Correspondence: Safe practice in TOE

Br J Cardiol 2012;19:15 Leave a comment
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Correspondence from the world of cardiology.

Recommendations for safe practice in transoesophageal echocardiography: a  summary document from the BSE education committee

Dear Sirs,

Transoesophageal echocardiography (TOE) is an established diagnostic technique, which is used with increasing frequency in a number of clinical settings. By definition it is semi-invasive with potential for significant complications.1 It therefore requires a high level of expertise and should only be performed by trained individuals. TOE often requires the use of sedation and it is recognised that there is wide variation in practice between cardiac units in the UK.2

It has become mandatory for NHS Trusts to have clear written guidelines for the use of sedation during procedures. The National Patient Safety Agency document on the safe use of midazolam from 20083 is one of the main drivers for this document and also one of the reasons why the British Society of Echocardiography (BSE) has focused on midazolam rather than the use of opiates, etc. Conscious sedation is the key principle4 that is likely to avoid adverse respiratory complications and not forgetting, of course, that in many patients no sedation will be required or requested.

This letter is a summary of a longer document available via the BSE website.5 The purpose is to guide safe practice during TOE, with a particular emphasis on safe sedation. The following recommendations are targeted at cardiology departments rather than the intensive care unit/intraoperative setting.

Departments should be encouraged to have robust written protocols for TOE to incorporate minimum staff and equipment requirements, patient preparation and checklists, sedation usage and post-procedure care. Regular audit is also desirable to ensure good practice is being followed and to allow any improvements to be implemented.

Key points – general

  • TOE is semi-invasive with potential for complications
  • TOE should only be performed by adequately trained individuals
  • Patient preparation is essential with identification of relevant comorbidity
  • There should be formal documentation of pre-procedure checklist
  • Main operator needs to be supported by an assistant who will monitor vital signs and manage the airway
  • Ensure appropriate environment and equipment including post procedure care

Key points – sedation

  • TOE is not a painful procedure
  • Not all patients will require or request sedation
  • Concept of ‘conscious sedation’ is central to safe practice
  • Midazolam should be given in 1 mg or 0.5 mg increments ensuring the minimum dose is achieved
  • Avoid additional intravenous drugs such as opiates, as this will increase the chance of respiratory depression
  • Flumazenil should be immediately available
  • Early anaesthetic input is essential if oxygen saturations drop below 90% or if verbal contact is lost despite corrective measure, e.g. flumazenil
  • Appreciation that some patients may require anaesthetic input and a more appropriate environment from the outset e.g. high dependency area, in order to perform TOE safely

Richard Wheeler
Consultant Cardiologist
University Hospital of Wales

Rick Steeds
Consultant Cardiologist
University Hospital of Birmingham  

On behalf of the BSE Education Committee


1 Daniel WG, Erbel R, Kasper W et al. Safety of transoesophageal echocardiography. A multicentre survey of 10419 examinations. Circulation 1991; 83:817–21. PMid:1999032

2 Sutaria N, Northridge D, Denvir M. A survey of current practice of transoesophageal echocardiography in the UK: Are recommended guidelines being followed? Heart 2000;84 (Supplement 2):19. PMCid:1766543

 3 National Patient Safety Agency (2008) Rapid Response Alert Reducing risk of overdose with midazolam injection in adults.

4 Skelly AM. Analgesia and sedation; in Watkinson A, Adam A (Eds) Interventional Radiology, Oxford: Radcliffe Medical Press, 1996:3–11.

5 Recommendations for safe practice in transoesophageal echocardiography. November 2011.