HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bokeriia, L. A. Articles by Polunina, A. G. Search for Related Content PubMed PubMed Citation Articles by Bokeriia, L. A. Articles by Polunina, A. G. Related Collections Cardiac - other Related Article

---

Correspondence

Postoperative Delirium in Cardiac Operations: Microembolic Load is an Important Factor

A. N. Bakulev Scientific Center of Cardiovascular Surgery, Russian Academy of Medical Sciences, Leninsky pr-t 156-368, Moscow 119571, Russia

(Email: anpolunina{at}mail.ru).

To the Editor:

We read with interest the recent article by Koster and colleagues [1]. The authors identified two independent predictors of postoperative delirium: preoperative disturbances in electrolytes (sodium/potassium) and overall impairment in health. However, the sensitivity of the developed risk checklist was low (25%). A range of studies [2–4] showed that intraoperative microemboli are an important factor inducing cerebral complications in cardiac surgical patients. Our data indicate that postoperative delirium in cardiac surgical procedures is associated with high cerebral microembolic load in most instances.

A total of 66 patients agreed to participate in the study. Inclusion criteria were age 16 to 69 years, absence of a neurologic disease, and carotid stenosis of less than 50%. Anesthesia was induced and maintained with propofol, fentanyl, and pancuronium. The perfusion apparatus consisted of the Stökert S3 roller pump (Munich, Germany), a Dideco-703 membrane oxygenator (Dideco S.p.A., Mirandola, Italy), and a 40-µm arterial filter. The operations were accomplished during moderate hypothermia (28°C). Thirty-six patients underwent open heart operations, and 30 patients had on-pump coronary procedures.

A 2-MHz transcranial Doppler system (ANGIODIN, BIOSS, Moscow, Russia) was used for continuous bilateral monitoring of middle cerebral artery (MCA) blood flow. Microemboli were registered intraoperatively as transient, short-duration, high-amplitude signals with intensity of more than 5 dB higher than background noise. We defined the occurrence of delirium as the patient meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for delirium on the first or second postoperative day assessments.

Overall, delirium developed in 7 of 66 patients (10.6%) after the operation. Patients with postoperative delirium were significantly older (58 ± 5 vs 49 ± 11 years) and were characterized by a significantly larger microembolic load at the right MCA compared with controls (741 ± 404 vs 401 ± 341; t = 2.66; p = 0.010). The microembolic load at the left MCA was almost equal in the two groups (316 ± 351 vs 238 ± 231; t = 0.888; p = 0.378). Age and right hemisphere microemboli independently predicted development of delirium (Wald coefficients = 3.89 and 5.30, p < 0.05, respectively). Analysis showed that the total number of microembolic signals at both MCAs exceeded 900 in 6 of 7 patients (86%) with delirium. In 5 patients, microemboli were registered predominantly at the right MCA, and in 1 patient, microemboli reached mostly the left hemisphere. Only 1 patient with delirium showed a relatively low microembolic load of 300 signals in total. In this patient, delirium was associated with multiple organ insufficiency. Only in 16 of 59 controls (27%) did the microembolic load exceed 900. The group differences were significant (² = 9.68; p = 0.002).

The present data show that cerebral microemboli are associated with delirium after cardiac operations in most patients; however, other pathologic factors may also contribute to the development of delirium.

	References

Top References

 

1. Koster S, Oosterveld FGJ, Hensens AG, Wijma A, van der Palen J. Delirium after cardiac surgery and predictive validity of a risk checklist Ann Thorac Surg 2008;86:1883-1887.[Abstract/Free Full Text]
2. Barbut D, Lo YW, Gold JP, et al. Impact of embolization during coronary artery bypass grafting on outcome and length of stay Ann Thorac Surg 1997;63:998-1002.[Abstract/Free Full Text]
3. Diegeler A, Hirsch R, Schneider F, et al. Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation Ann Thorac Surg 2000;69:1162-1166.[Abstract/Free Full Text]
4. Bokeriia LA, Golukhova EZ, Breskina NY, et al. Asymmetric cerebral embolic load and postoperative cognitive dysfunction in cardiac surgery Cerebrovascular Diseases 2007;23:50-56.[Medline]

This article has been cited by other articles:

				S. Koster, F. G.J. Oosterveld, A. G. Hensens, A. Wijma, and J. van der Palen Reply. Ann. Thorac. Surg., July 1, 2009; 88(1): 350 - 351. [Full Text] [PDF]

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bokeriia, L. A. Articles by Polunina, A. G. Search for Related Content PubMed PubMed Citation Articles by Bokeriia, L. A. Articles by Polunina, A. G. Related Collections Cardiac - other Related Article