Lizard anesthesia-a retrospective study of anesthetic protocol and monitoring quality of anesthetic episodes at a veterinary hospital over 23 years (2000-2023).

Abstract

Objective: This study's aim was to summarize the anesthetic events of lizards seen at a university hospital, identify challenges with record-keeping, and assess anesthesia-related mortality.

Methods: From October 2000 through January 2023, medical records of lizards that underwent general anesthesia were reviewed. Cases with complete anesthesia records were used to assess anesthetic parameters. Collected data included general patient details, diagnosis, procedures, premedication, induction, maintenance, monitoring, and recovery. The recorded duration of each of these periods, when documented, was reported for each patient, alongside what drug protocols were utilized and compiled to give an overarching view of trends in anesthesia at the hospital. The times were also analyzed to assess whether any drug/protocol led to more negative outcomes or prolonged anesthetic duration.

Results: A total of 104 anesthetic events were performed. Ninety-nine cases had detailed reports available for analysis. A records review identified issues that frequently resulted in poor record management and highlighted the most used anesthetic agents. For premedications, alfaxalone, butorphanol, midazolam, and hydromorphone were common. During induction, alfaxalone or propofol was the most common. For maintenance, isoflurane and sevoflurane were comparable, while alfaxalone was favored for noninhalants. Of the 99 cases analyzed, 95 recovered, 3 were euthanatized due to poor prognosis, and 1 failed to recover; the 1 that failed to recover had significant underlying disease identified.

Conclusions: The trend of maintenance alfaxalone constant rate infusions replacing inhalants is the major development. The records for anesthesia have improved over time, with the exception of anesthesia time records. It is recommended to implement an automated system that records vitals intermittently alongside implementation of an updated anesthesia sheet with areas dedicated to common research values.

Clinical relevance: General anesthesia can be reliably and safely undertaken in lizards without severe pre-existing disease. Efforts should focus on identifying preexisting disease, creating uniform systems for assessing anesthetic stages, and limiting record-keeping variance.