Table 1.
Baseline characteristics
| Characteristics | Overall | Groups | ||||
|---|---|---|---|---|---|---|
| 1 h | 6 h | 12 h | 18 h | 20 h | ||
| n | 228 | 46 | 46 | 45 | 45 | 46 |
| Sex = male/female (%) | 84/144 (36.8/63.2) | 19/27 (41.3/58.7) | 19/27 (41.3/58.7) | 15/30 (33.3/66.7) | 13/32 (28.9/71.1) | 18/28 (39.1/60.9) |
| Age (mean (SD)) | 60.38 (13.22) | 57.59 (15.84) | 61.98 (13.22) | 63.42 (13.87) | 59.73 (10.89) | 59.22 (11.42) |
| Type of surgery (%) | ||||||
| Right knee arthroplasty | 72 (31.6) | 14 (30.4) | 14 (30.4) | 12 (26.7) | 16 (35.6) | 16 (34.8) |
| Left knee arthroplasty | 43 (18.9) | 13 (28.3) | 9 (19.6) | 6 (13.3) | 6 (13.3) | 9 (19.6) |
| Right and left knee arthroplasty | 10 (4.4) | 2 (4.3) | 2 (4.3) | 2 (4.4) | 2 (4.4) | 2 (4.3) |
| Right hip arthroplasty | 46 (20.2) | 6 (13.0) | 12 (26.1) | 8 (17.8) | 13 (28.9) | 7 (15.2) |
| Left hip arthroplasty | 48 (21.1) | 8 (17.4) | 8 (17.4) | 15 (33.3) | 6 (13.3) | 11 (23.9) |
| Right and left hip arthroplasty | 9 (3.9) | 3 (6.5) | 1 (2.2) | 2 (4.4) | 2 (4.4) | 1 (2.2) |
| Hypertension = no/yes (%) | 171/57 (75.0/25.0) | 33/13 (71.7/28.3) | 35/11 (76.1/23.9) | 32/13 (71.1/28.9) | 32/13 (71.1/28.9) | 39/7 (84.8/15.2) |
| Diabetes = no/yes (%) | 224/4 (98.2/1.8) | 46/0 (100.0/0.0) | 44/2 (95.7/4.3) | 45/0 (100.0/0.0) | 45/0 (100.0/0.0) | 44/2 (95.7/4.3) |
| Nationality = Han/Minority (%) | 221/7 (96.9/3.1) | 42/4 (91.3/8.7) | 45/1 (97.8/2.2) | 45/0 (100.0/0.0) | 45/0 (100.0/0.0) | 44/2 (95.7/4.3) |
| BMI (kg/m2, mean (SD)) | 25.70 (4.23) | 26.10 (3.90) | 24.87 (5.34) | 26.14 (3.84) | 26.32 (4.23) | 25.10 (3.56) |
| Temperature (℃, mean (SD)) | 36.47 (0.32) | 36.40 (0.29) | 36.37 (0.29) | 36.54 (0.31) | 36.48 (0.35) | 36.56 (0.33) |
| Heart rate (mean (SD)) | 77.22 (7.09) | 77.87 (7.04) | 75.74 (6.62) | 78.40 (7.94) | 77.18 (8.09) | 76.96 (5.51) |
| Respiration rate (mean (SD)) | 18.05 (0.92) | 18.02 (0.71) | 18.26 (0.71) | 18.04 (0.88) | 18.00 (0.90) | 17.91 (1.28) |
| Systolic blood pressure (mmHg, mean (SD)) | 136.72 (15.98) | 137.83 (18.21) | 137.59 (15.45) | 138.44 (16.61) | 132.89 (14.75) | 136.83 (14.70) |
| Diastolic blood pressure (mmHg, mean (SD)) | 80.80 (9.84) | 79.61 (9.74) | 81.54 (11.70) | 81.87 (9.28) | 80.53 (8.65) | 80.48 (9.80) |
| Blood type (%) | ||||||
| A | 58 (25.4) | 12 (26.1) | 9 (19.6) | 14 (31.1) | 13 (28.9) | 10 (21.7) |
| AB | 21 (9.2) | 5 (10.9) | 5 (10.9) | 4 (8.9) | 2 (4.4) | 5 (10.9) |
