Evaluation of pimobendan effect on sublingual microcirculation in an experimental pharmacology induced hypotension porcine model.

New therapeutic approaches are needed to simultaneously resuscitate macro- and microcirculation during circulatory shock. The aims of this study were to explore the microcirculatory and macrocirculatory effects of pimobendan, an inodilator with dual phosphodiesterase 3 inhibitor and calcium-sensitizing effects, in an experimental porcine model of pharmacologically induced hypotension associating vasoplegia and decreased cardiac output. Eight piglets were anesthetized and monitored for their hemodynamic parameters. Hypotension was induced by sevoflurane overdose until a mean arterial pressure between 40 and 45 mmHg was reached. A bolus of pimobendan (0.25 mg/kg) was administered intravenously thereafter. Sublingual microcirculation was evaluated using a Sidestream Dark Field imaging device. Hemodynamic and microcirculatory parameters were recorded at the baseline period (A), immediately before pimobendan administration (B) and after pimobendan administration (C). Induction of hypotension was associated with a decreased cardiac index and microcirculation alterations. Pimobendan administration was associated with a significant increase in heart rate, cardiac index and decrease in systemic vascular resistance index. A significant increase in proportion of perfused vessels for all vessels (+8%, [2; 14], P = 0.01) and small vessels (+8% [1; 14], P = 0.03), in microvascular flow index (+0.31 AU, [0.04; 0,58], P = 0.03) were noticed, as well as a decrease in heterogeneity index (-0.34 [-0.66; -0.03], P = 0.04) and De Backer score for all vessels (-1.04, [-1.82; -0.25], P = 0.02). In conclusion, in a simple model of pharmacologically induced hypotension, pimobendan was associated with an improvement in several microcirculatory parameters.

Methadone or Butorphanol as Pre-Anaesthetic Agents Combined with Romifidine in Horses Undergoing Elective Surgery: Qualitative Assessment of Sedation and Induction.

While butorphanol is the most commonly used opioid in horses, methadone is not licensed in most countries. Our aim was to compare the effects of both drugs, combined with romifidine, regarding the quality of sedation and induction in horses undergoing elective surgery. Results indicate the suitability of both methadone and butorphanol in this patient population. Animals were scored 10 min after intravenous injection of sedatives. Despite lower overall sedation (OS) score in horses receiving methadone (p = 0.002), the quality and time of induction and intubation remained unchanged. None of the horses had the lowest OS score (no sedation), nor the highest score for ataxia (horse falling). Methadone induced a tendency for minor noise reaction yet minor head lowering scores, the latter being probably the most influencing parameter when scoring OS. Measured physiological parameters decreased in both groups, with greater bradycardia recorded after methadone (p = 0.017), including a higher incidence of atrioventricular blocks that resolved during general anaesthesia. The quality of induction was good-excellent in most of the animals. While comparisons between the degree of antinociception were beyond the scope of this study, analgesic potency might influence the choice when considering opioids as pre-anaesthetic drugs in combination with romifidine before surgery in equines.

Risk Factors of Anesthesia-Related Mortality and Morbidity in One Equine Hospital: A Retrospective Study on 1,161 Cases Undergoing Elective or Emergency Surgeries.

A retrospective analysis was performed to determine mortality and morbidity rates for elective and emergency cases in an equine university teaching hospital. It investigated the effect of horse-, anesthetic-, timing, and clinician experience-related variables on anesthetic complications. In total, 1,161 horses undergoing general anesthesia between January 2012 and December 2016 were included in the study. Patient information and details of the anesthetic, recovery period and immediate complications were retrieved from an archival database. Statistical analysis of qualitative and quantitative factors affecting anesthetic complications was performed using an univariable and multivariable ordinal logistic regression. Odds ratio of variables primarily affecting mortality and complications were calculated. Statistical significance was set at p < 0.05. General anesthesia-related global mortality rate was 1.4% (95% CI [7.1-10.4]) but was only 0.96% (95% CI [0.44-1.82]) for non-colic cases. The complication rate was 17.5% (n = 204; 95% CI [15.2-20.0]) of which 46.9% [39.4-54.5] were neuromuscular, 22.6% [16.7-29.5] were respiratory, 15.8% [10.8-22.0] were systemic, 13.6% [8.9-19.5] were cardiovascular, 1.1% [0.1-4.0] were other complications. Ninety two percent of complications occurred during recovery. Major risk factors for mortality and complications included high weight, surgeon experience, increasing age, high ASA score, long duration of anesthesia, quality of induction, lateral recumbency, orthopedic surgery, and hypotension. In these models, colic surgery did not influence the rate of any complications.