2. Definition
• Impairment of cognitive function after a surgical procedure.
• Preoperative cognitive functional status should be known.
3. Incidence
• POD is 20 to 45%
• POCD
cardiac surgery - 20 to 50%
other major surgeries- 5 to 55%
The incidence of PONCD ranges from 30 to 60%
Evered LA, Silbert BS. Postoperative cognitive dysfunction and
noncardiac surgery. Anesth Analg 2018; 127:496–505
4. Terminology- Still evolving !
• Perioperative neurocognitive disorders- an overarching term.
• Neurocognitive disorder-- Cognitive decline preop ( mild cognitive
impairment ,Dementia , delirium )
• Postoperative delirium--any form of acute event .
• Delayed neurocognitive recovery cognitive decline up to 30 days.
• Postoperative neurocognitive disorder--up to 12 months .
# Emergence delirium ??
Br J Anaesth. 2018 Nov;121(5):1005-1012. doi: 10.1016/j.bja.2017.11.087. Epub 2018
Jun 15. Recommendations for the nomenclature of cognitive change
associated with anaesthesia and surgery-2018.Evered L1, Silbert B2, Knopman DS3,
Scott DA2, DeKosky ST4, Rasmussen LS5, Oh ES6, Crosby G7, Berger M8, Eckenhoff RG9;
Nomenclature Consensus Working Group.
6. Postop delirium
• Defined in (DSM-V) - disturbance of attention/awareness/cognition
• Deficit of ATTENTION -most prominent feature of POD,
• Fluctuates during the course of the day
• Associated psychotic symptoms,
• Disturbances of sleep–wake cycle.
• Can be hyperactive or hypoactive form.
American Geriatrics Society Expert Panel on Postoperative Delirium in Older Adults.
Postoperative delirium in older adults: best practice statement from the American
Geriatric society. J Am Coll Surg. 2015;220:136-148
7. Delayed neurocognitive recovery
• Cognitive impairment resolving within 30 days of operation
Evered L, Silbert B, Knopman DS, et al. Recommendations for the
nomenclature of cognitive change associated with anaesthesia
and surgery-2018. Br J Anaesth 2018; 121:1005–1012.
8. PONCD
• 30 days but- less than 12 months
• Consc, orientation, attention NOT affected.
Impairment in
• Domains of memory, perceptual–motor function
• Learning, language, and executive function
• Evidence is still scarce .
9. After One year -NCD
• Cognitive impairment still present after one year.
• Comprises dementia (major NCD)
• Mild cognitive impairment(mild NCD).
10. Consequences
• Increased rate of postoperative complication
• Prolonged hospital stay
• Threefold increases of MCI or dementia
• loss of independence/ everyday activities
• Increased care dependency,
• Reduced quality of life patients/relatives
• Long-term increase in morbidity and mortality
Steinmetz J, Christensen KB, Lund T, et al. Long-term
consequences of postoperative cognitive dysfunction.
Anesthesiology 2009; 110:548–555.
11. Diagnosis of PONCD
• Compared with POD –DSM5
• Diagnosis of other types is more complex,
• Require neuro-psychometric testing.
12. Risk factors /Causes
Exact cause of POCD is not known.
• Age >60 years
• Pre-existing : CNS/CVS/ Psych/ Cognitive impairments
• Sleep deprivation
• Low educational status
• History of alcohol abuse
Anesthetic factors
• Anesthetic technique – GA convey the most risk
• Intra-operative complications (Hypoxia/Hypotension)
• Poor pain management
Operative factors
• Types of surgery – cardiac surgery, major surgery (orthopaedic/vascular)
• Post-operative complications -infection, respiratory complications
• Multiple surgeries – particularly if they occur in a short period of time
14. Surgery / anaesthesia is not the only trigger
• Occur in patients who do not undergo surgery at all
• 10% of elderly in AnE present with delirium
• 20–30% nonsurgical patients experience delirium during hospitalization
• POCD genesis is likely to be multifactorial
Siddiqi N, Harrison JK, Clegg A, et al. Interventions for preventing delirium in
hospitalised non-ICU patients. Cochrane Database Syst Rev 2016;
3:Cd005563.
15. TESTS for POCD
• Minicog
• Simple clock drawing test
• MMSE ( Mini mental state exam ) –Dementia
• IQ code (Informant Questionnaire on Cognitive Decline in the Elderly)
• MoCA (Montreal Cognitive Assessment):
16. MINICOG
• Three-word registration/ clock drawing / three-word recall.
• Advantages: Easy to administer, available in many
languages, results independent from language skills and education
• Disadvantages: Not sensitive for mild cognitive
dysfunction
www.mini-cog.com
23. PREVENTION: WHAT CAN THE
ANAESTHETIST DO?
