Postoperative delirium after major orthopedic surgery

Table 5 Spine fusion patient demographics and study population

	POD (Mean +/- SD or n, %), n = 137	non-POD (Mean +/- SD or n, %), n = 4107	P value
Age, yr	67.5+/-12.5	60.1+/-15.6	< 0.001a
≥ 65	91 (66.4)	1765 (43.0)	< 0.001a
Male	54 (39.4)	1810 (44.1)	0.28
BMI	28.5+/-6.5	28.1+/-5.9	0.40
Length of stay	9.0+/-5.1	5.6+/-3.6	< 0.001a
Latest creatinine before surgery			0.01a
< 1.2 mg/dL	116 (84.7)	3754 (91.4)
1.2-2.0 mg/dL	20 (14.6)	346 (8.4)
> 2.0 mg/dL	1 (0.7)	7 (0.2)
Preoperative hyponatremia			0.16
Yes	43 (31.4)	1070 (26.1)
No	94 (68.6)	3033 (73.9)
Missing	0 (0)	4 (0.1)
Postoperative thiamine order			< 0.001a
Yes	20 (14.6)	93 (2.3)
No	117 (85.4)	4013 (97.7)
Missing	0 (0)	1 (0.02)
Atrial fibrillation (present on admission)	12 (8.8)	135 (3.3)	0.003a
Pressure ulcers (present on admission)	3 (2.2)	13 (0.32)	< 0.001a
Opioid dependence or long-term use	11 (8.0)	124 (3.0)	0.004a
Psychiatric disease (present on admission)	65 (47.5)	1185 (28.9)	< 0.001a
Anesthesia type			1
General	136 (99.3)	4052 (98.7)
Other	0 (0)	8 (0.2)
Missing	1 (0.7)	47 (1.1)
Patient-controlled analgesia			1
Epidural	0 (0)	18 (0.4)
IV	136 (99.3)	3968 (96.6)
Missing	1 (0.7)	121 (3.0)
Received diazepam			< 0.001a
Yes	34 (24.8)	476 (11.6)
No	103 (75.2)	3630 (88.4)
Missing	0 (0)	1 (0.02)
CT, MRI or both performed			0.26
Yes	136 (99.3)	3999 (97.4)
No	1 (0.7)	107 (2.6)
Missing	0 (0)	1 (0.02)
ASA score			< 0.001a
1	1 (0.7)	214 (5.2)
2	78 (56.9)	2974 (72.4)
≥ 3	57 (41.6)	871 (21.2)
Missing	1 (0.7)	48 (1.2)

^aP < 0.05. POD: Postoperative delirium; ASA: American society of anesthesiologists; CT: Computed tomography; MRI: Magnetic resonance imaging; BMI: Body mass index; SD: Standard deviation.