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.

Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery.

At April 2020, this review has been withdrawn. It is correct at the date of publication, and previous versions can be accessed in the 'Other versions' tab on the Cochrane Library. We are aware of new studies to potentially change the conclusions, however the update did not meet the timelines and expectations of Cochrane and the PaPaS review group.

Bing-Neel syndrome - Bilateral cavernous sinus lymphoma causing visual failure.

We report the case of a 68-year-old male with right eye vision loss secondary to a compressive optic neuropathy from Waldenstrom macroglobulinaemia relapse in both cavernous sinuses. Central nervous system involvement is extremely uncommon in lymphoplasmacytic lymphoma. Known as Bing-Neel syndrome, this has not been previously reported to present simultaneously in bilateral cavernous sinuses. We discuss the pathophysiology, diagnostic and neuroradiological features of Bing-Neel syndrome. In this case, there was marked clinical and radiological response to chemotherapy. As outcomes following treatment for Waldenstrom macroglobulinaemia improve, greater awareness of its less common manifestations becomes important. Neurosurgical intervention may be indicated to obtain histological diagnosis or decompress critical structures.

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.

Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery.

BACKGROUND: The transversus abdominis plane (TAP) block is a peripheral nerve block which anaesthetises the abdominal wall. The increasing use of TAP block, as a form of pain relief after abdominal surgery warrants evaluation of its effectiveness as an adjunctive technique to routine care and, when compared with other analgesic techniques. OBJECTIVES: To assess effects of TAP blocks (and variants) on postoperative analgesia requirements after abdominal surgery. SEARCH STRATEGY: We searched specialised registers of Cochrane Anaesthesia and Cochrane Pain, Palliative and Supportive Care Review Groups, CENTRAL, MEDLINE, EMBASE and CINAHL to June 2010. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing TAP block or rectus sheath block with: no TAP or rectus sheath block; placebo; systemic, epidural or any other analgesia. DATA COLLECTION AND ANALYSIS: At least two review authors assessed study eligibility and risk of bias, and extracted data. MAIN RESULTS: We included eight studies (358 participants), five assessing TAP blocks, three assessing rectus sheath blocks; with moderate risk of bias overall. All studies had a background of general anaesthesia in both arms in most cases.Compared with no TAP block or saline placebo, TAP block resulted in significantly less postoperative requirement for morphine at 24 hours (mean difference (MD) -21.95 mg, 95% confidence interval (CI) -37.91 to 5.96; five studies, 236 participants) and 48 hours (MD -28.50, 95% CI -38.92 to -18.08; one study of 50 participants) but not at two hours (all random-effects analyses). Pain at rest was significantly reduced in two studies, but not a third.Only one of three included studies of rectus sheath blocks found a reduction in postoperative analgesic requirements in participants receiving blocks. One study, assessing number of participants who were pain-free after their surgery, found more participants who received a rectus sheath block to be pain-free for up to 10 hours postoperatively. As with TAP blocks, rectus sheath blocks made no apparent impact on nausea and vomiting or sedation scores. AUTHORS' CONCLUSIONS: No studies have compared TAP block with other analgesics such as epidural analgesia or local anaesthetic infiltration into the abdominal wound. There is only limited evidence to suggest use of perioperative TAP block reduces opioid consumption and pain scores after abdominal surgery when compared with no intervention or placebo. There is no apparent reduction in postoperative nausea and vomiting or sedation from the small numbers of studies to date. Many relevant studies are currently underway or awaiting publication.

Transversus abdominis plane block does not provide additional benefit to multimodal analgesia in gynecological cancer surgery.

BACKGROUND: The transversus abdominis plane (TAP) block is a recently described technique involving injecting local anesthetic between the internal oblique and transversus abdominis layers of the abdominal wall. It has been shown to be effective in reducing morphine consumption and improving postoperative pain relief in several clinical settings. METHODS: We performed a randomized placebo-controlled trial comparing bilateral ultrasound-guided TAP blocks (2 x 20 mL 0.5% ropivacaine or 0.9% saline) in adult female patients undergoing midline laparotomy for known or presumed gynecological malignancy. Both groups received multimodal IV analgesia. The primary outcomes for the study were defined as the incidence of "inadequate" analgesia (defined as a score >50 mm on a visual analog scale) with forced expiration at 2 hours postoperatively and total postoperative morphine consumption at 2 hours and 24 hours. RESULTS: Data from 65 patients were included in the study. The groups were comparable in terms of age, weight, surgical duration, and intraoperative morphine doses. There were no significant differences between the control and treatment groups in the proportion of patients with inadequate analgesia either at rest (39% vs. 22%, P = 0.13) or with coughing (61% vs. 53%, P = 0.54) at 2 hours. There was no significant difference in postoperative morphine consumption between the placebo and treatment groups at 2 hours (13.5 mg vs. 11.87 mg, P = 0.53) or 24 hours (34.0 mg vs. 36.1 mg, P = 0.76). There were no significant differences in the incidence of opioid side effects or patient satisfaction. CONCLUSION: This study demonstrated that TAP blockade conferred no benefit in addition to multimodal analgesia in women undergoing major gynecological cancer surgery.

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.