Table 1.
Characteristic at baseline between A and B group
| Total | A group | B group | P value | |
|---|---|---|---|---|
| Number of patients | 392 | 203 | 189 | |
| Age (years) | 61.2 (7.0) | 58.0 (6.8) | 64.6 (5.5) | < 0.001 |
| Sex (%) | ||||
| Female | 186 (47.4) | 75 (36.9) | 111 (58.7) | 0.04 |
| Male | 206 (52.6) | 128 (63.1) | 78 (41.3) | |
| BMI (kg/m2) | 25.2 (1.8) | 25.0 (1.6) | 25.3 (2.0) | 0.373 |
| Harris score | 44.2 (15.2) | 45.4 (12.8) | 42.8 (17.4) | 0.523 |
| Hip deformities (%) | ||||
| No | 334 (85.2) | 157 (77.3) | 177 (93.7) | 0.035 |
| Yes | 58 (14.8) | 46 (22.7) | 12 (6.3) | |
| Hip joint mobility (°) | 223.6 (28.0) | 230.0 (27.1) | 216.8 (27.3) | 0.008 |
| Preoperative VAS | 6.0 (2.0) | 5.6 (1.9) | 6.5 (2.1) | 0.012 |
| Preoperative Hb (g/L) | 134.7 (16.8) | 139.0 (12.9) | 130.0 (19.2) | 0.003 |
| Preoperative ALB (g/L) | 44.6 (5.1) | 44.0 (5.2) | 45.3 (4.9) | 0.227 |
| ASA (%) | ||||
| I | 18 (4.6) | 15 (7.4) | 3 (1.6) | 0.337 |
| II | 213 (54.3) | 119 (58.6) | 94 (49.7) | |
| III | 150 (38.3) | 66 (32.5) | 84 (44.4) | |
| IV | 11 (2.8) | 3 (1.5) | 8 (4.2) | |
| Operation time (min) | 74.4 (16.4) | 67.8 (12.9) | 81.6 (16.7) | < 0.001 |
| Anesthesia time (min) | 95.1 (22.3) | 87.6 (18.5) | 103.2 (23.2) | < 0.001 |
| Intraoperative infusion volume (ml) | 372.0 [334.0, 438.0] | 337.0 [317.0, 354.0] | 440.0 [414.0, 475.0] | < 0.001 |
| Intraoperative blood loss (ml) | 182.0 [146.0, 210.0] | 182.0 [151.0, 203.0] | 183.0 [145.0, 222.0] | 0.442 |
| Out of bed activities time (h) | 16.4 [13.1, 20.9] | 13.6 [11.2, 15.8] | 20.9 [17.5, 23.7] | < 0.001 |
| Postoperative infusion volume (ml) | 502.0 [474.0, 537.0] | 485.0 [466.0, 512.0] | 529.0 [481.0, 585.0] | < 0.001 |
| Total infusion volume on the day of surgery (ml) | 1050.1 (127.4) | 962.4 (80.1) | 1144.2 (98.3) | < 0.001 |
| VAS score on the day of surgery | 2.8 (0.9) | 2.5 (0.9) | 3.2 (0.8) | < 0.001 |
| Day 1 after surgery VAS score | 3.3 (1.0) | 2.7 (0.5) | 3.9 (1.1) | < 0.001 |
| POD Hb (g/L) | 121.6 (13.7) | 123.1 (14.9) | 120.1 (12.2) | 0.237 |
| POD ALB (g/L) | 39.1 (4.6) | 40.7 (4.6) | 37.4 (4.1) | < 0.001 |
| POD CRP (mg/L) | 18.2 (5.2) | 18.3 (5.4) | 18.1 (5.1) | 0.936 |
| POD IL-6 (pg/ml) | 20.8 (8.1) | 16.5 (6.4) | 25.5 (7.2) | < 0.001 |
| POD total blood loss 1 day after surgery (ml) | 308.8 (58.7) | 298.5 (55.7) | 319.8 (59.9) | 0.044 |
| POD Hb change rate (%) | 9.0 [8.0, 11.0] | 8.0 [6.0, 9.0] | 10.0 [9.0, 12.0] | < 0.001 |
A group: LOS ≤ 48 h group; B group: LOS > 48 h group; BMI, body mass index; VAS: visual analogue score; Hb: hemoglobin; ALB: albumin; ASA: American Society of Anesthesiologists; CRP: C-reactive protein; IL-6: interleukin-6; POD: one day after surgery
POD Hb change = (Preoperative Hb − POD Hb)/Preoperative Hb * 100%