Finding the optimal control level of intraoperative blood pressure in no tourniquet primary total knee arthroplasty combine with tranexamic acid: a retrospective cohort study which supports the enhanced recovery strategy

Table 1 Baseline characteristics and perioperative demographics

Variable	Group A (N = 82)	Group B (N = 105)	Group C (N = 91)	P value*
Patient characteristics
Age (year)^b	66.7 ± 7.6	67.0 ± 7.0	67.3 ± 10.1	0.89
Gender (male/female)^a	10/72	20/85	16/76	0.44
BMI (kg/m²)^b	25.1 ± 3.7	25.7 ± 3.6	25.6 ± 3.4	0.46
ASA classification (N, %)^a				0.41
I	15 (18.3)	24 (22.9)	20 (22.0)
II	50 (61.0)	69 (65.7)	53 (58.2)
III	17 (20.7)	12 (11.4)	18 (19.8)
Operated side (L/R)^a	39/43	49/56	47/44	0.77
Concomitant diseases
Hypertension (N, %)^a	15 (18.3)	25 (23.8)	19 (20.9)	0.66
Diabetes (N, %)^a	3 (3.7)	9 (8.6)	8 (8.8)	0.34
Chronic renal dysfunction (N, %)^a	1 (1.2)	1 (1.0)	2 (2.2)	0.75
Heart disease (N, %)^a	2 (2.4)	2 (1.9)	1 (1.1)	0.80
Preoperative laboratory values
Hemoglobin (g/l)^b	133.1 ± 8.9	132.3 ± 11.1	132.5 ± 12.3	0.72
Hematocrit (%)^b	41.5 ± 3.1	41.1 ± 3.4	40.9 ± 3.1	0.46
Platelet count (× 10⁹/l)^b	180.6 ± 45.9	184.7 ± 37.9	191.0 ± 50.1	0.79
APTT (s)^b	30.0 ± 4.5	29.4 ± 4.1	30.2 ± 4.5	0.40
International normalized ratio (INR)^b	1.01 ± 0.12	1.00 ± 0.32	1.02 ± 0.21	0.41
PBV (l)^b	3710.9 ± 459.3	3740.1 ± 501.8	3792 ± 498.2	0.86
Preoperative knee function
ROM (°)^b	93.2 ± 15.3	95.1 ± 18.2	94.6 ± 16.2	0.89
HSS score^b	45.7 ± 13.2	46.8 ± 12.2	46.9 ± 9.9	0.41
VAS pain score^b	4.8 ± 0.9	4.9 ± 1.0	4.7 ± 1.2	0.91

BMI body mass index, ASA American Society of Anesthesiologists, APTT activated partial thromboplastin time, PBV patient’s blood volume, ROM range of motion, HSS Hospital for Special Surgery score, VAS visual analog scale
^aData are presented as number of patients with percentage
^bData are presented as mean ± standard deviation
*P values were calculated using 1-way ANOVA, the Pearson chi-square test, or the Fisher exact test

ISSN: 1749-799X