Anesthetic agents and complications in Vietnamese potbellied pigs: 27 cases (1999-2006)

Miniature Companion Pig Sedation and Anesthesia

With their increase in popularity in North America as pets, miniature companion pigs are in need of veterinary professionals familiar with sedation and anesthesia for the species. This article provides a review of the agents used for sedation, premedication, induction, and maintenance of anesthesia for miniature companion pigs. This review also covers species-specific anatomic and physiologic factors of miniature companion pigs with respect to administration of anesthetics, endotracheal intubation, anesthetic maintenance, and common complications so that the reader can make an informed anesthetic plan for the species.

The ASA Physical Status Classification: What Is the Evidence for Recommending Its Use in Veterinary Anesthesia?-A Systematic Review

Background: The effectiveness of the American Society of Anesthesiologists (ASA) Physical Status (PS) classification to identify the animals at a greater risk of anesthesia-related death and complications is controversial. In this systematic review, we aimed to analyze studies associating the ASA PS scores with the outcome of anesthesia and to verify whether there was any evidence for recommending the use of the ASA PS in veterinary patients.

Methods: Research articles found through a systematic literature search were assessed for eligibility, and data were extracted and analyzed using random-effects analysis.

Results: A total of 15 observational prospective and retrospective studies including 258,298 dogs, cats, rabbits, and pigs were included. The analysis found consistency between the studies showing that dogs, cats and rabbits with an ASA-PS ≥III had 3.26 times (95% CI = 3.04–3.49), 4.83 times (95% CI = 3.10–7.53), and 11.31 times (95% CI = 2.70–47.39), respectively, the risk of anesthesia-related death within 24 h (dogs) and 72 h (cats and rabbits) after anesthesia compared with those with an ASA PS <III. In addition, the analysis showed that dogs and cats with ASA PS ≥III had 2.34 times the risk of developing severe hypothermia during anesthesia (95% CI = 1.82–3.01).

Conclusions: The simple and practical ASA PS was shown to be a valuable prognostic tool and can be recommended to identify an increased risk of anesthetic mortality until 24–72 h after anesthesia, and a greater risk of development severe intraoperative hypothermia.

Colorectal and cardiovascular effects of [Lys5,MeLeu9,Nle10]-NKA(4-10) in anesthetized macaques

The effects of the tachykinin NK2 receptor agonist LMN-NKA ([Lys⁵,MeLeu⁹,Nle¹⁰]-NKA_(4-10)) on colorectal and arterial blood pressure were examined in anesthetized macaques. Intravenous (IV) administration of 1-100 μg/kg caused dose-related increases in colorectal pressure up to 120 mmHg above baseline, and area under the curve (AUC) up to 24,987 mmHg*s. This was accompanied at all doses by transient hypotension, with up to 26% reduction in mean arterial pressure (MAP) from baseline. Hypotension, but not the increase in colorectal pressure, was inhibited by a 10-min pretreatment with the NK1 receptor antagonist CP-99,994. In a pilot experiment using subcutaneous (SC) injection, a similar dose range of LMN-NKA (3-100 μg/kg) again appeared to increase colorectal pressure with a similar AUC (up to 18,546 mmHg*s) to that seen after IV injection, but lower peak amplitude (up to 49 mmHg). Unlike the effects of IV injection, hypotension was only present after the highest SC dose (100 μg/kg) in one of two animals. Pharmacokinetic analysis revealed markedly lower plasma exposures after SC compared with IV administration. Cmax was 39.6 versus 1070 ng/mL, and AUC_inf was 627 versus 2090 ng/mL*min, respectively. These findings are consistent with previous observations in anesthetized dogs and indicate that the prokinetic effects of LMN-NKA may be achieved without hypotension using a route of administration that avoids unnecessarily high plasma exposures.

Development and refinement of a technique for short-term intravascular auricular vein catheter placement in mature sows

Intravenous drug administration in adult swine is difficult to perform due to inaccessible superficial veins and thick subcutaneous fat layers. However, successful intravenous drug administration is critical for many biomedical applications including pharmacokinetic studies as extravascular drug administration can influence the drug’s absorption and elimination rate. The purpose of this study was to develop and refine an effective technique for indwelling auricular vein catheter placement in the conscious mature sow. We developed a protocol using a topical anesthetic cream and minimal physical restraint to place indwelling catheters in the auricular vein of six multiparous sows. This method was quick (3 min 20 s ± 8 s [mean ± SE per catheter]), effective (11/12 catheters successfully placed) and reliable, allowing a large drug volume (20–22 mL) to be administrated successfully during the trial without relying on prolonged restraint or general anesthesia of the sow.

Pharmacokinetics of flunixin meglumine in mature swine after intravenous, intramuscular and oral administration

Background

The purpose of this study was to determine intravenous (IV), intramuscular (IM) and oral (PO) FM PK in mature swine. Appropriate pain management for lameness in swine is a critical control point for veterinarians and producers, but science-based guidance on optimal housing, management and treatment of lameness is deficient. Six mature swine (121–168 kg) were administered an IV, IM, or PO dose of flunixin meglumine at a target dose of 2.2 mg/kg in a cross-over design with a 10 day washout period between treatments. Plasma samples collected up to 48 hours post-administration were analyzed by high pressure liquid chromatography and mass spectrometry (HPLC-MS) followed by non-compartmental pharmacokinetic analysis.

Results

No adverse effects were observed with flunixin meglumine administration for all routes. Flunixin meglumine was administered at an actual mean dose of 2.21 mg/kg (range: 2.05-2.48 mg/kg) IV, IM and PO. A mean peak plasma concentration (C_MAX) for IM and PO administration was 3748 ng/ml (range: 2749–6004 ng/ml) and 946 ng/ml (range: 554–1593 ng/ml), respectively. T_MAX was recorded at 1.00 hour (range: 0.50-2.00 hours) and 0.61 hours (range: 0.17-2.00 hours) after PO and IM administration. Half-life (T ½ λ_z) for IV, IM and PO administration was 6.29 hours (range: 4.84-8.34 hours), 7.49 hours (range: 5.55-12.98 hours) and 7.08 hours (range: 5.29-9.15 hours) respectively. In comparison, bioavailability (F) for PO administration was 22% (range: 11-44%) compared to IM F at 76% (range: 54-92%).

Conclusions

The results of the present study suggest that FM oral administration is not the most effective administration route for mature swine when compared to IV and IM. Lower F and Cmax of PO-FM in comparison to IM-FM suggest that PO-FM is less likely to be an effective therapeutic administration route.