Anesthesia Alert - Prevent Post-Op Delirium and Dysfunction

Anesthesia

By: Christopher Jankowski

Published: 1/14/2013

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Elderly patients are at risk any time they undergo surgery.


Prevent Post-Op Delirium and Dysfunction DELIRIOUS Delirium after emergence from anesthesia is common in elderly patients.

The population is aging, and elderly patients have surgery at a higher rate than their younger counterparts. Post-operative delirium is among the most common complications in this group of surgical patients.

Although there's debate over whether a surgical procedure with anesthesia triggers long-term cognitive decline, post-operative delirium may persist for months and can be associated with delayed discharge, increased morbidity and mortality, and higher costs.

Here's a look at how post-op delirium develops, the factors that put patients at risk and what you can do to ameliorate it.

From delirium to dysfunction
There are 2 forms of post-op central nervous system dysfunction: cognitive decline and delirium. Cognitive decline isn't a formally recognized diagnosis, but can be defined essentially as a disturbance of consciousness that develops over a short period of time (hours to days) and tends to fluctuate over the course of a given day. Delirium, on the other hand, is a formally recognized diagnosis, and a more relevant issue in ambulatory surgery.

To be called delirium, the cognitive or perceptual disturbance must not be better accounted for by a pre-existing, established or evolving dementia; rather, it should occur as a direct result of the physiological consequences of an acute insult (that is, surgery). Delirium after emergence from anesthesia can result in events such as IV catheter removal, injuries to the patient or staff, and increased time in PACU.

Delirium can be expected in the 24 to 72 hours immediately post-op. Emergence delirium may predict longer-term post-operative delirium and, in some populations, may actually predict long-term functional decline. However, the relationship between post-op delirium and dementia is unclear.

Some postulated mechanisms of delirium that may be in place include decreased oxidative metabolism in the central nervous system, decreased presence of neurotransmitters, increased cortisol or other inflammatory mediator levels and embolic phenomena, along with genetic predisposition and effects of medications.

STEPS YOU CAN TAKE
Preventing Post-Operative Delirium

Steps to take intraoperatively:

  • Maintain adequate oxygenation and perfusion.
  • Correct glucose and electrolytes.
  • Adjust the doses of drugs and anesthesia as appropriate (anesthetic requirements are lower in patients as they age).
  • Use medications with short half-lives.
  • Avoid central-acting anticholinergics, benzodiazepines and meperidine.

Post-operatively, you should do the following:

  • Treat pain.
  • Avoid drugs associated with delirium.
  • Encourage earliest safe discharge to an environment that discourages delirium and is conducive to normal sleep.
  • Frequently reorient the patient.
  • Mobilize and ambulate the patient.
  • Appropriately hydrate the patient.
  • Modify steps as necessary to make allowances for visual and hearing impairment.

— Christopher J. Jankowski, MD

Predicting risk
Increasing age and duration of anesthesia, subsequent operations, post-operative infection and respiratory complications are risk factors for early post-op delirium. Other predictors include alcohol abuse, low physical function, major electrolyte and glucose abnormalities, vision impairment (<20/70), a previous history of illness, long-term anti-depressant treatment and BUN-to-creatinine ratio ≥18:1.

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