TEE for Noncardiac Surgery

TEE for Noncardiac Surgery
Ben Sommer1
Albert C. Perrino, Jr2
Scott T. Reeves2
1OUTLINE AUTHOR
2ORIGINAL CHAPTER AUTHORS
I. INTRODUCTION
  • Limited availability of echocardiographic systems and clinicians trained in TEE initially slowed the growth of TEE in noncardiac procedures.
  • TEE can provide rapid diagnosis in a patient not responding to standard therapies. This warrants TEE availability to most anesthetized patients.
IV. OPTIMIZATION OF VENTRICULAR PERFORMANCE DURING NONCARDIAC SURGERY
  • The principles underlying optimization of ventricular performance using TEE remain guided by the Frank-Starling relationship.5,6
  • The value of the Frank-Starling relationship is that it provides and interactive approach to optimizing the relationship between preload and systolic output.
  • The necessary parameters for deriving Frank-Starling relationship, preload and SV, are easily monitored intraoperatively with TEE.
A. Assessing preload (Fig. 16-1)
  • TEE is superb for both quantitative assessment and monitoring the adequacy of preload throughout surgery.7,8,9,10,11
  • The most popular approach to measure left ventricular (LV) preload is by determination of the LVEDA from the TG midpapillary SAX view.
  • LVEDA has been validated to accurately track changes in intraoperative fluid status and is simply calculated from manual tracings of still frame echoes at end-diastole.
  • Normal values for LVEDA are typically 12 to 18 cm2.
▪ FIGURE 16.1
B. Assessing stroke volume
  • Doppler techniques are preferred for SV determination.
  • SV is calculated as the time-velocity integral (TVI) multiplied by the cross-sectional area (CSA) of the conduit:
    SV = TVI × CSA
  • Cardiac output is determined from the product of SV and heart rate.
  • Echocardiographic techniques for SV measurement:
  • SV and CO measurements are best measured at the left ventricular outflow tract (LVOT) or at the aortic valve.12,13,14
  • Several studies have confirmed that the CO measurement obtained by TEE compare favorably to those obtained by thermodilution.13,14
  • LVOT or transaortic flows are most reliably obtained from the TG LAX and the deep TG LAX views.
  • CSA of the LVOT is best obtained from the ME LAX view.
  • CSA is calculated from a measurement of the LVOT diameter as
    CSAlvot = II (D/2)2
May 26, 2016 | Posted by in CARDIOLOGY | Comments Off on TEE for Noncardiac Surgery

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