Nitrous oxide does not increase vomiting in children after myringotomy

The aim of this study was to establish whether nitrous oxide has a clinically important effect on postoperative vomiting in children after myringotomy. We studied 320 healthy children of ages 0.5–13 yr undergoing elective myringotomy and tube insertion. Induction and maintenance of anaesthesia were randomized to inhalation with either 70% N₂O/30% O₂/halothane or 100%O₂/halothane. Surgical technique and postoperative management were not influenced by this study. Vomiting in the recovery room (PAR) and Day Care Surgical Unit (DCSU) was recorded by nurses unaware of the anaesthetic technique. Parents were contacted 24–48 hr after surgery to ascertain the incidence of vomiting after discharge. The groups were similar with respect to demographic data, except that the anaesthesia time was greater among the 158 patients in the N₂Otreated group (11 ± 4 vs 12 ± 4 min, mean ± SD. The incidence of vomiting was 13% in both groups. Most of the 42 patients that had emesis only vomited once or twice. The incidence of vomiting was not altered by sex (13% vs 13%) or duration of anaesthesia. The incidence of vomiting increased with increasing age. The children aged less than 3 yr vomited 4% of the time, those aged 3–5 vomited 11% of the time, those aged 6–8 yr vomited 17% of the time, while the incidence of vomiting among those aged 9–13 yr was 31% Vomiting prolonged the postoperative hospital stay from 75 to 92 min, P < 0.001, ANOVA. In summary, we have been unable to demonstrate that N₂O induces vomiting by children after a brief general anaesthetic for myringotomy.     

Postoperative nausea and vomiting. A comparison between intravenous and inhalation anaesthesia in breast surgery

Nausea and vomiting during the first 24 postoperative hours after breast surgery were studied. Ninety patients scheduled for elective breast surgery were randomly assigned to one of three anaesthetic methods: total intravenous anaesthesia with propofol, or propofol or thiopental for induction followed by isoflurane anaesthesia. All three groups received fentanyl for peroperative analgesia. A total of 46 (51%) patients experienced emetic sequelae: 19 (21%) complained about nausea and another 27 (30%) vomited once or more during the postoperative course. More than 50% of the patients with nausea and 70% with vomiting first suffered from these symptoms in the surgical wards after leaving the postoperative unit. Nausea and vomiting were seen in 18 (60%), 13 (43%) and 15 (50%) for the groups propofol–propofol, propofol–isoflurane and thiopental–isoflurane, respectively. In conclusion, every second patient experienced nausea or vomiting after breast surgery, the majority of these emetic symptoms occurring after leaving the postoperative unit. Propofol for induction or as a main anaesthetic did not make any major difference with regard to postoperative nausea or vomiting.     

Effect of a Small Dose of Droperidol on Nausea, Vomiting and Recovery after Outpatient Enflurane Anaesthesia

Young, healthy outpatients (100) undergoing restorative dentistry and/or oral surgery under enfluranenitrous oxide-oxygen anaesthesia were given 0.014 mg/kg of droperidol or a saline placebo i.v. in a double-blind random fashion 5 min after induction of anaesthesia to prevent postoperative nausea and vomiting. Overall, less patients given droperidol were nauseated (18%) or vomited (7%) in comparison with patients given saline (27% and 11%, respectively). During the first postoperative hour, 4% of patients given droperidol were nauseated and 2% vomited, whereas 16% of patients given saline were nauseated and 6% vomited. Four patients given saline were not discharged from the clinic 1 h after anaesthesia owing to prolonged nausea and vomiting. The time elapsed until the patients were oriented as to time and place after cessation of enflurane and nitrous oxide administration was similar in both groups (mean +/- s.d., 13.5 +/- 4.7 min). Thirty minutes after anaesthesia, the ability to walk on a straight line was significantly (P less than 0.001) worse in patients given droperidol as compared to patients given saline. After 60 min, only one patient given droperidol and four patients who received saline and vomited took side steps or were unable to walk. Psychomotor performance was significantly (P less than 0.05) better in a perceptual speed test both 30 and 60 min after anaesthesia in patients receiving saline as compared to those given droperidol. It is concluded that although droperidol is a less effective antiemetic after outpatient than after inpatient enflurane anaesthesia, small doses of droperidol may be used for outpatients prone to vomiting to prevent delayed discharge from the clinic due to prolonged vomiting.     

