Dolasetron for the prevention of postoperative nausea and vomiting following outpatient surgery with general anaesthesia: a randomized, placebo-controlled study. The Dolasetron PONV Prevention Study Group.

In a multicentre, randomized, double-blind, placebo-controlled dose-ranging study, 1030 patients undergoing outpatient surgery with general anaesthesia received i.v. dolasetron mesylate (12.5, 25, 50, or 100 mg) or placebo. The principal outcome measure was the proportion of patients who were free of emesis or rescue medication for the 24-h period after the study drug was given; the subsidiary outcome measure was survival time without rescue medication. Effects on nausea were quantified using a visual analogue scale. Compared with placebo, a complete response was significantly higher when all four dolasetron doses were combined (49% vs. 58%, P =0.025). In females, dolasetron, 12.5-mg, dolasetron provided maximum clinical benefit (effectiveness compared with adverse events), with no additional benefit in complete response rates or nausea visual analogue scale scores at higher doses. No significant differences were observed in complete response for any dolasetron dose in males compared with placebo. The majority of adverse events reported were mild or moderate. Dolasetron provided well-tolerated, safe, and effective prophylaxis for post-operative nausea and vomiting with maximum effectiveness observed at a dose of 12.5 mg.

Prevalence of gastrointestinal helminths in different poultry production systems.

A cross-sectional prevalence study of gastrointestinal helminths in Danish poultry production systems was conducted on 268 adult chickens selected at random from 16 farms in Denmark from October 1994 to October 1995. The trachea and the gastrointestinal tract of each bird was examined for the presence of helminths. In the free-range/organic systems the following helminths were found: Ascaridia galli (63.8%), Heterakis gallinarum (72.5%), Capillaria obsignata (53.6%), Capillaria anatis (31.9%) and Capillaria caudinflata (1.5%). In the deep-litter systems: A. galli (41.9%), H. gallinarum (19.4%) and C. obsignata (51.6%). In the battery cages: A. galli (5%) and Raillietina cesticillus or Choanotaenia infundibulum (3.3%). Exact identification of the cestodes was not possible because of missing scolexices. In the broiler/parent system: C. obsignata (1.6%), and finally for the backyard system: A. galli (37.5%) H. gallinarum (68.8%), C. obsignata (50.0%), C. anatis (56.3%) and C. caudinflata (6.3%). The results confirm the higher risk of helminth infections in free-range and backyard systems but prevalence may also be high in deep litter systems.

Efficacy of repeat intravenous dosing of ondansetron in controlling postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled multicenter trial.

STUDY OBJECTIVES: To compare repeat intravenous (i.v.) dosing of ondansetron 4 mg with placebo for the treatment of postoperative nausea and vomiting (PONV) in patients for whom prophylactic, preoperative ondansetron 4 mg i.v. was inadequate DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Ten outpatient surgical centers in the United States. PATIENTS: 2,199 male and female ASA physical status I, II, and III patients > or = 12 years old scheduled to undergo outpatient surgical procedures and receive nitrous oxide-based general anesthesia. INTERVENTIONS: Ondansetron 4 mg i.v. was administered to all patients before induction of general anesthesia. Patients who experienced PONV or requested antiemetic therapy within 2 hours after discontinuation of inhaled anesthesia were randomized (1:1) to either a repeat i.v. ondansetron 4 mg dose or placebo. MEASUREMENTS AND MAIN RESULTS: Of the 2,199 patients prophylactically treated with ondansetron 4 mg before anesthesia induction, 1,771 (80.5%) did not experience PONV or request antiemetic therapy during the 2 hours following discontinuation of anesthesia. Of the 428 patients who experienced PONV or requested antiemetic therapy during the same period, and were randomized to additional treatment (214 randomized to ondansetron, 214 randomized to placebo), the incidence of complete response (no emesis, no rescue medication, no study withdrawal) was similar for both ondansetron-randomized and placebo-randomized groups for the 2-hour (34% and 43%, respectively, p = 0.074) and 24-hour (28% and 32%, respectively, p = 0.342) postrandomization study periods. Repeat ondansetron dosing was not more effective than placebo in controlling either postoperative emesis or the severity/duration of postoperative nausea. The administration of an additional dose of ondansetron 4 mg postoperatively did not result in an increased incidence of adverse effects. CONCLUSIONS: In patients for whom preoperative prophylaxis with ondansetron 4 mg i.v. is not successful, a repeat dose of ondansetron 4 mg i.v. in the postanesthesia care unit does not appear to offer additional control of PONV.

Studies on Ascaridia galli in chickens kept at different stocking rates.

