Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist, and nabilone, a synthetic cannabinoid.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist and nabilone, a synthetic cannabinoid.     

Physiology and pharmacology of nausea and vomiting

The physiology of nausea and vomiting is poorly understood. The initiation of vomiting varies and may be due to motion, pregnancy, chemotherapy, gastric irritation or post-operative causes. Once initiated, vomiting occurs in two stages, retching and expulsion. The muscles responsible for this sequence of events are controlled by either a vomiting centre or a central pattern generator, probably in the area postrema and the nearby nucleus tractus solitarius. Drugs which induce vomiting include ipecacuanha, a gastric irritant, and apomorphine, a dopamine-receptor agonist. Opioid drugs also induce vomiting, but opioid antagonists are not useful to treat nausea and vomiting. Anti-emetic drugs consist of a variety of neurotransmitter antagonists and may act in the periphery, the CNS or both sites. The most important drugs are antagonists at muscarinic, dopamine D₂, 5-HT₃, histamine H₁ and neurokinin NK₁ receptors. These drugs are discussed with particular attention to post-operative nausea and vomiting (PONV).     

Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: an abridged Cochrane network meta-analysis

Postoperative nausea and vomiting is a common adverse effect of anaesthesia. Although dozens of different anti-emetics are available for clinical practice, there is currently no comparative ranking of efficacy and safety of these drugs to inform clinical practice. We performed a systematic review with network meta-analyses to compare, and rank in terms of efficacy and safety, single anti-emetic drugs and their combinations, including 5-hydroxytryptamine₃, dopamine-2 and neurokinin-1 receptor antagonists; corticosteroids; antihistamines; and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anaesthesia. We systematically searched for placebo-controlled and head-to-head randomised controlled trials up to November 2017 (updated in April 2020). We assessed how trustworthy the evidence was using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Confidence In Network Meta-Analysis (CINeMA) approaches for vomiting within 24 h postoperatively, serious adverse events, any adverse event and drug class-specific side-effects. We included 585 trials (97,516 participants, 83% women) testing 44 single drugs and 51 drug combinations. The studies' overall risk of bias was assessed as low in only 27% of the studies. In 282 trials, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared with placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single neurokinin-1 receptor antagonists were as effective as other drug combinations. Out of the 10 effective single drugs, certainty of evidence was high for aprepitant, with risk ratio (95%CI) 0.26 (0.18–0.38); ramosetron, 0.44 (0.32–0.59); granisetron, 0.45 (0.38–0.54); dexamethasone, 0.51 (0.44–0.57); and ondansetron, 0.55 (0.51–0.60). It was moderate for fosaprepitant, 0.06 (0.02–0.21) and droperidol, 0.61 (0.54–0.69). Granisetron and amisulpride are likely to have little or no increase in any adverse event compared with placebo, while dimenhydrinate and scopolamine may increase the number of patients with any adverse event compared with placebo. So far, there is no convincing evidence that other single drugs effect the incidence of serious, or any, adverse events when compared with placebo. Among drug class specific side-effects, evidence for single drugs is mostly not convincing. There is convincing evidence regarding the prophylactic effect of at least seven single drugs for postoperative vomiting such that future studies investigating these drugs will probably not change the estimated beneficial effect. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation.     

Comparison of surgical site and patient's history with a simplified risk score for the prediction of postoperative nausea and vomiting

Although site of surgery and previous occurrence of postoperative nausea and vomiting are often used to decide whether prophylactic anti-emetic drugs are indicated, the value of these predictors is unclear. We compared these two risk factors against a simplified four-factor risk score. We analysed data from 1566 adult inpatients who received balanced anaesthesia without prophylactic anti-emetics. Sensitivity, specificity, predictive value and area under the receiver operating characteristic curve were used to quantify predictive properties. Nausea and vomiting occurred in 600 (38.3%) patients within 24 h. Sensitivity and specificity were, respectively, 47% and 59% for surgical site; 47% and 70% for history of postoperative nausea and vomiting; and 58% and 70% for risk score with three or more factors. The area under the curve for surgical site was 0.53 (95% CI 0.50-0.56); that for patient's history was 0.58 (95% CI 0.56-0.61) while for risk score it was 0.68 (95% CI 0.66-0.71; P < 0.001). Prediction using surgical site or patient's history alone was poor while the simplified risk score provided clinically useful sensitivity and specificity.     

