In equine anesthesia, name two commonly used anesthetic agents and one major vital sign to monitor intraoperatively.

• A. Halothane or desflurane; propofol induction; monitor skin temperature.
• B. Isoflurane or sevoflurane; ketamine for induction; monitor heart rate only.
• C. Isoflurane or sevoflurane; propofol induction; monitor heart rate and oxygenation.
• D. Isoflurane or sevoflurane; ketamine for induction; monitor heart rate, blood pressure, and oxygenation.

Answer: (D)

Two inhalant anesthetic agents commonly used to maintain anesthesia in horses are isoflurane and sevoflurane. They provide reliable, controllable depth of anesthesia and are well tolerated in large animals, with smooth adjustments during surgery. For induction, ketamine is a typical choice because it offers analgesia and preserves cardiovascular function better than some other agents, which is important in horses where abrupt drops in blood pressure can be risky.

Monitoring intraoperative vital parameters is essential, with heart rate, blood pressure, and oxygenation being key. Heart rate helps assess the animal’s response to anesthesia and overall cardiac status. Blood pressure reflects tissue perfusion and can indicate clinically significant drops under inhalant anesthesia. Oxygenation shows whether the blood is effectively carrying oxygen to tissues, usually monitored with pulse oximetry. While other monitoring like capnography and ventilation status is also important, these three provide the most critical real-time insight into cardiovascular and respiratory adequacy during equine surgery.

Other options are less ideal because propofol induction is less commonly used in large-animal induction due to risks like apnea, and some inhalants listed are not the primary choices for routine maintenance in horses. Also, monitoring that focuses on only one parameter would miss important perfusion and oxygenation issues.