• Mark A. OldhamEmail author


Delirium can be identified by the four A’s: acute change in mentation, impaired attention, reduced awareness of environment (“confusion”), and another cognitive deficit. Level of arousal is also typically altered in delirium and may present as hypoactive, hyperactive, or mixed level of activity. Postoperative delirium incidence ranges widely—10–80%—and reflects the range of surgical invasiveness and cognitive vulnerability of surgical cohorts. Delirium and its severity are associated with a higher risk of subsequent cognitive and functional decline as well as mortality.

Confusion is common upon anesthesia emergence. Whereas this early confusion usually clears within hours, it predicts the development of postoperative delirium, thereby serving as a convenient stress test of cognitive vulnerability. Classically defined, postoperative delirium peaks on postoperative day 2 and lasts 2–5 days. Confusional states that do not meet full delirium criteria (i.e., subsyndromal delirium) are more common than delirium proper and predict outcomes of intermediate severity relative to those of delirium.

Universal risk factors for delirium include advanced age, cognitive and functional impairment, multimorbidity, and surgical invasiveness. Additional risk factors vary by surgical cohort and procedure. Delirium risk stratification is important because non-pharmacological interventions can prevent up to a third of delirium in sufficiently at-risk patients. Routine use of validated delirium screening instruments is recommended to enhance delirium detection. Once delirium is identified, reversible contributors should be remediated promptly. Non-pharmacological interventions are first-line management of the neuropsychiatric symptoms associated with delirium. Judicious use of neuroleptics may be considered to manage severe or dangerous symptoms.


Delirium Acute confusion Acute brain failure Postoperative delirium Non-pharmacological interventions 


  1. 1.
    American Psychiatric Association. Diagnostic and statistical manual of mental disorders. Washington, DC: American Psychiatric Association; 2013.CrossRefGoogle Scholar
  2. 2.
    Marcantonio ER. Delirium in hospitalized older adults. N Engl J Med. 2017;377(15):1456–66.PubMedPubMedCentralCrossRefGoogle Scholar
  3. 3.
    Leslie DL, et al. One-year health care costs associated with delirium in the elderly population. Arch Intern Med. 2008;168(1):27–32.PubMedPubMedCentralCrossRefGoogle Scholar
  4. 4.
    Pollard C, Fitzgerald M, Ford K. Delirium: the lived experience of older people who are delirious post-orthopaedic surgery. Int J Ment Health Nurs. 2015;24(3):213–21.PubMedCrossRefGoogle Scholar
  5. 5.
    Flaherty JH, et al. Delirium is a serious and under-recognized problem: why assessment of mental status should be the sixth vital sign. J Am Med Dir Assoc. 2007;8(5):273–5.PubMedCrossRefGoogle Scholar
  6. 6.
    Auerswald KB, Charpentier PA, Inouye SK. The informed consent process in older patients who developed delirium: a clinical epidemiologic study. Am J Med. 1997;103(5):410–8.PubMedCrossRefGoogle Scholar
  7. 7.
    Inouye SK, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999;340(9):669–76.PubMedCrossRefGoogle Scholar
  8. 8.
    Abraha I, et al. Efficacy of non-pharmacological interventions to prevent and treat delirium in older patients: a systematic overview. The SENATOR project ONTOP series. PLoS One. 2015;10(6):e0123090.PubMedPubMedCentralCrossRefGoogle Scholar
  9. 9.
    Fok MC, et al. Do antipsychotics prevent postoperative delirium? A systematic review and meta-analysis. Int J Geriatr Psychiatry. 2015;30(4):333–44.PubMedCrossRefGoogle Scholar
  10. 10.
    Khan BA, Gutteridge D, Campbell NL. Update on pharmacotherapy for prevention and treatment of post-operative delirium: a systematic evidence review. Curr Anesthesiol Rep. 2015;5(1):57–64.PubMedPubMedCentralCrossRefGoogle Scholar
  11. 11.
    Teslyar P, et al. Prophylaxis with antipsychotic medication reduces the risk of post-operative delirium in elderly patients: a meta-analysis. Psychosomatics. 2013;54(2):124–31.PubMedCrossRefGoogle Scholar
  12. 12.
    Lipowski JZ. Delirium: acute confusional states. New York: Oxford University Press; 1990.Google Scholar
  13. 13.
    Maneta E, Garcia G. Psychiatric manifestations of anti-NMDA receptor encephalitis: neurobiological underpinnings and differential diagnostic implications. Psychosomatics. 2014;55(1):37–44.PubMedCrossRefGoogle Scholar
  14. 14.
    Vanderploeg R. The interpretation process. In: Vanderploeg R, editor. Clinician’s guide to neuropsychological assessment. 2nd ed. New York: Lawrence Erlbaum Associates, Inc; 2014. p. 123.CrossRefGoogle Scholar
  15. 15.
    Durcan L. Coma and disorders of consciousness. In: McKean S, et al., editors. Principles and practice of hospital medicine. 2nd ed. New York: McGraw-Hill Education Medical; 2017.Google Scholar
  16. 16.
    Tieges Z, Brown LJ, MacLullich AM. Objective assessment of attention in delirium: a narrative review. Int J Geriatr Psychiatry. 2014;29(12):1185–97.PubMedCrossRefGoogle Scholar
  17. 17.