Dexamethasone versus ondansetron in combination with dexamethasone for the prophylaxis of postoperative vomiting in pediatric outpatients: a double‐blind,randomized, placebo‐controlled clinical trial

Objectives: To determine the frequency of postoperative vomiting (POV) in children submitted to outpatient surgery and to compare the efficacy of antiemetic drugs in preventing this complication. Background: Nausea and vomiting are common in the immediate postoperative period following anesthetic and surgical procedures. Compared to adults, pediatric patients are more likely to develop postoperative nausea and vomiting, the incidence of which ranges from 8.9% to 42%. Methods: This double‐blind, randomized, placebo‐controlled clinical trial included 129 children. The participants were randomized into three prophylactic treatment groups: dexamethasone (n = 43), ondansetron in combination with dexamethasone (n = 44), and placebo (n = 42). The variables studied were the frequency of POV and the incidence of vomiting after the patient had been discharged from hospital, the need for antiemetic rescue therapy in the postanesthesia care unit (PACU), need for hospitalization, and the time the patient remained in the PACU. A significance level of 5% was adopted. Results: Postoperative vomiting occurred in 12.4% of the children, with no statistically significant difference between the groups: 6.8% in the group receiving ondansetron combined with dexamethasone, 14.3% in the placebo group, and 14% in the group that received dexamethasone alone (P = 0.47). Furthermore, no significant difference was found between the groups with respect to the time the children remained in the PACU, and only five patients reported having vomited following discharge from hospital. Conclusions: The prophylactic use of antiemetic drugs failed to reduce the incidence of POV in pediatric outpatient surgery with a low emetic potential; therefore, routine prophylaxis may be unnecessary.     

The incidence of postoperative nausea and vomiting after caesarean section in patients with hyperemesis gravidarum: a retrospective cohort study

BackgroundPostoperative nausea and vomiting is one of the most common anaesthetic complications of caesarean section. This study examined the association between hyperemesis gravidarum during pregnancy and nausea and vomiting after caesarean section.MethodsA single-centre, retrospective cohort study, using electronic databases of patients with and without hyperemesis gravidarum, undergoing caesarean section from 2015 to 2019. The incidence and severity of postoperative nausea and vomiting were established by a review of the documentation of administration of postoperative anti-emetics within the 24-h period after surgery, and examined using univariable, multivariable binary and ordered logistic regression models.ResultsData were compared for 76 patients with hyperemesis gravidarum and 315 patients without the condition. The incidence of postoperative nausea and vomiting in the hyperemesis group versus the non-hyperemesis group was 43.4% vs 29.6%, respectively. The odds of experiencing postoperative nausea and vomiting was 1.95 times higher in women with hyperemesis gravidarum than in those without (aOR 1.95, 95% CI 1.13 to 3.36, P=0.016). The odds of having more severe postoperative nausea and vomiting were greater in the hyperemesis gravidarum group (aOR 1.91, 95% CI 1.14 to 3.20, P=0.014).ConclusionPatients with hyperemesis gravidarum are more likely to develop nausea and vomiting after caesarean section, and this is likely to be of greater severity than in those without the condition. This finding should assist the effective provision of intra-operative and postoperative anti-emetics for patients with hyperemesis gravidarum undergoing caesarean section.     

Effect of intraoperative intravenous crystalloid infusion on postoperative nausea and vomiting after gynaecological laparoscopy: comparison of 30 and 10 ml kg(-1)

