The relationship between hypotension, cerebral flow, and the surgical field during endoscopic sinus surgery

Thanh Ha, van Renen Robert, Guy Ludbrook, Rowan Valentine, Judy Ou, Peter Wormald

    Research output: Contribution to journalArticlepeer-review

    25 Citations (Scopus)


    Objectives/Hypothesis: Hypotensive 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 Design: Prospective, observational cohort study. Methods: Thirty-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. Results: Three 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. Conclusions: Hypotensive 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.

    Original languageEnglish
    Pages (from-to)2224-2230
    Number of pages7
    Issue number10
    Publication statusPublished - 1 Oct 2014


    • Bleeding score
    • Endoscopic sinus surgery
    • Hypotensive anesthesia
    • Intraoperative bleeding
    • Middle cerebral artery blood flow velocity
    • Transcranial Doppler ultrasonography


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