    Adamis D, et al. Evaluating attention in delirium: a comparison of bedside tests of attention. Geriatr Gerontol Int. 2016;16(9):1028–35.PubMedCrossRefGoogle Scholar
  18. 18.
    World Health Organization. The ICD-10 classification of mental and behavioural disorders: diagnostic criteria for research. Geneva: World Health Organization; 1992.Google Scholar
  19. 19.
    Morandi A, et al. Detecting delirium superimposed on dementia: evaluation of the diagnostic performance of the Richmond agitation and sedation scale. J Am Med Dir Assoc. 2016;17(9):828–33.PubMedPubMedCentralCrossRefGoogle Scholar
  20. 20.
    Chester JG, et al. Serial administration of a modified Richmond agitation and sedation scale for delirium screening. J Hosp Med. 2012;7(5):450–3.PubMedCrossRefGoogle Scholar
  21. 21.
    Mattoo SK, et al. Symptom profile and etiology of delirium in a referral population in northern India: factor analysis of the DRS-R98. J Neuropsychiatry Clin Neurosci. 2012;24(1):95–101.PubMedCrossRefGoogle Scholar
  22. 22.
    Meagher DJ, et al. Phenomenology of delirium. Assessment of 100 adult cases using standardised measures. Br J Psychiatry. 2007;190:135–41.PubMedCrossRefGoogle Scholar
  23. 23.
    Oldham MA, Lee HB, Desan PH. Circadian rhythm disruption in the critically ill: an opportunity for improving outcomes. Crit Care Med. 2016;44(1):207–17.PubMedCrossRefGoogle Scholar
  24. 24.
    Adamis D, et al. Delirium scales: a review of current evidence. Aging Ment Health. 2010;14(5):543–55.PubMedCrossRefGoogle Scholar
  25. 25.
    De J, Wand AP. Delirium screening: a systematic review of delirium screening tools in hospitalized patients. Gerontologist. 2015;55(6):1079–99.PubMedCrossRefGoogle Scholar
  26. 26.
    Wei LA, et al. The confusion assessment method: a systematic review of current usage. J Am Geriatr Soc. 2008;56(5):823–30.PubMedPubMedCentralCrossRefGoogle Scholar
  27. 27.
    Wong CL, et al. Does this patient have delirium?: value of bedside instruments. JAMA. 2010;304(7):779–86.PubMedCrossRefGoogle Scholar
  28. 28.
    Marcantonio ER, et al. 3D-CAM: derivation and validation of a 3-minute diagnostic interview for CAM-defined delirium: a cross-sectional diagnostic test study. Ann Intern Med. 2014;161(8):554–61.PubMedPubMedCentralCrossRefGoogle Scholar
  29. 29.
    Pompei P, et al. Detecting delirium among hospitalized older patients. Arch Intern Med. 1995;155(3):301–7.PubMedCrossRefGoogle Scholar
  30. 30.
    Gusmao-Flores D, et al. The confusion assessment method for the intensive care unit (CAM-ICU) and intensive care delirium screening checklist (ICDSC) for the diagnosis of delirium: a systematic review and meta-analysis of clinical studies. Crit Care. 2012;16(4):R115.PubMedPubMedCentralCrossRefGoogle Scholar
  31. 31.
    Boettger S, et al. Delirium in the intensive care setting: a reevaluation of the validity of the CAM-ICU and ICDSC versus the DSM-IV-TR in determining a diagnosis of delirium as part of the daily clinical routine. Palliat Support Care. 2017;15(6):675–83.PubMedCrossRefPubMedCentralGoogle Scholar
  32. 32.
    Neufeld KJ, et al. Evaluation of two delirium screening tools for detecting post-operative delirium in the elderly. Br J Anaesth. 2013;111(4):612–8.PubMedPubMedCentralCrossRefGoogle Scholar
  33. 33.
    Haenggi M, et al. Effect of sedation level on the prevalence of delirium when assessed with CAM-ICU and ICDSC. Intensive Care Med. 2013;39(12):2171–9.PubMedCrossRefPubMedCentralGoogle Scholar
  34. 34.
    Radtke FM, et al. Comparison of three scores to screen for delirium in the recovery room. Br J Anaesth. 2008;101(3):338–43.PubMedCrossRefPubMedCentralGoogle Scholar
  35. 35.
    Gaudreau JD, et al. Fast, systematic, and continuous delirium assessment in hospitalized patients: the nursing delirium screening scale. J Pain Symptom Manag. 2005;29(4):368–75.CrossRefGoogle Scholar
  36. 36.
    Trzepacz PT, et al. Validation of the delirium rating scale-revised-98: comparison with the delirium rating scale and the cognitive test for delirium. J Neuropsychiatry Clin Neurosci. 2001;13(2):229–42.PubMedCrossRefPubMedCentralGoogle Scholar
  37. 37.
    Inouye SK, et al. The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts. Ann Intern Med. 2014;160(8):526–33.PubMedPubMedCentralCrossRefGoogle Scholar
  38. 38.
    Breitbart W, et al. The memorial delirium assessment scale. J Pain Symptom Manag. 1997;13(3):128–37.CrossRefGoogle Scholar
  39. 39.