Background. I.V. fluid administration has been shown to reducepostoperative nausea and vomiting (PONV). The optimum dose isunknown. We tested the hypothesis that administration of i.v.crystalloid of 30 ml kg^–1 would reduce the incidence ofPONV compared with 10 ml kg^–1 of the same fluid. Methods. A total of 141 ASA I female patients undergoing electivegynaecological laparoscopy were randomized, in double-blindfashion, to receive either 10 ml kg^–1 (n=71; CSL-10 group)or 30 ml kg^–1 (n=70; CSL-30 group) of i.v. compound sodiumlactate (CSL). Results. In the first 48 h after anaesthesia, the incidenceof vomiting was lower in the CSL-30 group than in the CSL-10group (8.6% vs 25.7%, P=0.01). Anti-emetic use was less in theCSL-30 group at 0.5 h (2.9% vs 14.3%, P=0.04). The incidenceof severe nausea was significantly reduced in the treatmentgroup at awakening (2.9% vs 15.7%, P=0.02), 2 h (0.0% vs 8.6%,P=0.04) and cumulatively (5.7% vs 27.1%, P=0.001). The numbersneeded to treat to prevent vomiting, severe nausea and antiemeticuse in the first 48 h were 6, 5 and 6, respectively. Conclusion. I.V. administration of CSL 30 ml kg^–1 to healthywomen undergoing day-case gynaecological laparoscopy reducedthe incidence of vomiting, nausea and anti-emetic use when comparedwith CSL 10 ml kg^–1.     

Dexamethasone is as effective as ondansetron for the prevention of postoperative nausea and vomiting following breast surgery

INTRODUCTION: Postoperative nausea and vomiting remain a common problem following breast surgery. This study assesses whether dexamethasone is as effective as ondansetron in the control of postoperative nausea and vomiting (PONV). METHODS: Eighty ASA I-III patients undergoing breast surgery for carcinoma of the breast were included in the study. Following premedication with diazepam 5-10 mg, patients were induced with fentanyl 50 micro g and propofol 2-2.5 mg kg-1. A larynx mask was inserted and anesthesia maintained with sevoflurane in oxygen and nitrous oxide. Patients were then randomly divided into two groups: Group D (dexamethasone) was given 4 mg dexamethasone i.v. after induction and Group O (ondansetron) was given 4 mg ondansetron at the same time point. Postoperatively, nausea, vomiting and pain were recorded at 1-h intervals during 4 h, and thereafter every 4 h during 24 h. RESULTS: The incidence of PONV during 24 h was 37% and 33% in Group D and Group O, respectively (NS). No differences were found between the groups in the incidence of postoperative nausea, vomiting or pain at the different time intervals. No differences were found in the incidence of PONV in smokers vs. non-smokers. No side-effects of these drugs were observed. CONCLUSIONS: Ondansetron 4 mg or dexamethasone 4 mg are equally effective in the prevention of postoperative nausea and vomiting following breast surgery. Other factors being similar, the difference in cost between these drugs would favor the use of dexamethasone instead of ondansetron when monotherapy against PONV is used.     

Intravenous fluid and postoperative nausea and vomiting after day-case termination of pregnancy

Background : Deprivation of oral fluid before minor surgery has been alleged to cause postoperative nausea. We examined the effect of intraoperative fluid load on postoperative nausea and vomiting over 3 d after day-case termination of pregnancy.
Methods : In a randomized study, 100 patients were allocated into one of two groups; receiving 1000 ml of compound sodium lactate solution during surgery or no intraoperative fluid. Propofol and alfentanil was used to induce and maintain anaesthesia with nitrous oxide (67%) and oxygen (33%). Visual analogue scores for nausea and pain, the time and frequency of emetic episodes, analgesic and antiemetic consumption were recorded for 3 d postoperatively.
Results : The scores of nausea were significantly lower in the fluid group ( P <0.05) compared with the control group at 1, 2, 4 h and during 24–48 h following surgery. The incidence of emesis was lower ( P <0.01) after discharge, and the time to first oral fluid was shorter ( P <0.05) in the fluid group. There was no difference in pain score or analgesic consumption between the groups. Five patients (10%) in the control group requested antiemetic medication compared with none in the fluid group.
Conclusion : Intraoperative fluid administration may offer some benefit in decreasing the incidence of postoperative nausea and vomiting following day-case surgery.     

