Table 1 Patients’ baseline characteristics, surgical, and anaesthesiologic factors in CPBS and No-CPBS groups

Patient characteristics

 Age (years)

56.2 ± 12.4

55.3 ± 12.4

53.6 ± 11.2

0.99 [0.97–1.01]

0.275

 Height (cm)

163.5 ± 6.3

163.6 ± 6.6

163.4 ± 5.3

0.99 [0.96–1.04]

0.824

 Weight (kg)

64.5 ± 12.5

55.3 ± 5.9

55.2 ± 4.8

0.10 [0.99–1.03]

0.212

 BMI (Kg/m²)

24.1 ± 4.4

23.9 ± 4.1

24.7 ± 4.9

1.04 [0.98–1.10]

0.168

 Preoperative pain

95 (30.9%)

56 (25.3%)

39 (45.3%)

1.13 [0.64–1.97]

0.686

 Chronic use of pain drugs

19 (6.2%)

9 (4.1%)

10 (11.6%)

3.10 [1.21–7.92]

0.018

 Anxiety/depression

43 (14%)

33 (14.9%)

10 (11.6%)

0.75 [0.35–1.60]

0.446

 Fibromyalgia

2 (0.7%)

1 (0.5%)

1 (1.2%)

2.59 [0.16–41.90]

0.511

 Neoadjuvant-CHT

23 (7.5%)

15 (6.8%)

8 (9.3%)

1.41 [0.58–3.45]

0.461

 Preop. hormone therapy

37 (12.1%)

28 (12.7%)

9 (10.5%)

0.81 [0.36–1.79]

0.589

 Neoadjuvant-RT

1 (0.33%)

1 (0.5%)

0 (0.0%)

–

–

 Previous ipsilateral breast surgery

108 (35.18%)

78 (35.3%)

30 (34.9%)

0.98 [0.58–1.66]

1.000

 School education

0.517

  Primary school

30 (9.77%)

24 (10.9%)

6 (7.0%)

0.79 [0.28–2.24]

  Secondary school

57 (18.57%)

40 (18.1%)

17 (19.8%)

1.35 [0.62–2.93]

  High school

145 (47.23%)

100 (45.2%)

45 (52.3%)

1.42 [0.75–2.69]

   University

75 (24.43%)

57 (25.8%)

18 (20.9%)

Ref.

Surgical factors

 Breast-conserving surgery

149 (48.5%)

110 (49.8%)

39 (45.3%)

0.84 [0.51–1.38]

0.526

 Mastectomy

91 (29.6%)

61 (27.6%)

30 (34.9%)

1.41 [0.83–2.39]

0.214

 Implant-based reconstructive surgery (tissue-expandersor prosthesis)

113 (36.8%)

81 (36.7%)

32 (37.2%)

1.02 [0.61–1.72]

0.928

  Pre-pectoral prosthesis

23 (7.5%)

17 (21.0%)

6 (18.8%)

Ref.

–

  Under-pectoral prosthesis or tissue-expander

47 (15.3%)

32 (39.5%)

15 (46.9%)

1.33 [0.44–4.05]

0.618

  Tissue-expander substitution with prosthesis

43 (14.0%)

32 (39.5%)

11 (34.4%)

0.97 [0.31–3.09]

0.964

 Axillary surgery

146 (47.6%)

95 (43.0%)

51 (59.3%)

1.93 [1.17–3.21]

0.011

  Sentinel node biopsy

99 (32.3%)

64 (29.0%)

35 (40.7%)

0.94 [0.46–1.96]

0.877

  Axillary lymph node dissection

47(15.3%)

31 (14.0%)

16 (18.6%)

 Cosmetic surgery

68 (22.2%)

48 (21.7%)

20 (23.3%)

1.09 [0.60–1.98]

0.762

 Dorsal-flap reconstructive surgery

1 (0.3%)

1 (0.5%)

0 (0.0%)

–

–

 Bilateral surgery

103 (33.6%)

70 (31.8%)

33 (38.4%)

1.33 [0.79–2.24]

0.276

 Selective pectoral nerves dissection

19 (6.2%)

12 (5.5%)

7 (8.1%)

1.53 [0.58–4.02]

0.390

Anaesthesiologic factors

 Total intravenous anaesthesia

251 (81.8%)

180 (81.4%)

71 (82.6%)

0.93 [0.48–1.78]

0.821

  Propofol

251 (81.8%)

180 (81.4%)

71 (82.6%)

1.08 [0.56–2.07]

0.821

  Remifentanil

221 (72.0%)

157 (71.0%)

64 (74.4%)

1.19 [0.67–2.09]

0.554

  Sufentanil

29 (9.5%)

22 (10.0%)

7 (8.1%)

0.80 [0.33–1.95]

0.626

  Fentanil

14 (4.6%)

9 (4.1%)

5 (5.8%)

1.45 [0.47–4.47]

0.513

 Inhaled anaesthesia

56 (18.2%)

41 (18.6%)

15 (17.4%)

1.07 [0.56–2.07]

0.999

  Sevorane

40 (13%)

29 (13.1%)

11 (12.8%)

0.88 [0.23–3.32]

0.846

  Desflurane

16 (5.2%)

12 (5.4%)

4 (4.7%)

1.14 [0.30–4.29]

0.846

  Remifentanil

32 (10.4%)

22 (10.0%)

10 (11.6%)

0.58 [0.16–1.94]

0.384

  Fentanil

24 (7.8%)

19 (8.6%)

5 (5.8%)

1.73 [0.50–5.95]

0.384

 Regional anaesthesia

66 (21.5%)

53 (24.0%)

13 (15.1%)

0.56 [0.29–1.10]

0.092

  PECS 1

28 (9.1%)

22 (10.0%)

6 (7.0%)

0.68 [0.27–1.74]

0.418

  PECS 2

17 (5.6%)

12 (5.4%)

5 (5.8%)

1.08 [0.37–3.15]

0.895

  Local anaesthetics infiltration

21 (6.8%)

19 (8.6%)

2 (2.3%)

0.25 [0.03–1.09]

0.075

 Intraoperative analgesia

  Paracetamol

265 (86.3%)

188 (85.1%)

77 (89.5%)

1.50 [0.69–3.29]

0.309

  Ketorolac

49 (16.0%)

33 (14.9%)

16 (18.6%)

1.30 [0.68–2.51]

0.431

  Morphine

242 (7.8%)

169 (76.5%)

73 (84.9%)

1.73 [0.89–3.37]

0.108