were measured at intervals of 0, 6, 12, and 24 hours.

FINDINGS

The results showed there was no statistically significant difference between the groups in terms of pain intensity as well as nausea and vomiting at different time periods after surgery (P>0.05). A total of 36 patients in the nicotine group and 24 patients in the placebo group received meperidine. There was also no statistically significant difference between the two groups in terms of analgesics (P=0.096) and antiemetics (P=0.1). Moreover, the frequency of severe nausea and vomiting during the study in the nicotine group was higher than in the placebo group (4 vs. 1) but this difference was not statistically significant (P>0.05).

CONCLUSION

Receiving a 17.5-mg nicotine patch had a similar effect to receiving placebo in controlling postoperative pain, nausea, and vomiting in non-smokers. Nicotine use had no effect on reducing analgesia.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUND

Nausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and in the postoperative period.  OBJECTIVES: To assess the efficacy of pharmacological and non-pharmacological interventions versus placebo or no intervention given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (16 April 2020), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of studies and conference abstracts, and excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Our primary outcomes are intraoperative and postoperative nausea and vomiting. Data entry was checked. Two review authors independently assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Eighty-four studies (involving 10,990 women) met our inclusion criteria. Sixty-nine studies, involving 8928 women, contributed data. Most studies involved women undergoing elective caesarean section. Many studies were small with unclear risk of bias and sometimes few events. The overall certainty of the evidence assessed using GRADE was moderate to very low. 5-HT3 antagonists: We found intraoperative nausea may be reduced by 5-HT3 antagonists (average risk ratio (aRR) 0.55, 95% confidence interval (CI) 0.42 to 0.71, 12 studies, 1419 women, low-certainty evidence). There may be a reduction in intraoperative vomiting but the evidence is very uncertain (aRR 0.46, 95% CI 0.29 to 0.73, 11 studies, 1414 women, very low-certainty evidence). There is probably a reduction in postoperative nausea (aRR 0.40, 95% CI 0.30 to 0.54, 10 studies, 1340 women, moderate-certainty evidence), and these drugs may show a reduction in postoperative vomiting (aRR 0.47, 95% CI 0.31 to 0.69, 10 studies, 1450 women, low-certainty evidence). Dopamine antagonists: We found dopamine antagonists may reduce intraoperative nausea but the evidence is very uncertain (aRR 0.38, 95% CI 0.27 to 0.52, 15 studies, 1180 women, very low-certainty evidence). Dopamine antagonists may reduce intraoperative vomiting (aRR 0.41, 95% CI 0.28 to 0.60, 12 studies, 942 women, low-certainty evidence) and postoperative nausea (aRR 0.61, 95% CI 0.48 to 0.79, 7 studies, 601 women, low-certainty evidence). We are uncertain if dopamine antagonists reduce postoperative vomiting (aRR 0.63, 95% CI 0.44 to 0.92, 9 studies, 860 women, very low-certainty evidence). Corticosteroids (steroids): We are uncertain if intraoperative nausea is reduced by corticosteroids (aRR 0.56, 95% CI 0.37 to 0.83, 6 studies, 609 women, very low-certainty evidence) similarly for intraoperative vomiting (aRR 0.52, 95% CI 0.31 to 0.87, 6 studies, 609 women, very low-certainty evidence). Corticosteroids probably reduce postoperative nausea (aRR 0.59, 95% CI 0.49 to 0.73, 6 studies, 733 women, moderate-certainty evidence), and may reduce postoperative vomiting (aRR 0.68, 95% CI 0.49 to 0.95, 7 studies, 793 women, low-certainty evidence). Antihistamines: Antihistamines may have little to no effect on intraoperative nausea (RR 0.99, 95% CI 0.47 to 2.11, 1 study, 149 women, very low-certainty evidence) or intraoperative vomiting (no events in the one study of 149 women). Antihistamines may reduce postoperative nausea (aRR 0.44, 95% CI 0.30 to 0.64, 4 studies, 514 women, low-certainty evidence), however, we are uncertain whether antihistamines reduce postoperative vomiting (average RR 0.48, 95% CI 0.29 to 0.81, 3 studies, 333 women, very low-certainty evidence). Anticholinergics: Anticholinergics may reduce intraoperative nausea (aRR 0.67, 95% CI 0.51 to 0.87, 4 studies, 453 women, low-certainty evidence) but may have little to no effect on intraoperative vomiting (aRR 0.79, 95% CI 0.40 to 1.54, 4 studies; 453 women, very low-certainty evidence). No studies looked at anticholinergics in postoperative nausea, but they may reduce postoperative vomiting (aRR 0.55, 95% CI 0.41 to 0.74, 1 study, 161 women, low-certainty evidence). Sedatives: We found that sedatives probably reduce intraoperative nausea (aRR 0.65, 95% CI 0.51 to 0.82, 8 studies, 593 women, moderate-certainty evidence) and intraoperative vomiting (aRR 0.35, 95% CI 0.24 to 0.52, 8 studies, 593 women, moderate-certainty evidence). However, we are uncertain whether sedatives reduce postoperative nausea (aRR 0.25, 95% CI 0.09 to 0.71, 2 studies, 145 women, very low-certainty evidence) and they may reduce postoperative vomiting (aRR 0.09, 95% CI 0.03 to 0.28, 2 studies, 145 women, low-certainty evidence). Opioid antagonists: There were no studies assessing intraoperative nausea or vomiting. Opioid antagonists may result in little or no difference to the number of women having postoperative nausea (aRR 0.75, 95% CI 0.39 to 1.45, 1 study, 120 women, low-certainty evidence) or postoperative vomiting (aRR 1.25, 95% CI 0.35 to 4.43, 1 study, 120 women, low-certainty evidence). Acupressure: It is uncertain whether acupressure/acupuncture reduces intraoperative nausea (aRR 0.55, 95% CI 0.41 to 0.74, 9 studies, 1221 women, very low-certainty evidence). Acupressure may reduce intraoperative vomiting (aRR 0.52, 95% CI 0.33 to 0.80, 9 studies, 1221 women, low-certainty evidence) but it is uncertain whether it reduces postoperative nausea (aRR 0.46, 95% CI 0.27 to 0.75, 7 studies, 1069 women, very low-certainty evidence) or postoperative vomiting (aRR 0.52, 95% CI 0.34 to 0.79, 7 studies, 1069 women, very low-certainty evidence). Ginger: It is uncertain whether ginger makes any difference to the number of women having intraoperative nausea (aRR 0.66, 95% CI 0.36 to 1.21, 2 studies, 331 women, very low-certainty evidence), intraoperative vomiting (aRR 0.62, 95% CI 0.38 to 1.00, 2 studies, 331 women, very low-certainty evidence), postoperative nausea (aRR 0.63, 95% CI 0.22 to 1.77, 1 study, 92 women, very low-certainty evidence) and postoperative vomiting (aRR 0.20, 95% CI 0.02 to 1.65, 1 study, 92 women, very low-certainty evidence). Few studies assessed our secondary outcomes including adverse effects or women's views.