Efficacy of prophylactic intravenous granisetron in postoperative emesis in adults

Purpose This randomized, double-blind, placebo-controlled trial evaluated the efficacy, safety, and optimal dose of granisetron in the prophylactic control of postoperative nausea and vomiting in patients undergoing gynecologic surgery or cholecystectomy.Methods Three-hundred and fifteen patients (age, 20–65 years) received intravenous granisetron (1mg or 3mg) or placebo immediately before the end of anesthesia. After treatment, patients were observed for 24h, and the occurrence of nausea and vomiting was recorded and safety was assessed. The no-vomiting rate, time-to-first vomiting episode, and severity of nausea were recorded.Results The no-vomiting rates in patients receiving granisetron 1mg and 3mg were significantly higher than that in the placebo group (83.7%, 78.8%, and 57.9%, respectively; P = 0.0004 for 1mg vs placebo, P = 0.001 for 3mg). Time-to-first vomiting episode was longer in the granisetron 1-mg and 3-mg groups than in the placebo group (time-to-event analysis, Kaplan-Meier, log-rank test; 83.2%, 80.1%, and 59.1%, respectively; P = 0.0002 and P = 0.0010). The severity of nausea was also less in granisetron-treated patients (25.2%, 11.5%, and 15.4% severe nausea incidence for placebo, granisetron 1mg, and granisetron 3mg, respectively; P = 0.00003 and P = 0.002). Fewer rescue medications were required in the two granisetron-treated groups compared with those receiving placebo. Adverse events were similar in all groups. No differences in efficacy or safety were observed between granisetron doses.Conclusion Granisetron is well-tolerated and more effective than placebo in the prophylactic control of nausea and vomiting after surgery. This study suggests that the optimum dose of granisetron is 1mg.*See Appendix.     

The use of droperidol decreases postoperative nausea and vomiting after gynecological laparoscopy

We evaluated whether or not routine prophylaxis with 2.5 mg of droperidol would efficiently prevent postoperative nausea and vomiting (PONV). Fifty-two patients scheduled for elective gynecological laparoscopic surgery were eligible for this study. Anesthesia was induced using propofol, fentanyl, and vecuronium, and maintained with sevoflurane in nitrous oxide, fentanyl, and vecuronium. Patients were randomized to one of two groups: group 1 patients (n = 23) received 2.5 mg droperidol intravenously when the surgery was started, while group 2 patients (n = 29) did not receive any droperidol. At the conclusion of the surgery, the patient was extubated on satisfactory emergence from general anesthesia. Any episodes of nausea and vomiting, rescue medications, and adverse effects were recorded until the next morning after the surgery. There were no differences in the duration of anesthesia on surgery between the groups, but the total fentanyl dose in group 1 was higher than that in group 2. Episodes of nausea and vomiting and the need for metoclopramide in group 1 were lower than in group 2, though the total fentanyl dose in group 1 was higher than in group 2. There were no differences in the need for analgesics between the groups. The use of 2.5 mg droperidol safely decreased PONV after gynecological laparoscopy.     

The effect of postoperative fasting on vomiting in children and their assessment of pain

Background:  Mandatory postoperative food intake has been shown to increase nausea and vomiting, and so postoperative fasting has become common practice even if patients request food or drink.
Objective:  We sought to investigate whether postoperative fasting reduces the incidence of postoperative vomiting in children when compared with a liberal regimen in which they are allowed to eat and drink upon request.
Methods:  One hundred forty-seven children scheduled for outpatient surgery were randomized to one of two groups. After anesthesia, patients in the 'fasting' group were expected to fast for 6 h. The children in the 'liberal' group were allowed to eat and drink according to their own needs. The incidence of vomiting and the children's well-being were recorded at several time points over a 24-hour period. Parents were also asked to rate, on a scale of 0–6, how much their children were bothered by fasting, pain, and nausea/vomiting.
Results:  Age (4.8 ± 2.6 years), weight (20 ± 9 kg) and gender (73% boys) were comparable between the groups. The incidence of vomiting was 15% in the liberal and 22% in the fasting group ( P  = 0.39) and, between 1 and 12 h after extubation, children in the liberal group were significantly happier ( P  < 0.001). Children in the liberal group were significantly less bothered by their pain than those in the fasting group ( P  < 0.001).
Conclusion:  Postoperative fasting did not reduce the incidence of vomiting after general anesthesia in children when compared with a liberal regimen. Furthermore, the ability to eat and drink at will decrease the bothersome aspects of pain and lead to happier patients.     

