Risk factors for venous thromboembolism of total hip arthroplasty and total knee arthroplasty: a systematic review of evidences in ten years

Table 7 Laboratory indexes

Risk factors(laboratory indexes)	Studies reporting on a risk factor for THA or TKA:total number,number reporting a significant (p ≤ .05)increased (+) or decreased (−) risk,and number with no significant association(p > .05)
	THA				TKA
	N	p ≤ .05		p > .05	N	p ≤ .05		p > .05
		+	-			+	-
Preoperative index
blood glucose ≥ 200 mg/dl	1	1	0	0	1	1	0	0
Resting PaO2 < 75 mmHg	-	-	-	-	1	0	0	1
Resting PaCO2 ≥ 45 mmHg	-	-	-	-	1	1	0	0
RVSP ≥ 35 mmHg*	-	-	-	-	1	0	0	1
Postoperative index
Higher platelet counts	-	-	-	-	1	1	0	0
Hemoglobin ≥ 10.5 g/dl	-	-	-	-	1	1	0	0
AaDO2 ≥ 34 Torr^†	-	-	-	-	1	1	0	0
Seroconvertion of IgG-class HIT Antibody^‡	-	-	-	-	1	1	0	0

*RVSP = right ventricular systolic pressure, referring to pulmonary hypertension.
^†AaDO2 = alveolar-arterial oxygen gradient.
^‡HIT = heparin-induced thrombocytopenia, which is a thromboembolic complication that can occur with unfractionated heparin (UFH) or low molecular weight heparin (LMWH).