Prophylactic anti-emetic therapy with granisetron, droperidol and metoclopramide in female patients undergoing middle ear surgery

The efficacy of granisetron, droperidol and metoclopramide for the prevention of postoperative nausea and vomiting in female patients undergoing middle ear surgery was compared. In a randomised, double-blind study, 180 patients received granisetron 40 micrograms.kg-1, droperidol 20 micrograms.kg-1 or metoclopramide 0.2 mg.kg-1 given intravenously immediately before induction of anaesthesia (n = 60 for each). A standardised general anaesthetic technique was employed throughout. A complete response, defined as no postoperative nausea and vomiting and no need for another rescue anti-emetic, during the first 3 h after anaesthesia was achieved in 83%, 58% and 55% of patients who had received granisetron, droperidol and metoclopramide, respectively. The corresponding incidence during the next 21 h after anaesthesia was 85%, 54% and 47% (p < 0.05). No clinically important adverse effects were observed in any of the groups. We conclude that prophylactic therapy with granisetron is superior to droperidol or metoclopramide in the prevention of postoperative nausea and vomiting after middle ear surgery.     

The effect on outcome of peribulbar anaesthesia in conjunction with general anesthesia for vitreoretinal surgery

The purpose of this study was to evaluate peri‐operative outcome after vitreoretinal surgery when peribulbar anaesthesia is combined with general anaesthesia. Sixty adult patients undergoing elective primary retinal detachment surgery with scleral buckling or an encircling procedure received either peribulbar anaesthesia in conjunction with general anaesthesia or general anaesthesia alone. For peribulbar anaesthesia a single percutaneous injection of 5–7 ml of local anaesthetic solution (0.75% ropivacaine with hyaluronidase 15 iu.ml^?1) was used. The incidence of intra‐operative oculocardiac reflex and surgical bleeding interfering with the surgical field, postoperative pain and analgesia requirements, and postoperative nausea and vomiting were recorded. In the block group there was a lower incidence of oculocardiac reflex and surgical bleeding intra‐operatively. Patients in the block group also had better postoperative analgesia and a lower incidence of postoperative nausea and vomiting compared with the group without a block. The use of peribulbar anaesthesia in conjunction with general anesthesia was superior to general anaesthesia alone for vitreoretinal surgery with scleral buckling.     

Nerve-stimulator guided paravertebral blockade vs. general anaesthesia for breast surgery: a prospective randomized trial

BACKGROUND AND OBJECTIVE: Different anaesthetic techniques are used during breast surgery but are frequently associated with unsatisfactory postoperative analgesia. Paravertebral nerve blockade has recently been proposed as a favourable alternative for this type of surgical procedure, providing excellent pain relief and a reduced incidence of postoperative nausea and vomiting. The aim of the present study was to compare the use of a nerve-stimulator guided paravertebral nerve blockade technique to regular general anaesthesia for breast surgery. METHODS: Sixty patients were prospectively randomized to receive either paravertebral nerve blockade or general anaesthesia for breast surgery. The primary end-point of the study was to assess postoperative analgesia (visual analogue scale and supplemental opioid requirements); the incidence of postoperative nausea and vomiting and length of hospital stay were considered as secondary outcome measures. RESULTS: Visual analogue scores both at rest and at movement, as well as the need for supplemental opioid administration during the first 3 days postoperatively, were significantly lower in patients handled with para-vertebral nerve blockade compared to patients receiving general anaesthesia (P < 0.05). The number of patients free from nausea and vomiting after operation was significantly higher in the paravertebral nerve blockade group (93%) compared to the general anaesthesia group (67%) (P < 0.05). The use of paravertebral nerve blockade was also associated with a significantly shorter hospital stay (median 1 day) compared to general anaesthesia (2 days) (P < 0.01). Both the performance of the block and the intraoperative conditions was well accepted by the vast majority of patients treated by paravertebral nerve blockade (97%). CONCLUSION: The use of paravertebral nerve blockade was associated with improved postoperative pain relief, a reduced incidence of nausea and vomiting after operation and a shorter duration of hospital stay compared to general anaesthesia in patients undergoing breast surgery.     

