Incidence

The incidence of postoperative delirium in clinical trials varies from 4-66%.([FOOTNOTE=Eide LS, Ranhoff AH, Fridlund B, et al. Comparison of frequency, risk factors, and time course of postoperative delirium in octogenarians after transcatheter aortic valve implantation versus surgical aortic valve replacement. Am J Cardiol. 2015;115(6):802-809.],[ANCHOR=],[LINK=])^,([FOOTNOTE=Krzych LJ, Wybraniec MT, Krupka-Matuszczyk I, et al. Detailed insight into the impact of postoperative neuropsychiatric complications on mortality in a cohort of cardiac surgery subjects: a 23,000-patient-year analysis. J Cardiothorac Vasc Anesth. 2014;28(3):448-457.],[ANCHOR=],[LINK=]) Patient-specific and iatrogenic factors may place patients at greater risk.([FOOTNOTE=Yang Y, Zhao X, Dong T, Yang Z, Zhang Q, Zhang Y. Risk factors for postoperative delirium following hip fracture repair in elderly patients: a systematic review and meta-analysis. Aging Clin Exp Res. 2017;29(2):115-126.],[ANCHOR=],[LINK=])

High, low, and mean, incidence of postoperative delirium by procedure.

View Data

Risk factor for postoperative delirium

An understanding of the risk factors for postoperative delirium is important for identifying patients who may benefit from increased vigilance.

Risk factors for postoperative delirium by type

Procedural

Back

Risk Factor	Odds Ratio
Emergency surgery²⁶	2.65
Surgery duration, min¹⁸	1.01

Blood loss/ Transfusion Management

Back

Risk Factor	Odds Ratio
Blood loss ≥1517 mL⁵	2.7
Higher volume of red blood cell transfusions¹⁸	0.83
High amount of blood transfusions²⁰	1.001
Fresh frozen plasma administration²⁶	1.2
Pre-operative anemia²⁵	1.66
Postoperative hematocrit <30%¹³	2
Postoperative hemoglobin level(mmol/l)²⁰	2.16
Volume load during operation¹⁶	2.77

Medications

Back

Risk Factor	Odds Ratio
Morphine usage³	3.01
Preoperative beta-blocker use¹¹	1.7

Cognitive Impairment

Back

Risk Factor	Odds Ratio
Cognitive impairment^3,11,12	2.5-3.231
MMSE <25([FOOTNOTE=Bohner H, Hummel TC, Habel U, et al. Predicting delirium after vascular surgery: a model based on pre- and intraoperative data. Ann Surg. 2003;238(1):149-156.],[ANCHOR=],[LINK=])	28

Postoperative Course

Back

Risk Factor	Odds Ratio
Highest temp recorded in ICU¹⁶	2.23
LOS⁷	4.71
Mechanical ventilation time in ICU¹⁶	1.2
Postoperative acute infection¹³	6.9
Postoperative cardiogenic shock¹³	2.75
Postoperatirve Pneumonia⁷	5.34

Co-morbidities

Back

Risk Factor	Odds Ratio
Atrial fibrillation^10,12,27	2.65-2.75
Carotid artery disease²⁷	3.88
Cerebralvascular disease⁷	4.91
Chronic heart failure^3,7	2.46-5.28
Depression([FOOTNOTE=Tse L, Bowering JB, Schwarz SK, Moore RL, Burns KD, Barr AM. Postoperative delirium following transcatheter aortic valve implantation: a historical cohort study. Can J Anaesth. 2015;62(1):22-30.],[ANCHOR=],[LINK=])	3.3
Diabetes mellitus^16,([FOOTNOTE=van Eijsden WA, Raats JW, Mulder PG, van der Laan L. New aspects of delirium in elderly patients with critical limb ischemia. Clin Interv Aging. 2015;10:1537-1546.],[ANCHOR=],[LINK=])	3.49-6.23
End stage renal failure([FOOTNOTE=Sasajima Y, Sasajima T, Azuma N, et al. Factors related to postoperative delirium in patients with lower limb ischaemia: a prospective cohort study. Eur J Vasc Endovasc Surg. 2012;44(4):411-415.],[ANCHOR=],[LINK=])	5
Gastritis/Peptic Ulcer¹⁶	4
History of hypertension¹⁰	3.66
Hypercholesterolemia³⁰	5.5
Hypertension([FOOTNOTE=Visser L, Prent A, van der Laan MJ, et al. Predicting postoperative delirium after vascular surgical procedures. J Vasc Surg. 2015;62(1):183-189.],[ANCHOR=],[LINK=])	7.6
Multiple Comorbidities³	1.37
Stroke^11,18	8.618

Lab Abnormalities

Back

Risk Factor	Odds Ratio
Creatinine > 1.3 mg/dl¹⁰	2.05
CRP value¹⁸	1.028
Electrolyte disturbance¹²	2.09
Higher blood glucose,(umol/l)¹⁸	1.228
Higher total bilirubin, (umol/l)¹⁸	1.077
Hypoalbuminemia^13,18	2.4
Potassium <3.5 mmol/L³⁰	3.18
Sodiurm concentration in ICU (mmol/l)¹⁶	1.19

Patient-specific

Back

Risk Factors	Odds Ratio
Advancing age^{5,7,10,11,16,18,25,26,27}	1.05-2.0
High ASA Score^25,26	2.23-3.7
Delirium in medical history^11,25	3.57-12
Living in an institution³	2.94
Male sex⁷	7.6
Smoking^27,34	3.99-10.5