    McCusker J, et al. Reliability and validity of a new measure of severity of delirium. Int Psychogeriatr. 1998;10(4):421–33.PubMedCrossRefPubMedCentralGoogle Scholar
  40. 40.
    van Eijk MM, et al. Comparison of delirium assessment tools in a mixed intensive care unit. Crit Care Med. 2009;37(6):1881–5.PubMedCrossRefGoogle Scholar
  41. 41.
    Katznelson R, et al. Hospital administrative database underestimates delirium rate after cardiac surgery. Can J Anaesth. 2010;57(10):898–902.PubMedCrossRefGoogle Scholar
  42. 42.
    Albrecht JS, et al. Stability of postoperative delirium psychomotor subtypes in individuals with hip fracture. J Am Geriatr Soc. 2015;63(5):970–6.PubMedPubMedCentralCrossRefGoogle Scholar
  43. 43.
    Bigatello LM, et al. Effects of routine monitoring of delirium in a surgical/trauma intensive care unit. J Trauma Acute Care Surg. 2013;74(3):876–83.PubMedCrossRefGoogle Scholar
  44. 44.
    Todd KS, et al. Delirium detection and improved delirium management in older patients hospitalized for hip fracture. Int J Orthop Trauma Nurs. 2015;19(4):214–21.PubMedCrossRefGoogle Scholar
  45. 45.
    Radtke FM, et al. Risk factors for inadequate emergence after anesthesia: emergence delirium and hypoactive emergence. Minerva Anestesiol. 2010;76(6):394–403.PubMedGoogle Scholar
  46. 46.
    Xara D, et al. Inadequate emergence after anesthesia: emergence delirium and hypoactive emergence in the postanesthesia care unit. J Clin Anesth. 2013;25(6):439–46.PubMedCrossRefGoogle Scholar
  47. 47.
    Lepouse C, et al. Emergence delirium in adults in the post-anaesthesia care unit. Br J Anaesth. 2006;96(6):747–53.PubMedCrossRefGoogle Scholar
  48. 48.
    Milstein A, et al. Confusion/delirium following cataract surgery: an incidence study of 1-year duration. Int Psychogeriatr. 2002;14(3):301–6.PubMedCrossRefGoogle Scholar
  49. 49.
    Sharma PT, et al. Recovery room delirium predicts postoperative delirium after hip-fracture repair. Anesth Analg. 2005;101(4):1215–20, table of contents.PubMedCrossRefGoogle Scholar
  50. 50.
    Neufeld KJ, et al. Outcomes of early delirium diagnosis after general anesthesia in the elderly. Anesth Analg. 2013;117(2):471–8.PubMedPubMedCentralCrossRefGoogle Scholar
  51. 51.
    Youngblom E, et al. The temporal relationship between early postoperative delirium and postoperative cognitive dysfunction in older patients: a prospective cohort study. Can J Anaesth. 2014;61(12):1084–92.PubMedCrossRefGoogle Scholar
  52. 52.
    Shim J, et al. Prognostic significance of postoperative subsyndromal delirium. Psychosomatics. 2015;56(6):644–51.PubMedPubMedCentralCrossRefGoogle Scholar
  53. 53.
    Zhang W, et al. Profiles of delirium and the clinical outcomes of patients who underwent coronary artery bypass grafting: a prospective study from China. J Clin Nurs. 2016;25(5–6):631–41.PubMedCrossRefGoogle Scholar
  54. 54.
    DeCrane SK, et al. Factors associated with recovery from early postoperative delirium. J Perianesth Nurs. 2011;26(4):231–41.PubMedPubMedCentralCrossRefGoogle Scholar
  55. 55.
    de Jonghe JF, et al. Early symptoms in the prodromal phase of delirium: a prospective cohort study in elderly patients undergoing hip surgery. Am J Geriatr Psychiatry. 2007;15(2):112–21.PubMedCrossRefGoogle Scholar
  56. 56.
    Duppils GS, Wikblad K. Delirium: behavioural changes before and during the prodromal phase. J Clin Nurs. 2004;13(5):609–16.PubMedCrossRefGoogle Scholar
  57. 57.
    Kohl BA, Deutschman CS. The inflammatory response to surgery and trauma. Curr Opin Crit Care. 2006;12(4):325–32.PubMedCrossRefGoogle Scholar
  58. 58.
    Rudberg MA, et al. The natural history of delirium in older hospitalized patients: a syndrome of heterogeneity. Age Ageing. 1997;26(3):169–74.PubMedCrossRefGoogle Scholar
  59. 59.
    Robinson TN, et al. Postoperative delirium in the elderly: risk factors and outcomes. Ann Surg. 2009;249(1):173–8.PubMedCrossRefGoogle Scholar
  60. 60.
    Robinson TN, et al. Motor subtypes of postoperative delirium in older adults. Arch Surg. 2011;146(3):295–300.PubMedPubMedCentralCrossRefGoogle Scholar
  61. 61.
    Pandharipande P, et al. Motoric subtypes of delirium in mechanically ventilated surgical and trauma intensive care unit patients. Intensive Care Med. 2007;33(10):1726–31.PubMedCrossRefGoogle Scholar
  62. 62.
    Lundstrom M, Stenvall M, Olofsson B. Symptom profile of postoperative delirium in patients with and without dementia. J Geriatr Psychiatry Neurol. 2012;25(3):162–9.PubMedCrossRefGoogle Scholar
  63. 63.
