The effect of smoking on postoperative nausea and vomiting

In an attempt to quantify the postoperative effects of smoking, 327 consecutive patients undergoing arthroscopic day case knee surgery were given a standard anaesthetic consisting of an intravenous induction with propofol and fentanyl followed by inhalational maintenance using isoflurane in an oxygen and nitrous oxide mixture. Pre-operatively, patients were asked inter alia to give details of social smoking habits. Postoperatively, patients were given standard analgesic and anti-emetic drugs. Prior to discharge patients were asked to give details of postoperative nausea and vomiting together with details of the severity of postoperative pain. There were 85 smokers and 242 nonsmokers. Of the 327 patients, a total of 42 (13%) complained of postoperative nausea and vomiting. Of the smokers, only 6% complained of postoperative nausea and vomiting in contrast to 15% of the nonsmokers (p < 0.05). It is postulated that enzyme induction is the most likely reason for this anti-emetic effect. Possible ways in which this clinically beneficial mechanism can be utilised to improve outcome after anaesthesia are discussed.     

Double–blind comparison of transdermal scopolamine, droperidol and placebo against postoperative nausea and vomiting

Since transdermal scopolamine (TS) seems effective against seasickness, we compared its antiemetic effect with intravenous droperidol (DHBP), our routine antidote for postoperative emesis. Ninety-six female patients (ASA I-II) scheduled for short-stay surgery were randomly allocated to three study groups after giving their informed consent. The three groups were as follows: TS adhesive, delivering 140 micrograms initially and 5 micrograms/h thereafter + placebo 0.5 ml i.v. 5 min before the end of surgery; transdermal placebo adhesive preoperatively + DHBP 0.5 ml (1.25 mg) i.v. 5 min before the end of surgery; transdermal placebo + 0.5 ml placebo i.v. as indicated above. Oxycodone i.m. and glycopyrrolate i.v. were given for premedication together with the test adhesive. Anaesthesia was induced with thiopental and maintained with nitrous oxide and oxygen, enflurane, vecuronium and fentanyl. Neostigmine and glycopyrrolate were administered for reversal. In the recovery room no differences in nausea or vomiting were observed between the groups. Sedation was significantly more marked (P less than 0.15-0.0001) after DHBP than after either TS or the given DHBP and 6% of those given the placebo (P less than 0.05). During the following 24 h nausea was reported more by the placebo patients (25) than by those on TS (20) or DHBP (15) (P less than 0.05). However, actual vomiting on the ward did not differ between the groups. Visual disturbances were more frequent after TS (P less than 0.01). We conclude that prophylactic transdermal scopolamine does not diminish postoperative emetic sequelae.     

Prevention and control of postoperative nausea and vomiting in post-craniotomy patients

Postoperative nausea and vomiting (PONV) are the most frequent side-effects in the postoperative period, impairing subjective well-being and having economic impact due to delayed discharge. However, emetic symptoms can also cause major medical complications, and post-craniotomy patients may be at an increased risk. A review and critical appraisal of the existing literature on PONV in post-craniotomy patients, and a comparison of these findings with the current knowledge on PONV in the general surgical population, leads to the following conclusions: (1) Despite the lack of a documented case of harm caused by retching or vomiting in a post-craniotomy patient, the potential risk caused by arterial hypertension and high intra-abdominal/intra-thoracic pressure leading to high intracranial pressure, forces to avoid PONV in these patients. (2) There is unclarity about a specifically increased (or decreased) risk for PONV in post-craniotomy patients compared with other surgical procedures. (3) The decision whether or not to administer an antiemetic should not be based primarily on risk scores for PONV but on the likelihood for potential catastrophic consequences of PONV. If such a risk cannot be ruled out, a multimodal antiemetic approach should be considered regardless of the individual risk. (4) Randomized controlled trials with antiemetics in post-craniotomy patients are limited with respect to sample size and methodological quality. This also impacts upon the meaning of meta-analyses performed with trials that showed marked heterogeneity and inconclusive results. (5) No studies on the treatment of established PONV are available. This highlights the need to transfer knowledge about PONV treatment from other surgical procedures. (6) Despite the possibility that PONV in post-craniotomy patients can be triggered by specific conditions (e.g. surgery near the area postrema at the floor of the fourth ventricle with the vomiting centre located nearby), recommendations based on trials in post-craniotomy patients may be flawed. Thus, general knowledge on prevention and treatment of PONV must adopted for craniotomy settings.     

Postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) remains a common clinical problem that increases patient morbidity, healthcare costs and affects patient satisfaction. This article outlines the physiology, reviews the available drugs and suggests a structure using risk stratification that helps to plan sensible clinical management.     

防治术后恶心呕吐的研究进展

背景 术后恶心呕吐(postoperative nausea and vomiting,PONV)是麻醉手术后最常见的并发症之一,其发生率可高达30％.虽然国际上已公布了防治PONV共识和指南,但尚存在缺陷的PONV预测模型和复杂的防治策略成为临床防治PONV最大的障碍. 目的 探究在临床工作中防治PONV的主要障碍,为临床防治PONV工作提供更有效的途径. 内容 尚存在缺陷的PONV预测模型和复杂的防治策略是临床防治PONV最大的障碍,多模式防治PONV是一种简单、有效的预防PONV发生的方法. 趋向 多模式防治PONV更容易被临床麻醉医生接受和应用,新型的抗PONV药物和传统经典的抗呕吐药物为临床多模式防治提供了更大的选择空间.     

Postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) is a prevalent side effect following general anaesthetic and surgery. Areas of the brainstem that coordinate the process of vomiting receive inputs from a number of areas, including high cortical areas and, importantly, the chemoreceptor trigger zone of the area postrema in the medulla oblongata of the brainstem, which can be affected directly by anaesthetic agents. A number of risk factors for PONV have been identified, and scores developed to help stratify risk. Based on this stratified risk pharmacological therapy can be given prophylactically intraoperatively, or as rescue postoperatively. The mechanisms and side effects of these drugs is discussed alongside a recent review of efficacy, and some potential future developments.     

Cost-effectiveness of ondansetron for postoperative nausea and vomiting

The decision as to whether prophylaxis against postoperative nausea and vomiting is better than treatment of established postoperative nausea and vomiting could be made on the basis of cost-effectiveness. The cost-effectiveness of ondansetron was calculated using data from published quantitative systematic reviews of randomised trials. Milligrams of ondansetron required to achieve a desired endpoint were chosen as a cost unit. Modelling was based on a cohort of 1000 patients, and examined control event rates (i.e. incidence of postoperative nausea and vomiting without prophylaxis) of between 10 and 90%. In a sensitivity analysis, cost-effectiveness of recommended intravenous doses (4 mg for treatment and prophylaxis) was compared with minimal effective doses as shown by meta-analysis (1 mg for treatment, 8 mg for prophylaxis). Fewer patients experience any postoperative nausea and vomiting symptoms with prophylaxis compared with treatment. But prophylaxis is only marginally more effective than treatment, and treatment of established postoperative nausea and vomiting with effective doses (i.e. 1 or 4 mg) is more cost-effective and safer than prophylaxis with effective doses (i.e. 4 or 8 mg). Reasons for this are the selective treatment of patients who actually need treatment, the high success rate with a lowest dose tested (1 mg) in established postoperative nausea and vomiting, and the disappointing antinausea effect of prophylactic ondansetron even at an eight-fold higher dose.     

Preoperative oral granisetron prevents postoperative nausea and vomiting

Background: Postoperative nausea and vomiting (PONV) is a commonly observed adverse effect of anaesthesia. This study was designed to evaluate the efficacy of granisetron administered orally for preventing PONV in female patients undergoing major gynaecological surgery.
Methods: In a prospective, randomized, placebo-controlled, double-blind study, 120 patients received orally either placebo or granisetron (1 mg, 2 mg or 4 mg) (n=30 for each) 1 h before surgery. The same standard general plus regional anaesthetic technique was employed throughout. Postoperatively, during the first 24 h after anaesthesia, the incidence of PONV and adverse events was recorded by nursing staff.
Results: The incidence of PONV was 47% with placebo, 37% with granisetron 1 mg, 10% with granisetron 2 mg and 10% with granisetron 4 mg (P<0.05; overall Fisher's exact probability test). No difference in the incidence of adverse events was observed among the groups.
Conclusion: Preoperative oral granisetron in a minimum dose of 2 mg is effective for preventing PONV after major gynaecological surgery.     

Supplemental oxygen does not reduce postoperative nausea and vomiting after thyroidectomy

Background. Supplemental intra-operative oxygen 80% halves theincidence of nausea and vomiting after open and laparoscopicabdominal surgery, perhaps by ameliorating intestinal ischaemiaassociated with abdominal surgery. It is unlikely that thyroidsurgery compromises intestinal perfusion. We therefore testedthe hypothesis that supplemental perioperative oxygen does notreduce the risk of postoperative nausea and vomiting (PONV)after thyroidectomy. Methods. One hundred and fifty patients undergoing thyroidectomywere given sevoflurane anaesthesia. After induction, patientswere randomly assigned to the following treatments: (i) 30%oxygen, (ii) 80% oxygen, or (iii) 30% oxygen with droperidol0.625 mg. Results. The overall incidence of nausea during the first 24 hafter surgery was 48% in the patients given oxygen 30%, 46%in those given oxygen 80%, and 22% in those given droperidol(P=0.004). There were no significant differences between theoxygen 30% and 80% groups in incidence or severity of PONV,the need for rescue antiemetics, or patient satisfaction. Droperidolsignificantly shortened the time to first meal. Conclusions. Supplemental oxygen was ineffective in preventingnausea and vomiting after thyroidectomy, but droperidol reducedthe incidence. Br J Anaesth 2003; 91: 857–61     

术后恶心呕吐的风险评估及防治方法

术后恶心呕吐是最常见的术后并发症之一,防治其发生有重要的临床意义。现就近几年来关于术后恶心呕吐的风险因素、评估方法以及防治方面的研究进展作一综述。