AUTHORS' CONCLUSIONS

This review indicates that 5-HT3 antagonists, dopamine antagonists, corticosteroids, sedatives and acupressure probably or possibly have efficacy in reducing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. However the certainty of evidence varied widely and was generally low. Future research is needed to assess side effects of treatment, women's views and to compare the efficacy of combinations of different medications.

Effect of fentanyl on nausea and vomiting in cesarean section under spinal anesthesia: a randomized controlled study

Objective

Although opioids may induce nausea and vomiting, they possess sedative effects and can reduce intraoperative nausea and vomiting (IONV). This study assessed the effect of adding fentanyl to midazolam on sedation levels and IONV during cesarean section under spinal anesthesia.

Methods

Eighty parturients scheduled for elective cesarean section were enrolled in the study. Following fetal delivery, patients were administered 0.05 mg/kg of midazolam plus 0.03 mL/kg of normal saline (M group) or 0.05 mg/kg of midazolam plus 1.5 μg/kg of fentanyl (MF group). The primary outcome was the incidence of IONV. The secondary outcomes were incidence of postoperative nausea and vomiting (PONV), intraoperative sedation level, and five-point patient satisfaction score (PSS).

Results

The IONV incidence was significantly lower in the MF group compared with the M group (5% [2/40] vs. 25% [10/40]). The PONV incidence did not differ significantly between the groups. The intraoperative sedation level tended to be deeper in the MF group. The 5-point PSS was significantly higher in the MF group. There was a strong correlation between the sedation level and IONV incidence.

Conclusions

Adding fentanyl to midazolam is effective for sedation and to prevent IONV in women who are undergoing cesarean section under spinal anesthesia.