| B | 76 (33.3) | 15 (32.6) | 13 (28.3) | 16 (35.6) | 16 (35.6) | 16 (34.8) |
| O | 73 (32.0) | 14 (30.4) | 19 (41.3) | 11 (24.4) | 14 (31.1) | 14 (30.4) |
| Anesthesia = General/ Epidural (%) | 202/26 (88.6/11.4) | 40/6 (87.0/13.0) | 38/8 (82.6/17.4) | 39/6 (86.7/13.3) | 42/3 (93.3/6.7) | 43/3 (93.5/6.5) |
| Blood loss (ml, mean (SD)) | 213.97 (168.81) | 237.39 (161.43) | 232.61 (127.46) | 205.00 (146.42) | 219.56 (210.10) | 175.22 (186.44) |
| Operation time (min, mean (SD)) | 138.43 (57.97) | 146.54 (54.84) | 120.98 (38.13) | 139.13 (59.82) | 139.49 (80.63) | 146.07 (46.84) |
| Catheterization = no/yes (%) | 227/1 (99.6/0.4) | 46/0 (100.0/0.0) | 46/0 (100.0/0.0) | 45/0 (100.0/0.0) | 44/1 (97.8/2.2) | 46/0 (100.0/0.0) |
| Blood transfusion = no/yes (%) | 167/61 (73.2/26.8) | 29/17 (63.0/37.0) | 36/10 (78.3/21.7) | 30/15 (66.7/33.3) | 31/14 (68.9/31.1) | 41/5 (89.1/10.9) |
| Perioperative use of hemostatics = no/yes (%) | 140/88 (61.4/38.6) | 23/23 (50.0/50.0) | 33/13 (71.7/28.3) | 30/15 (66.7/33.3) | 26/19 (57.8/42.2) | 28/18 (60.9/39.1) |
| Drainage = no/yes (%) | 160/68 (70.2/29.8) | 31/15 (67.4/32.6) | 35/11 (76.1/23.9) | 28/17 (62.2/37.8) | 33/12 (73.3/26.7) | 33/13 (71.7/28.3) |
| Perioperative use of hormone = no/yes (%) | 182/46 (79.8/20.2) | 34/12 (73.9/26.1) | 33/13 (71.7/28.3) | 40/5 (88.9/11.1) | 35/10 (77.8/22.2) | 40/6 (87.0/13.0) |
| TT (s, mean (SD)) | 16.64 (2.55) | 16.49 (2.69) | 15.60 (2.53) | 16.67 (2.43) | 16.70 (2.52) | 17.73 (2.19) |
| APTT (s, mean (SD)) | 29.98 (5.24) | 29.99 (4.80) | 32.17 (5.28) | 29.38 (6.18) | 29.75 (5.17) | 28.58 (4.11) |
| PT (s, mean (SD)) | 12.20 (1.49) | 12.33 (1.51) | 12.58 (1.47) | 12.04 (1.72) | 12.10 (1.47) | 11.95 (1.22) |
| D-dimer (mg/L, mean (SD)) | 0.91 (2.14) | 0.59 (0.82) | 1.64 (4.12) | 0.93 (1.25) | 0.63 (0.67) | 0.77 (1.64) |
| Fibrin (mean (SD)) | 3.27 (2.05) | 3.05 (0.54) | 3.23 (1.24) | 3.34 (1.14) | 3.23 (2.67) | 3.53 (3.33) |
| Hemoglobin (mean (SD)) | 131.19 (15.24) | 133.17 (15.56) | 131.52 (16.07) | 127.42 (14.09) | 128.91 (15.99) | 134.78 (13.79) |
| Platelet (mean (SD)) | 222.88 (64.74) | 230.37 (73.90) | 215.61 (60.49) | 226.44 (70.00) | 227.00 (61.30) | 215.15 (57.92) |
| ESR (mean (SD)) | 12.39 (11.57) | 11.65 (8.50) | 14.39 (15.72) | 14.84 (11.65) | 9.76 (8.49) | 11.29 (11.58) |
BMI: body mass index; TT: thrombin time; APTT: active partial thromboplastin time; PT: prothrombin time; ESR: erythrocyte sedimentation rate