• Evidence shows - multiprofessional perioperative approach
Mahanna-Gabrielli E, Schenning KJ, Eriksson LI, et al. State of the clinical science
of perioperative brain health: report from the American Society of
Anesthesiologists Brain Health Initiative Summit 2018. Br J Anaesth
2019;123:464–478.
25. Prevention strategies
Preop
• Discuss with relatives
• Avoid prolonged fasting/postponement of surgery
• Dehydration and discomfort add to the risk
• Avoid premedication with benzodiazepines / Anticholinergics
• Encouraged to wear glasses/hearing aids /dentures
• Pain and opioids increase the risk of POD.
26. Prevention
• Deep sedation be avoided.
• Monitoring of sedation by BIS/ Entropy
• Fluctuations in blood pressure .
• Early postoperative mobilization /orientation
• Early removal of catheters and lines,
• Regulation of the sleep–wake cycle,
• Involvement of relatives/stimulating environment.
• Multicomponent programs more effective
27. Anaesthesia Technique
• Anaesthesia implicated in the pathogenesis.
• Choice of anaesthetic agent ?
• ESA - insufficient evidence to make a recommendation
Aldecoa C, Bettelli G, Bilotta F. European Society of Anaesthesiology evidence-based
and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol.
2017;34:192-214.
28. Regional Anesthesia ??
• Large meta analyses failed to show the protective effects
• Biased - many patients receive additional sedation
Sieber FE, Gottshalk A, Zakriya KJ, et al. General anesthesia occurs frequently
in elderly patients during propofol-based sedation and spinal anesthesia. J
Clin Anesth 2010; 22:179–183
Llango S, Pulle R, Bell J, et al. General versus spinal anaesthesia and
postoperative delirium in an orthogeriatric population. Australasian J Ageing.
2015;35:42-47
29. Depth Of Anesthesia
• BIS guided reduced incidence of Delirium
• Exact mechanism remains unclear.
Radke F, Franck M, Lendner J, et al. Monitoring depth of anaesthesia in a randomized
trial decreases the rate of postoperative delirium but not postoperative cognitive
dysfunction. Br J Anaesth. 2013;110:98-115.
Chan M, Cheng B, Lee T. BIS-guided anesthesia decreases postoperative delirium and
cognitive decline. J Neurosurg Anesthesiol. 2013;25:33-42
30. Delirogenic Drugs
• Benzodiazepines
• Narcotics -Pethdine ? Morphine OK
• Inhalational
• Anticholinergic
• Antihistamines
• Phenothiazine
• Metocloperamide
Pandharipande P, Cotton B, Shintani A. Prevalence and risk factors for
development of delirium in surgical and trauma intensive care patients. J
Trauma. 2008;65:34-41.
31. Less Delirogenic
• Ketamine- Controversial
• Dexmedetomidine
• Propofol
Avidan MS. Intraoperative ketamine for prevention of postoperative delirium or
pain after major surgery in older adults: an international, multicentre, double-
blind, randomised clinical trial. Lancet. 2017;390:267-275.
Su X, Meng Zhoo-ting, Zin-hai WU, et al. Dexmedetomidine for prevention of
delirium in elderly patients after non-cardiac surgery: a randomised, double-
blind, placebo-controlled trial. Lancet. 2016;388:1893-1902.
32. Treatment of established cases
• Prevention best strategy
• No recommendations
• Traditional restrain or more heavier sedation !
• Starts and stops @ Haloperidol
• Quetiapine
• Alternatively Risperidone , Olanzapine
33. Take home
• Definition impairment of cognitive function postop
• Preoperative functional status is known.
• Pathogenesis is multifactorial.
Risk #s
• Age, major illness / low educational level/ extensive surgery
• Meticulous care by the anesthesia /surgical teams prevent complications
PAC - Screen all – MiniCOG Document
• Take informed consent
• Treatment of established cases difficult ??
• Long-term follow-up
POCD is defined as an impairment of cognitive function arising after a surgical procedure.
The diagnosis can only be made if the patient’s preoperative cognitive functional status is known.
The incidence of postoperative delirium is 20 to 45% among older adult surgery patients
postoperative cognitive dysfunction is experienced by 20 to 50% of older patients three months after cardiac surgery
and in 5 to 55% of those undergoing other major surgeries.
The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period.