    Slor CJ, et al. Delirium motor subtypes in elderly hip fracture patients: risk factors, outcomes and longitudinal stability. J Psychosom Res. 2013;74(5):444–9.PubMedCrossRefGoogle Scholar
  64. 64.
    Rudolph JL, et al. Delirium is associated with early postoperative cognitive dysfunction. Anaesthesia. 2008;63(9):941–7.PubMedPubMedCentralCrossRefGoogle Scholar
  65. 65.
    Breu A, et al. Subsyndromal delirium after cardiac surgery. Scand Cardiovasc J. 2015;49(4):207–12.PubMedCrossRefGoogle Scholar
  66. 66.
    Li HC, et al. Delirium, subsyndromal delirium, and cognitive changes in individuals undergoing elective coronary artery bypass graft surgery. J Cardiovasc Nurs. 2015;30(4):340–5.PubMedCrossRefGoogle Scholar
  67. 67.
    Cole MG, et al. Subsyndromal delirium in older people: a systematic review of frequency, risk factors, course and outcomes. Int J Geriatr Psychiatry. 2013;28(8):771–80.PubMedCrossRefGoogle Scholar
  68. 68.
    Farrell KR, Ganzini L. Misdiagnosing delirium as depression in medically ill elderly patients. Arch Intern Med. 1995;155(22):2459–64.PubMedCrossRefGoogle Scholar
  69. 69.
    Golinger RC. Delirium in surgical patients seen at psychiatric consultation. Surg Gynecol Obstet. 1986;163(2):104–6.PubMedGoogle Scholar
  70. 70.
    Armstrong SC, Cozza KL, Watanabe KS. The misdiagnosis of delirium. Psychosomatics. 1997;38(5):433–9.PubMedCrossRefGoogle Scholar
  71. 71.
    Cheung CZ, et al. Recognition and labeling of delirium symptoms by intensivists: does it matter? Intensive Care Med. 2008;34(3):437–46.PubMedCrossRefGoogle Scholar
  72. 72.
    Engel GL, Romano J. Delirium, a syndrome of cerebral insufficiency. J Chronic Dis. 1959;9(3):260–77.PubMedCrossRefGoogle Scholar
  73. 73.
    van der Kooi AW, et al. What are the opportunities for EEG-based monitoring of delirium in the ICU? J Neuropsychiatry Clin Neurosci. 2012;24(4):472–7.PubMedCrossRefGoogle Scholar
  74. 74.
    van der Kooi AW, et al. Delirium detection using EEG: what and how to measure. Chest. 2015;147(1):94–101.PubMedCrossRefGoogle Scholar
  75. 75.
    Plaschke K, et al. Early postoperative delirium after open-heart cardiac surgery is associated with decreased bispectral EEG and increased cortisol and interleukin-6. Intensive Care Med. 2010;36(12):2081–9.PubMedCrossRefGoogle Scholar
  76. 76.
    Maldonado JR. Neuropathogenesis of delirium: review of current etiologic theories and common pathways. Am J Geriatr Psychiatry. 2013;21(12):1190–222.PubMedCrossRefGoogle Scholar
  77. 77.
    Maldonado JR. Pathoetiological model of delirium: a comprehensive understanding of the neurobiology of delirium and an evidence-based approach to prevention and treatment. Crit Care Clin. 2008;24(4):789–856, ix.PubMedCrossRefGoogle Scholar
  78. 78.
    Cerejeira J, et al. The cholinergic system and inflammation: common pathways in delirium pathophysiology. J Am Geriatr Soc. 2012;60(4):669–75.PubMedCrossRefGoogle Scholar
  79. 79.
    Baranyi A, Rothenhausler HB. The impact of soluble interleukin-2 receptor as a biomarker of delirium. Psychosomatics. 2014;55(1):51–60.PubMedCrossRefGoogle Scholar
  80. 80.
    Rudolph JL, et al. Chemokines are associated with delirium after cardiac surgery. J Gerontol A Biol Sci Med Sci. 2008;63(2):184–9.PubMedPubMedCentralCrossRefGoogle Scholar
  81. 81.
    Westhoff D, et al. Preoperative cerebrospinal fluid cytokine levels and the risk of postoperative delirium in elderly hip fracture patients. J Neuroinflammation. 2013;10:122.PubMedPubMedCentralCrossRefGoogle Scholar
  82. 82.
    Vasunilashorn SM, et al. Cytokines and postoperative delirium in older patients undergoing major elective surgery. J Gerontol A Biol Sci Med Sci. 2015;70(10):1289–95.PubMedPubMedCentralCrossRefGoogle Scholar
  83. 83.
    Liu P, et al. High serum interleukin-6 level is associated with increased risk of delirium in elderly patients after noncardiac surgery: a prospective cohort study. Chin Med J. 2013;126(19):3621–7.PubMedGoogle Scholar
  84. 84.
    van Munster BC, et al. Time-course of cytokines during delirium in elderly patients with hip fractures. J Am Geriatr Soc. 2008;56(9):1704–9.PubMedCrossRefGoogle Scholar
  85. 85.
    van Munster BC, et al. Cortisol, interleukins and S100B in delirium in the elderly. Brain Cogn. 2010;74(1):18–23.PubMedCrossRefGoogle Scholar
  86. 86.
