Optimised anaesthesia to reduce post operative cognitive decline (POCD) in older patients undergoing elective surgery, a randomised controlled trial.

PLoS ONE. 2012;7(6):e37410 DOI 10.1371/journal.pone.0037410

 

Journal Homepage

Journal Title: PLoS ONE

ISSN: 1932-6203 (Online)

Publisher: Public Library of Science (PLoS)

LCC Subject Category: Medicine | Science

Country of publisher: United States

Language of fulltext: English

Full-text formats available: PDF, HTML, XML

 

AUTHORS


Clive Ballard

Emma Jones

Nathan Gauge

Dag Aarsland

Odd Bjarte Nilsen

Brian K Saxby

David Lowery

Anne Corbett

Keith Wesnes

Eirini Katsaiti

James Arden

Derek Amoako

Nicholas Prophet

Balaji Purushothaman

David Green

EDITORIAL INFORMATION

Peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 24 weeks

 

Abstract | Full Text

BACKGROUND: The study determined the one year incidence of post operative cognitive decline (POCD) and evaluated the effectiveness of an intra-operative anaesthetic intervention in reducing post-operative cognitive impairment in older adults (over 60 years of age) undergoing elective orthopaedic or abdominal surgery. METHODS AND TRIAL DESIGN: The design was a prospective cohort study with a nested randomised, controlled intervention trial, using intra-operative BiSpectral index and cerebral oxygen saturation monitoring to enable optimisation of anaesthesia depth and cerebral oxygen saturation in older adults undergoing surgery. RESULTS: In the 52 week prospective cohort study (192 surgical patients and 138 controls), mild (χ(2) = 17.9 p<0.0001), moderate (χ(2) = 7.8 p = 0.005) and severe (χ(2) = 5.1 p = 0.02) POCD were all significantly higher after 52 weeks in the surgical patients than among the age matched controls. In the nested RCT, 81 patients were randomized, 73 contributing to the data analysis (34 intervention, 39 control). In the intervention group mild POCD was significantly reduced at 1, 12 and 52 weeks (Fisher's Exact Test p = 0.018, χ(2) = 5.1 p = 0.02 and χ(2) = 5.9 p = 0.015), and moderate POCD was reduced at 1 and 52 weeks (χ(2) = 4.4 p = 0·037 and χ(2) = 5.4 p = 0.02). In addition there was significant improvement in reaction time at all time-points (Vigilance Reaction Time MWU Z = -2.1 p = 0.03, MWU Z = -2.7 p = 0.004, MWU Z = -3.0 p = 0.005), in MMSE at one and 52 weeks (MWU Z = -2.9 p = 0.003, MWU Z = -3.3 p = 0.001), and in executive function at 12 and 52 weeks (Trail Making MWU Z = -2.4 p = .0.018, MWU Z = -2.4 p = 0.019). CONCLUSION: POCD is common and persistent in older adults following surgery. The results of the nested RCT indicate the potential benefits of intra-operative monitoring of anaesthetic depth and cerebral oxygenation as a pragmatic intervention to reduce post-operative cognitive impairment. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN39503939.