Data from: Risk factors for burst suppression ratio during general anesthesia: A retrospective monocenter study

Burst suppression (BS), characterized by alternating high-voltage bursts
and suppressed EEG activity, is common during deep anesthesia and may be
associated with adverse outcomes. The bispectral index (BIS) monitor
calculates a suppression ratio (SR) to quantify BS, but risk factors for
high SR remain underexplored, particularly by sex. The main purpose of the
present study was to identify preoperative and intraoperative factors
associated with high SR in patients undergoing general anesthesia with
tracheal intubation, stratified by sex. Retrospective, single-center
cohort study of adult patients undergoing general anesthesia for scheduled
non-cardiac surgery between October 2014 and December 2019. SR was
calculated as the area under the curve (AUC) of SR values >0, with
the highest quartile defining the High SR group. Logistic regression
models identified risk factors using stepwise variable selection. Our
study examined 10,827 patients. SR occurred in 71.5% of patients, more
frequently in men (76.2%) than women (66.4%; p<0.001). High SR (SR
>124.5 for men, >67 for women) was associated with age
>46 years and propofol maintenance in both sexes. Men had
additional risks from higher ASA scores, ATC Blood/Nervous System
medications, rocuronium, or no neuromuscular blocker. Women showed risks
from neurosurgery, ENT, thoracic, or vascular surgeries, and remifentanil
use. Age and propofol are key risk factors for high SR, with sex-specific
factors suggesting tailored monitoring strategies. These findings
underscore the need for refined BIS-guided anesthesia protocols.