-
Observational Study
The relationship between hypotension, cerebral flow, and the surgical field during endoscopic sinus surgery.
- Thanh Ngoc Ha, Robert Graham van Renen, Guy L Ludbrook, Rowan Valentine, Judy Ou, and Peter-John Wormald.
- Department of Surgery-Otolaryngology Head and Neck Surgery, The University of Adelaide, Adelaide, Australia.
- Laryngoscope. 2014 Oct 1;124(10):2224-30.
Objectives/HypothesisHypotensive anesthesia is often used in endoscopic sinus surgery (ESS) to improve surgical visibility; however, its safety and efficacy in this role are yet to be justified. This study aimed to evaluate the effect of hypotensive anesthesia on both real-time middle cerebral artery blood flow velocity (Vmca) and the severity of surgical bleeding in patients undergoing ESS.Study DesignProspective, observational cohort study.MethodsThirty-two patients undergoing hypotensive anesthesia for ESS at a single tertiary institution during February 2011 to July 2012 were recruited for the study. Transcranial Doppler ultrasonography measured periodic Vmca, which were time-matched for hemodynamic and respiratory factors. One-minute video segments corresponding with each Vmca reading were randomized and distributed to two blinded observers for bleeding assessment.ResultsThree hundred and fifty-six data time points were recorded for systolic, diastolic, and mean arterial blood pressure (MAP), pulse rate, respiratory rate, end-tidal carbon dioxide concentration, Vmca, and bleeding assessment score (BAS). A direct relationship exists between MAP and Vmca (r = 0.77, P < .0001) as well as MAP and BAS (r = 0.36, P < .0001). MAP levels above 60 mm Hg maintained at least 50% of baseline Vmca flow in almost 90% of all time points.ConclusionsHypotensive anesthesia is an effective method of controlling intraoperative bleeding during endoscopic sinus surgery; however the effect is clinically small in low MAP ranges. In otherwise healthy patients undergoing ESS with general anesthesia, reducing MAP to below 60 mm Hg may increase the risk of cerebral ischemia.© 2014 The American Laryngological, Rhinological and Otological Society, Inc.
Notes
Knowledge, pearl, summary or comment to share?You can also include formatting, links, images and footnotes in your notes
- Simple formatting can be added to notes, such as
*italics*
,_underline_
or**bold**
. - Superscript can be denoted by
<sup>text</sup>
and subscript<sub>text</sub>
. - Numbered or bulleted lists can be created using either numbered lines
1. 2. 3.
, hyphens-
or asterisks*
. - Links can be included with:
[my link to pubmed](http://pubmed.com)
- Images can be included with:
![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
- For footnotes use
[^1](This is a footnote.)
inline. - Or use an inline reference
[^1]
to refer to a longer footnote elseweher in the document[^1]: This is a long footnote.
.