Balloon distension at distal esophagus is a method of visceral pain induction. We are looking for reliable methods for making balloons. The balloon will be fixed at the end of a NG tube and be distended rapidly with high pressure air. We already have tried using surgical glove but its not strong enough for multiple distensions. Any suggestion?
Why would you want to?Are you planning to do this to your colleagues, or some other form of experimental preparation? Is there any effect on heart rate or blood pressure?
I see you are interested in visceral pain and epidurals. Could you not find some way of stimulating c fibres from a peripheral site of the same dermatomal distribution (T1-2?)?
There are dangers associated with oesophageal dilatation.
Christopher, Tnx for your response.
This is an experimental study about visceral pain and will be done on healthy volunteers. In addition to be a pain stimulus, esophageal pain may affect HR and BP also through viscero-visceral reflexes. We'll measure both continuously.
Stimulating same dermatomes is a good idea, however it wouldn't be the same perception and our focus is on visceral pain perception not somatic pain. Also, in that way we miss other possible pathways like the vagal afferents.
The balloon that we'll use is small (2.5 cm) and will be distended to max diameter of ~3-4 cm in a very short amount of time (~250 ms), it is done before for visceral pain induction in several studies (also in our group) and has been safe. We also have a probe for electrical stimulation of the esophagus but it's not as natural as distension, I think.
Check if you can find a urinary (Foley's) catheter that's the right length and use the balloon on that; it should distend to 2.5 cm or more, but may not be large enough for you, and I suspect they would be difficult to swallow. There are surgical balloon dilators for oesophageal strictures, but I they might require general anaesthesia, or at least deep sedation for insertion. You say this has been done before - what was used then and how did you get it in position?
There are also catheters used for monitoring intragastric pressure on ICU. Manu Malbrain in Antwerp might be of help.
I remember swallowing oesophageal catheters when I was in training, for studies of respiratory function, and even those were a bit unpleasant.
Good luck
The problem with Foley is that it's usually made from Latex and Latex becomes loose after repetitive distentions. The Foley made fully from silicone is quite expensive.
We previously made balloons from silicone fully compliant tube which worked well but we no longer have access to such tubing system ! We also made balloon from surgical glove (using a finger) but it's not strong enough for repetitive distentions at pain level.
The problem with other available balloons is the cost unless they can be used for several subjects ! Also, surgical balloons may not tolerate rapid distentions. Moreover, our deflation phase is passive and the balloon must deflate rapidly by its own so some surgical balloons (more like a bag) may not be useful for us. But, I'll look for it.
Insertion of nasal catheter (~ 3 mm) is unpleasant (not a lot) at first and provoke autonomic response but after about 10 - 15 min subject will habituate to the catheter. I also did it for 3 times ;)
Tnx
I have not familiar with this procedure and the GI specialists should answer to this question.
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