Postdischarge nausea and vomiting: A review of current literature

Postoperative nausea and vomiting continues to occur in approximately one-third of patients who have surgery despite newer medications and emerging guidelines for care. There is a paucity of literature that relates to patients who experience postdischarge nausea and vomiting after outpatient surgery. The purpose of this article is to review the current knowledge in the area of postdischarge nausea and vomiting. The findings were that the problems with postdischarge nausea and vomiting (PDNV) have not been as thoroughly assessed and evaluated as nausea and vomiting immediately postsurgery. More research needs to be conducted in this population, as the rate of surgeries performed in this setting will only increase.     

Effects of therapeutic suggestion in children undergoing general anesthesia: a randomized controlled trial

Objectives and aim: The goal of this randomized controlled trial was to examine the effect of intraoperative positive therapeutic suggestion on postoperative nausea and vomiting (PONV) in children undergoing general anesthesia and otolaryngological surgery. Background: Because of the high incidence of PONV following otolaryngological surgery and its negative impact on recovery, researchers have examined various nonpharmacological interventions to target this phenomenon. To date, the effectiveness of therapeutic suggestion has not been studied in children. Methods: Participants were 67 children undergoing tonsillectomy and adenoidectomy and their mothers. Children received a standardized anesthetic procedure and were randomly assigned to one of three interventions administered under general anesthesia: therapeutic suggestion, story (prosody control), or standard operating room noise. Children, parents, and healthcare personnel were blinded to group assignment. Nausea and vomiting were recorded in the postanesthesia care unit (PACU) and for the first 3 days at home. Results: Results demonstrated a decrease in nausea severity across the first 3 days, F_2,49 = 10.37, P < 0.001, but no group differences in nausea severity in the PACU (F_2,49 = 0.87, P = 0.43) or at home (F_2,49 = 0.80, P = 0.46). There were also no group differences in vomiting episodes in the PACU (χ² (2) = 1.25, P > 0.05) or at home (F_2,49 = 1.59, P = 0.21). Conclusions: In this blinded controlled trial, therapeutic suggestion delivered intraoperatively did not impact children’s PONV. However, because this is the first study of this kind, replication may be needed.     

A prospective randomized blinded study of the effect of intravenous fluid therapy on postoperative nausea and vomiting in children undergoing strabismus surgery

BACKGROUND: Nausea and vomiting is a common postoperative complication that often necessitates the use of antiemetic agents. METHODS: In a prospective, randomized, double blind trial, the effect of perioperative fluid administration on postoperative adverse outcomes following anesthesia was studied. One hundred children undergoing strabismus repair were randomly assigned to receive 10 ml x kg(-1) x h(-1) (control group) or 30 ml x kg(-1) x h(-1) (superhydration group) of lactated Ringer's solution during the operation. During the first 24 h postoperatively, nausea and vomiting, thirst, pain, and fever were evaluated. RESULTS: Groups were similar with respect to demographic data, surgical procedures and baseline hemodynamic variables. In the first 24 h postoperatively, nausea and vomiting occurred in 27 patients (54%) of the control group and 11 (22%) of patients in the superhydration group (P = 0.001). Comparison of the superhydration group with the control group also showed a statistically significant benefit of superhydration on postoperative thirst (P = 0.0002) and fever (P = 0.02). The differences in nausea and vomiting, thirst, and fever remained significant after adjustment for age, gender, weight, and duration of surgery. There was no significant difference between the two groups in postoperative pain. CONCLUSIONS: Intravenous superhydration administration is an inexpensive and safe therapy for reducing postoperative nausea and vomiting and discomfort.     

Applicability of risk scores for postoperative nausea and vomiting in adults to paediatric patients

Background. Scores to predict the occurrence of postoperativevomiting (PV) or nausea and vomiting (PONV) are well establishedin adult patients. The aim of this survey was to evaluate theapplicability of risk scores developed and tested in adult patientsin 983 paediatric patients (0–12 yr) undergoing varioussurgical procedures. Method. The predictive properties of five models were comparedwith respect to discriminating power (measured by the area undera receiver operating characteristic curve) and calibration (comparisonof the predicted and the actual incidences of the disease byweighed linear regression analysis). Results. The cumulative incidence of PV was 33.2% within 24h. The discriminating power was low and insufficient in allmodels tested (0.56–0.65). Furthermore, the predictedincidences of the scores correlated only vaguely with the actualincidences observed. Conclusion. Specialized scores for children are required. Thesemight use the history of PV, strabismus surgery, duration ofanaesthesia     