This includes cognitive decline diagnosed before operation (described as neurocognitive disorder);
any form of acute event (postoperative delirium)
cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery)
up to 12 months (postoperative neurocognitive disorder)
Terms
Pre-existing cognitive impairment
MCI, Dementia , Delirium
Emergence delirium- immediate
POD- upto 1 week
Delayed cogn recovery -30 days
POCD -12months
Postoperative delirium has been reported to affect between 32% and 53.3% of patients and is associated with prolonged hospital stay, discharge to care homes, difficulty in regaining function in activities of daily living and increased risk of development of cognitive dysfunction and dementia in the future.8–13 The aetiology of delirium is multifactorial, with both modifiable and non-modifiable risk factors.14 15 There is no known treatment for delirium; however, a careful approach in the perioperative period may reduce its incidence and severity.6 9 15–18 Guideline committees have cautiously recommended that regional anaesthesia should be given unless contraindicated.1 9 19 Despite this, the type of anaesthesia administered in patients with hip fractures remains varied
POCD beyond delirium
Cognitive impairment resolving within first 30 days of operation
Evered L, Silbert B, Knopman DS, et al. Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018. Br J Anaesth 2018; 121:1005–1012.
persists for more than 30 days but
less than 12 months following surgery, postoperative neurocognitive disorder.
unlike POD,
consciousness, orientation, and attention are not
typically affected.
However, impairment lies in the
domains of memory, perceptual–motor function,
learning, language, and executive function, although
evidence is still scarce in this regard
Cognitive impairment still present after one year is termed merely NCD
comprises dementia (major NCD) as well mild cognitive impairment(mild NCD).
increased rate of almost any postoperative complication
prolonged hospital stay
The risk of the development of a later MCI or dementia increases threefold
loss of independence/ everyday activities, functional decline,
Increased care dependency,
reduced quality of life for the patients/relatives
a long-term increase in morbidity and mortality
Compared with POD –DSM5
the diagnosis of PONCD is more complex,
require neuropsychometric testing.
It can be diagnosed if the subjective impression of a postoperative decrease in cognitive function is mentioned by the patient
The exact cause of POCD is not known. Currently, researchers think that POCD is the result of an interplay between the stress and inflammation induced by surgery and anesthesia with the underlying sensitive brain of patients at risk. Inflammation is the body’s response to harmful stimuli such as bacteria and viruses that has a domino effect on one’s health.
Certain risk factors put patients more at risk for developing POCD:
Operative factors
Certain types of surgery – cardiac surgery, major surgery (orthopaedic or vascular procedures, etc.)
Post-operative complications (infection, respiratory complications)
Multiple surgeries – particularly if they occur in a short period of time
Anesthetic factors
Anesthetic technique – general anesthesia (being fully asleep during surgery) convey the most risk
Prolonged and deep general anesthesia
Intra-operative complications (low oxygen, low blood pressure)
Poor pain management
Patient factors
60 years of age or older
Pre-existing health conditions: cerebral, cardiac or vascular disease
Pre-existing cognitive impairments
Pre-existing depression, mood disorders, or other psychiatric conditions
Sleep deprivation
Low educational status
History of alcohol abuse
Each of these risk factors individually may not result in the development of POCD. However, when combined, the chance of detrimental cognitive changes increases and can result in POCD. 60 years of age or older
Pre-existing health conditions: CNS/CVS
Pre-existing cognitive impairments
Pre-existing psychiatric conditions
Sleep deprivation
Low educational status
History of alcohol abuse
It has to be emphasized, however, that
NCD even occur in patients who do not undergo
surgery at all [72,73]. About 10% of elderly patients
in emergency departments with acute illness or
injury present with delirium upon arrival at the
hospital, 20–30% of nonsurgical patients experience
delirium during their hospitalization [74,75,76]. This
is crucial to the understanding of NCD, especially
because former scientific discussions were controversial
regarding whether anesthesia or the surgical
stimulus itself could be made responsible for its
development. pNCD genesis is likely to be multifactorial
can only be linked to the interplay of different
factors, not to single events [27].
Table 1. Synopsis of selected assessment instruments of cognitive function commonly used in clinical settings
Instrument Properties Available at
MiniCog Very short test consisting of a three-word registration, a clock drawing test and
the three-word recall. Advantages: Easy to administer, available in many
languages, results independent from language skills and education, parallel
versions available. Disadvantages: Not sensitive for mild cognitive
dysfunction although higher sensitivity for medium cognitive impairment
compared to MMSE.
www.mini-cog.com
.
Increasing evidence shows that pNCD prevention
can only be realized in a multiprofessional perioperative approach
Mahanna-Gabrielli E, Schenning KJ, Eriksson LI, et al. State of the clinical science of perioperative brain health: report from the American Society of Anesthesiologists Brain Health Initiative Summit 2018. Br J Anaesth 2019;123:464–478.
