Influence of Different Sevoflurane Concentrations on Postoperative Cognitive Function in Aged Rats

Area of Science:

• Anesthesiology
• Neuroscience
• Gerontology

Background:

• Postoperative cognitive dysfunction is linked to neuroinflammation.
• Sevoflurane is known to suppress surgery-induced inflammation.

Purpose of the Study:

• To investigate the hypothesis that low concentrations of sevoflurane would cause more impaired postoperative cognitive function than high concentrations.
• To evaluate the impact of different sevoflurane concentrations on neuroinflammation and cognitive function in aged rats.

Main Methods:

• Aged male Sprague-Dawley rats were divided into control, 2% sevoflurane, and 4% sevoflurane groups.
• Rats underwent femoral fracture surgery under sevoflurane anesthesia.
• Cognitive function was assessed using the Morris water maze (MWM) test, and hippocampal CA1 cells were evaluated histopathologically.

Main Results:

• The 2% sevoflurane group exhibited prolonged swimming latency in the MWM compared to the 4% sevoflurane and control groups.
• Fewer intact CA1 hippocampal cells were observed in the 2% sevoflurane group compared to the other groups.

Conclusions:

• Low-concentration sevoflurane anesthesia was associated with greater spatial cognitive impairment and reduced intact CA1 hippocampal neurons in aged rats.
• These findings suggest that sevoflurane concentration significantly influences postoperative cognitive outcomes and hippocampal health in aged populations.