***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Because no completely effective antiemetic exists for the prevention of postoperative nausea and vomiting ( PONV ) , we hypothesize that a multimodal approach to management of PONV may reduce both vomiting and the need for rescue antiemetics in high-risk patients . After IRB approval , women undergoing outpatient laparoscopy were r and omized to one of three groups . Group I ( n = 60 ) was managed by using a predefined multimodal clinical care algorithm .  Patients undergoing the same surgical procedure who received a st and ard balanced outpatient anesthetic with ondansetron 4 mg ( Group II , n = 42 ) or placebo ( Group III , n = 37 ) prophylaxis were chosen to establish baseline incidence of nausea and vomiting . None of the Group I patients vomited before discharge , compared with 7 % in Group II ( P = 0.07 ) and 22 % in Group III ( P = 0.0003 ) . However , one patient ( 2 % ) in Group I required treatment for symptoms in the postanesthesia care unit , compared with 24 % in Group II ( P < 0.0001 ) and 41 % in Group III ( P < 0.0001 ) . Time to discharge-ready was significantly shorter in Group I ( 128 , 118–139 min ; mean , 95 % confidence interval ) versus Group II ( 162 , 145–181 min;P = 0.0015 ) and Group III ( 192 , 166–222 min;P = 0.0001 ) . Patient satisfaction with control of PONV was not different between Group I and Group II . Return to normal daily activity and overall satisfaction were not different among groups . Multimodal management result ed in a 98 % complete response rate and a 0 % incidence of vomiting before discharge ; however , this improvement did not result in an increased level of patient satisfaction when compared with routine monotherapy prophylaxis . We conclude that both multimodal management and routine monotherapy antiemetic prophylaxis result ed in an increased level of patient satisfaction than symptomatic treatment in this high-risk population . Implication s Use of a multimodal clinical care algorithm eliminates predischarge vomiting and improves satisfaction in patients undergoing outpatient laparoscopy We have compared the effects of ondansetron and perphenazine on  vomiting after tonsillectomy in 216 healthy children , aged 2 - 12 yr . The study was r and omized , stratified , blocked and double blind . Anaesthesia was induced with propofol i.v . or by inhalation of halothane and nitrous oxide . Ondansetron 150 micrograms kg-1 or perphenazine 70 micrograms kg-1 was administered i.v . after induction of anaesthesia in a double-blind manner . Perioperative management of emesis , pain , fluids and patients discharge were st and ardized . Ondansetron and perphenazine had similar effects on postoperative vomiting ( 44 % vs 41 % ; ondansetron vs perphenazine P = 0.77 ) . By logistic regression analysis , the only significant predictor of postoperative vomiting was sex , that is males had a greater incidence of vomiting ( 49 % vs 35 % ; P = 0.016 ) . In-hospital vomiting was associated with a prolongation of stay in the day-care surgical unit of 7 min per episode of vomiting ( P = 0.015 ) . We conclude that ondansetron and perphenazine had similar effects on vomiting in children after tonsillectomy in a day-case setting BACKGROUND Postoperative nausea and vomiting ( PONV ) are common after thyroidectomy .  Granisetron , a selective 5-hydroxytryptamine type 3 ( 5-HT3 ) receptor antagonist , is more effective than the traditional antiemetics droperidol and metoclopramide for the prevention of PONV after thyroidectomy . Ramosetron , another new selective antagonist of 5-HT3 receptor , has been shown to have more potent and longer-acting properties than granisetron against cisplatin-induced emesis in ferrets . OBJECTIVE This study was undertaken to compare the efficacy and tolerability of granisetron and ramosetron for the prevention of PONV after thyroidectomy . METHODS In this r and omized , double-blind study , patients received granisetron 3 mg or ramosetron 0.3 mg intravenously at the end of surgery . A st and ard general anesthetic technique and postoperative analgesia were used . Emetic episodes and safety were assessed during the first 24 hours and the second 24 hours after anesthesia . RESULTS Eighty patients ( 15 men , 65 women ) aged 33 to 58 years were included