Table 5.

Adverse events.

Adverse events	PCAIB group	PCA group	p
Dizziness	2 (2%)	7 (15%)	0.005∗
Nausea	3 (3%)	5 (10%)	0.110
Vomiting	2 (2%)	3 (6%)	0.327
Respiratory depression	0	0	—
Skin itching	0	0	—
Urine retention	0	0	—
Muscle weakness	0	—	—
Numbness	3 (3%)	—	—
Hemidiaphragmatic paresis	0	—
Local hematoma or infection	0	—	—

Categorical variables as number of events (n); Chi-square test was used, events less than 5 were compared with Fisher's exact test, and ^∗statistical significance was considered when p < 0.05.

PCAIB: patients with interscalene block in combination with intravenous patient-controlled analgesia.

PCA: patients receiving intravenous patient-controlled analgesia alone without interscalene block.