    Cape E, et al. Cerebrospinal fluid markers of neuroinflammation in delirium: a role for interleukin-1beta in delirium after hip fracture. J Psychosom Res. 2014;77(3):219–25.PubMedPubMedCentralCrossRefGoogle Scholar
  87. 87.
    Kazmierski J, et al. Raised IL-2 and TNF-alpha concentrations are associated with postoperative delirium in patients undergoing coronary-artery bypass graft surgery. Int Psychogeriatr. 2014;26(5):845–55.PubMedCrossRefGoogle Scholar
  88. 88.
    Kazmierski J, et al. Cortisol levels and neuropsychiatric diagnosis as markers of postoperative delirium: a prospective cohort study. Crit Care. 2013;17(2):R38.PubMedPubMedCentralCrossRefGoogle Scholar
  89. 89.
    Cerejeira J, et al. The stress response to surgery and postoperative delirium: evidence of hypothalamic-pituitary-adrenal axis hyperresponsiveness and decreased suppression of the GH/IGF-1 Axis. J Geriatr Psychiatry Neurol. 2013;26(3):185–94.CrossRefGoogle Scholar
  90. 90.
    Leung JM, et al. Preoperative sleep disruption and postoperative delirium. J Clin Sleep Med. 2015;11(8):907–13.PubMedPubMedCentralGoogle Scholar
  91. 91.
    Manenschijn L, et al. Glucocorticoid receptor haplotype is associated with a decreased risk of delirium in the elderly. Am J Med Genet B Neuropsychiatr Genet. 2011;156B(3):316–21.PubMedCrossRefGoogle Scholar
  92. 92.
    Kazmierski J, et al. The assessment of the T102C polymorphism of the 5HT2a receptor gene, 3723G/A polymorphism of the NMDA receptor 3A subunit gene (GRIN3A) and 421C/A polymorphism of the NMDA receptor 2B subunit gene (GRIN2B) among cardiac surgery patients with and without delirium. Gen Hosp Psychiatry. 2014;36(6):753–6.PubMedCrossRefGoogle Scholar
  93. 93.
    van Munster BC, et al. Genetic polymorphisms in the DRD2, DRD3, and SLC6A3 gene in elderly patients with delirium. Am J Med Genet B Neuropsychiatr Genet. 2010;153B(1):38–45.PubMedGoogle Scholar
  94. 94.
    Hall RJ, et al. Delirium and cerebrospinal fluid S100B in hip fracture patients: a preliminary study. Am J Geriatr Psychiatry. 2013;21(12):1239–43.PubMedCrossRefGoogle Scholar
  95. 95.
    Robinson TN, et al. Low tryptophan levels are associated with postoperative delirium in the elderly. Am J Surg. 2008;196(5):670–4.PubMedPubMedCentralCrossRefGoogle Scholar
  96. 96.
    Nakamura J, et al. Association of plasma free-3-methoxy-4-hydroxyphenyl (ethylene)glycol, natural killer cell activity and delirium in postoperative patients. Int Clin Psychopharmacol. 2001;16(6):339–43.PubMedCrossRefGoogle Scholar
  97. 97.
    Golinger RC, Peet T, Tune LE. Association of elevated plasma anticholinergic activity with delirium in surgical patients. Am J Psychiatry. 1987;144(9):1218–20.PubMedCrossRefGoogle Scholar
  98. 98.
    Tune LE, et al. Association of postoperative delirium with raised serum levels of anticholinergic drugs. Lancet. 1981;2(8248):651–3.PubMedCrossRefGoogle Scholar
  99. 99.
    Cerejeira J, et al. Low preoperative plasma cholinesterase activity as a risk marker of postoperative delirium in elderly patients. Age Ageing. 2011;40(5):621–6.PubMedCrossRefGoogle Scholar
  100. 100.
    van Munster BC, et al. Longitudinal assessment of serum anticholinergic activity in delirium of the elderly. J Psychiatr Res. 2012;46(10):1339–45.PubMedCrossRefGoogle Scholar
  101. 101.
    Klein Klouwenberg PM, et al. The attributable mortality of delirium in critically ill patients: prospective cohort study. BMJ. 2014;349:g6652.PubMedPubMedCentralCrossRefGoogle Scholar
  102. 102.
    Zywiel MG, et al. Health economic implications of perioperative delirium in older patients after surgery for a fragility hip fracture. J Bone Joint Surg Am. 2015;97(10):829–36.PubMedCrossRefGoogle Scholar
  103. 103.
    Edelstein DM, et al. Effect of postoperative delirium on outcome after hip fracture. Clin Orthop Relat Res. 2004;422:195–200.CrossRefGoogle Scholar
  104. 104.
    Kat MG, et al. Long-term cognitive outcome of delirium in elderly hip surgery patients. A prospective matched controlled study over two and a half years. Dement Geriatr Cogn Disord. 2008;26(1):1–8.PubMedCrossRefGoogle Scholar
  105. 105.
    Bickel H, et al. High risk of cognitive and functional decline after postoperative delirium. A three-year prospective study. Dement Geriatr Cogn Disord. 2008;26(1):26–31.PubMedCrossRefGoogle Scholar
  106. 106.
    Bellelli G, et al. Duration of postoperative delirium is an independent predictor of 6-month mortality in older adults after hip fracture. J Am Geriatr Soc. 2014;62(7):1335–40.PubMedCrossRefGoogle Scholar
  107. 107.
