The comparison of the effects of propofol and etomidate on patients with stress reactions during operations reveals that tracheal intubation for general anesthesia induction and throughout the operation period represents a time of intense stress stimulation. Additionally, due to strong stimulation during anesthesia, the stress response is enhanced, increasing sympathetic nervous activity, CA, and GCS secretion.
Propofol and etomidate were studied under stress conditions affecting IL-6 levels. Group P patients exhibited a lower increase in serum IL-6 content compared to Group E. At T4, during the peak secretion of IL-6 in the perioperative period, Group P's serum IL-6 levels were significantly lower than those of Group E at the same time points, inhibiting the sustained elevation of IL-6 during the stress response, showcasing propofol’s effect over etomidate.
Through animal experiments, Taniguehi found that propofol administration during sepsis could reduce endotoxin-induced IL-6 generation and decrease experimental animal mortality. Propofol can significantly inhibit the production of pro-inflammatory cytokines such as IL-6, IL-8, and TNF-Ot induced by endotoxins. It can also suppress the rise in blood pressure and enhanced sympathetic nervous system activity caused by continuous inhalation of sevoflurane, thereby improving stress induced by inhalational anesthetics [3J. In conclusion, propofol improves the synthesis and secretion of IL-6 during the stress state, alleviating the imbalance of anti-inflammatory cytokines and reducing systemic damage to vital organs from IL-6-like cytokines.
In terms of cortisol synthesis and secretion under stress states in rats, serum cortisol content in Group P patients gradually increased with extended operation and anesthesia time. Conversely, in Group E patients, the trend was opposite, with cortisol content decreasing as operation and anesthesia time progressed, continuing until 24 hours postoperatively when it gradually returned to preoperative levels, both showing statistical significance, indicating that etomidate can inhibit cortisol synthesis and secretion. Therefore, research results in Group E show consistently lower cortisol levels within the group compared to pre-anesthesia levels and are lower than those of Group P at the same moment, describing etomidate's inhibition of cortisol synthesis and secretion. Thus, in terms of inhibiting the stress response to cortisol synthesis, etomidate's effect surpasses that of propofol. Theoretically, maintaining preoperative levels should be more ideal, as both excessive stress and inhibition are inappropriate.
Etomidate differs structurally from other commonly used intravenous anesthetic drugs, being an imidazole compound with a molecular weight of 324.36KD. Etomidate inhibits cortisol synthesis mainly through reversible inhibition of the 11β-hydroxylase enzyme in the carbon chain within the fascicular zone of adrenal cortex mitochondria, which is a key enzyme in the GCS synthesis process, thus reducing cortisol synthesis. Due to this inhibition of cortisol synthesis, it is not recommended for prolonged use during operations, especially in severely traumatized patients.
In conclusion, etomidate inhibits the elevation of cortisol under stress but reducing cortisol levels during the initial and prolonged stress response may not be beneficial for cancer patients' postoperative recovery; propofol has minimal effects on serum IL-6 levels.