Cognitive impairment – the missing

piece of the puzzle?

Associate Professor Sue Berney

sue.berney@austin.org.au

Post Intensive care Syndrome (PICS)

Needham (2012) CCM

Perminder (2014) Nature Reviews Neurol

It’s important to patients

Fried (2002)

Perc

ent

imp

aire

d

Cognitive Impairment Rates Across ICU

Populations

Overview

• Mechanically ventilated patients approx 36% demonstrate cognitive impairment 6 months after discharge and 25%-54% at 12 months1,2

• Deficits in executive function; memory and mental processing abilities3

• Effects include attention problems, inability to plan and execute a task, inability to access short and working memory, slow mental processing, visio-spatial deficits4

• Increased odds of disability in in activities of daily living and worse motor sensory function at 12 months5

• Patients with co-morbidities particularly vulnerable6

1Pandharipande (2013) NEJM; 2Needham (2013) AJRCCM; 3Jackson (2015) Psych Clin N. America; 4Hopkins (2012) Sem Crit Care Med; 5Brummel (2013) CCM; 6Schillerstrom (2007) Psychomatics

In sepsis

• Cognitive impairment more likely in sepsis OR 3.34 (95% CI1.53-7.25) Iwashyna

2010 JAMA

• Mechanisms include:

– Cerebrovascular damage

– Metabolic disorders

– Brain inflammation Annane 2015 Lancet Respir Med

This representation of a clock was drawn at hospital discharge by an 81 year old man with sepsis who spent 14 days in ICU and 140 hours on mechanical ventilation. No previous cognitive impairment.

Occupation: Accountant.

Needham (2016) Lancet Resp Med

Causes of cognitive impairment in general ICU population

• Hypoxaemia1

• Hyperglycaemia2

• Delirium duration3

• Hypotension4

• ?Sedatives and Analgesics4

• Hospitalisation5

1Hopkins (1999) AJRCCM; 2Hopkins (2005) AJRCCM ; 3Girard (2006) AJRCCM; 4Hopkins (2004) J.Int NeoruPschol ; 5Ehlenbach (2010) JAMA

Delirium

• “Neurobehavioral condition that occurs widely in a variety of health care settings is associated with adverse outcomes and is the most common manifestation of acute brain dysfunction during critical illness”1

• Delirium occurs in approx 74%-80% of patients in ICU2,3,5,6

• Delirium results in hypoperfusion in in frontal, temporal and subcortical regions of the brain4

1Jackson (2015) Psych Clin N Am 2015; 2Pandharipande (2013) NEJM; 3Ely (2001) JAMA; 4Fong (2007) J. Gerontol A Bio;Sci Med Sci; 5Needham (2016) Lancet Resp Med; 6Needham (2013 )AJRCCM

Brain-ICU

• N=821 septic and respiratory failure

• Median age =59years

• 74% of patients developed delirium in ICU

• Delirium independent predictor of cognitive impairment

• Cognitive impairment occurred irrespective of age an co-morbidity

% Cognitive impairments

3 months 12 months

66% 54%

Prevention – “A long habit of not thinking a thing wrong,

gives it a superficial appearance of being right”

• Exercise is recognised as treatment for cognitive decline in older adults1

– Exercise in ICU reduced delirium from 57%-33%2

• Cognitive rehab - feasible3

• Improved sleep efficiency – QA project - daily delirium/coma free status (OR 1.64 [95%CI 1.04-2.58])4. Promising area for further research required establishing link between sleep interventions and delirium5

1Hopkins (2012) AJRCCM; 2Schweickert (2009) Lancet; 3Brummel (2014) ICM; 4Kamdur (2014) CCM; 5Flannery (2016) CCM

Wilcox (2013) CCM

Jackson (2015)

Take home message(s)

• Cognitive impairment occurs in approx 1/3 of patients

• Exposures in ICU are associated with cognitive impairment

• Delirium is not inevitable – measure and treat

• Opportunities for functional activities and good night time sleep may be important

Thank you for listening