Early delirium after cardiac surgery: an analysis of incidence and risk factors in elderly (≥65 years) and very elderly (≥80 years) patients

Introduction Postoperative delirium is a common complication of cardiac surgery associated with increased mortality, morbidity, and long-term cognitive dysfunction. The aim of this study was to identify incidence and risk factors of delirium in elderly (≥65 years) and very elderly (≥80 years) patients undergoing major cardiac surgery. Materials and methods We performed a retrospective cohort analysis of prospectively collected data from a register of the cardiac surgery department of a tertiary referral university hospital between 2014 and 2016. Analysis was performed in two groups, ≥65 years and ≥80 years. Results We analyzed 1,797 patients ≥65 years, including 230 (7.24%) patients ≥80 years. Delirium was diagnosed in 21.4% (384/1,797) of patients above 65 years, and in 33.5% (77/230) of octogenarians. Early mortality did not differ between patients with and without delirium. Intensive care unit (ICU) stay (p<0.001), hospital stay (p<0.001), and intubation time (p=0.002) were significantly longer in patients undergoing cardiac surgery ≥65 years with delirium. According to multivariable analysis, <65 years, age (odds ratio [OR] 1.036, p=0.002), low ejection fraction (OR 1.634, p=0.035), diabetes (1.346, p=0.019), and extracardiac arteriopathy (OR 1.564, p=0.007) were found to be independent predictors of post-cardiac surgery delirium. Postoperative risk factors for developing delirium ≥65 years were atrial fibrillation (1.563, p=0.001), postoperative pneumonia (OR 1.896, p=0.022), elevated postoperative creatinine (OR 1.384, p=0.004), and prolonged hospitalization (OR 1.019, p=0.009). Conclusion Patients above 65 years of age with postoperative delirium have poorer outcome and are more likely to have prolonged hospitalization and ICU stay, and longer intubation times, but 30-day mortality is not increased. In our study, eight independent risk factors for development of post-cardiac surgery delirium were age, low ejection fraction, diabetes, extracardiac arteriopathy, postoperative atrial fibrillation, pneumonia, elevated creatinine, and prolonged hospitalization time.

[1]  Y. Okita,et al.  Impact of delirium on postoperative frailty and long term cardiovascular events after cardiac surgery , 2017, PloS one.

[2]  S. Kim,et al.  Early postoperative delirium after hemiarthroplasty in elderly patients aged over 70 years with displaced femoral neck fracture , 2017, Clinical interventions in aging.

[3]  V. Rao,et al.  Cerebral oximetry and postoperative delirium after cardiac surgery: a randomised, controlled trial , 2017, Anaesthesia.

[4]  A. Shaw,et al.  Predicting, preventing, and identifying delirium after cardiac surgery , 2016, Perioperative Medicine.

[5]  Y. Okita,et al.  Preoperative physical activity in relation to postoperative delirium in elective cardiac surgery patients. , 2015, International journal of cardiology.

[6]  A. Slooter,et al.  Risk factors for delirium after on-pump cardiac surgery: a systematic review , 2015, Critical Care.

[7]  R. Stevens,et al.  Outcome of delirium in critically ill patients: systematic review and meta-analysis , 2015, BMJ : British Medical Journal.

[8]  M. Bonten,et al.  The attributable mortality of delirium in critically ill patients: prospective cohort study , 2014, BMJ : British Medical Journal.

[9]  R. Jaeschke,et al.  Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the Intensive Care Unit , 2013, Critical care medicine.

[10]  Zhinong Wang,et al.  Meta‐Analysis of Factors Which Influence Delirium Following Cardiac Surgery , 2012, Journal of cardiac surgery.

[11]  A. Absalom,et al.  A review of postoperative cognitive dysfunction and neuroinflammation associated with cardiac surgery and anaesthesia , 2012, Anaesthesia.

[12]  P. Pagel,et al.  Postoperative delirium and short-term cognitive dysfunction occur more frequently in patients undergoing valve surgery with or without coronary artery bypass graft surgery compared with coronary artery bypass graft surgery alone: results of a pilot study. , 2011, Journal of cardiothoracic and vascular anesthesia.

[13]  S. Clarke,et al.  Delirium in older cardiac surgery patients: directions for practice. , 2010, Journal of gerontological nursing.

[14]  I. Kloszewska,et al.  Incidence and predictors of delirium after cardiac surgery: Results from The IPDACS Study. , 2010, Journal of psychosomatic research.

[15]  A. Monsch,et al.  Modifiable and nonmodifiable risk factors for postoperative delirium after cardiac surgery with cardiopulmonary bypass. , 2010, Journal of cardiothoracic and vascular anesthesia.

[16]  E. Marcantonio,et al.  Delirium: An Independent Predictor of Functional Decline After Cardiac Surgery , 2010, Journal of the American Geriatrics Society.

[17]  E. Mukaetova-Ladinska,et al.  The neuroinflammatory hypothesis of delirium , 2010, Acta Neuropathologica.

[18]  S. Zeger,et al.  Delirium after coronary artery bypass graft surgery and late mortality , 2009, Annals of neurology.

[19]  J. van der Palen,et al.  The long-term cognitive and functional outcomes of postoperative delirium after cardiac surgery. , 2009, The Annals of thoracic surgery.

[20]  L. Lipsitz,et al.  Derivation and Validation of a Preoperative Prediction Rule for Delirium After Cardiac Surgery , 2009, Circulation.

[21]  Ben Eiseman,et al.  Postoperative delirium in the elderly: diagnosis and management , 2008, Clinical interventions in aging.

[22]  E. Marcantonio,et al.  Chemokines are associated with delirium after cardiac surgery. , 2008, The journals of gerontology. Series A, Biological sciences and medical sciences.

[23]  S. Scarrow,et al.  Delirium in the Postoperative Cardiac Patient: A Review , 2005, Journal of cardiac surgery.

[24]  E. Marcantonio,et al.  Atherosclerosis Is Associated with Delirium After Coronary Artery Bypass Graft Surgery , 2005, Journal of the American Geriatrics Society.

[25]  Ying Zhang,et al.  A Chart‐Based Method for Identification of Delirium: Validation Compared with Interviewer Ratings Using the Confusion Assessment Method , 2005, Journal of the American Geriatrics Society.

[26]  L C Mion,et al.  Nurses' recognition of delirium and its symptoms: comparison of nurse and researcher ratings. , 2001, Archives of internal medicine.

[27]  S. Inouye.  Prevention of delirium in hospitalized older patients: risk factors and targeted intervention strategies , 2000, Annals of medicine.

[28]  I. S. Sveinsson.  Postoperative psychosis after heart surgery. , 1975, The Journal of thoracic and cardiovascular surgery.

[29]  J. Fishman,et al.  PSYCHIATRIC COMPLICATIONS FOLLOWING CORONARY BYPASS SURGERY , 1975, The Journal of nervous and mental disease.

[30]  Y. Okita,et al.  Preoperative exercise capacity is associated with the prevalence of postoperative delirium in elective cardiac surgery , 2017, Aging Clinical and Experimental Research.