Preventing postoperative nausea and vomiting after laparoscopic cholecystectomy: a prospective, randomized, double-blind study

BACKGROUND

Postoperative nausea and vomiting (PONV) are potential complications in patients after laparoscopic cholecystectomy (LC). Combination antiemetic therapy often is effective for preventing PONV in patients undergoing LC, and combinations of antiemetics targeting different sites of activity may be more effective than monotherapy.

OBJECTIVE

The aim of this study was to compare the administration of a subhypnotic dose of propofol combined with dexamethasone with one of propofol combined with metoclopramide to prevent PONV after LC.

METHODS

Sixty adult patients scheduled for LC were randomly assigned to 1 of 2 treatment groups. The patients in group 1 received 0.5 mg/kg propofol plus 8 mg dexamethasone, and those in group 2 received 0.5 mg/kg propofol plus 0.2 mg/kg metoclopramide. The number of patients experiencing nausea and vomiting at 0 to 4, 4 to 12, and 12 to 24 hours postoperatively and as well as additional use of rescue antiemetics were recorded.

RESULTS

The total PONV rates up to 24 hours postanesthesia were 23.3% and 50% for group 1 and group 2, respectively. Comparisons of the data revealed that at 0 to 4 hours, the number of patients experiencing vomiting was 6 (20%) in group 1 and14 (46.7%) in group 2 (P = 0.028). The frequency of vomiting in group 1 was significantly lower than that for group 2 (P = 0.028), and the rate of rescue antiemetic use in group 2 was higher than that in group 1 (20% vs 46.7%; P = 0.028). In the evaluation of PONV based on the nausea and vomiting scale scores, the mean PONV score was 0.4 (0.2) in group 1 compared with 1.0 (0.2) in group 2 (P = 0.017). There were no significant differences between the values at 4 to 12 hours and at 12 to 24 hours. The frequency of adverse reactions (respiratory depression: 1.3%, 1.3%; laryngospasm: 1.3%, 0%; cough: 1.3%, 0%; hiccup: 1.3%, 0%;) was not significantly different in the 2 groups.

CONCLUSIONS

Administration of a subhypnotic dose of 0.5 mg/kg propofol plus 8 mg dexamethasone at the end of surgery was more effective than administration of 0.5 mg/kg propofol plus metoclopramide in preventing PONV in the early postoperative period in adult patients undergoing LC.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis

BACKGROUND

Aspiration pneumonitis is a syndrome resulting from the inhalation of gastric contents. The incidence in obstetric anaesthesia has fallen, largely due to improved anaesthetic techniques and the increased use of regional anaesthesia at caesarean section. However, aspiration pneumonitis is still a cause of maternal morbidity and mortality, and it is important to use effective prophylaxis.

OBJECTIVES

To determine whether interventions given prior to caesarean section reduce the risk of aspiration pneumonitis in women with an uncomplicated pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013).

SELECTION CRITERIA

Randomised controlled trials were included. Quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. Fixed-effect meta-analysis was used to combine data where it was reasonable to assume that studies were estimating the same underlying treatment effect. If substantial clinical or statistical heterogeneity was detected, we used random-effects analysis to produce an overall summary.

MAIN RESULTS

Thirty-two studies were included in this review. However, only 22 studies, involving 2658 women, provided data for analysis. All the women in the included studies had a caesarean section under general anaesthesia. The studies covered a number of comparisons, but were mostly small and of unclear or poor quality.When compared with no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09 to 0.32, two studies, 108 women), H2 antagonists (RR 0.09, 95% CI 0.05 to 0.18, two studies, 170 women) and proton pump antagonists (RR 0.26, 95% CI 0.14 to 0.46, one study 80 women). H2 antagonists were associated with a reduced the risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists (RR 0.39, 95% CI 0.16 to 0.97, one study, 120 women), but compared with antacids the findings were unclear. The combined use of 'antacids plus H2 antagonists' was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo (RR 0.02, 95% CI 0.00 to 0.15, one study, 89 women) or compared with antacids alone (RR 0.12, 95% CI 0.02 to 0.92, one study, 119 women).

AUTHORS' CONCLUSIONS

The quality of the evidence was poor, but the findings suggest that the combination of antacids plus H2 antagonists was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. However, none of the studies assessed potential adverse effects or substantive clinical outcomes. These findings are relevant for all women undergoing caesarean section under general anaesthesia.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUND

Nausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and can also occur in the period following the procedure. 

