Outcome measures
Patients were instructed to use a visual analog scale (VAS) from 0 cm
(no pain) to 10 cm (most severe pain). VAS scores were measured at 2, 6,
12, 24, and 48 hours after continuous SAPB. The primary outcome was the
VAS score of pain while coughing at 48 hours after surgery. The blood
concentration of ropivacaine at different time points after continuous
SAPB was used as the secondary outcome.