Effect of intravenous low-dose norepinephrine on blood loss in non-tourniquet total knee arthroplasty under general anesthesia: a randomized, double-blind, controlled, single-center trial

Table 1 Baseline demographic characteristics

	NE group (n = 60)	C group (n = 60)	t/χ²/Z	P value
Age (yr)	68.30 ± 6.65	67.63 ± 7.14	− 0.530	0.597*
Gender			0.196	0.658‡
Male	12 (20.0%)	14 (23.3%)
Female	48 (80.0%)	46 (76.7%)
BMI (kg/m²)	25.50 ± 3.11	26.41 ± 3.51	1.513	0.133*
ASA grade			0.159	0.690‡
II	19 (31.7%)	17 (28.3%)
III	41 (68.3%)	43 (71.7%)
K-L grade			0.051	0.822‡
III	48 (80.0%)	47 (78.3%)
IV	12 (20.0%)	13 (21.7%)
Preoperative blood detection
RBC (× 10⁹/L)	4.49 ± 0.52	4.53 ± 0.45	0.429	0.669*
Hb (g/L)	133.03 ± 11.31	136.32 ± 13.00	1.476	0.143*
Hct	0.41 ± 0.03	0.42 ± 0.03	1.646	0.102*
PLT (× 10⁹/L)	240.30 ± 54.52	246.08 ± 55.96	0.573	0.567*
PT (s)	10.66 ± 0.71	10.69 ± 0.72	0.243	0.809*
APTT (s)	25.65 ± 2.21	25.68 ± 1.78	0.073	0.942*
D-D (mg/L)	0.35 (0.25, 0.75)	0.49 (0.26, 0.91)	− 1.449	0.147†
Chronic diseases
Osteoporosis			0.086	0.769‡
Yes	6 (10.0%)	7 (11.7%)
No	54 (90.0%)	53 (88.3%)
Hypertension			0.304	0.581‡
Yes	35 (58.3%)	32 (53.3%)
No	25 (44.2%)	28 (46.7%)
Preoperative MAP (mmHg)	93.83 (89.33, 98.83)	94.54 ± 9.79	− 0.068	0.946†
Diabetes			0.164	0.685‡
Yes	18 (30.0%)	16 (26.7%)
No	42 (70.0%)	44 (73.3%)
Preoperative blood sugar (mmol/L)	5.39 (5.01, 6.38)	5.67 (5.20, 6.33)	− 0.908	0.364†

BMI, Body Mass Index, ASA, American Society of Anesthesiologists, RBC, Red Blood Cell, Hb, Hemoglobin, Hct, Hematocrit, PLT, Platelet, PT, Prothrombin Time, APTT, Activated Partial Thromboplastin Time, D-D, D-Dimer, MAP, Mean Arterial Pressure
*Student's t test
^†Mann–Whitney U test
^‡Chi-squared test

ISSN: 1749-799X