A prospective survey of postoperative nausea and vomiting with special regard to incidence and relations to patient characteristics, anesthetic routines and surgical procedures

We performed a prospective study on 421 patients subjected to routine general-, orthopaedic-, urologic-, gynecological and paediatric surgery to estimate the current incidences of nausea and vomiting during the first 24 hours after surgery.
The overall incidences of postoperative nausea or vomiting were 17% and 28%, respectively. Postoperative emetic symptoms were not related to age in adults. Women had more often emetic symptoms than men ( P <0.01). In general, opiate premedication was more frequently associated with postoperative nausea and vomiting than benzodiazepines ( P <0.01), but in otherwise comparable subgroups of patients undergoing major surgery, this difference was not confirmed. Balanced general anaesthesia caused more nausea (23%) and vomiting (53%) than face-mask anaesthesia (13% and 15%, respectively) or regional blocks (12% and 7%, respectively) ( P <0.001). There was a positive correlation between the duration of anaesthesia and the incidence of postoperative emetic symptoms ( P <0.001). The incidences of postoperative nausea and vomiting after abdominal surgery were 23% and 58% respectively. Corresponding figures for orthopaedic surgery were 25% and 34%, other kinds of extra-abdominal surgery 18% and 32% and for laparoscopy 21% and 25%. After minor gynecological-, urological-and paediatric surgery the incidences were less than 20%.
In conclusion female gender, balanced anaesthesia, lengthy duration of anaesthesia, and abdominal and orthopaedic operations appeared to be most frequently associated with postoperative emetic symptoms.     

Bilateral paravertebral somatic nerve block for ventral hernia repair

BACKGROUND AND OBJECTIVE: Unilateral paravertebral nerve blockade has been reported to produce excellent afferent nerve block, reduce the incidence of postoperative nausea and vomiting, and reduce hospital stay following inguinal hernia repair. The aim was to compare the use of bilateral paravertebral blocks to regular general anaesthesia for ventral hernia repair. METHODS: Sixty patients were prospectively allocated to receive either bilateral paravertebral nerve blockade (midazolam for block; supplemented with light intraoperative sedation if needed) or general anaesthesia for ventral hernia repair. The end-points of the study were length of hospital stay, postoperative analgesia (visual analogue scale, supplemental opioid requirement) and incidence of postoperative nausea and vomiting. RESULTS: The duration of hospital stay was observed to be shorter in patients handled with bilateral paravertebral nerve blockade (2.3 [SD 1.3] days) compared with patients receiving general anaesthesia (4.1 (3.0) days). Paravertebral analgesia resulted in both lower visual analogue scores and a significantly reduced need for supplemental opioid administration during the first 48 h postoperatively compared with general anaesthesia (P < 0.001). The rate of postoperative nausea and vomiting in the paravertebral nerve blockade group was only 3.3%, while 26.7% of patients in the general anaesthesia group suffered from postoperative nausea and vomiting (P < 0.05). Paravertebral nerve blockade was associated with good patient acceptance in 90% of patients. CONCLUSIONS: Bilateral paravertebral blockade combined with light intravenous sedation was superior to general anaesthesia for ventral hernia repair. Paravertebral blockade was associated with shorter hospital stay, improved analgesia and less postoperative nausea and vomiting. It is suggested that this technique deserves more widespread use in patients undergoing ventral hernia repair.     

Sub-Tenon's block reduces both intraoperative and postoperative analgesia requirement in vitreo-retinal surgery under general anaesthesia

BACKGROUND AND OBJECTIVE: We compared the effects of sub-Tenon's local anaesthetic block and placebo on peri-operative opioid requirement and cardiovascular stability and on postoperative pain, nausea and vomiting in patients undergoing vitreo-retinal surgery under general anaesthesia. METHODS: We studied 43 patients undergoing vitreo-retinal surgery under general anaesthesia in a randomized double blind study. Patients received a standard general anaesthetic followed by a sub-Tenon's injection of 4-5 mL of either bupivacaine 0.75% or saline. We recorded intraoperative invasive arterial pressure, then the incidence and severity of pain and of nausea and vomiting, for 24 h postoperatively. RESULTS: In the sub-Tenon's bupivacaine group, there was a significant reduction in the perioperative opioid use and a reduction in the frequency of bradycardia and hypertensive episodes, defined as a rise > 25% of baseline for a duration of > 3 min. The sub-Tenon's bupivacaine group also had significantly lower pain scores and nausea scores at 12 h, concomitant with a lower consumption of analgesia and antiemetics. CONCLUSIONS: This local anaesthetic technique is effective in vitreo-retinal surgery and can be safely applied to this population of patients regardless of axial length.     

