Toe skin temperature as a guide to epidural anaesthesia dosing

Area of Science:

• Anesthesiology
• Surgical Monitoring

Background:

• Epidural anesthesia is commonly used for mastectomy procedures.
• Determining the optimal timing for additional anesthetic doses is crucial for patient comfort and surgical success.
• Current methods for monitoring anesthetic levels can be indirect or invasive.

Purpose of the Study:

• To evaluate the utility of big toe skin temperature as a monitor for epidural anesthesia duration in mastectomy patients.
• To establish a correlation between skin temperature changes and the need for additional anesthetic administration.
• To assess the reliability of skin temperature monitoring in predicting the timing of the first supplemental epidural dose.

Main Methods:

• Fifty patients undergoing mastectomy received epidural anesthesia with lidocaine and epinephrine.
• Big toe skin temperature and systolic arterial blood pressure (ABP) were monitored.
• Additional anesthetic doses were administered when skin temperature decreased by 0.3°C without a significant ABP increase (>20%).

Main Results:

• Toe skin temperature monitoring was effective in 78% of patients (39 out of 50).
• The mean intervals between initial and subsequent anesthetic injections were 96.5, 69.7, and 50.1 minutes.
• Skin temperature decrease reliably indicated the need for redosing, while ABP increase without temperature change suggested monitor ineffectiveness.

Conclusions:

• Big toe skin temperature serves as a practical and useful monitor for guiding additional epidural anesthetic administration.
• This non-invasive method is particularly valuable when epidural anesthesia is administered at upper thoracic levels.
• Skin temperature monitoring can improve the management of epidural anesthesia by providing objective data for redosing decisions.