Investigating the Relationship between Anesthesia Depth Monitoring and Field Transparency in Limited Surgery Fields (Ear, Noise, and Sinus) in Moradi Hospital of Rafsanjan City in 2016: A Short Report

Operation field in surgeries like sinus endoscopy, rhinoplasty, tympanoplasty, and mastoidectomy is limited and difficult to achieve. Bleeding in the field of these surgeries can opaque operation fields and ultimately affect surgery outcome. This study aimed to evaluate the relationship between anesthesia depth and transparency of operation field in the first and second hours after limited surgery fields (ear, noise and sinus).
Material and In this descriptive study bispectral index was used for monitoring anesthesia depth in limited surgical fields. Average anesthesia depth was obtained from 91 patients during first and second hours of surgery. Field transparency was defined via equipped eye (microscope) and amount of bleeding (bleeding in suction and number of small surgical gas) in three patterns as transparent, semi -transparent and opaque filed. The data was analyzed using descriptive statistics (frequency, percent, mean and standard deviation) and chi-square test.
In this study, there was no relationship between anesthesia depth and field transparency in the first hour of the surgery (P=0.404), but this relationship in the second hour of operation was statistically significant (P=0.024). As a general result, the greatest frequency of anesthesia depth for transparent field via bispectral index was 40-50 percent in the first and second hours of surgery.
Monitoring anesthesia depth and its adjustment in the range of 40-50 percent can help to make desirable transparent field and decrease need for using hypotensive drugs in the limited operation fields.