3.2. Secondary Outcomes
post-sternotomy, ESPB
Intergroup comparisons showed that, following skin incision, the NOL index was significantly lower in the ESPB compared to the control group at post-incision, pre-sternotomy, and post-sternotomy (Intragroup comparisons were performed in each group between two consecutive time points (i.e., pre-incision vs. post-incision; post-incision vs. pre-sternotomy; pre-sternotomy vs. post-sternotomy; and post-sternotomy vs. pre-CPB) (The NOL index was not significantly different between any two consecutive time points in the ESPB group. Conversely, the control group exhibited significantly different NOL index values between all the consecutive time points (For further analysis, the NOL index was treated as a categorical variable (i.e., NOL index > 25 representing an inadequate, nociceptive response to noxious stimuli vs. NOL index ≤ 25 representing an adequate, non-nociceptive response to noxious stimuli). An alluvial diagram depicts the flow of patients across the five time points exhibiting nociceptive and non-nociceptive responses (In addition, the statistical significance for intergroup comparison at each time point is shown in Compared to the controls, significantly fewer ESPB patients reached a NOL index > 25 at post-incision, pre-sternotomy, and post-sternotomy (