JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS
AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
A&A International Anesthesia Research Society
 QUICK SEARCH:   [advanced]


     


This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Liu, N.
Right arrow Articles by Fischler, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Liu, N.
Right arrow Articles by Fischler, M.

Anesth Analg 2006;103:1609-1610
© 2006 International Anesthesia Research Society
doi: 10.1213/01.ane.0000246268.58067.99


LETTER TO THE EDITOR

Editor-in-Chief Steven L. Shafer

Elevated Burst Suppression Ratio: The Possible Role of Hypoxemia

Ngai Liu, MD, Thierry Chazot, MD, Catherine Mutter, MD, and Marc Fischler, MD

Department of Anesthesiology; Hôpital Foch; Université Paris Ile-de-France Ouest; Suresnes, France (Liu, Chazot) Departments of Anesthesiology and Intensive Care; Hôpital Hautepierre; Strasbourg, France (Mutter) Department of Anesthesiology; Hôpital Foch; Université, Paris Ile-de-France Ouest; Suresnes, France; m.fischler{at}hopital-foch.org (Fischler)

To the Editor:

We report a case characterized by the simultaneous occurrence of increased suppression ratio number (SR) and hypoxemia without a concomitant decrease in bispectral index (BIS).

A 59-yr-old man was scheduled for tracheal granuloma removal by laser, using a rigid bronchoscopy. The patient’s history included two lobectomies for epidermoid carcinoma. Anesthesia induction was induced and maintained with infusions of propofol and remifentanil. A bolus of succinylcholine was injected to facilitate introduction of the bronchoscope. The lungs were mechanically ventilated through the lumen of the bronchoscope using a high frequency jet ventilator. Six minutes after the succinylcholine bolus, his Spo2 decreased dramatically below 80% despite ventilation with pure oxygen, and we also observed an increase of the SR. BIS was in the range of 40–60 and signal quality index was more than 75%. His mean arterial blood pressure was 80 mm Hg. The bronchoscope was withdrawn and replaced by an endotracheal tube; the lungs were mechanically ventilated using pure oxygen. High airway pressure and auscultation revealed bronchospasm. Spo2 improved after inhalation of a beta2-agonist and we observed a decrease of the SR (Fig. 1). The endotracheal tube was removed. The patient’s postoperative neurological examination was normal.


Figure 195
View larger version (15K):
[in this window]
[in a new window]

 
Figure 1. Acute decrease of Spo2 during rigid bronchoscopy. BIS, bispectral index; SR, burst suppression ratio; A, high frequency jet-ventilation; B, tracheal intubation; C to D, inhalation of beta2 agonist; E, recovery.

 

In general, burst suppression patterns appear at BIS levels below 40. The effect of an increasing concentration of a volatile anesthetic on the electroencephalogram is a progressive slowing until burst suppression patterns occur. Our observation of an increased SR appearing while BIS was at an adequate anesthetic level could have been a coincidence, but we cannot exclude a relationship between SR and poor brain tolerance of hypoxemia. This hypothesis is supported by animal studies demonstrating that hypoxemia induces isoelectric electroencephalograms, oxygenation allowing the restoration of a baseline electroencephalogram (1), and a reduction in cerebral tissue damage (2).

REFERENCES

  1. Feet BA, Brun NC, Hellstrom-Westas L, et al. Early cerebral metabolic electrophysiological recovery during controlled hypoxemic resuscitation in piglets. J Appl Physiol 1998;84:1208–16.[Abstract/Free Full Text]
  2. Burda J, Marsala M, Radonak J, Marsala J. Graded postischemic reoxygenation ameliorates inhibition of cerebral cortical protein synthesis in dogs. J Cereb Blood Flow Metab 1991;11:1001–5.[Web of Science][Medline]




This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Liu, N.
Right arrow Articles by Fischler, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Liu, N.
Right arrow Articles by Fischler, M.


Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins and Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press