OBJECTIVES

To assess the efficacy of pharmacological and non-pharmacological interventions given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 February 2012) and reference lists of identified studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked.  

MAIN RESULTS

Fifty-two studies met the inclusion criteria but only 41 studies, involving 5046 women, provided useable data for the review involving women having caesareans under regional anaesthesia. The majority of the studies involved women undergoing elective caesarean section. Only two studies included emergency surgery, however, they did not stratify data according to type of surgery. The studies covered numerous comparisons, but the majority of studies involved 5-HT(3) receptor antagonists, dopamine receptor antagonists, corticosteroids or acupressure. Studies were mainly small and of unclear quality.Three classes of intervention were found to be effective in at least three out of four of our primary outcomes (intraoperative nausea, intraoperative vomiting, postoperative nausea and postoperative vomiting). These interventions were 5-HT(3) antagonists, dopamine antagonists and sedatives. Other classes of intervention were effective for fewer than three of our primary outcomes.With 5-HT antagonists, we found a reduction in intraoperative nausea (average risk ratio (RR) 0.64, 95% confidence interval (CI) 0.46 to 0.88, eight studies, 720 women). There were also reductions in postoperative nausea (average RR 0.40, 95% CI 0.25 to 0.64, four studies, 405 women) and vomiting (average RR 0.50, 95% CI 0.32 to 0.77, five studies, 565 women). We did not detect a significant reduction in intraoperative vomiting (average RR 0.56, 95% CI 0.31 to 1.00, seven studies, 668 women).Dopamine antagonists demonstrated a reduction in intraoperative nausea (average RR 0.38, 95% CI 0.25 to 0.57, nine studies, 636 women) and intraoperative vomiting (average 0.39, 95% CI 0.24 to 0.64, eight studies, 536 women), with similar reductions in postoperative nausea (average RR 0.60, 95% CI 0.40 to 0.91, five studies, 412 women) and vomiting (average RR 0.57, 95% CI 0.36 to 0.91, six studies, 472 women). These differences were observed with both metoclopramide and droperidol.Sedatives (most commonly propofol) demonstrated a reduction in intraoperative nausea (average RR 0.71, 95% CI 0.52 to 0.96, four studies, 285 women) and intraoperative vomiting (average RR 0.42, 95% CI 0.26 to 0.68, four studies, 285 women), also with a reduction in postoperative nausea (average RR 0.25, 95% CI 0.09 to 0.71, two studies 145 women) and vomiting (average RR 0.09, 95% CI 0.03 to 0.28, two studies, 145 women).Acupressure was found to be effective for intraoperative nausea (average RR 0.59, 95% CI 0.38 to 0.90, six studies, 649 women) but not postoperative nausea (average RR 0.83, 95% CI 0.68 to 1.00, three studies, 429 women). Acupressure was not effective at reducing vomiting either intraoperatively (average RR 0.74, 95% CI 0.46 to 1.18, six studies, 649 women) or postoperatively (average RR 0.69, 95% CI 0.45 to 1.06, three studies, 429 women).Other effective intervention classes included corticosteroids, antihistamines, and anticholinergics.There were insufficient data to demonstrate any class of intervention was superior to another. There were no significant differences observed in the comparison of combined versus single interventions.Few studies assessed our secondary outcomes or the incidence of adverse effects. However, one study showed an increase in respiratory depression with sedation (midazolam) compared with dopamine antagonists.

AUTHORS' CONCLUSIONS

This review indicates that many different interventions have efficacy in preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. There is little evidence that combinations of treatment are better than single agents.

Metoclopramide for nausea and vomiting prophylaxis during and after Caesarean delivery: a systematic review and meta-analysis

