Effect of preoperative ondansetron on postoperative nausea in healthy dogs undergoing laparoscopic gastropexy and castration.

OBJECTIVE: To investigate if preoperative ondansetron reduces postoperative nausea associated with laparoscopic gastropexy and castration in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Twenty client-owned, healthy male dogs. METHODS: Dogs were premedicated with dexmedetomidine (2-5 mcg kg-1) and methadone (0.2-0.5 mg kg-1) intramuscularly. General anesthesia was induced with propofol and maintained with an inhalant anesthetic agent. Dogs were randomized into group S (saline 0.1 mL kg-1, intravenously) or group O (ondansetron 0.2 mg kg-1, intravenously). Plasma and serum were collected before premedication and 3 hours postextubation to measure arginine vasopressin (AVP) and cortisol concentrations. Nausea scoring occurred before and 10 minutes after premedication, immediately after extubation, and at 1, 2 and 3 hours postextubation. Data were analyzed by mixed and split-plot anova with Bonferroni adjustment for the number of group comparisons. Significance was set at p < 0.05. RESULTS: Nausea scores increased over time at 1 (p = 0.01) and 2 (p < 0.001) hours postextubation in both groups compared with before premedication. Median nausea score (0-100 mm) for groups S and O before premedication were 2.5 and 0.5 mm, respectively. At 1 and 2 hours postextubation, group S scored 7.5 and 4.0 mm and group O scored 6.0 and 5.0 mm, respectively. No significant differences in nausea scores within or between groups were observed before premedication and 3 hours postextubation. Cortisol concentrations increased significantly 3 hours postextubation in both groups (p < 0.001) compared with before premedication, with no differences between groups. AVP concentrations showed no significant differences within or between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Preoperative intravenous administration of ondansetron (0.2 mg kg-1) did not impact postoperative nausea after laparoscopic gastropexy and castration. Investigation of higher doses of ondansetron on the incidence of postoperative nausea and vomiting in dogs after surgery is warranted.

Post-operative nausea and vomiting (PONV) observed in a clinical study designed to assess the analgesic effects of intravenous and subcutaneous methadone in dogs.

Opioids are a key component of multimodal analgesia. Methadone is licensed in Europe for IV, IM and SC use in dogs despite there being no published studies assessing the analgesic efficacy of SC administration. Our intention was to compare the analgesic effect of IV or SC methadone. Fifteen dogs presenting for stifle surgery were administered 0.4 mg/kg methadone IV followed by a randomised 0.0.4 mg/kg methadone IV or SC dose 3 h later. All dogs received ultrasound-guided sciatic and saphenous nerve blocks with bupivacaine prior to surgery. This protocol resulted in opioid adverse effects (hypersalivation, vomiting and/or regurgitation) in 5/15 dogs (33%). Thus, in consultation with the ethical review committee, an otherwise identical protocol using a revised 0.2 mg/kg methadone dose was implemented. In the next three dogs studied, similar opioid adverse effects were found in all three dogs and the study was terminated. This paper highlights the potential for post operative nausea and vomiting (PONV), which may have been induced by methadone when used in combination with efficacious locoregional anaesthesia.

Low incidence of postoperative nausea, vomiting, regurgitation, and aspiration pneumonia in geriatric dogs receiving maropitant, famotidine, and fentanyl as part of an anesthesia protocol.

OBJECTIVE: To determine the incidence of and potential risk factors for postoperative regurgitation and vomiting (PORV), postoperative nausea and vomiting (PONV), and aspiration pneumonia in geriatric dogs using premedication with maropitant and famotidine, intraoperative fentanyl, and postoperative fentanyl as part of an anesthetic protocol. ANIMALS: 105 client-owned geriatric dogs that underwent general anesthesia for a major surgical procedure between January 2019 and March 2020. PROCEDURES: Medical records were reviewed to collect data on signalment, historical gastrointestinal signs, American Society of Anesthesiologists (ASA) score, indication for surgery, duration of anesthesia and surgery, patient position during surgery, mode of ventilation, and perioperative administration of maropitant, famotidine, anticholinergics, opioids, colloidal support, NSAID, corticosteroids, and appetite stimulants. The incidence of postoperative regurgitation, vomiting, nausea, and aspiration pneumonia was calculated, and variables were each analyzed for their association with these outcomes. RESULTS: 2 of 105 (1.9%) dogs regurgitated, 1 of 105 (1.0%) dogs developed aspiration pneumonia, 4 of 105 (3.8%) dogs exhibited nausea, and no dogs vomited. Identified possible risk factors included older age (≥ 13 years old) for postoperative regurgitation, regurgitation for postoperative aspiration pneumonia, and high ASA score (≥ 4) for both regurgitation and aspiration pneumonia. CONCLUSIONS AND CLINICAL RELEVANCE: The use of an antiemetic protocol including maropitant, famotidine, and fentanyl in geriatric dogs resulted in very low incidences of PORV, PONV, and aspiration pneumonia. Future prospective studies are warranted to further evaluate and mitigate postoperative risks.

