Maintenance of equine anaesthesia over the last 50 years: Controlled inhalation of volatile anaesthetics and pulmonary ventilation.

This research paper explores the evolution and advancements in the field of equine anaesthesia, particularly inhalational anaesthesia and controlled ventilation, over the past 50 years. It discusses the journey from the widespread use of halothane as an inhalation agent to the introduction and effects of newer agents such as isoflurane and sevoflurane. The paper also examines the effects of anaesthesia on lung functionality and the common issues of gas exchange and ventilation during anaesthesia. Furthermore, it discusses the best mechanical ventilation practices for anaesthetic management and anticipates future developments in the field.

Development of Inhalational Anaesthesia

• The paper outlines the journey of anaesthesia in equine medical practice over the past half-century. During this timeline, the widely accepted practice was premedication, induction, and then maintenance through controlled inhalation.
• Halothane was the initial inhalation agent of choice due to its perceived benefits. However, further understanding of its effects led to changes in equine anaesthetic practices.
• The study discusses the transition from halothane to the use of different agents like isoflurane and sevoflurane.

Effects of New Inhalation Agents

• The study reveals a greater understanding of the effects of ‘newer’ inhalation agents, which has resulted in further changes in equine anaesthetic practice.
• Notwithstanding the unlikely introduction of new inhalation agents in the near future, the research suggests that enhancement in anaesthetic practices may still result in improved outcomes.

Understanding of Equine Lung and Effect of Anaesthesia

• The authors review the growing understanding of the anatomy and pathophysiology of the equine lung. They also highlight how anaesthesia can impact lung function.
• Particular focus is given to gas exchange and ventilation difficulties during anaesthesia, predisposed by the effects of anaesthesia on the lungs.

Optimal Mechanical Ventilation Practices

• The paper identifies the goal of achieving optimal mechanical ventilation for anaesthetic management, scrutinizing the various methods used for ventilatory support during equine anaesthesia.
• Finally, the article highlights anticipation of further developments in equipment and optimal ventilation modes in the near future.