Research &
Publications

Further Reading

Learn more about postoperative delirium and perioperative brain health.

Articles and References

Sprung J, Roberts RO, Weingarten TN, etal. Postoperative delirium in elderly patients is associated with subsequent cognitive impairment. Br J Anaesth. 2017;119(2):316-323.

Schenning KJ, Murchison CF, Mattek NC, Silbert LC, Kaye JA, Quinn JF. Surgery is associated with ventricular enlargement as well as cognitive and functional decline. Alzheimers Dement. 2016;12(5):590-597.

Hshieh TT, Saczynski J, Gou RY, et al; SAGES Study Group. Trajectory of functional recovery after postoperative delirium in elective surgery. Ann Surg. 2017;265(4):647-653.

Inouye SK, Marcantonio ER, Kosar CM, et al. The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients. Alzheimers Dement. 2016;12(7):766-775.

Evered LA, Silbert BS, Scott DA, Maruff P, Ames D. Prevalence of dementia 7.5 years after coronary artery bypass graft surgery. Anesthesiology. 2016;125(1):62-71

Lee HB, Oldham MA, Sieber FE, Oh ES. Impact of delirium after hip fracture surgery on one-year mortality in patients with or without dementia: a case of effect modification. Am J Geriatr Psychiatry. 2017 ;25(3):308-315.

Research References

Postoperative delirium as a target for surgical quality improvement

Berian, JR.; Zhou, L; Russell, MM, et al. Postoperative delirium as a target for surgical quality improvement [published online: July 24, 2017]Annals of Surgery. doi: 10.1097/SLA.0000000000002436.

This article used the new geriatric specific variables from the American College of Surgeons National Surgical Quality Improvement Program® (ACS NSQIP®) and showed large variability in delirium across hospitals (8.5 fold) with the strongest predictors as operation specific risk and preoperative cognitive impairment. These findings suggest that preoperative factors (procedure and underlying brain health) strongly influence whether a patient will develop delirium. However, adjusting for these risk factors some institutions appear to have a much higher incidence than others suggesting that postoperative environment may be important as well.

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The association between preoperative frailty and postoperative delirium after cardiac surgery

Brown CH 4th, Max L, LaFlam A, et al. The association between preoperative frailty and postoperative delirium after cardiac surgery. Anesthesia & Analgesia. 2016;123(2):430–435.

This prospective study screened patients for frailty prior to cardiac surgery and assessed for postoperative delirium. Frail patients had a much higher incidence of delirium (47.1%) as compared to non-frail patients (2.6%). The authors concluded that "frailty may identify patients who would benefit from delirium prevention strategies because of increased baseline risk for delirium."

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Effect of a modified hospital elder life program on delirium and length of hospital stay in patients undergoing abdominal surgery - a cluster randomized clinical trial

Chen CC, Li HC, Liang JT, et al. Effect of a modified hospital elder life program on delirium and length of hospital stay in patients undergoing abdominal surgery - a cluster randomized clinical trial. JAMA Surg. 2017;152(9):827-834.

This study consisted of three protocols (the mHELP intervention) implemented daily by a dedicated nurse for orienting communication, oral and nutritional assistance and early mobilization for 377 older patients undergoing major intra-abdominal surgery. This was a clustered RCT. For those patients who received the mHELP intervention the odds of delirium were reduced by 56% and length of stay by 2 days, compared with those patients who did not receive the intervention. The interventions are simple, applied to surgical patients, and the outcome’s impressive. The authors note that reliable implementation and delivery are key to success. The protocols are available within the Appendix in the paper.

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The AWOL tool: derivation and validation of a delirium prediction rule

Douglas VC, Hessler CS, Dhaliwal G et al. The AWOL tool: derivation and validation of a delirium prediction rule. J Hosp Med. 2013;8(9):493-499.

The AWOL tool is easily applied in a busy hospital floor or admission setting and takes less than two minutes. Derived and validated by Douglas et al AWOL is a simple risk prediction score to assess the risk of developing delirium in hospitalized adults.

The acronym AWOL is easy to remember, and stands for:
A: Age 80 years or greater
W: inability to spell the word "World" backwards
O: not fully Oriented to place
L: iLlness severity score assessed by a nurse - severity of moderately ill, severely ill, or moribund (as opposed to not ill or mildly ill)

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More about AWOL:

Predicting delirium: are we there yet?

Evered LA. Predicting delirium: are we there yet? August 2017. Br J Anaesth. 2017;119(2):281-283.

This editorial appears in the August 2017 edition of the British Journal of Anaesthesia which has a whole section dedicated to articles on delirium. The editorial gives a good overview with some useful references.

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The AWOL tool: derivation and validation of a delirium prediction rule

Douglas VC, Hessler CS, Dhaliwal G, et al. The AWOL tool: derivation and validation of a delirium prediction rule. J Hosp Med. 2013;8(9):493-499.

The AWOL prediction rule characterizes medical patients' risk for delirium at the time of hospital admission and could be used for clinical stratification and in trials of delirium prevention. Univariate analysis of the derivation study identified 10 variables significantly associated with delirium (see Table 2). Predictors of delirium included abnormal scores on 4 subtests of the MMSE, low score on the Mini‐Cog, living in an assisted living or skilled nursing facility, moderate to severe illness, old age, a past history of dementia, and hearing loss as assessed by the whisper test.

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Managing and preventing postoperative delirium

Kuza C, Cobb JP, Managing and preventing postoperative delirium. Anesthesiology News: CMEZone The Frost Series #330. Released August 1, 2017. Expires July 31, 2018.

Postoperative delirium (POD) is a common adverse event in surgery, resulting in increased mortality, cost, and long-term cognitive and physical complications. After completion of this educational activity, the reader should be able to: Define postoperative delirium; Describe the two most common tools used to diagnose postoperative delirium; Identify risk factors for postoperative delirium; Recognize the long-term implications and outcomes of postoperative delirium; Review the treatment of postoperative delirium.

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Podcasts

Delirium: Prevention, Diagnosis, and Treatment [Podcast]

Esther S. Oh, M.D., Ph.D., Tammy T. Hshieh, M.D., MPH, and Sharon K. Inouye, M.D., MPH, Audio 23 minutes 14 seconds, JAMA, September 26, 2017

Useful podcast to learn more about the diagnosis and treatment of delirium.

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