in the study . Each study group consisted of 40 patients . There were no differences between groups with regard to patient demographics . The percentage of patients who were emesis free ( no nausea , no retching , no vomiting ) 0 to 24 hours after anesthesia was 83 % ( 33 of 40 ) with granisetron and 88 % ( 35 of 40 ) with ramosetron ; the corresponding rates 24 to 48 hours after anesthesia were 63 % ( 25 of 40 ) and 90 % ( 36 of 40 ) , respectively ( P = 0.004 ) . The safety profile of the two 5-HT3 receptor antagonists was comparable , as no clinical ly serious adverse effects caused by the study drug were observed in either of the groups . CONCLUSIONS Prophylactic antiemetic therapy with ramosetron was comparable to therapy with granisetron for the prevention of PONV 0 to 24 hours after anesthesia in patients who underwent thyroidectomy ; 24 to 48 hours after anesthesia , ramosetron was more ef- fective than granisetron for prophylaxis against PONV in this population Background It is commonly stated that risk factors for postoperative nausea are the same as for vomiting . The authors design ed a prospect i ve study to identify and differentiate the risk factors for postoperative nausea and vomiting in various surgical population s in a clinical audit setting . Methods The study included 671 consecutive surgical in patients , aged 15 yr or more , undergoing various procedures . The study focused on postoperative  nausea visual analog scale scores every 4 h and vomiting episodes within 72 h. Both vomiting and retching were considered as emetic events . Patient- , anesthesia- , and surgery-related variables that were considered to have a possible effect on the proportion of patients experiencing postoperative nausea and /or vomiting were examined . The bivariate Dale model for binary correlated outcomes was used to identify selectively the potential risk factors of postoperative nausea and vomiting . Results Among the 671 patients in the study , 126 ( 19 % ) reported one or more episodes of nausea , and 66 patients ( 10 % ) suffered one or more emetic episodes during the studied period . There was a highly significant association between the two outcomes . Some risk factors were predictive of both nausea and vomiting ( female gender , nonsmoking status , and general anesthesia ) . History of migraine and type of surgery were mainly responsible for nausea but not for vomiting . The predictive effect of risk factors was controlled for postoperative pain and analgesic drugs . Conclusion This study shows that differences exist in risk factors of postoperative nausea and vomiting . These could be explained by differences in the physiopathology of the two symptoms In this prospect i ve , r and omized , double-blind study , we compared the efficacy and safety of ondansetron and metoclopramide in the treatment of  postoperative nausea and vomiting ( PONV ) . One hundred seventyfive patients with PONV during recovery from anesthesia for gynecological laparoscopy were treated intravenously with either ondansetron 4 mg ( 58 patients ) , metoclopramide 10 mg ( 57 patients ) , or placebo ( 60 patients ) . Early antiemetic efficacy ( abolition of vomiting within 10 min and of nausea within 30 min from the administration of the study drugs with no further vomiting or nausea episodes during the first hour ) was obtained in 54 of 58 patients ( 93.1 % ) in the ondansetron group , in 38 of 57 patients ( 66.7 % ) in the metoclopramide group , and in 21 of 60 patients ( 35 % ) in the placebo group ( P < 0.001 ) . This difference was still significant when controlling for age , body weight , history of motion sickness , previous PONV episodes , duration of anesthesia , and intraoperative fentanyl consumption using a logistic model . Early antiemetic efficacy was inversely related to the amount of fentanyl administered during anesthesia , regardless of treatment . According to the Kaplan-Meier method , the probability of remaining PONV-free for 48 h after a successful treatment was 0.59 ( 95 % confidence interval 0.45 - 0.71 ) in the ondansetron group , 0.45 ( 0.29 - 0.60 ) in the metoclopramide group , and 0.33 ( 0.15 - 0.53 ) in the placebo group ( P = 0.003 ) . In conclusion , ondansetron 4 mg is more effective than metoclopramide 10 mg and placebo in the treatment of