Discussion
extraocular muscle
AQUEOUS HUMOR
IOP refers to the pressure exerted by the ocular contents on the walls of the eyeball, typically ranging from 11 to 21 mmHg. Various factors influence IOP, including demographic factors such as age and gender and individual physiological factors such as aqueous humor circulation, extraocular muscle tension, and respiratory circulation [Pediatric ophthalmic surgery often requires general anesthesia, and anesthesiologists must ensure the stability of IOP during the induction period to prevent sudden fluctuations. Commonly used drugs for intravenous induction of anesthesia in children include propofol, opioids, and esketamine. In current clinical settings, the combination of propofol and sufentanil is frequently employed, which has been shown to significantly reduce IOP [The pharmacological mechanism of esketamine, similar to ketamine, involves the stimulation of sympathetic nerves by blocking N-methyl-D-aspartate (NMDA) receptors, leading to increased aqueous humor production and extraocular muscle tension, as well as restricted aqueous humor outflow, ultimately resulting in elevated IOP [There are benefits when using esketamine in combination with other anesthetic drugs. Esketamine has a certain sedative and analgesic effect, which can reduce the dosage of other drugs (e.g., opioids, propofol, etc.) in anesthesia induction [Limited studies have investigated the effect of esketamine in combination with other commonly used anesthetics on IOP. Therefore, this study aimed to explore the effect of different doses of esketamine combined with propofol and sufentanil on IOP during the induction of general anesthesia, which appears to be innovative and practical.The study results revealed that the EH group had significantly higher IOP than the other two groups, indicating that esketamine could elevate IOP. However, the IOP of all three groups after induction was lower than at baseline, suggesting that the IOP-reducing effect of propofol and sufentanil was stronger than the IOP-elevating effect of esketamine. Therefore, it is believed that administering esketamine at a dosage not exceeding 0.5 mg/kg, in combination with propofol and sufentanil, does not elevate IOP compared to the pre-induction status. Additionally, the study revealed that the impact of esketamine on IOP was dose-dependent, consistent with the findings of Ausinsch’s study [Using a laryngeal mask airway (LMA) during induction in this study helped reduce the elevation of IOP caused by tracheal intubation in ophthalmic surgery [Prior studies have identified BP as one of the important factors of IOP [This study made several improvements based on previous research. Sobczak et al. [Some limitations present in this study should be acknowledged. Firstly, we did not use bispectral index (BIS) monitoring to assess the depth of anesthesia, as the use of multiple drugs, especially esketamine, may affect BIS readings [