Nausea and vomiting occur commonly during and after Caesarean delivery (CD) performed under neuraxial anaesthesia. Metoclopramide is a prokinetic agent reported to be safe in parturients. This meta-analysis assesses the efficacy of metoclopramide for prophylaxis against intra- and postoperative nausea and vomiting (IONV and PONV) in parturients undergoing CD under neuraxial anaesthesia. We performed a literature search of MEDLINE (1966-2011), Cochrane Central Register of Controlled Trials, EMBASE (1947-2011), Google scholar, and CINAHL for randomized controlled trials which compared metoclopramide with placebo in women having CD under neuraxial anaesthesia. Eleven studies with 702 patients were included in the analysis. Administration of metoclopramide (10 mg) resulted in a significant reduction in the incidence of ION and IOV when given before block placement [relative risk (RR) (95% confidence interval, 95% CI)=0.27 (0.16, 0.45) and 0.14 (0.03, 0.56), respectively] or after delivery [RR (95% CI)=0.38 (0.20, 0.75) and 0.34 (0.18, 0.66), respectively]. The incidence of early (0-3 or 0-4 h) PON and POV [RR (95% CI)=0.47 (0.26, 0.87) and 0.45 (0.21, 0.93), respectively] and overall (0-24 or 3-24 h) PON (RR 0.69; 95% CI 0.52, 0.92) were also reduced with metoclopramide. Extra-pyramidal side-effects were not reported in any patient. In conclusion, this review suggests that metoclopramide is effective and safe for IONV and PONV prophylaxis in this patient population. Given the quality of the studies and the infrequent use of neuraxial opioids, these results should be interpreted with caution in current practice and further studies are needed to confirm those findings.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis

BACKGROUND

Aspiration pneumonitis is a syndrome resulting from the inhalation of gastric contents. The incidence in obstetric anaesthesia has fallen, largely due to improved anaesthetic techniques and the increased use of regional anaesthesia at caesarean section. However, aspiration pneumonitis is still a cause of maternal morbidity and mortality, and it is important to use effective prophylaxis.

OBJECTIVES

To determine whether interventions given prior to caesarean section reduce the risk of aspiration pneumonitis in women with an uncomplicated pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2009).

SELECTION CRITERIA

Randomised controlled trials were included. Quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked.

MAIN RESULTS

Twenty-two studies, involving 2658 women, are included, all having a caesarean section under general anaesthesia. The studies covered a number of comparisons, but were mostly small and of unclear or poor quality.When compared to no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09 to 0.32, two studies, 108 women), H(2) antagonists (RR 0.09, 95% CI 0.05 to 0.18, two studies, 170 women) and proton pump antagonists (RR 0.26, 95% CI 0.14 to 0.46, one study 80 women). H(2) antagonists were associated with a reduced the risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists (RR 0.39, 95% CI 0.16 to 0.97, one study, 120 women), but compared with antacids the findings were unclear. The combined use of 'antacids plus H(2) antagonists' was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo (RR 0.02, 95% CI 0.00 to 0.15, one study, 89 women) or compared with antacids alone (RR 0.12, 95% CI 0.02 to 0.92, one study, 119 women).

AUTHORS' CONCLUSIONS

The quality of the evidence was poor, but the findings suggest that the combination of antacids plus H(2) antagonists was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. However, none of the studies assessed potential adverse effects or substantive clinical outcomes. These findings are relevant for all women undergoing caesarean section under general anaesthesia.

A Comparison of Pain on Intravenous Injection Between Two Preparations of Propofol

Propofol is frequently used for sedation, induction, and maintenance of anesthesia. It is, however, associated with pain on injection. Propofol-Lipuro has an oil phase that allows a larger proportion of propofol to be dissolved in it and, thereby, apparently reduces pain. However, studies investigating this have had methodological limitations. We devised a randomized, double-blind, crossover study comparing pain on injection between two preparations of propofol, Diprivan and Propofol-Lipuro, in subanesthetic doses. Sixty healthy patients received the drugs in random order via the same injection site separated by 10 min and a 0.9% saline flush. Pain was assessed using a verbal rating score (VRS) during and at 1-min time points after injection. Differences in VRS between the two propofol preparations at different time points in each patient were analyzed. In patients who were given Diprivan first followed by Propofol-Lipuro (group D-P), pain was significantly reduced with Propofol-Lipuro compared with Diprivan during initial injection (median difference in VRS = 2 [interquartile range 0-2], P = 0.002) and at 1 min (3 [0-4], P < 0.001). In patients who were given Propofol-Lipuro first followed by Diprivan (group P-D), no significant differences in VRS were shown. Propofol-Lipuro is associated with reduced injection pain compared with Diprivan and also seems to attenuate subsequent injection pain of Diprivan when administered first. The mechanism is unknown, but may be related to a reduction in the concentration of propofol in the aqueous phase.