Postoperative regurgitation in dogs after upper airway surgery to treat brachycephalic obstructive airway syndrome: 258 cases (2013-2017).

OBJECTIVE: To determine the incidence of and risk factors for regurgitation in dogs within 24 hours of surgical management of brachycephalic obstructive airway syndrome (BOAS). STUDY DESIGN: Retrospective single center study of dogs undergoing BOAS surgery over four years (2013-2017). ANIMALS: Two hundred fifty-eight client-owned dogs referred for surgical intervention for BOAS. METHODS: Electronic medical records were searched for dogs that had undergone surgery for BOAS at a UK specialist referral hospital. Data were assessed by using univariable binomial logistic regression; confounding factors were then identified in a multivariable model. RESULTS: There was an increase in the proportion of dogs that regurgitated while hospitalized preoperatively vs during the first 24 hours postoperatively, from 28 (10.9%) to 89 (34.5%), respectively (P < .0001). History of regurgitation (P = .017, odds ratio [OR] 2.539, 95% confidence interval [CI] 1.178-5.469) and age (P = .008, OR 0.712, 95% CI 0.553-0.916) were detected as risk factors for postoperative regurgitation. For every 1-year increase in age, the odds of experiencing postoperative regurgitation were reduced by 28.8%. CONCLUSION: Corrective surgery for BOAS was associated with a marked incidence of postoperative regurgitation. Younger dogs and those with a history of regurgitation were predisposed to postoperative regurgitation. CLINICAL SIGNIFICANCE: The increased frequency of regurgitation after surgical treatment of BOAS, especially in younger dogs, provides justification for counseling owners regarding this postoperative complication.

The effect of maropitant on intraoperative isoflurane requirements and postoperative nausea and vomiting in dogs: a randomized clinical trial.

OBJECTIVE: To establish if preoperative maropitant significantly reduced intraoperative isoflurane requirements and reduced clinical signs associated with postoperative nausea and vomiting (PONV) in dogs. STUDY DESIGN: Randomized clinical trial. ANIMALS: Twenty-four healthy, client-owned dogs undergoing routine ovariohysterectomy. METHODS: Premedication involved acepromazine (0.03 mg kg-1) combined with methadone (0.3 mg kg-1) intramuscularly 45 minutes before anaesthetic induction with intravenous (IV) propofol, dosed to effect. Meloxicam (0.2 mg kg-1) was administered intravenously. Dogs were randomly assigned to administration of saline (group S; 0.1 mL kg-1, n=12) or maropitant (group M; 1 mg kg-1, n=12) subcutaneously at time of premedication. Methadone (0.1 mg kg-1 IV) was repeated 4 hours later. Anaesthesia was maintained with isoflurane in oxygen, dosed to effect by an observer unaware of group allocation. The dogs were assessed hourly, starting 1 hour postoperatively, using the short form of the Glasgow Composite Pain Score (GCPS), and for ptyalism and signs attributable to PONV [score from 0 (none) to 3 (severe)] by blinded observers. Owners completed a questionnaire at the postoperative recheck. RESULTS: Overall mean±standard deviation end-tidal isoflurane percentage was lower in group M (1.19±0.26%) than group S (1.44±0.23%) (p=0.022), but was not significantly different between groups at specific noxious events (skin incision, ovarian pedicle clamp application, cervical clamp application, wound closure). Cardiorespiratory variables and postoperative GCPS were not significantly different between groups. Overall, 50% of dogs displayed signs attributable to PONV, with no difference in PONV scores between groups (p=0.198). No difference in anaesthetic recovery was noted by owners between groups. CONCLUSIONS: Maropitant reduced overall intraoperative isoflurane requirements but did not affect the incidence of PONV. CLINICAL RELEVANCE: Maropitant provided no significant benefits to dogs undergoing ovariohysterectomy with this anaesthetic and analgesic protocol, although clinically significant reductions in isoflurane requirements were noted.

Maropitant administered orally 2-2.5 h prior to morphine and dexmedetomidine reduces the incidence of emesis in cats.

Objectives The main goal of this study was to test the antiemetic effects of maropitant administered orally 2-2.5 h prior to morphine and dexmedetomidine in cats. Methods Eighty-three healthy female cats were randomized to receive maropitant (8 mg orally; n = 39) or no treatment (control; n = 44), 2-2.5 h prior to morphine 0.1 mg/kg and dexmedetomidine 20 µg/kg intramuscularly. The incidence of sialorrhea, lip licking, retching and vomiting were recorded after morphine/dexmedetomidine injection. Results There were no differences between groups in terms of age or weight. The treated group received a mean ± SD dose of maropitant of 2.9 ± 0.6 mg/kg. The incidence of sialorrhea and lip licking was no different between groups. The incidence of retching (control 36% vs maropitant 13%; P = 0.012) and emesis (control 32% vs maropitant 13%; P = 0.03) was significantly reduced in cats treated with maropitant. Conclusions and relevance Maropitant 8 mg (total dose) administered orally 2-2.5 h prior to morphine and dexmedetomidine significantly reduced, but did not eliminate, the incidences of retching and vomiting. Maropitant did not decrease the occurrence of sialorrhea and lip licking, signs that may be indicative of nausea. Maropitant might be useful for morning administration to prevent emesis in outpatient cats requiring sedation or anesthesia; however, dose regimens or interval of administration might require improvement.

