Postoperative Delirium (POD) and Cognitive Dysfunction (POCD)

SJMH Clinical Conference 7/12

Ryan Pirooz, M.D.

pirooz

Definitions:

 POCD – a drop in cognitive performance on a set of neuropsychological tests taken before and after surgery, typically can span in range of weeks to years. POD – characterized by acute onset + fluctuating course + inattention + (either disorganized thinking – or – altered level of consciousness); requires increased vigilance because it can present as both hyperactive and hypo-active; typically ranges over hospital course.  Associated complications: POD associated with increased mortality, ventilator/hospital/ICU days, and health-care cost;also associated with increased rate of POCD. POCD associated with increased risk of leaving workforce, disability/unemployment, and mortality.

Prevalence: Across all adult age ranges, 30-40% of surgical patients demonstrate POCD in the first week.  Only older adults (age > 60) demonstrate persistent POCD after months/years.

Persistent POCD is associated with increased mortality.

Risk factors:

Many suspected risk factors including: multiple comorbidities, more severe illness, HTN,

Abnormally high or low BMI, hypoalbuminemia, EtOH abuse, respiratory failure, but…

…Only advanced age (>60-75 depending on study) and poor preoperative cognitive status

(E.g. lower educational level, dementia, prior CVA) show consistent predictive capability

Perioperative strategy:

 Target high-risk patients (elderly, cognitively-impaired)

  1. Limit or avoid antidopaminergic antiemetics (e.g. metoclopramide, ondansetron), antihistamines (e.g. diphenhydramine), benzodiazapines, opioids
  2. Consider regional anesthesia when possible, though evidence does not yet support it’s superiority over GA
  3. Monitor and limit depth of anesthesia; studies demonstrate less POCD (and less mortality) with use of BIS and cerebral oximeter, even in regional cases
  4. Treatment in recovery area should begin with correcting underlying problems (e.g. hypotension, hypoxia, hypercapnia, etc.) and attempting to orient patient (return eyeglasses and hearing aids, bring family back, use of a sitter) before medical intervention.

Medical intervention in recovery area begins with antipsychotics (haloperidol most readily-available, dose 0.5-1 mg repeated q5-10mins). Benzos are theoretically second-line but should only be used when patient is a threat to themselves or others, because they are associated with increased confusion, sedation, rebound delirium, paradoxical rxn.

Future considerations:

¨ Better and more consistent testing for POCD and POD?

¨ Truly significant difference between regional and GA?

¨ Prehab? Rehab?

¨ Role of perioperative surgical home? Continuity of care?

References

Ballard C, Jones E, Gauge N, et al. Optimised Anaesthesia to Reduce Post Operative Cognitive Decline (POCD) in Older Patients Undergoing Elective Surgery, a Randomised Controlled Trial. Xie Z, ed. PLoS ONE. 2012; 7(6):e37410.

Berger M et al. Postoperative Cognitive Dysfunction. Anesthesiology Clin. 2015; 33(3):517-550.

Davis N et al. Postoperative Cognitive Function Following General versus Regional Anesthesia: A Systematic Review. J Neurosurg Anesthesiology. 2014; 26(4):369-76.

Deiner S et al. Postoperative Delirium and Cognitive Dysfunction. Br. J. Anaesth. 2009; 103:41-46.

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.

Inouye SK et al. Postoperative Delirium in Older Adults: Best Practice Statement from the American Geriatrics Society. J. of Amer College of Surg. 2015; 220(2):136-148.

Monk T et al. Predictors of Cognitive Dysfunction after Major Noncardiac Surgery. Anesthesiology. 2008; 108:18-30

Saczynski JS et al. Cognitive Trajectories after Postoperative Delirium. The New England Journal of Medicine. 2012; 367(1)30-39.

Steinmetz J et al. Long-term Consequences of Postoperative Cognitive Dysfuntion. Anesthesiology. 2009; 110:548-55.