Comparison of the Effects of Opioid-Based Anesthesia Versus Opioid-Free Anesthesia on Postoperative Cognitive Dysfunction in Transsphenoidal Pituitary Surgeries

Postoperative cognitive dysfunction refers to disorders affecting orientation, attention, perception, consciousness, and judgment that develop after surgery. It is a common postoperative complication and a serious threat to the quality of life, particularly for elderly patients. Strategies to prevent surgery and anesthesia-induced cognitive dysfunction are being investigated, considering the choice and depth of anesthesia, perioperative anesthetic and other drugs, and surgical strategy.

Opioid-free anesthesia involves the administration of intraoperative anesthesia without the use of intraoperative opioids. Currently available non-opioid drugs include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) (ketorolac, ibuprofen, celecoxib), alpha-2 agonists (dexmedetomidine, clonidine, tizanidine), and N-methyl-D-aspartate (NMDA) receptor antagonists (ketamine). Dexmedetomidine (DEX) is an alpha-2 adrenoceptor agonist with a selectivity ratio of 1600:1 (α2:α1). It promotes sedation by acting on the α2 receptors of the locus coeruleus and produces analgesia by reducing the release of substance P in the spinal cord dorsal horn.

The goals of opioid use during anesthesia are to reduce the need for hypnotic agents and provide effective analgesia. However, the potential side effects of opioids can be described as having a threefold negative impact, ranging from sudden adverse reactions in the patient to the long-term sequelae of chronic effects.

In this study, the patients undergoing pituitary surgery in our clinic have examined in two groups. In the first group, anesthesia maintenance was provided with remifentanil and propofol infusion. In the second group, anesthesia maintenance was provided with dexmedetomidine and propofol infusion. Demographic data, vital signs during the operation, wake-up time, extubation time, and drug consumption amounts were recorded. The mini-mental test was applied preoperatively, 24 hours postoperatively, and 3 weeks postoperatively to examine whether there is a difference in cognitive dysfunction between the two groups.