Developing a nomogram for postoperative delirium in elderly patients with hip fractures

Table 2 Laboratory indexes and perioperative indicators

Variable	Total	Non-delirium group (n = 453)	Delirium group (n = 79)	Z/χ2/t	P value
Preoperative RBC count, × 109/L	3.78 ± 0.45	3.81 ± 0.44	3.59 ± 0.50	-3.614	< 0.001
Preoperative WBC, × 109/L	8.21 ± 1.73	8.21 ± 1.74	8.23 ± 1.72	0.108	0.914
Preoperative albumin, g/L	36.00 [33.00, 38.00]	36.00 [34.00, 38.00]	34.00 [31.00, 36.00]	-5.158	< 0.001
Preoperative serum creatinine, μmol/L	66.53 ± 10.68	66.38 ± 10.64	67.40 ± 10.95	0.772	0.442
Preoperative hemoglobin, g/L	115.90 ± 12.88	116.81 ± 13.17	110.71 ± 9.65	-4.883	< 0.001
Preoperative PLT, × 109/L	173.96 ± 34.33	176.61 ± 33.22	158.73 ± 36.79	-4.041	< 0.001
Time from admission to surgery, days	6.00 [5.00, 6.00]	6.00 [5.00, 6.00]	6.00 [5.00, 7.00]	1.533	0.11
Mode of anesthesia
Intravertebral/nerve block/local anesthesia	443	381	62	1.528	0.216
General anesthesia	89	72	17
Operation time, minutes	137.00 [123.00, 160.00]	137.00 [123.00, 160.00]	137.00 [126.00, 158.00]	0.296	0.767
Intraoperative blood loss, mL	200.00 [100.00, 300.00]	200.00 [100.00, 300.00]	300.00 [200.00, 300.00]	3.238	< 0.001
RBC transfusion ≥ 2 units
With	255	204	51	10.274	0.001
Without	277	249	28
Postoperative ICU care
With	88	63	25	15.332	< 0.001
Without	444	390	54

RBC: Red blood cell; WBC: White blood cell; PLT: Platelet count; ICU: Intensive care unit.