This document discusses cognitive impairment in ICU patients. It notes that approximately 36% of mechanically ventilated patients and 25-54% of all ICU patients demonstrate cognitive impairment 6-12 months after discharge. The impairment affects executive function, memory, and mental processing. Risk factors include hypoxemia, hyperglycemia, delirium duration, hypotension, and sedative use. Delirium occurs in 74-80% of ICU patients and is associated with hypoperfusion in brain regions. Prevention strategies may include exercise in ICU to reduce delirium rates and cognitive rehabilitation. Maintaining good sleep and reducing delirium are important to mitigate cognitive impairment.

1. Cognitive impairment – the missing
piece of the puzzle?
Associate Professor Sue Berney
sue.berney@austin.org.au

2. Post Intensive care Syndrome (PICS)
Needham (2012) CCM

3. Perminder (2014) Nature Reviews Neurol

4. It’s important
to patients
Fried (2002)

5. Percentimpaired Cognitive Impairment Rates Across ICU
Populations

6. 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

7. 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

8. 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

9. 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

10. 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%

11. 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

12. Jackson (2015)

13. 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