Anesthesia and the beach chair position...2. To be aware of potential cerebral monitoring options....

Anesthesia and the beach chair position

Paul PictonAssociate ProfessorSenior Associate Chair of Clinical Affairs and QualityUniversity of Michigan Medical School, Ann Arbor

Disclosures

NIH UL1TR000433

Objectives1. To understand the potential impact of cerebral

hypoperfusion for patients anesthetized in the beach chair position.

2. To be aware of potential cerebral monitoring options.

3. To understand the various influences on cerebral oxygenation for patients anesthetized in the beach chair position.

4. To be aware of the latest research concerning patients at potential risk of cerebral hypoperfusion under anesthesia.

Chiang AC, et al. J Bone Joint Surg 2012

Demographics

Catastrophic neurological injury• 1 case visual loss / opthalmoplegia

Bhatti MT, et al. Anesth Analg 2003• 4 cases severe CNS injury

Pohl A, Cullen DJ. J Clin Anesth 2005• 8 cases stroke reported in a survey of ASESS

Friedman DJ, et al. Orthopedics 2009• 24% cervical cord injury recorded in closed claim data base occurred in

BCPHindman BJ,et al. Anesthesiology 2011

• 1 case hemiplegic strokeDrummond JC, et al. Anesth Analg 2011

• 8 cases severe neurological injury (unreported) discussed in editorialMurphy GS & Szokol JW. Can J Anesth 2011

Abnormal circle of Willis

Drummond JC, et al, Anesth Analg 2011

J Clin Anesth 2005, 17(6):463-469

Autoregulation

Drummond JC, Patel PM. Neurosurgical anesthesia. In: Miller RD, Cucchiara RF, Miller ED, Jr., et al., eds. Anesthesia, 5th ed. Philadelphia: Churchill Livingstone, 2000:1903-5.

Drummond JC. Anesthesiology 1997;86:1431-1433

Autoregulation is impaired in the beach chair position

Laflam A. et al. Anesth Analg 2015

Prospective observational, LDC vs BCP, autoregulation measured by Cox, n=218

No relationship between pre-op BP and LLA in the beach chair position

Laflam A. et al. Anesth Analg 2015

Prospective observational, LDC vs BCP, autoregulation measured by Cox, n=218

“Syphon” vs “waterfall”

Beach chair position and EEG evidence of ischemia

Gillespie R. et al. J Bone Joint Surg Am. 2012;94:1284-90

Prospective, controlled hypotension (90-100mmHg SBP), n=52

MAP and safety?

Pin-on P, et al. Anesth Analg 2013, 116(6):1317-1324

Summary 11) Catastrophic neurological injury has occurred with BCP2) Lower limit of autoregulation likely much

higher than 50mmHg and has wide inter-individual variability

3) Autoregulation is impaired in beach chair position

3) Correct for hydrostatic gradient

Monitoring

Nelson T and Picton P. Chapt 26. In: Case Studies in Neuroanesthesiaand Neurocritical Care, 2011.

Near infrared spectroscopy (NIRS)

Casati A et al Minerva Anestesiol 2006;72:605-25

Cerebral desaturation (measured by NIRS) and neurologic injury

Summary 2

1) rSO2 provides a non-invasive continuous measure of cerebral oxygenation 2) It is far from perfect!3) A decrease from baseline of 20% associated with neurological injury

Cerebral desaturation in the beach chair position

Murphy GS, et al. Anesth Analg 2010, 111(2):496-505

Increased Oxygen Administration Improves Cerebral Oxygenation in Patients

Undergoing Awake Carotid Surgery

Stoneham MD, et al. Anesth Analg 2008;107:1670-5

The influence of basic ventilation strategies on cerebral oxygenation

Picton P, et al. J Clin Monit Comput 2010;24:421-425Picton P, et al. Br J Anaesth, 2012 Feb; 108 (2):326-7

Inspired oxygen fraction and end tidal carbon dioxide during CEA with GA

Picton P, et al. Anesth Analg. 2010 Feb 1;110(2):581-7

End tidal carbon dioxide in the beach chair position

Murphy G S et al. Brit J Anaesth 2014, 113:618-27

Summary 3

1) BCP with GA results in cerebral desaturation2) Small increases in CaO2 may make a significant difference to under-perfused brain 3) Increasing FiO2 results in a measurable improvement in cerebral oxygenation4) Modulating PaCO2 may change cerebral oxygenation

Anesthetic choice

Picton P, Deakin CD. Trauma Critical Care 2007 (2):1-22

Beach chair position and anesthetic choice

Jeong H, et al. Anesthesiology 2012, 116(5):1047-1056.

Cerebral oxygenation, ventilation strategy and anesthetic choice

Picton P et al. Anesthesiology 2015

Prospective within-group evaluation of ventilation strategy with randomized comparison of anesthetic choice, n=56

Blood pressure and anesthetic choice in beach chair position

Picton P et al. Anesthesiology 2015

Blood pressure and anesthetic choice in beach chair position

Picton P et al. Unpublished data

Blood pressure and anesthetic choice in beach chair position

Picton P et al. Unpublished data

Which vasoactive drug?

Meng L. et al. Brit J Anaesth 107 (2): 209-17 (2011)

PE EPH

Which pressor / inotrope?

Meng L. et al. Brit J Anaesth 108 (5): 815-22 (2012)

Summary 41) Anesthetic agents have differing effects on brain circulation and metabolism2) Choice of agent for patients at risk of cerebral hypo-perfusion is under investigated3) BCP related cerebral desaturation is attenuated by normocarbic hyperoxia and moderate hypercarbia – independent of anesthetic agent4) Ephedrine may have advantage over phenylephrine

High risk patients?

Trentman TL, Fassett SL, Thomas JK, et al. Can J Anesth 2011; 58

Retrospective, GA ETT, BCP, n=384

Risk factors for and risk of perioperative stroke

Mashour GA, et al. Anesthesiology. 2011 Jun;114(6):1289-96

Patients with cerebrovascular disease

Vlisides P, Mashour GA, Picton P et al. Unpublished data

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Prospective observational study patients undergoing major surgery (supine), CVD vs matched controls, n=48

Patients with cerebrovascular disease

Vlisides P, Mashour GA, Picton P et al. Unpublished data

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Cognitive Function Score Trends - CVD vs. Control

CVDControls

Patients with cerebrovascular disease

Vlisides P, Mashour GA, Picton P et al. Unpublished data

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Cognitive Function Score Trends - Desat vs. Non-Desat

Desat Group(N=6)

Non-DesatGroup (N=39)

Tumor

Licox Probe

Excision Canal

PbrO2 vs rSO2 in normal human brain with changes in ventilation strategy

Picton P et al. NCT03128957

Recruitment underway

Jennifer Lucaj

Conclusions• Surgeries requiring beach chair positioning increasing in frequency• Devastating neurological sequelae in healthy patients have been

reported• Lower limit of autoregulation?• Allow for hydrostatic gradient and keep the blood pressure up• No widely agreed monitoring standard• Increasing FiO2 and ETCO2 results in a measurable improvement in

cerebral oxygenation for patients anesthetized in the beach chair position

• Anesthetic agents have differing effects on the brain but there is no proven benefit of one approach over another for patients in BCP

Thanks to

NIH UL1TR000433

Thanks to

George A. Mashour, MD, PhD

Andrew Dering, MBChB, FRCA

Mary Neff, CRNA Bruce Miller, MD, MS

Amy Shanks, MS,PhD

Michelle Housey, MPH

Thanks to

Phil Vlisides, MD Magnus Teig, MBChB, FRCA

Amy McKinney, MA Jason Heth, MD