Postoperative complaints after spinal and thiopentone-isoflurane anaesthesia in patients undergoing orthopaedic surgery Spinal versus general anaesthesia

Background. The present prospective study investigates the impact of a standardized technique of spinal and general anaesthesia on the incidence and consequences of postanaesthetic complaints dependent on age and sex of patients.
Methods. 433 orthopaedic patients underwent lower limb surgery in spinal (group 1) or general (group 2) anaesthesia. Spinal anaesthesia was performed with 0.5% hyperbaric bupivacaine using a 26-gauge Quincke needle. General anaesthesia was induced with i.v. injection of thiopentone, fentanyl and atracurium and maintained with 65% nitrous oxide and 1-1.5 Vol% isoflurane in oxygen. On postoperative day 4, patients were interviewed for onset and duration of postoperative complaints.
Results. The overall incidence of nausea/vomiting ( P =0.025) and sore throat ( P =0.001) was higher in group 2. In addition, nausea/vomiting was higher in patients between 20 and 60 years in group 2 compared with group 1. While the incidence of urinary dysfunction was higher in men after spinal ( P =0.04), nausea/vomiting was more frequent in women after general anaesthesia ( P =0.008). Analgetic requirements ( P =0.013), time of postoperative surveillance ( P =0.042) and frequency of treatment of postoperative complaints ( P =0.0001) was higher in group 2.
Conclusion. Spinal anaesthesia was associated with a lower incidence of postoperative complaints and treatments and a shorter surveillance compared to general anaesthesia. Specific complications related to spinal anaesthesia did not depend on age or sex and may allow for recommendation of this technique even in younger and female patients undergoing orthopaedic surgery.     

Comparison of domperidone, droperidol, and metoclopramide in the prevention and treatment of nausea and vomiting after balanced general anesthesia

Women (185) undergoing elective orthopedic surgery under balanced general anesthesia were given 5 or 10 mg of domperidone, 1.25 mg of droperidol, 10 mg of metoclopramide, or a saline placebo intravenously in a double-blind random fashion 5 minutes before the end of anesthesia to prevent postoperative vomiting. Administration of the same antiemetic was repeated intramuscularly during the first 24 hours postoperatively if the patient complained of nausea or retched or vomited. Sigificantly (p less than 0.05 to p less than 0.001), fewer of the patients given droperidol were nauseated (25%) or vomited (17%) in comparison with patients given saline (incidence of nausea was 55% and vomiting 40%). Incidences of nausea and vomiting were similar in patients given domperidone, metoclopramide, or saline. Furthermore, 39 to 45% of the patients given domperidone, metoclopramide, or saline needed additional doses of the same drug, whereas only 22% of the patient given droperidol required a second dose. It is concluded that droperidol is effective in the prevention and treatment of postoperative nausea and vomiting after balanced general anesthesia but that domperidone or metoclopramide are not.     

A comparison of cyclizine and granisetron alone and in combination for the prevention of postoperative nausea and vomiting

We conducted a randomised double-blinded study of 960 women undergoing day-case surgery to determine whether combination anti-emetic therapy of granisetron and cyclizine was more effective at decreasing the incidence of postoperative nausea and vomiting than these agents used alone. The women were randomly allocated to three groups to receive intravenous granisetron 1 mg, cyclizine 50 mg or both before induction of general anaesthesia. The incidence of postoperative nausea and vomiting was 77/322 (24%) in the granisetron group, 73/316 (23%) in the cyclizine group and 53/322 (17%) in those women given both drugs (p = 0.04). There was no difference in the requirement for rescue anti-emetic drugs. There were no differences in the anaesthetic techniques used in the three groups. We conclude that the risk of postoperative nausea and vomiting is less with cyclizine and granisetron given together than with either given alone.     

A prospective randomised double blind study to evaluate the effect of peribulbar block or topical application of local anaesthesia combined with general anaesthesia on intra-operative and postoperative complications during paediatric strabismus surgery

We studied 45 ASA I/II children aged between 2 and 13 years scheduled for elective strabismus surgery, randomly allocated to receive either a peribulbar block or topical lidocaine 2% combined with general anaesthesia, or general anaesthesia alone. The incidence and severity of the occulocardiac reflex, the requirement for atropine, the occurrence of arrhythmias and incidence of postoperative nausea and vomiting following surgery at 1, 2 and 4 h were studied. We found the incidence and severity of occulocardiac reflex intra-operatively was significantly reduced in children who received a peribulbar block. The incidence of postoperative nausea and vomiting was significantly reduced in patients receiving either peribulbar block or topical local anaesthesia combined with general anaesthesia, compared to general anaesthesia alone (p = 0.008).     