The development of Ascaridia galli infections was investigated over a period of 378 days in parasite naive chicken flocks ('permanent flocks') kept at different stocking rates and infected by introducing previously infected chickens (seeder birds). The results of this study indicated that differences in stocking rate may lead to different levels of establishment of A. galli infections in chickens. Furthermore, significantly higher weight gains were seen in the medium stocking rate (MSR) group than in either the low stocking rate (LSR) or the high stocking rate (HSR) groups. Periodically, the egg excretion was significantly different between the groups. Although not significant for the whole period, the general trend was that the egg excretion was lower in the MSR group than the LSR and HSR groups. The mean worm burdens in the permanent flocks at the end of the experiment were not significantly different from each other. To estimate the availability of infective eggs in the houses and pens, tracer animals were introduced into each of the permanent flocks every month. Information derived from tracer animals did not confirm an effect of stocking rate on the availability of infective eggs in the environment, although there was a trend towards higher mean worm burdens in the tracers from the MSR group.

Ascaridia galli populations in chickens following single infections with different dose levels.

In all, 3 groups of 20 Lohman Brown chickens aged 1 day were orally infected with doses of 100, 500, or 2,500 embryonated Ascaridia galli eggs, respectively. After 8 weeks, egg counts (eggs per gram of feces, EPG) were determined for all animals prior to slaughter. The gastrointestinal tracts were examined for the presence of adult and immature stages of A. galli. All groups had roughly similar worm burdens and, hence, significantly different establishment rates of 14.2%, 2.9%, and 0.5%, respectively. A significantly lower mean female worm burden was seen in the high-dose group (P = 0.02), which also showed a significantly lower level of egg excretion (P = 0.01). However, fecundity (EPG per female) did not significantly differ between the groups (P = 0.55). The mean lengths of adult worms as well as the weight of the mean worm burdens were significantly smaller in the high-dose group. This study demonstrated that single infections with varying doses of A. galli eggs influenced the establishment rate, sex ratio, egg excretion, and worm size and weight but not the worm fecundity.

Ondansetron prevents postoperative emesis in male outpatients. S3A-379 Study Group.

STUDY OBJECTIVES: To determine (1) the efficacy and safety of ondansetron in the prevention of postoperative nausea and vomiting (PONV) in male outpatients; (2) prognostic factors for PONV in male outpatients; and (3) patients' perceptions of the debilitating effects of PONV in the ambulatory surgery setting. DESIGN: Prospective, randomized, stratified, double-blind study. SETTING: Multicenter-24 medical centers. PATIENTS: 468 ASA physical status I and II males at least 12 years of age scheduled for general anesthesia. INTERVENTIONS: All patients received intravenous ondansetron 4 mg or placebo prior to undergoing general balanced (opioid) anesthesia. MEASUREMENTS AND MAIN RESULTS: In the postanesthesia care unit (PACU), the number of emetic episodes, vital signs, adverse events, and nausea assessments were recorded by a blinded observer. After discharge, and until the end of the 24-hour study period, patients completed a diary that collected emetic episodes, adverse events, nausea, and pharmacoeconomic data. There were no differences in patient demographics or safety profiles between groups. The number of patients with no emesis and no nausea during the 24-hour study period was significantly greater (p < 0.05) with ondansetron 4 mg compared with placebo. Prognostic factors for an increased likelihood of developing PONV in males included a history of motion sickness or previous PONV, patients undergoing nonorthopedic procedures, and surgeries lasting longer than one hour. Finally, 38% of patients experiencing PONV perceived PONV to be as, or more debilitating than, the aftereffects of surgery itself. CONCLUSIONS: Ondansetron 4 mg was more effective than placebo in preventing PONV in male outpatients. Males at potential risk for developing PONV include: (1) those with a history of motion sickness and/or PONV; (2) patients undergoing nonorthopedic procedures; and (3) procedures lasting longer than one hour. Such patients may benefit from receipt of a prophylactic antiemetic. Postoperative nausea and vomiting has a debilitating effect that can be differentiated by patients from the effects of surgery itself.

Single dose intravenous ondansetron in the prevention of postoperative nausea and vomiting.

Postoperative nausea and vomiting continues to pose problems for surgical patients. Three studies were undertaken to evaluate the efficacy and safety of prophylactic intravenous ondansetron in male and female patients undergoing outpatient surgery. Studies 1 and 2 included a total of 1169 female patients scheduled to undergo surgery on a day case basis. In study 3, 468 male patients scheduled for outpatient surgery were enrolled. Patients received ondansetron or placebo prior to induction of anaesthesia. Efficacy and safety data were collected for 24 h postoperatively. Studies 1 and 2, individually, revealed that ondansetron 4 mg and 8 mg were significantly (p < or = 0.05) better than placebo at preventing emesis. A combined analysis showed that the 4 mg and 8 mg doses were significantly (p < or = 0.05) better than ondansetron 1 mg at preventing emesis, while 8 mg was not statistically different from 4 mg. Therefore, 4 mg was chosen as the optimal dose. In study 3, ondansetron 4 mg was significantly (p < or = 0.001) more effective than placebo in preventing emesis in males. There were no differences between treatment groups with respect to vital signs, laboratory values, or adverse events. Intravenous ondansetron is safe and effective at preventing postoperative nausea and vomiting in male and female patients undergoing day case surgery.