Effects of dexamethasone on emesis in cats sedated with xylazine hydrochloride

Efficacy of Corticosteroid Addition to a Periarticular Cocktail Injection to Counteract Nausea and Vomiting After Total Knee Arthroplasty

BACKGROUND

Intraoperative periarticular injection of a "cocktail" of drugs is undertaken commonly in total knee arthroplasty (TKA). The addition of a corticosteroid to the periarticular injection is believed to offer greater pain relief because of its local anti-inflammatory effects, but the prevalence of postoperative nausea and vomiting (PONV) is not known. This retrospective observational study aimed to elucidate the relationship between corticosteroid addition to a periarticular cocktail injection (PCI) and PONV.

MATERIALS AND METHODS

Fifty-nine patients who underwent unilateral TKA for primary osteoarthritis were divided into two groups: corticosteroid and non-corticosteroid. The former had triamcinolone acetonide (40 mg) added to the same PCI. The primary outcome was the prevalence of nausea and vomiting within 48 hours following TKA.

RESULTS

There was no significant difference between the two groups in terms of patient demographics. The overall prevalence of PONV was 16.9%. Fewer patients in the corticosteroid group complained of PONV than in the non-corticosteroid group (6.4% vs. 58.3%; p = 0.012).

CONCLUSIONS

The addition of a corticosteroid to a PCI suppressed PONV. Our results suggested that cocktail injections may have local and systemic effects.

Retrospective evaluation of the effectiveness of xylazine for inducing emesis in cats: 48 cats (2011-2015)

OBJECTIVE

To determine the effectiveness of xylazine for the induction of emesis in cats that were suspected of ingesting potentially toxic substances or foreign objects.

DESIGN

Retrospective study.

SETTING

Private emergency and specialty referral hospital.

ANIMALS

Forty-eight client-owned cats that were administered xylazine to induce emesis for decontamination of a toxic substance or expulsion of an ingested foreign object.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The medical records of 48 cats presenting for known or suspected ingestion of foreign material that underwent decontamination with xylazine were reviewed. Signalment, material ingested, dose and route of xylazine administration, success of emesis and recovery of foreign material ingested, use of a reversal agent, and adverse effects were noted. The induction of emesis was successful in 29/48 (60%) of cats. Sedation was the most common adverse effect and was noted in 15/48 (31%) of patients.

CONCLUSIONS

Xylazine is safe and reasonably effective at inducing emesis in cats.

Evaluation of oral maropitant as an antiemetic in cats receiving morphine and dexmedetomidine

Objectives The aim of the study was to evaluate the antiemetic effects of maropitant, after oral administration, in cats receiving morphine and dexmedetomidine. Methods This prospective, blinded, randomized controlled trial involved 98 healthy female domestic shorthair cats. Cats were randomly assigned to receive maropitant PO 8 mg total (group M) administered 18 h prior to sedation with intramuscular dexmedetomidine 20 µg/kg and morphine 0.1 mg/kg, or no antiemetic treatment (group C). The occurrence of signs of nausea (sialorrhea and lip-licking), retching and emesis during the 30 mins following administration of dexmedetomidine and morphine was measured for each group. Results Two cats were excluded from the investigation. Cats in group M (n = 46) received an average of 2.5 mg/kg of maropitant PO. Compared with group C (n = 50), cats in group M had lower incidences of emesis (M: 4% vs C: 40%), retching (M: 8% vs C: 40%) and lip-licking (M: 30% vs C: 52%) (all P <0.05). The incidence of sialorrhea was not different between groups (M: 21% vs C: 22%). Conclusions and relevance Maropitant 8 mg total PO was effective in reducing morphine and dexmedetomidine-induced emesis by 10-fold, when administered as early as 18 h in advance to healthy cats. Maropitant PO could be useful for administration the evening prior to a scheduled procedure requiring sedation/anesthesia to decrease the incidence of emesis.

Mechanisms, causes, investigation and management of vomiting disorders in cats: a literature review

Vomiting is a common presenting complaint in feline practice. This article differs from previous reviews in that it is an evidence-based review of the mechanisms, causes, investigation and management of vomiting in the domestic cat. Published evidence was reviewed, and then used to make recommendations for clinical assessment, diagnosis, antiemetic drug treatment, dietary management and monitoring of cats presenting with vomiting. The strength of the evidence on which recommendations are made (and areas where evidence is lacking for cats) has been highlighted throughout.

Effects of metoclopramide on emesis in cats sedated with xylazine hydrochloride

The prophylactic anti-emetic effect of five dosages of metoclopramide (0.2, 0.4, 0.6, 0.8 and 1mg/kg, IM) was evaluated against saline solution, both injected 1h before administration of xylazine in cats. Saline was administered to cats (day 0) followed by sequentially increasing dosages of metoclopramide at 1-week intervals. After xylazine injection, all cats were carefully observed to record the frequency of emesis and the time until onset of the first emetic episode. The onset of sedation in these cats was also studied. Prior treatment with each dosage of metoclopramide significantly reduced the frequency of emetic episodes (P<0.05). Metoclopramide administration prior to xylazine injection did not alter the time until onset of the first emetic episode at any of mentioned dosages, but significantly reduced the time until onset of sedation only at the dose of 1mg/kg. Metoclopramide may be used as a prophylactic anti-emetic in cats sedated with xylazine hydrochloride.

Dexamethasone has a central antiemetic mechanism in decerebrated cats

Dexamethasone is an effective antiemetic drug, but its mechanism of action is unclear. We designed this study to investigate the direct antiemetic action of dexamethasone in the medulla of cats. By using an oscillographic vomiting model, decerebrated cats received microinjections of dexamethasone 100 nL (1 microg, n = 7; 0.1 microg, n = 7) into the bilateral nuclei tractus solitarii, which led to a significant prolongation of the latency (1 microg, 6.4 +/- 1.1 min versus 28.2 +/- 4.9 min, P < 0.05; 0.1 microg, 6.7 +/- 1.1 min versus 27.1 +/- 5.0 min, P < 0.05) of the first emetic episode and significantly decreased the frequency of emetic episodes (1 microg, 2.7 +/- 0.8 versus 0.1 +/- 0.4, P < 0.05; 0.1 microg, 2.9 +/- 0.9 versus 0.3 +/- 0.5, P < 0.05) induced by xylazine. Pretreatment with mifepristone, a glucocorticoid receptor antagonist, blocked the antiemetic effect of dexamethasone in the bilateral nuclei tractus solitarii. However, microinjection of dexamethasone into the unilateral nucleus tractus solitarius alone did not alter the latency of the first emetic episode or the frequency of emetic episodes induced by xylazine. Local application of dexamethasone into the area postrema had no effect on the latency of the first emetic episode or the frequency of emetic episodes induced by xylazine. These results suggest that dexamethasone exerts its central antiemetic action through an activation of the glucocorticoid receptors in the bilateral nuclei tractus solitarii in the medulla.