Association between perioperative blood transfusion and early postoperative cognitive dysfunction in aged patients following total hip replacement surgery

Figures & data

Figure 1. The CONSORT diagram showing patients' flow through the study.

Table I. Demographic characteristics of the study population.

Factors	POCD (n = 56)	Non-POCD (n = 149)	p value
Age (y)	76 ± 6	74 ± 6	0.007
Gender (male/ female)	34/ 22	97/ 52	0.736
Weight (kg)	56 ± 9	63 ± 11	0.024
Education (y)	7.1 ± 2.8	8.6 ± 2.8	0.001
ASA classification (I/ II/ III)	3/ 48/ 5	7/ 130/ 12	0.958
Fracture characteristics (n)			0.9
Femoral neck	17	43
Intertrochanteric	30	78
Other	9	28
History of hypertension (n)	29	71	0.640
Intraoperative hypotension (n)	28	65	0.435
Ringer's lactate infusion (mL)	968 ± 145	959 ± 144	0.698
HES infusion (mL)	654 ± 265	569 ± 170	0.008
Length of surgery (min)	80 ± 12	79 ± 10	0.635
Estimated blood loss (mL)	772 ± 126	618 ± 127	0.001
Postoperative drainage (mL)	130 ± 68	120 ± 50	0.283
Hemoglobin concentration (g/L)
Preoperative level	116 ± 13	122 ± 12	0.006
7 d after surgery	101 ± 12	99 ± 11	0.654
Perioperative RBCs transfusion			0.012
0 unit (n)	27	102
1 unit (n)	5	15
2 units (n)	7	14
3 units (n)	9	13
≥4 units (n)	8	5
Perioperative FFP transfusion (n)	9	17	0.371
MMSE scores
Before surgery	28.0 ± 1.2	28.1 ± 1.6	0.661
7 d after surgery	25.7 ± 1.2	27.7 ± 1.5	0.001
VAS scores
1 d after surgery	3.7 ± 0.9	3.8 ± 1.0	0.462
2 d after surgery	3.5 ± 0.7	3.7 ± 0.9	0.149
7 d after surgery	1.5 ± 0.6	1.5 ± 0.5	0.765
Tramadol consumption (mg)	896 ± 129	932 ± 143	0.109
Pethidine administration (n)	14	56	0.09

Values are means ± standard deviations, or number as appropriate.

ASA = American Society of Anesthesiologists; FFP = fresh frozen plasma; HES = hydroxyethyl starch; MMSE = Mini-Mental State Examination; POCD = postoperative cognitive dysfunction; RBCs = red blood cells; VAS = visual analog scale.

Table II. Predictors of POCD identified by multivariable logistic regression.

Factors	p value	Odds ratio (95% CI)
Age (y)	0.005	1.08 (1.023–1.14)
Weight (kg)	0.164	0.43 (0.12–1.37)
Education (y)	0.002	0.83 (0.74–0.93)
Estimated blood loss (mL)	0.067	1.23 (0.98–1.56)
HES infusion (mL)	0.12	1.35 (0.67–1.78)
Preoperative hemoglobin concentration (g/L)	0.032	0.87 (0.72–0.99)
Perioperative RBCs transfusion >3 units	0.045	1.57 (1.09–2.32)