Patients at risk for NCD should be carefully preparedPerioperative sensory orientation
Encouraged to wear glasses/hearing aids /dentures
Pain and opioids increase the risk of POD.
Analgesia mandatory, but opioid-saving concept for the planned operation in elective surgery.
Involving relatives or confidantes when informing
the patient about the upcoming procedure and
including information about pNCD and preventive
measures has been found to be advantageous (Odds
Ratio (OR) 0.47) [78]. Preoperative fasting should
not exceed the minimum time required, and unnecessary
postponement of the scheduled surgery
should be avoided, because dehydration and discomfort
add to the risk of the development of POD
(OR 2.7–10.6) [79]. Routine premedication with benzodiazepines
should be refrained from, as these drugs
have high delirogenic potential [43,80,81].
Deep sedation has been identified as a risk
factor for pNCD genesis and should be avoided.
Therefore, continuous monitoring of sedation
depth is recommended as it has the potential
to reduce pNCD incidence by 20–30% [43,89].
Inadequate or highly anticholinergic medication
can be considered potentially delirogenic [90&&]
and should also be avoided during anesthesia.
Although the evidence is still low, it can be
assumed that fluctuations in blood pressure contribute
to the risk of pNCD [91&&]. Maintenance of
homeostasis and careful hemodynamic management
might, therefore, play an important role in
the patient’s anesthetic care. Early postoperative
mobilization and re-orientation have been proven
to be protective for pNCD and can be considered as
a primary objective in perioperative care for these
patients. This can be ensured through early
removal of catheters and lines, (nonpharmacological)
regulation of the sleep–wake cycle, involveme
Anaesthesia has been implicated in the pathogenesis of delirium.
It is unclear whether choice of anaesthetic agent
ESA found there was insufficient evidence to make a recommendation
Aldecoa C, Bettelli G, Bilotta F. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214.
Large meta analyses have failed to show the protective effects of RA over GA
results, however, might be biased by the fact that many patients routinely undergoing RA receive additional
sedation, which can be as deep as during general anesthesia [88.
Sieber FE, Gottshalk A, Zakriya KJ, et al. General anesthesia occurs frequently
in elderly patients during propofol-based sedation and spinal anesthesia. J
Clin Anesth 2010; 22:179–183
Llango S, Pulle R, Bell J, et al. General versus spinal anaesthesia and postoperative delirium in an orthogeriatric population. Australasian J Ageing. 2015;35:42-47
Evidence suggests that the use of (BIS)–guided anaesthetic care is associated with a reduced incidence of postoperative delirium
. The exact mechanism remains unclear.
Radke F, Franck M, Lendner J, et al. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth. 2013;110:98-115.
Chan M, Cheng B, Lee T. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol. 2013;25:33-42.
is derived from analysis of a patient’s electroencephalogram with values between 0 and 100. The
BIS monitor is used to guide titration of anaesthetic drugs. A target value of between 40 and 60 for general anaesthesia is
considered ideal, thereby avoiding excessively deep anaesthesia. Two randomised controlled trials demonstrated that in the
group randomised to BIS-guided care (between 40-60), there was a reduction in either propofol or volatile agent administered
and the incidence of postoperative delirium as compared with routine care.10, 11 This suggests that avoiding excessive depth of
anaesthesia is an important preventative strategy for the management of delirium. The exact mechanism linking the depth of
anaesthesia to postoperative delirium remains unclear.
midazolam exposure as the strongest independent risk factor
Opiate exposure showed an inconsistent message such that fentanyl was a risk factor
whereas morphine exposure was associated with a lower risk of delirium
an N-methyl-D-aspartate antagonist with psychoactive properties, showed promising benefit for reduction in delirium
when given prophylactically in a small trial in cardiac surgery, but this has not been supported by larger randomised control
trials. Subanaesthetic doses of ketamine have been demonstrated to reduce postoperative markers of inflammation, pain, and
opioid consumption as well as having an antidepressant effect. A large, multicentre trial that randomised patients to either 0.5
mg/kg, 1.0 mg/kg, or normal saline did not demonstrate a statistically significant difference in delirium, but there were higher
rates of hallucinations and nightmares reported with each increased dose of ketamine.13
reduce the incidence of delirium in patients older than 65 years after noncardiac surgery
when given prophylactically (0.1 lg/kg/h) to patients admitted to the intensive care unit.
defined as an impairment of cognitive function postop
for Diagnosis preoperative cognitive functional status is known.
Risk #s
Advanced age, pre-existing major illness low educational level, and extensive surgery
Its pathogenesis is multifactorial,
Meticulous care by the anesthesia and surgical teams to prevent intra- and postoperative complications can reduce the risk of POCD
