European Journal of Anaesthesiology

Table of Contents - 2005 - Volume 22, Issue 04  


Original Article

Plasma concentrations of nitric oxide products and cognitive dysfunction following coronary artery bypass surgery

D. Harmon a1c1, N. Eustace a2, K. Ghori a2, M. Butler a3, S. O'Callaghan a2, A. O'Donnell a4, G. M. Moore-Groarke a5 and G. Shorten a2
a1 Walton Centre for Neurology and Neurosurgery, Liverpool, UK
a2 Cork University Hospital and University College Cork, Department of Anaesthesia and Intensive Care Medicine, Cork, Ireland
a3 Cork University Hospital, Department of Biochemistry, Cork, Ireland
a4 Cork University Hospital, Department of Cardiothoracic Surgery, Cork, Ireland
a5 Cork clinic, Department of Psychology, Cork, Ireland

Article author query
harmon d   [PubMed][Google Scholar] 
eustace n   [PubMed][Google Scholar] 
ghori k   [PubMed][Google Scholar] 
butler m   [PubMed][Google Scholar] 
o'callaghan s   [PubMed][Google Scholar] 
o'donnell a   [PubMed][Google Scholar] 
moore-groarke gm   [PubMed][Google Scholar] 
shorten g   [PubMed][Google Scholar] 

Summary

Background and objective: Prospective longitudinal studies now indicate that cognitive dysfunction following coronary artery bypass surgery (CABG) is both common and persistent. This dysfunction is due in part to the inflammatory response and cerebral ischaemia–reperfusion, with nitric oxide (NO) as an important mediator of both. We hypothesized that a clinically significant association exists between plasma concentrations of nitrate/nitrite (NO3−/NO2−) and cognitive dysfunction after CABG.

Methods: Cognitive assessment was performed on 36 adult patients the day before CABG, on the fourth postoperative day and 3 months postoperatively. Patient spouses (n = 10) were also studied.

Results: A new cognitive deficit was present in 22/36 (62%) 4 days postoperatively and in 16/35 (49%) of patients, 3 months postoperatively. Patients who had cognitive dysfunction 3 months postoperatively were more likely to have cognitive dysfunction and increased plasma NO3−/NO2− concentrations compared to the non-deficit group preoperatively (22.6 (9.2) vs. 27.6 (8.4)) (P = 0.002). Plasma NOx (NO3− plus NO2−) concentrations were greater in patients with cognitive dysfunction 3 months postoperatively, 2 h (24.2 (6.3) vs. 19.1 (5.2)) (P = 0.002), and 12 h postoperatively (24.8 (7.6) vs. 18.8 (5.6)) (P = 0.001). There was, however, a time course similarity in NOx elevations for both deficit and non-deficit groups.

Conclusions: Perioperative plasma NOx concentrations do not serve as an effective biomarker of cognitive deficit after CABG.

(Accepted January 2004)


Key Words: CORONARY ARTERY BYPASS SURGERY; MENTAL PROCESSES, cognition; HYPOXIA–ISCHAEMIA, brain; BIOLOGICAL MARKERS; REACTIVE NITROGEN SPECIES, nitric oxide; NEUROPSYCHOLOGICAL TESTS.

Correspondence:
c1 Correspondence to: Dominic Harmon, Walton Centre for Neurology and Neurosurgery, Lower Lane, Fazakerley, Liverpool L9 7LJ, UK. E-mail: dominicharmon@hotmail.com; Tel: +353 21 4546400 ext 22566; Fax: +353 21 4546434

--