Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Manual defibrillation - 2

  • Comment

VOL: 98, ISSUE: 24, PAGE NO: 41


Sponsored by Pfizer

A number of factors determine whether or not defibrillation will be successful. These include:

A number of factors determine whether or not defibrillation will be successful. These include:

- The time between cardiac arrest and defibrillation. A successful outcome is reduced by about 7-10% for each minute defibrillation is delayed (Cobbe et al., 1991) Defibrillation within three minutes is associated with an increased chance of survival (Gwinnutt et al., 2000)

- Placing the paddles in the correct position (see Part 1)

- The shock sequence: 200J, 300J and 360J, or their biphasic equivalents are recommended (Resuscitation Council (UK), 2000)

- Transthoracic impedance: this is reduced if shocks are delivered in close sequence and at the end of expiration. Transthoracic impedance is also reduced when defibrillation pads are used and adequate paddle pressure (10kg force) is applied.

Conventional defibrillators deliver current with monophasic waveforms - that is, the current flows from one paddle to the other in one direction. However, most modern defibrillators deliver current with biphasic waveforms - the current flows in a positive and then negative direction for a specified duration (Jevon, 2002). The main advantage of biphasic waveforms is that lower energy levels may be required, although currently there are no agreed optimum energy levels.

  • Comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Links may be included in your comments but HTML is not permitted.