Application of α₂‐adrenergic agonists combined with anesthetics and their implication in pulmonary intravascular macrophages‐insulted pulmonary edema and hypoxemia in ruminants

Abstract

Alpha2‐adrenergic agonists have been implicated in the development of pulmonary edema (PE) and sustained hypoxemia that lead to life‐threatening pulmonary distress in ruminants, especially with sensitive and compromised animals. Recently, there is limited understanding of exact mechanism underlying pulmonary alterations associated with α2‐adrenergic agonist administration. Ruminants have a rich population of pulmonary intravascular macrophages (PIMs) in the pulmonary circulation, which may be involved in the development of pulmonary alveolo‐capillary barrier damage. Hence, the central thesis of this review is overviewing the literatures regarding the systemic use of α2‐adrenergic agonists in domestic ruminants, focusing on their pulmonary side effects, especially on the influence of PIMs on the lung. At this moment, further studies are needed to provide a clear emphasis and better understanding of the potential role of PIMs in the lung pathophysiology associated with α2‐adrenergic agonists. These preliminary studies would be potentially to develop future medications and intervention targets that may be helpful to alleviate or prevent the critical striking pulmonary effects, and thereby improving the safety of α2‐agonist application in ruminants.

Intrathecal adenosine enhances the antinociception of Xylazine in goats

“…Furthermore, XYL sedation has been reported to decrease RBC, WBC, MCV, HCT and HGB [ 36 , 44 ], which might be explained by xylazine-induced hemolysis and hemodilution caused by fluid displacement from the lumen into the blood circulation. Alpha 2 -adrenergic agonists have been suggested to activate pulmonary intravascular macrophages and stimulate a series of inflammatory events resulting in recruitment of leukocytes in the lung circulation [ 49 , 50 ]. This mechanism might be implicated in a decrease in WBC within the peripheral circulation.…”

Determination of the Minimum Infusion Rate of Alfaxalone Combined with Electroacupuncture in Goats

“…EA has been shown to substantially reduce the required dosage of anesthetics in humans [17], rats [18] and goats [19,20], by 40 to 46%, 50%, and >70%, respectively. In goats, the application of EA seems to produce safe analgesia compared to other commonly used injectable analgesics, such as alpha 2 adrenergic agonists, which are associated with pulmonary adverse effects [4].…”

“…TIVA is defined as a protocol of using an anesthetic agent as a constant rate infusion (CRI) alone or in a combination with premedication to provide hypnosis, antinociception, and reducing dosage requirements of anesthetic drugs, thus minimizing adverse effects [3]. The application of TIVA has not extensively been used in goats because of its possible complications in such species, including tympany, regurgitation, excessive salivation, and hypoxemia [4]. Therefore, there is limited information about TIVA protocols in goats.…”

Immediate Postoperative Analgesia of Nalbuphine-Ketamine Combination Compared with Ketamine Alone in Xylazine-Sedated Goats Undergoing Left Flank Laparotomy

“…In ruminants, a lower dose of xylazine is needed to induce same analgesic and sedative effects as in other domestic species, such as horses, donkeys, and dogs [ 18 ]. Additionally, a dose-dependent depression in cardiopulmonary function could be associated with xylazine administration in ruminants [ 19 ].…”