Randomization and Blinding
Eligible patients were randomly allocated in a 1:1 ratio to either
continuous SAPB Group L or Group H. Allocation sequence was created by a
computer-generated list. Allocation concealment was implemented by using
sequentially numbered, opaque, sealed envelopes. Block randomization was
performed with a 1:1 allocation ratio by fixed block size.
The drug concentration was assigned
by specialized staff, and the user, follow-up personnel, and patients
were not informed of the grouping. The data analysis was performed by
independent research staff who did not inform the group assignment.