Preoperative oral granisetron for the prevention of postoperative nausea and vomiting after breast surgery.

OBJECTIVE: To evaluate the efficacy and safety of oral granisetron for the prevention of postoperative nausea and vomiting after breast surgery. DESIGN: Prospective, randomised, double-blind, placebo-controlled study. SETTING: University affiliated hospital, Japan. SUBJECTS: 100 women listed for partial or modified radical mastectomy with or without axillary dissection. INTERVENTIONS: Patients were given either placebo or granisetron in three different doses (1 mg, 2 mg, 4 mg) orally 1 hour preoperatively (n = 25 in each group). A standard general anaesthetic technique and postoperative analgesia were used. MAIN OUTCOME MEASURES: All episodes of nausea and vomiting during the first 24 hours after anaesthesia. RESULTS: Complete response, defined as no nausea and vomiting and no need for a "rescue" antiemetic, during the first 24 hours after anaesthesia was recorded in 13 (52%) with placebo, 14 (56%) with granisetron 1 mg, 22 (88%) with 2 mg, and 22 (88%) with 4 mg, respectively (p = 0.006, Fisher's exact test). No clinically serious adverse events were seen in any of the groups. CONCLUSION: Preoperative oral granisetron, in doses of more than 2 mg, is effective for the prevention of postoperative nausea and vomiting in women undergoing general anaesthesia for breast surgery.     

Prophylactic antiemetic effect of dexamethasone in women undergoing ambulatory laparoscopic surgery

The aim of this study was to evaluate the prophylactic antiemetic effect of i.v. dexamethasone in women undergoing ambulatory laparoscopic tubal ligation. Ninety patients requiring general anaesthesia for laparoscopic tubal ligation were enrolled in a randomized, double-blind, placebo-controlled study. Forty-five patients received dexamethasone 10 mg i.v. and 45 received saline 2 ml i.v. at the induction of anaesthesia. We found that 27% of patients in the dexamethasone group, compared with 63% of patients in the saline group, reported nausea and vomiting within 4 h after surgery (P < 0.01). Seven per cent of patients in the dexamethasone group, compared with 28% of patients in the saline group, received a rescue antiemetic (P < 0.05). During the 24-h postoperative observation period, 34% of patients in the dexamethasone group, compared with 73% of patients in the saline group, reported nausea and vomiting (P < 0.001). We conclude that dexamethasone 10 mg significantly decreases the incidence of postoperative nausea and vomiting in women undergoing ambulatory laparoscopic tubal ligation.      

Postoperative symptoms 24 hours after ambulatory anaesthesia

Purpose

To test the hypothesis that the type of surgical procedure influences the incidence of postoperative symptoms. Also the effect of demographic and clinical risk variables: age, sex, ASA status, duration of anaesthesia on the postoperative symptoms were evaluated for each type of surgery.

Methods

Demographic, medical, anaesthetic and surgical data on 1,017 patients were prospectively collected by a research assistant who telephoned each patient 24 hr after discharge to administer a questionnaire to determine postoperative symptoms. Postoperative symptoms included incisional pain, nausea/vomiting, drowsiness, dizziness, headache and fever. In addition, 270 patients were asked the % (0–100) of their return to daily living function at 24 hr.

Results

Incisionat pain (26.9%), headache (11.6%), and drowsiness (11.5%) were the most frequently reported symptoms. Dizziness was reported by 9.7% and nausea/vomiting by 7.1%. Approximately 50% of patients undergoing laparoscopy, orthopaedic and general surgery reported 24-hr postoperative incisionat pain. The incidence of 24-hr postoperative nausea/vomiting was highest after general 17.4%, orthopaedic, 11.2%, and laparoscopic surgery, 9.4%. Drowsiness was highest after laparoscopy 36.1%, followed by general surgery, 21.4%. Dizziness was most frequent after laparoscopy, 24.1%, followed by general surgery, 16.1%. After laparoscopy, postoperative drowsiness or dizziness was related to anaesthesia duration. After general surgery, postoperative dizziness or drowsiness were related to age; the younger the patient, the more likely the symptoms.

Conclusions

Postoperative pain, nausea/vomiting, drowsiness, dizziness, and headache were the more frequent postoperative symptoms 24 hr after ambulatory surgery and they were influenced by the type of surgical procedure. In addition, the type of surgery and the 24-hr postoperative symptoms determined the degree of return to daily living function.     