    Crocker E, et al. Long-term effects of postoperative delirium in patients undergoing cardiac operation: a systematic review. Ann Thorac Surg. 2016;102(4):1391–9.PubMedCrossRefGoogle Scholar
  108. 108.
    Rudolph JL, et al. Delirium: an independent predictor of functional decline after cardiac surgery. J Am Geriatr Soc. 2010;58(4):643–9.PubMedPubMedCentralCrossRefGoogle Scholar
  109. 109.
    Saczynski JS, et al. Cognitive trajectories after postoperative delirium. N Engl J Med. 2012;367(1):30–9.PubMedPubMedCentralCrossRefGoogle Scholar
  110. 110.
    Martin BJ, et al. Delirium: a cause for concern beyond the immediate postoperative period. Ann Thorac Surg. 2012;93(4):1114–20.PubMedCrossRefGoogle Scholar
  111. 111.
    Koster S, Hensens AG, van der Palen J. The long-term cognitive and functional outcomes of postoperative delirium after cardiac surgery. Ann Thorac Surg. 2009;87(5):1469–74.PubMedCrossRefGoogle Scholar
  112. 112.
    Salluh JI, et al. Outcome of delirium in critically ill patients: systematic review and meta-analysis. BMJ. 2015;350:h2538.PubMedPubMedCentralCrossRefGoogle Scholar
  113. 113.
    Gleason LJ, et al. Effect of delirium and other major complications on outcomes after elective surgery in older adults. JAMA Surg. 2015;150(12):1134–40.PubMedPubMedCentralCrossRefGoogle Scholar
  114. 114.
    Raats JW, et al. Risk factors and outcomes for postoperative delirium after major surgery in elderly patients. PLoS One. 2015;10(8):e0136071.PubMedPubMedCentralCrossRefGoogle Scholar
  115. 115.
    Lescot T, et al. Postoperative delirium in the intensive care unit predicts worse outcomes in liver transplant recipients. Can J Gastroenterol. 2013;27(4):207–12.PubMedPubMedCentralCrossRefGoogle Scholar
  116. 116.
    Markar SR, et al. The clinical and economic costs of delirium after surgical resection for esophageal malignancy. Ann Surg. 2013;258(1):77–81.PubMedCrossRefGoogle Scholar
  117. 117.
    Inouye SK, Charpentier PA. Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability. JAMA. 1996;275(11):852–7.PubMedCrossRefGoogle Scholar
  118. 118.
    Elie M, et al. Delirium risk factors in elderly hospitalized patients. J Gen Intern Med. 1998;13(3):204–12.PubMedPubMedCentralCrossRefGoogle Scholar
  119. 119.
    Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014;383(9920):911–22.PubMedCrossRefGoogle Scholar
  120. 120.
    Yang Y, et al. Risk factors for postoperative delirium following hip fracture repair in elderly patients: a systematic review and meta-analysis. Aging Clin Exp Res. 2016;29(2):115–26.PubMedCrossRefGoogle Scholar
  121. 121.
    Bruce AJ, et al. The incidence of delirium associated with orthopedic surgery: a meta-analytic review. Int Psychogeriatr. 2007;19(2):197–214.PubMedCrossRefGoogle Scholar
  122. 122.
    Shi C, et al. Risk factors for delirium after spinal surgery: a meta-analysis. World Neurosurg. 2015;84(5):1466–72.PubMedCrossRefGoogle Scholar
  123. 123.
    Lin Y, Chen J, Wang Z. Meta-analysis of factors which influence delirium following cardiac surgery. J Card Surg. 2012;27(4):481–92.PubMedCrossRefGoogle Scholar
  124. 124.
    Rudolph JL, et al. Atherosclerosis is associated with delirium after coronary artery bypass graft surgery. J Am Geriatr Soc. 2005;53(3):462–6.PubMedCrossRefGoogle Scholar
  125. 125.
    Raats JW, et al. Risk factors of post-operative delirium after elective vascular surgery in the elderly: a systematic review. Int J Surg. 2016;35:1–6.PubMedCrossRefGoogle Scholar
  126. 126.
    Scholz AF, et al. Systematic review and meta-analysis of risk factors for postoperative delirium among older patients undergoing gastrointestinal surgery. Br J Surg. 2016;103(2):e21–8.PubMedCrossRefGoogle Scholar
  127. 127.
    Zaal IJ, et al. A systematic review of risk factors for delirium in the ICU. Crit Care Med. 2015;43(1):40–7.PubMedCrossRefGoogle Scholar
  128. 128.
    van Meenen LC, et al. Risk prediction models for postoperative delirium: a systematic review and meta-analysis. J Am Geriatr Soc. 2014;62(12):2383–90.PubMedCrossRefGoogle Scholar
  129. 129.
    Jansen CJ, et al. Performance and agreement of risk stratification instruments for postoperative delirium in persons aged 50 years or older. PLoS One. 2014;9(12):e113946.PubMedPubMedCentralCrossRefGoogle Scholar
  130. 130.
    Mason SE, Noel-Storr A, Ritchie CW. The impact of general and regional anesthesia on the incidence of post-operative cognitive dysfunction and post-operative delirium: a systematic review with meta-analysis. J Alzheimers Dis. 2010;22(Suppl 3):67–79.PubMedCrossRefGoogle Scholar
  131. 131.
