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Ketamine attenuates post‐operative cognitive dysfunction after cardiac surgery
Author(s) -
HUDETZ J. A.,
IQBAL Z.,
GANDHI S. D.,
PATTERSON K. M.,
BYRNE A. J.,
HUDETZ A. G.,
PAGEL P. S.,
WARLTIER D. C.
Publication year - 2009
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.2009.01978.x
Subject(s) - medicine , ketamine , anesthesia , placebo , postoperative cognitive dysfunction , mann–whitney u test , isoflurane , neurocognitive , surgery , cognition , psychiatry , alternative medicine , pathology
Background: Post‐operative cognitive dysfunction (POCD) commonly occurs after cardiac surgery. Ketamine exerts neuroprotective effects after cerebral ischemia by anti‐excitotoxic and anti‐inflammatory mechanisms. We hypothesized that ketamine attenuates POCD in patients undergoing cardiac surgery concomitant with an anti‐inflammatory effect. Methods: Patients randomly received placebo (0.9% saline; n =26) or an i.v. bolus of ketamine (0.5 mg/kg; n =26) during anesthetic induction. Anesthesia was maintained with isoflurane and fentanyl. A nonsurgical group ( n =26) was also included as control. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after surgery or a 1‐week waiting period for the nonsurgical controls. Serum C‐reactive protein (CRP) concentrations were determined before surgery and on the first post‐operative day. Results: Baseline neurocognitive and depression scores were similar in the placebo, ketamine, and nonsurgical control groups. Cognitive performance after surgery decreased by at least 2 SDs ( z ‐score of 1.96) in 21 patients in the placebo group and only in seven patients in the ketamine group compared with the nonsurgical controls ( P <0.001, Fisher's exact test). Cognitive performance was also significantly different between the placebo‐ and the ketamine‐treated groups based on all z ‐scores ( P <0.001, Mann–Whitney U ‐test). Pre‐operative CRP concentrations were similar ( P <0.33, Mann–Whitney U ‐test) in the placebo‐ and ketamine‐treated groups. The post‐operative CRP concentration was significantly ( P <0.01, Mann–Whitney U ‐test) lower in the ketamine‐treated than in the placebo‐treated group. Conclusions: Ketamine attenuates POCD 1 week after cardiac surgery and this effect may be related to the anti‐inflammatory action of the drug.