ACID–BASE BALANCE AND GAS EXCHANGE IN PATIENTS WITH DRUG-RESISTANT EPILEPSY DURING THE PERIOPERATIVE PERIOD: THE ROLE OF CLINICAL CHARACTERISTICS AND THERAPY

Abstract

Objective: To evaluate the impact of epilepsy duration and type of antiepileptic therapy on acid–base balance and
oxygenation parameters in patients with pharmacoresistant focal epilepsy during the perioperative period.
Methods: A retrospective cohort study included 93 adult patients who underwent neurosurgical treatment for
pharmacoresistant focal epilepsy between 2019 and 2024. Demographic data, intraoperative fluid therapy, acid–base
balance, gas exchange, and respiratory outcomes were analyzed. Patients were stratified by epilepsy duration (≤15 years,
>15 years) and therapy type (monotherapy, polytherapy).
Results: Neither epilepsy duration nor therapy type significantly affected acid–base balance or gas exchange. Patients
with epilepsy duration >15 years required longer mechanical ventilation. Polytherapy was associated with a higher positive
fluid balance (p=0.02). Early postoperative seizures occurred in 9.7% of patients and were linked to increased pH and
HCO₃⁻ without gas exchange deterioration.
Conclusions: Epilepsy duration and type of antiepileptic therapy did not significantly influence acid–base balance or
oxygenation in the early postoperative period but were related to fluid balance and ventilation duration. A personalized
approach to perioperative fluid and respiratory management is recommended.