established PONV . ( Anesth Analg 1997;85:395 - 9 Background Postoperative nausea and vomiting ( PONV ) is still common , especially among female patients . Our hypothesis is that coinduction with clonidine reduces the incidence of PONV in adult patients undergoing breast cancer surgery . Methods Sixty-eight women premedicated with midazolam were r and omly allocated to coinduction with intravenous clonidine ( group C ) or placebo ( group P ) in this prospect i ve , double-blind study . Anesthesia was st and ardized ( laryngeal mask airway , fentanyl , propofol , sevoflurane , nitrous oxide , and oxygen ) . Hemodynamic parameters and the requirements for propofol , sevoflurane , and the postoperative need for ketobemidone were noted . The primary endpoints studied were the number of PONV-free patients and patient satisfaction with respect to PONV . Results Patients in group C had a significantly reduced need for propofol ( P < 0.04 ) and sevoflurane ( P < 0.01 ) and a reduced early need for ketobemidone ( P < 0.04 ) . There were significantly more PONV-free patients in group C compared with group P ( 20 and 11 of 30 , respectively;P < 0.04 ) . The number needed to treat was 3.3 ( 95 % confidence interval , 1.8 , 16.9 ) . Intraoperative blood pressure , postoperative heart rate , and postoperative blood pressure were all significantly lower in group C compared with group P , but were not considered to be of clinical importance . No negative side effects were recorded . Conclusion Coinduction with clonidine significantly increased the number of PONV-free patients after breast cancer surgery with general anesthesia In view of the similarity in chemical structure of the available 5HT3-receptor antagonists it is assumed , whilst these agents all act at the same receptor , that failure to one agent would predict subsequent failure to all 5HT3-receptor antagonists . We conducted a r and omized double blind trial of granisetron 3 mg plus dexamethasone 10 mg versus continued treatment with ondansetron 8 mg plus dexamethasone 10 mg in patients with protection failure on ondansetron 8 mg plus dexamethasone 10 mg during the first 24 hours following highly emetogenic chemotherapy .  Of 40 eligible patients , 21 received ondansetron + dexamethasone and 19 received granisetron + dexamethasone . We found a significant benefit from crossing-over to granisetron after failure on ondansetron . Of the 19 patients who crossed over to granisetron , 9 patients obtained complete protection , whereas this was observed in 1 of the 21 patients continuing ondansetron , P = 0.005 . These results indicate that there is no complete cross-resistance between 5HT3-receptor antagonists , and that patients who have acute protection failure on one 5HT3-receptor antagonist should be offered cross-over to another 5HT3-receptor antagonist . © 2001 Cancer Research Campaign Supplemental oxygen maintained during and for 2 h after colon resection halves the incidence of nausea and vomiting . Whether supplemental oxygen restricted to the intraoperative period is sufficient remains unknown . Similarly , the relative efficacy of supplemental oxygen and ondansetron is unknown . We tested the hypothesis that intraoperative supplemental oxygen reduces the incidence of postoperative nausea and vomiting .  Patients ( n = 240 ) undergoing gynecological laparoscopy were given a st and ardized isoflurane anesthetic . After induction , they were r and omly assigned to the following three groups : routine oxygen administration with 30 % oxygen , balance nitrogen ( 30 % Oxygen group ) , supplemental oxygen administration with 80 % oxygen , balance nitrogen ( 80 % Oxygen group ) , and Ondansetron 8 mg ( immediately after induction ) , combined with 30 % oxygen , balance nitro 
    Output:
    
No prophylaxis is needed for patients at low risk for PONV .
La méthode de traitement des NVPO la plus rentable sera différente selon qu’il s’agit d’un patient ambulatoire ou hospitalisé .
Le traitement des NVPO établis chez des patients qui n’ont pas répondu au traitement préventif ne doit pas comporter une seconde dose de l’antiémétique prophylactique .
Au delà de six heures après l’opération , on peut traiter avec n’importe quel médicament utilisé comme prévention , sauf la dexaméthasone et la scopolamine transdermique .