Impact of adding opioids to paravertebral blocks in breast cancer surgery patients: A systematic review and meta-analysis

Table 1 Details of included studies

Ref.	Yr	Study location	Surgery type	Sample size		Age (yr)	Common protocol for PVB	Opioid added to PVB in intervention group)	Drug added to PVB in control group	Post-operative analgesics used
				Study	Control
Mostafa et al[21]	2018	Egypt	MRM or breast conservation surgery with axillary node dissection	20	20	18-78	Nalbuphine 10 mg	PVB at the level of T4 with bupivacaine 0.5% 0.3 mL/kg	No drug	Tramadol as PCA
Pushparajan et al[22]	2017	India	MRM	20	20	18-60	Fentanyl 2 μg/mL at 0.1 mL/kg/h for 24 h	Continuous PVB at the level of T4 with 0.2% ropivacaine for 24 h	No drug	Fentanyl as PCA. Paracetamol or tramadol or fentanyl for breakthrough pain
Morsy et al[23]	2017	Egypt	MRM	15	15	NR	Morphine 2 mg	PVB at the level of T3 with 20 mL of bupivacaine 0.25%	No drug	Meperidine for breakthrough pain
Bhuvaneshwari et al[24]	2012	India	Total mastectomy and axillary lymph node dissection	12	12	Study: 49.1 ± 7.1; Control: 50.7 ± 11	Fentanyl 2 μg/mL	PVB at the level of T3 with bupivacaine 0.25% and epinephrine 5 μg/mL	No drug	Morphine for breakthrough pain
Omar et al[25]	2011	Egypt	MRM	19	20	Study: 47.5 ± 9.3; Control: 49.3 ± 10.5	Tramadol 1.5 mg/kg (maximum of 150 mg)	PVB at the level of T1 (1/3rd of the dose) and T4 (2/3rd of the dose) with bupivacaine 0.5% 2 mg/kg	No drug	Fentanyl as PCA. Paracetamol 1 g thrice daily and ibuprofen 400-600 mg thrice daily
Burlacu et al[26]	2006	Ireland	Wide local excisions (at least one breast quadrant), mastectomies, and mastectomies with reconstruction	13	13	Study: 54 ± NR; Control: 51 ± NR	Fentanyl 50 μg with bolus followed by 4 μg/mL infusion	Continuous PVB at the level of T3 with initial bolus of 19 mL levobupivacaine 0.25% followed by continuous infusion of 0.1% solution for 24 h	Saline	Morphine as PCA

PVB: Paravertebral block; MRM: Modified radical mastectomy; PCA: Patient controlled analgesia; T: Thoracic vertebral level.