Intraoperative nausea and vomiting during cesarean section under regional anesthesia

Nausea and vomiting during regional anesthesia for cesarean section are very common and unpleasant events. They cause significant distress to the patient and also interfere with the surgical procedure. They have multiple etiologies, which include hypotension, vagal hyperactivity, visceral pain, i.v. opioid supplementation, uterotonic agents and motion. The obstetric anesthesia literature has addressed these causative factors for nausea and vomiting individually, making it difficult for the anesthesiologists to have a comprehensive understanding of these important complications. This review highlights the anesthetic and non-anesthetic causes of intraoperative nausea and vomiting during regional anesthesia for cesarean section and the appropriate prophylactic and therapeutic management. Intraoperative nausea and vomiting can be best prevented by controlling hypotension, optimizing the use of neuraxial and i.v. opioids, improving the quality of block, minimizing surgical stimuli and judicious administration of uterotonic agents. Although prophylactic antiemetics have been advocated during cesarean sections, strict adherence to these practices can effectively lower the incidence of intraoperative nausea and vomiting without the requirement of antiemetic agents. Antiemetics, therefore, should be reserved for the prevention of intraoperative nausea and vomiting in high-risk patients and for the treatment of nausea and vomiting not responding to routine measures.

What’s new and novel in obstetric anesthesia? Contributions from the 2003 scientific literature

THE PREGNANT PATIENT: Age; maternal disease; prophylactic antibiotics; gastroesophageal reflux; obesity; starvation; genotyping; coagulopathy; infection; substance abuse; altered drug responses in pregnancy; physiological changes of pregnancy. THE FETUS: Fetal monitoring; intrauterine surgery. THE NEWBORN: Breastfeeding; maternal infection, fever, and neonatal sepsis evaluation. OBSTETRIC COMPLICATIONS: Embolic phenomena; hemorrhage; preeclampsia; preterm delivery. OBSTETRIC MANAGEMENT: External cephalic version and cervical cerclage; elective cesarean delivery; fetal malpresentation; vaginal birth after cesarean delivery; termination of pregnancy. OBSTETRIC ANESTHESIA: Analgesia for labor and delivery; anesthesia for cesarean delivery; anesthesia for short obstetric operations; complications of anesthesia. MISCELLANEOUS: Consent; ethics; history; labor support; websites/books/leaflets/journal announcements.

RETRACTED: Randomized, double-blind comparison of subhypnotic-dose propofol alone and combined with dexamethasone for emesis in parturients undergoing cesarean delivery

BACKGROUND

Nausea, retching, and vomiting are common in parturients undergoing cesarean delivery performed under regional anesthesia. Subhypnotic-dose propofol 1.0 mg/kg per hour has been used to reduce the incidence of these emetic symptoms. Dexamethasone has been shown to reduce chemotherapy-induced emesis when added to an antiemetic regimen.

OBJECTIVE

The aim of this study was to examine the difference in efficacy and tolerability between subhypnoticdose propofol 1.0 mg/kg per hour alone and combined with dexamethasone 8 mg for reducing postdelivery emetic episodes in parturients undergoing cesarean delivery.

METHODS

In a randomized, double-blind trial, parturients received IV placebo (saline) or dexamethasone 8 mg followed by a continuous infusion of propofol at subhypnotic dose (1.0 mg/kg per hour) immediately after clamping of the umbilical cord. Intraoperative, postdelivery emetic episodes and safety assessments were performed by an investigator.

RESULTS

One hundred twenty parturients (mean [SD] age, 29 [5] years; age range, 21-38 years; mean [SD] height, 158 [7] cm; height range, 145-172 cm; mean [SD] body weight, 72 [8] kg; weight range, 54-90 kg) were enrolled in the study, 60 in each treatment group. The treatment groups were comparable with respect to maternal demographics and operative management. The rate of emetic symptoms (nausea, retching, and vomiting) in an intraoperative, postdelivery period was lower in patients who received the combination regimen than in those who received subhypnotic-dose propofol 1.0 mg/kg per hour alone (5% [3/60] vs 20% [12/60], respectively; P = 0.012). No clinically important adverse events attributable to the study drug were observed in either group.

CONCLUSION

In the parturients undergoing cesarean delivery performed under spinal anesthesia in this study, the combination of subhypnotic-dose propofol 1.0 mg/kg per hour and dexamethasone 8 mg was more effective than propofol alone for reducing the incidence of postdelivery emetic symptoms.