Anesthetic effects of isoflurane and propofol on cerebrospinal fluid biochemical markers in healthy dogs.

Background: The study of brain energy metabolism (BEM) markers in the cerebrospinal fluid (CSF) is a potential diagnostic and prognostic tool for many central nervous system (CNS) diseases. To date, in veterinary medicine, few studies are reporting physiologic ranges for some BEM markers. Recently, the influence of anesthetic drugs on BEM markers has been described in mice; subsequently, the study of CSF-BEM markers has gained increasing attention.

Objectives: The effects of anesthetic agents on BEM are poorly understood in dogs. The aim of this study was to evaluate the influence of propofol, isoflurane, and the duration of anesthesia on CSF-BEM markers in dogs.

Methods: Nine dogs were anesthetized at two different periods, one month apart. In the first period, the dogs were intravenously anesthetized with propofol (PRO-group), and in the second period, the dogs received inhalant anesthesia with isoflurane (ISO-group). In both cases, CSF and blood were collected 15 minutes (T0) and 3 hours after induction (T3) and analyzed for lactate, pyruvate, glucose, creatine kinase, glutamate, and electrolyte concentrations.

Results: CSF lactate (CSF-L) showed variation depending on the anesthetic agent and time, being significantly lower after 3 hours of anesthesia in the PRO-group and showing a trend to increase over time in the ISO-group. No changes were detected over time or between groups in CSF glutamate, glucose, or electrolytes.

Conclusions: The results of this study support that the anesthetic drug choice and length of the general anesthesia should be considered when CSF-L analyses are interpreted in dogs.