    Caplan JP, Stern TA. Mnemonics in a mnutshell: 32 aids to psychiatric diagnosis. Curr Psychiatr Ther. 2008;7(10):27–33.Google Scholar
  132. 132.
    Maldonado JR. Delirium: neurobiology, characteristics, and management. In: Fogel BS, Greenberg DB, editors. Psychiatric care of the medical patient. 3rd ed. New York: Oxford University Press; 2015. p. 823–907.CrossRefGoogle Scholar
  133. 133.
    Oldham M. Autoimmune encephalopathy for psychiatrists: when to suspect autoimmunity and what to do next. Psychosomatics. 2017;58(3):228–44.PubMedCrossRefGoogle Scholar
  134. 134.
    Sedel F, et al. Psychiatric manifestations revealing inborn errors of metabolism in adolescents and adults. J Inherit Metab Dis. 2007;30(5):631–41.PubMedCrossRefGoogle Scholar
  135. 135.
    Pisani MA, et al. Days of delirium are associated with 1-year mortality in an older intensive care unit population. Am J Respir Crit Care Med. 2009;180(11):1092–7.PubMedPubMedCentralCrossRefGoogle Scholar
  136. 136.
    Kiely DK, et al. Persistent delirium predicts greater mortality. J Am Geriatr Soc. 2009;57(1):55–61.PubMedPubMedCentralCrossRefGoogle Scholar
  137. 137.
    MacLullich AM, et al. Delirium and long-term cognitive impairment. Int Rev Psychiatry. 2009;21(1):30–42.PubMedCrossRefGoogle Scholar
  138. 138.
    Pandharipande PP, et al. Long-term cognitive impairment after critical illness. N Engl J Med. 2013;369(14):1306–16.PubMedPubMedCentralCrossRefGoogle Scholar
  139. 139.
    Inouye SK, et al. The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients. Alzheimers Dement. 2016;12(7):766–75.PubMedPubMedCentralCrossRefGoogle Scholar
  140. 140.
    American Geriatrics Society Expert Panel on Postoperative Delirium in Older, A. American Geriatrics Society abstracted clinical practice guideline for postoperative delirium in older adults. J Am Geriatr Soc. 2015;63(1):142–50.CrossRefGoogle Scholar
  141. 141.
    Barr J, et al. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med. 2013;41(1):263–306.PubMedCrossRefPubMedCentralGoogle Scholar
  142. 142.
    Aldecoa C, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34(4):192–214.PubMedCrossRefGoogle Scholar
  143. 143.
    National Institute for Health and Clinical Excellence. Delirium: prevention, diagnosis and management. 2010 March 3, 2017; Available from:
  144. 144.
    Heymann A, et al. Delayed treatment of delirium increases mortality rate in intensive care unit patients. J Int Med Res. 2010;38(5):1584–95.PubMedCrossRefGoogle Scholar
  145. 145.
    Kratz T, et al. Preventing postoperative delirium. Dtsch Arztebl Int. 2015;112(17):289–96.PubMedPubMedCentralGoogle Scholar
  146. 146.
    Balas MC, et al. Effectiveness and safety of the awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle. Crit Care Med. 2014;42(5):1024–36.PubMedPubMedCentralCrossRefGoogle Scholar
  147. 147.
    Marcantonio ER, et al. Reducing delirium after hip fracture: a randomized trial. J Am Geriatr Soc. 2001;49(5):516–22.PubMedCrossRefGoogle Scholar
  148. 148.
    Gosch M, Nicholas JA. Pharmacologic prevention of postoperative delirium. Z Gerontol Geriatr. 2014;47(2):105–9.PubMedCrossRefGoogle Scholar
  149. 149.
    Kalisvaart KJ, et al. Haloperidol prophylaxis for elderly hip-surgery patients at risk for delirium: a randomized placebo-controlled study. J Am Geriatr Soc. 2005;53(10):1658–66.PubMedCrossRefGoogle Scholar
  150. 150.
    Gilmore ML, Wolfe DJ. Antipsychotic prophylaxis in surgical patients modestly decreases delirium incidence—but not duration—in high-incidence samples: a meta-analysis. Gen Hosp Psychiatry. 2013;35(4):370–5.PubMedCrossRefGoogle Scholar
  151. 151.
    Djaiani G, et al. Dexmedetomidine versus propofol sedation reduces delirium after cardiac surgery: a randomized controlled trial. Anesthesiology. 2016;124(2):362–8.PubMedCrossRefGoogle Scholar
  152. 152.
    Shehabi Y, et al. Prevalence of delirium with dexmedetomidine compared with morphine based therapy after cardiac surgery: a randomized controlled trial (DEXmedetomidine COmpared to Morphine-DEXCOM Study). Anesthesiology. 2009;111(5):1075–84.PubMedCrossRefGoogle Scholar
  153. 153.
    Su X, et al. Dexmedetomidine for prevention of delirium in elderly patients after non-cardiac surgery: a randomised, double-blind, placebo-controlled trial. Lancet. 2016;388(10054):1893–902.PubMedCrossRefGoogle Scholar
  154. 154.
    Yang X, et al. Effect of dexmedetomidine on preventing agitation and delirium after microvascular free flap surgery: a randomized, double-blind, control study. J Oral Maxillofac Surg. 2015;73(6):1065–72.PubMedCrossRefGoogle Scholar
  155. 155.
