Epilepsy is a prevalent neurological condition [1]. It poses significant risks during surgery [2]. Interactions between anesthetic agents and antiepileptic drugs (AEDs) can induce drug-drug interactions, as well as perioperative seizures, that can threaten the outcome of the procedure and produce long-term effects [1]. Accordingly, anesthesiologists working with patients who suffer from seizures must consider several factors, including choice of anesthetic, perioperative monitoring, and recourses in the event of a perioperative seizure.

Although drug-drug interactions are risky, epileptic patients should continue taking their antiepileptic medications up to as close to surgery as possible [3]. Therefore, choosing an appropriate anesthetic for use while operating on patients who experience seizures is crucial. Some anesthetic agents, such as certain opioids and ketamine, can promote convulsive activity, and thus should be avoided [4]. Conversely, other anesthetic agents can reduce a patient’s chance of experiencing a seizure from surgery, and therefore may promote better outcomes [4]. Anticonvulsant agents include isoflurane and halothane, both of which are notable for their potent effects [3]. Meanwhile, other anesthetic agents have neither anticonvulsant nor proconvulsant effects [4]. Accordingly, they may be appropriate for use depending on the likelihood of adverse drug-drug interactions between them and AEDs [4]. Dexmedetomidine belongs to this latter category of agents [4].

During surgery, practitioners should closely monitor patients to ensure that adverse events are detected as early as possible. Generally, medical teams should keep close watch over patients’ end-tidal carbon dioxide, urine output, temperature, blood pressure, and blood oxygen levels [4]. Electrocardiography (ECG) is also a recommended form of monitoring [4]. If physicians expect significant blood loss to occur during the procedure, central venous pressure monitoring may be appropriate [4].

If a patient experiences a perioperative seizure, primary resuscitative measures are essential [4]. The risks associated with perioperative seizure are numerous: cerebral and systemic acidosis, elevated intracranial pressure, cerebral edema, compromised airway patency and ventilation, and abrupt movement [2]. However, the primary objective should be to ensure that the patient does not develop status epilepticus (SE), a serious condition with 43% long-term mortality [2]. Benzodiazepines are a primary recourse for preventing convulsive SE [2]. In the event of perioperative seizure, medical teams should also manage the patient’s airway well while administering 100% oxygen and securing intravenous access [4]. Furthermore, the team should closely monitor the patient’s ECG, SPO2 levels, and vital signs [4]. One important fact to note is that epileptic patients may experience psychogenic non-epileptic attacks during the operation, which should be distinguished from perioperative seizures [5].

One last set of considerations concerns pediatric patients [6]. Young patients pose additional risks to perioperative teams because of their brains have a lower seizure threshold than adults [6]. This is because children have comparatively lower autoregulatory reserves and mean arterial blood pressure, which increases their likelihood of experiencing hemodynamic instability during neurosurgery [6]. Regardless, to promote the best outcomes for pediatric patients, physicians should follow many of the same guidelines that apply to adult patients. These include maximizing the timeliness of emergence from anesthesia and ensuring that patients are immobilized during surgery, with careful monitoring [6]. For pediatric neurosurgery patients, researchers emphasize the importance of neurological examination after emergence [6].

References 

[1] M. Jaber et al., “Anesthesia considerations for patients with epilepsy: Findings of a qualitative study in the Palestinian practice,” Epilepsy & Behavior, vol. 123, p. 410-417, October 2021. [Online]. Available: https://doi.org/10.1016/j.yebeh.2021.108278. 

[2] A. Zuleta-Alarcon et al., “Anesthesia-Related Perioperative Seizures: Pathophysiology, Predisposing Factors and Practical Recommendations,” Anesthesia and Analgesia, vol. 2, no. 4, p. 1-9, May 2014. [Online]. Available: https://doi.org/10.4103/0259-1162.113978. 

[3] M. S. Dhallu et al., “Perioperative Management of Neurological Conditions,” Health Service Insights, vol. 10, p. 1-8, June 2017. [Online]. Available: https://doi.org/10.1177/1178632917711942. 

[4] S. J. S. Bajwa and R. Jindal, “Epilepsy and nonepilepsy surgery: Recent advancements in anesthesia management,” Anesthesia Essays and Researchers, vol. 7, no. 1, p. 10-17, November 2017. [Online]. Available: https://doi.org/10.4103/0259-1162.113978. 

[5] A. Perks, S. Cheema, and R. Mohanraj, “Anaesthesia and epilepsy,” British Journal of Anaesthesia, vol. 108, no. 4, p. 562-571, April 2012. [Online]. Available: https://doi.org/10.1093/bja/aes027. 

[6] B. J. Wong, R. Agarwal, and M. I. Chen, “Anesthesia for the Pediatric Patient With Epilepsy and Minimally Invasive Surgery for Epilepsy,” Current Anesthesiology Reports, vol. 11, p. 233-242, August 2021. [Online]. Available: https://doi.org/10.1007/s40140-021-00457-2.