Changes in percutaneous oxygen tension induced by spinal anesthesia

Area of Science:

• Anesthesiology
• Neurosurgery
• Medical Monitoring

Background:

• Assessing spinal anesthesia levels can be challenging, particularly in patients with dementia.
• Spinal anesthesia may cause peripheral oxygen tension to increase due to vasodilatation from sympathetic block.

Purpose of the Study:

• To evaluate the utility of percutaneous oxygen tension (tcPO(2)) changes for verifying spinal anesthesia levels.
• To determine if tcPO(2) can objectively differentiate anesthetized and non-anesthetized regions.

Main Methods:

• Thirty patients (40-70 years) undergoing lower extremity surgery under spinal anesthesia were studied.
• Spinal anesthesia was induced with tetracaine; anesthesia levels were confirmed using a cold test (T3-T11).
• TcPO(2) was measured at T3 and T11 levels before and after anesthesia, and during oxygen administration.

Main Results:

• TcPO(2) significantly increased at the T11 level post-spinal anesthesia.
• Oxygen administration elevated tcPO(2) at both T3 and T11 levels.
• The increase in tcPO(2) following oxygen was more pronounced at T3 than T11.

Conclusions:

• TcPO(2) measurement shows potential as an objective tool for assessing spinal anesthesia depth.
• This method may aid in distinguishing between anesthetized and non-anesthetized areas during spinal anesthesia.