Incidence of and risk factors for postoperative regurgitation and vomiting in dogs: 244 cases (2000-2012).

OBJECTIVE: To determine the incidence of and risk factors for postoperative regurgitation and vomiting (PORV) in dogs. DESIGN: Retrospective cohort study. ANIMALS: 244 client-owned dogs. PROCEDURES: Dogs referred for nonelective surgery in the first 3 months of 2000 and 2012 were included. Breed; sex; age; weight; body condition score; emergency status; food withholding status; history of vomiting or regurgitation; American Society of Anesthesiologists score; presence of diabetes or hypothyroidism; preoperative PCV and total solids concentration; anesthesia protocol; corticosteroid, opioid, neuromuscular blocking agent, and nitrous oxide usage; anesthesia time; surgery time; type of surgery; and occurrence of vomiting or regurgitation within 24 hours after recovery from anesthesia were recorded. Data were analyzed by means of the Fisher exact test, Wilcoxon rank sum test, and logistic regression. RESULTS: 30 of 244 (12.3%) dogs meeting study inclusion criteria developed PORV. There was no significant difference in the incidence of PORV between the 2000 (12/111 [10.8%]) and 2012 (18/133 [13.5%]) cohorts, although the incidence of regurgitation was higher in 2012. Univariate logistic regression identified the most significant risk factors as gastrointestinal surgery (OR, 11.15; 95% confidence interval [CI], 3.11 to 40.03), premedication without strong sedatives including either an α2-adrenoceptor agonist or acepromazine (OR, 5.36; 95% CI, 1.89 to 15.17), American Society of Anesthesiologists score of 4 (OR, 5.25; 95% CI, 1.05 to 26.15), history of vomiting or regurgitation (OR, 5.12; 95% CI, 1.83 to 14.31), emergency surgery (OR, 4.08; 95% CI, 1.29 to 12.90), neurologic surgery (OR, 3.18; 95% CI, 1.02 to 9.92), sevoflurane inhalation anesthesia (OR, 2.78; 95% CI, 1.25 to 6.13), and being sexually intact (OR, 2.37; 95% CI, 1.07 to 5.27). Multivariate analysis was not clinically useful owing to the low sensitivity and specificity of the model. CONCLUSIONS AND CLINICAL RELEVANCE: Between 2000 and 2012, there was no change in the incidence of PORV for dogs undergoing neurologic, orthopedic, and soft tissue surgical procedures; however, the proportion of dogs that regurgitated increased significantly in 2012. Preoperative antiemetic prophylaxis should be considered in dogs undergoing gastrointestinal surgery and in those in which other risk factors are present.

Effects of maropitant citrate or acepromazine on the incidence of adverse events associated with hydromorphone premedication in dogs.

BACKGROUND: Vomiting is a common complication associated with the use of hydromorphine for pre-emptive analgesia in dogs. The ideal anti-emetic protocol for prevention of this complication has not been established. HYPOTHESIS: Maropitant administered concurrently or before hydromorphone would reduce the incidence of vomiting, signs of nausea, ptyalism, and increased panting compared to administration of acepromazine or a 0.9% saline control. ANIMALS: Sixty mixed-breed female dogs scheduled for ovariohysterectomy. METHODS: Randomized, blinded, placebo-controlled experimental study. Dogs were assigned to 4 experimental groups with 15 dogs per group. All groups received 0.2 mg/kg of hydromorphone IM. Group "Control" received 0.1 mL/kg saline SC 30-45 minutes before hydromorphone, group "Marop1" received 1 mg/kg maropitant SC 30-45 minutes before hydromorphone, group "Ace" received 0.02 mg/kg IM acepromazine 30-45 minutes before hydromorphone, and group "Marop2" received 1 mg/kg SC maropitant concurrently with hydromorphone. A trained and blinded observer documented adverse events from the time hydromorphone was administered until the time dogs were induced for surgery. RESULTS: Marop1 had significantly less vomiting (0%) compared to Control (87%; P < .01) and Ace (53%; P < .01). Marop2 had significantly less vomiting (27%) compared to Control (P < .01). Marop1 had significantly greater incidence of ptyalism (73%) compared to Ace (P < .01; 20%). Ace showed significantly less panting (33%) compared to Marop2 (93%; P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: In healthy dogs, maropitant citrate administered before hydromorphone significantly decreases the incidence of vomiting in dogs but does not improve signs of nausea, ptyalism, or increased panting.