Eligibility Criteria
To determine study eligibility, we used the following PICOS criteria: cardiac surgical patients (age >18 y) requiring median sternotomy (P), single-shot ultrasound-guided RA technique (I), placebo or no intervention (C), 24-h postoperative opioid consumption, pain after extubation 12 h, pain after extubation 24 h, postoperative nausea and vomiting (PONV), extubation time, intensive care unit discharge time, hospital length of stay (LOS) (O), and randomized controlled trials (RCTs) (S).
Studies were excluded if they met the following additional criteria: 1) the use of RA techniques in combination, 2) the use of continuous RA techniques, 3) minimally invasive cardiac surgery, and 4) off-pump cardiac surgery.