Granisetron reduces the incidence of nausea and vomiting after middle ear surgery

We studied the efficacy of granisetron, a selective 5-hydroxytryptamine type-3 receptor antagonist, in preventing postoperative nausea and vomiting (PONV) after middle ear surgery. In a randomized, double- blind, placebo-controlled study, 60 ASA I patients received placebo (saline) or granisetron 40 micrograms kg-1 i.v. immediately before induction of anaesthesia (n = 30 in each group). A standard general anaesthetic technique was used. During the first 24 h after anaesthesia, the incidence of PONV in patients who had received granisetron was lower than in those who had received placebo (17% vs 63%; P < 0.05). There were no clinically important adverse effects in either group. We conclude that granisetron, given before anaesthesia, reduced the incidence of PONV after middle ear surgery.      

Propofol reduces the incidence of vomiting after tonsillectomy in children

We compared the effect of a propofol-based anaesthetic to an isoflurane-based anaesthetic on the incidence of postoperative vomiting in children following tonsillectomy. Thirty-nine children were enrolled in the study and randomized to receive one of the proposed anaesthetics. All patients underwent a mask induction with halothane, nitrous oxide, and oxygen. Intravenous access was established and all children received fentanyl (2–4 μg·kg^-1) i.v., mivacurium (0.3 mg·kg^-1) i.v. and acetaminophen (10–15 mg·kg^-1) p.r. Following tracheal intubation, patients received either isoflurane (0.8–1.6%) or propofol (120–180 μg·kg^-1 min^-1) i.v. with nitrous oxide 70%/oxygen 30% for maintenance of anaesthesia. Vital signs were maintained within 20% of baseline. All patients were extubated in the operating room. PACU nursing staff recorded episodes of vomiting for 4–6 h prior to discharge. A telephone interview the following day was also used for data recovery. Age, sex, and duration of the procedure were not significantly different between the two study groups. Of 19 patients who received propofol, four vomited (21%); in contrast, of the 20 patients who received isoflurane, 11 vomited (55%). This difference is significant (P= 0.048 two-tailed Fisher's Exact Test). These data suggest that using propofol for anaesthesia can diminish the incidence of vomiting following tonsillectomy.     

Effect of cricoid pressure on the incidence of nausea and vomiting in the immediate postoperative period

This study aimed to evaluate whether the application of cricoid pressure at the time of induction of anaesthesia was associated with a lesser incidence of postoperative nausea or vomiting in the immediate postoperative period compared with a group in which no cricoid pressure was applied, in patients undergoing day care gynaecological laparoscopy. One hundred ASA I and II females were randomly allocated to receive cricoid pressure at the time of induction. The peri-operative anaesthetic technique was standardised. The incidence of postoperative nausea and vomiting in the group who received cricoid pressure was 16% in the recovery room compared with 26% in the no cricoid group. When the period was extended to the first 6 h post anaesthesia the incidence was 30% in the cricoid and 44% in the no cricoid group. This difference did not achieve statistical significance in either period (p > 0.05). The results suggest that application of cricoid pressure at the time of induction does not significantly alter the incidence of postoperative nausea and vomiting in the first 6 h of recovery from anaesthesia.     

Droperidol, alizapride and metoclopramide in the prevention and treatment of post-operative emetic sequelae

Women (182) undergoing elective orthopaedic surgery under general anaesthesia received 100 or 200 mg alizapride, 1.25 mg droperidol, 20 mg metoclopramide or a saline placebo intravenously 5-10 min before the end of anaesthesia in a double-blind random fashion to prevent post-operative nausea and vomiting. Administration of the same anti-emetic was repeated during 24 h post-operatively if the patient complained of nausea or retched or vomited. Significantly fewer patients given any of the anti-emetics prophylactically were nauseated or vomited in comparison with patients given saline. The incidence of nausea and vomiting in the saline group was 83%, while in those patients who received an anti-emetic it was as follows: droperidol 35% (P less than 0.001 vs. saline), alizapride, 100 mg 46% (P less than 0.01), alizapride 200 mg 53% (P less than 0.05) and metoclopramide 58% (P less than 0.05). The number of patients needing an additional dose of the same substance in the post-operative period was significantly higher in the saline group (67%) than in the groups which had received droperidol (32%, P less than 0.01) and alizapride 100 mg (37%, P less than 0.05) or 200 mg (33%, P less than 0.05). The patients who received metoclopramide, however, did not differ statistically from the saline group in the treatment of nausea and vomiting. It is concluded that droperidol was the most effective, and metoclopramide the least effective, anti-emetic in this study.