open ended tube versus temed gas diffuser in a deep field

It has been written about for many years that an open ended tube is not an effective method of de-airing. 

“Introduction of CO2 through open-ended tubes is an unsatisfactory method of displacing the air” Selman et al. Journal of Thoracic and Cardiovascular Surgery. 1966.

Is using a swab the answer? 

You will see that even when the CO2 flow is increased the flame on the left is not extinguished. 

Using a Gas Diffuser it has been shown that the time taken for there to be detectable micro emboli fell from 19 minutes to 7 minutes. Therefore a 12 minute reduction in de-airing time. Circulation. Volume 109, Issue 9, 9 March 2004 

Just because a sump sucker has numerous holes does not mean it will be as effective as the TEMED Gas Diffuser.  

gauze sponge and the multi perforated catheter immediately became inefficient (70% and 96% air, respectively), whereas the gas-diffuser remained efficient (0.4% air). During surgery, the gas-diffuser provided a median air content of 1.0% (J Cardiothorac Vasc Anesth. 2004 Apr;18(2):180-4.

Which is the most effective method?

How would you like to be protected?

 “Clinical strokes were detected in 17%, Transient Ischemic Attack in 2%, and in-hospital mortality was 5%" Stroke after Aortic Valve Surgery: Results from a Prospective Cohort .Circulation. 2014 June 3; 129(22). Steven R. Messé et al. Hospital of the University of Pennsylvania, Philadelphia 

Using a FLIR GF343 camera which works on the wavelength of 4.2 to 4.4 micron, so that it can see CO2, one can understand why using an open ended tube is not an effective means of creating a CO2 atmosphere. The plate on the left and right of the screen are set 40cm apart. At 2.5LPM flow the CO2 does not start to descend until approximately 20cm. If the tube has a smaller bore, the jetting effect will be even greater.  

Using the GF343 camera one can see that with the TEMED Gas Diffuser at a C02 flow of 2.5LPM the CO2 is immediately able to drop and therefore start creating a stable CO2 atmosphere. The field in this demonstration is open at the back and front and therefore the CO2 is able to flow away 

You will see that at 5LPM using the 1/4inch open ended tube that the CO2 travels 40cm across the screen and hits the plate on the right hand side.  

If the tube was a smaller diameter then the jetting affect would be even greater. You see now why it is difficult to create a stable CO2 atmosphere using this delivery method.

You will see that at 5LPM the TEMED Gas Diffuser allows the CO2 to descend and create and create an even cushion of CO2. The front and back of the delivery area in this video are open and therefore the CO2 just flows away. It should also be noted that the TEMED Gas Diffuser is in the horizontal position in this film which does not maximise the spread of CO2. This was done to directly compare with the open ended tube.