POST-OPERATIVE BRAIN DAMAGE

SUMMARY: After non-cardiac surgery at least, loss of cognitive functioning is relatively common in the elderly.  Post-operative delirium can result in iatrogenic damage or self-injury.  Stroke during or after surgery is rare but often lethal.  Brain death as a result of anesthetic mishap is exceedingly rare. 

Cognitive Deficits

Early reports of cognitive deterioration after cardiac surgery1 were not confirmed by a large, well-designed prospective study2

It is perhaps surprising then that after non-cardiac surgery an international study in the elderly3 showed unequivocally that the rate of Post-Operative Cognitive Dysfunction (POCD) was still high (10%) 3 months after surgery.  Of those older than 69 years, 14% still had new-onset Cognitive Dysfunction at 3 months. 

Also surprising is that hypotension and hypoxemia were not risk factors for POCD.  Indeed, although general anesthesia appeared to be a major factor, no deviations from standard procedure or preventive interventions could be identified. 

Pre-operative deterioration in short-term memory may be the only indicator of pre-clinical dementia4 or it may be a feature of normal aging5.  If new-onset permanent confusion develops following operation and anesthesia, dementia may be diagnosed and it may remain uncertain whether the condition would have developed, absent the surgery. 

PRACTICE POINT

In the elderly, new onset or accelerated cognitive loss is relatively common following major surgery and may be compensable

Delirium

Post-operative delirium can result in iatrogenic damage or self-injury.  About 10% of elderly patients suffer postoperative delirium following major elective surgery, but the figure is considerably higher following cardiac surgery and operations for hip fracture6

Various co-existing medical conditions and disturbances of body chemistry7 predispose surgical patients to delirium, and its occurrence does not appear to be largely determined by the type8 of anesthesia.  With appropriate care, the delirium is usually short-lived but secondary injury may result if the patient is not adequately protected or remediable factors7 not addressed. 

PRACTICE POINT

Delirium following major surgery requires prompt and detailed analysis of co-existing medical conditions to minimise secondary injury

Stroke

Stroke during or after surgery is rare but often lethal.  Stroke during surgery or in the postoperative period occurs in 29-710 per thousand general surgical operations.  This complication is to some degree predictable and preventable11

The mortality can be as high as 46%12, three times the death rate of stroke that occurs remote from surgery. 

PRACTICE POINT

If personal injury requires major surgery, death more commonly follows any resulting stroke

Death

Brain death as a result of anesthetic mishap is exceedingly rare. Nevertheless, maternal brain death is one of the commonest causes of obstetric anesthetic malpractice claims13.  It usually signifies extensive brain damage.

Copyright 2008 Electronic Handbook of Legal Medicine