    Deiner S, et al. Intraoperative infusion of dexmedetomidine for prevention of postoperative delirium and cognitive dysfunction in elderly patients undergoing major elective noncardiac surgery: a randomized clinical trial. JAMA Surg. 2017;152(8):e171505.PubMedPubMedCentralCrossRefGoogle Scholar
  156. 156.
    van Eijk MM, et al. Effect of rivastigmine as an adjunct to usual care with haloperidol on duration of delirium and mortality in critically ill patients: a multicentre, double-blind, placebo-controlled randomised trial. Lancet. 2010;376(9755):1829–37.PubMedCrossRefGoogle Scholar
  157. 157.
    Bourne RS, Mills GH, Minelli C. Melatonin therapy to improve nocturnal sleep in critically ill patients: encouraging results from a small randomised controlled trial. Crit Care. 2008;12(2):R52.PubMedPubMedCentralCrossRefGoogle Scholar
  158. 158.
    Sultan SS. Assessment of role of perioperative melatonin in prevention and treatment of postoperative delirium after hip arthroplasty under spinal anesthesia in the elderly. Saudi J Anaesth. 2010;4(3):169–73.PubMedPubMedCentralCrossRefGoogle Scholar
  159. 159.
    Al-Aama T, et al. Melatonin decreases delirium in elderly patients: a randomized, placebo-controlled trial. Int J Geriatr Psychiatry. 2011;26(7):687–94.PubMedCrossRefPubMedCentralGoogle Scholar
  160. 160.
    de Jonghe A, et al. Effect of melatonin on incidence of delirium among patients with hip fracture: a multicentre, double-blind randomized controlled trial. CMAJ. 2014;186(14):E547–56.PubMedPubMedCentralCrossRefGoogle Scholar
  161. 161.
    Hatta K, et al. Preventive effects of ramelteon on delirium: a randomized placebo-controlled trial. JAMA Psychiat. 2014;71(4):397–403.CrossRefGoogle Scholar
  162. 162.
    Taguchi T, Yano M, Kido Y. Influence of bright light therapy on postoperative patients: a pilot study. Intensive Crit Care Nurs. 2007;23(5):289–97.PubMedCrossRefGoogle Scholar
  163. 163.
    Ono H, et al. The usefulness of bright light therapy for patients after oesophagectomy. Intensive Crit Care Nurs. 2011;27(3):158–66.PubMedCrossRefPubMedCentralGoogle Scholar
  164. 164.
    Simons KS, et al. Dynamic light application therapy to reduce the incidence and duration of delirium in intensive-care patients: a randomised controlled trial. Lancet Respir Med. 2016;4(3):194–202.PubMedCrossRefGoogle Scholar
  165. 165.
    Hoffmann H, Kettelhack C. Fast-track surgery—conditions and challenges in postsurgical treatment: a review of elements of translational research in enhanced recovery after surgery. Eur Surg Res. 2012;49(1):24–34.PubMedCrossRefGoogle Scholar
  166. 166.
    Salata K, et al. Endovascular versus open approach to aortic aneurysm repair surgery: rates of postoperative delirium. Can J Anaesth. 2012;59(6):556–61.PubMedCrossRefGoogle Scholar
  167. 167.
    Sieber FE, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc. 2010;85(1):18–26.PubMedPubMedCentralCrossRefGoogle Scholar
  168. 168.
    Whitlock EL, et al. Postoperative delirium in a substudy of cardiothoracic surgical patients in the BAG-RECALL clinical trial. Anesth Analg. 2014;118(4):809–17.PubMedPubMedCentralCrossRefGoogle Scholar
  169. 169.
    Chan MT, et al. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol. 2013;25(1):33–42.PubMedCrossRefGoogle Scholar
  170. 170.
    Radtke FM, et al. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth. 2013;110(Suppl 1):i98–105.PubMedCrossRefGoogle Scholar
  171. 171.
    Rudolph JL, et al. A delirium risk modification program is associated with hospital outcomes. J Am Med Dir Assoc. 2014;15(12):957. e7–11.PubMedCrossRefGoogle Scholar
  172. 172.
    Flaherty JH, Little MO. Matching the environment to patients with delirium: lessons learned from the delirium room, a restraint-free environment for older hospitalized adults with delirium. J Am Geriatr Soc. 2011;59(Suppl 2):S295–300.PubMedCrossRefGoogle Scholar
  173. 173.
    Neufeld KJ, et al. Antipsychotic medication for prevention and treatment of delirium in hospitalized adults: a systematic review and meta-analysis. J Am Geriatr Soc. 2016;64(4):705–14.PubMedPubMedCentralCrossRefGoogle Scholar
  174. 174.
    Schrijver EJ, et al. Efficacy and safety of haloperidol for in-hospital delirium prevention and treatment: a systematic review of current evidence. Eur J Intern Med. 2016;27:14–23.PubMedCrossRefGoogle Scholar
  175. 175.
    Schuckit MA. Recognition and management of withdrawal delirium (delirium tremens). N Engl J Med. 2014;371(22):2109–13.PubMedCrossRefGoogle Scholar

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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of PsychiatryUniversity of Rochester Medical CenterRochesterUSA

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