A risk score for postoperative nausea and/or vomiting in women undergoing cesarean delivery with intrathecal morphine

BackgroundPostoperative nausea and/or vomiting affects up to 80% of parturients undergoing cesarean delivery, but there is a lack of obstetric-specific risk-prediction models. We performed this study to identify postoperative nausea/vomiting risk factors in parturients undergoing cesarean delivery, formulate an obstetric-specific prediction model (Duke score), and compare its performance against the Apfel score.MethodsA post-hoc analysis of data from two randomized controlled trials studying nausea/vomiting in women undergoing cesarean delivery with intrathecal morphine. Potential risk factors for postoperative nausea/vomiting within 24 h of surgery with univariate associations with P ≤0.20 were considered for inclusion in the multivariable analysis. After identifying the final multivariable model, we derived our Duke score by assigning points to the selected factors. We then tested the association of the Duke and Apfel scores with postoperative nausea and vomiting, and compared the area-under-the-receiver operating characteristic curve.ResultsAnalysis included 260 parturients, of whom 146 (56.2%) experienced postoperative nausea/vomiting. Non-smoking during pregnancy (OR 2.29 [95% CI 1.12 to 4.67], P=0.023), and history of postoperative nausea/vomiting after cesarean delivery and/or morning sickness (2.09 [1.12 to 3.91], P=0.021) were independent predictors of postoperative nausea/vomiting and included in the Duke score. Both Duke and Apfel scores trended linearly with postoperative nausea/vomiting risk (Duke P=0.001; Apfel P=0.049) and had comparable areas-under-the-receiver operating characteristic curve (Duke 0.63 [0.57 to 0.70]; Apfel 0.59 [0.52 to 0.65], P=0.155).ConclusionsBoth Duke and Apfel scores exhibited similar but poor predictive performance. Until better tools are developed, routine prophylactic anti-emetics appears to be a reasonable approach in this patient population.     

Immediate postoperative refeeding in orthopedic surgery is safe

The purpose of this retrospective study was to investigate the morbidity of immediate postoperative refeeding after orthopedic surgery. We included all the 1077 patients who underwent orthopedic surgery between January and December 2003 at our military teaching hospital. General anesthesia was performed in 37% of the patients (n = 398), 24% (n = 259) had combined general and regional anesthesia, and 39% (n = 420) had isolated regional anesthesia (spinal anesthesia and/or peripheral regional anesthesia). After surgery, each patient was allowed free access to solid and liquid food immediately after discharge from the postanesthetic care unit. Although no systematic nausea and vomiting prophylaxis was performed, only 7% (n = 75) of the patients had postoperative nausea and vomiting during the first 48 h. Moreover, neither deglutition trouble nor aspiration syndrome was observed during that period. Our results suggest that immediate postoperative refeeding after orthopedic surgery is safe, does not increase postoperative nausea and vomiting, and probably increases the comfort of patients.     

Incidence of nausea and vomiting in children after strabismus surgery following desflurane anaesthesia

In a prospective, randomized parallel study, 60 ASA I-III children aged 1-17 years, scheduled for elective strabismus surgery, were anaesthetized with desflurane without prophylactic antiemetic medication. The objective of the study was to determine the incidence of postoperative nausea and vomiting after general anaesthesia with desflurane. To decide whether nitrous oxide further influences these symptoms, the patients were randomly assigned to two groups of 30 patients each. One group received desflurane in oxygen/air and a second group received desflurane in oxygen/nitrous oxide. In all children, after intravenous induction and tracheal intubation, anaesthesia was administered as minimal flow anaesthesia with oxygen and nitrous oxide or air according to the random plan. The patients were observed for 48 postoperative hours until their discharge from the ward. The overall incidence of nausea was found to be 37%, and vomiting was seen in 32% of all patients. No statistical correlation was found between the incidence of postoperative emesis and the administration of nitrous oxide or the duration of general anaesthesia. Instead, the incidence of vomiting was 2.5-fold higher when surgery was performed on both eyes compared with one eye. The relatively low incidence of postoperative nausea and vomiting, as well as the quick recovery from anaesthesia, permitting an early discharge from the postoperative care unit to the ward, show desflurane to be a suitable volatile anaesthetic in strabismus surgery in children.