Epidural with Air or Saline

Started by yogenbhatt1, October 21, 2009, 12:29:20 PM

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Feeling lost for a while. No one filling Gas in our Bag for over a month. Does it mean that I alone have to have a complication and put it on net for ppl to disect it?
A lot is said about saline. But I , being an oldtimer, am still in pref of Air. I use NS most of the time for location of epidural space, but still I am fond of Air. No, I do not inject air in the space, just use it to feel the give way sensation. Not even half ML of air goes in.
Am I wrong in this tech?
Should I change over to only NS?
Group members are all quite young and bruoght up with NS only. But I still preffer air. Not always, but I do use it in treaky cases.


identifying the epidural space by loss of resistance to air is a time tested technique; nobody need be ashamed about it; me too, i use only air for epidural technique and it has let me down so far.


I have also been trained to identify the epidural space by LORT – AIR technique and am quite  happy with it and the results have mostly been good

There are certain definite advantages of LORT-SALINE technique
1.   The flowing saline pushes the dura away and hence the chances of accidental dural puncture are minimized
2.   Even a small amount of air injected into the space if it  accidentally enters the epidural vein it can precipitate air embolism. This is particularly relevant in paediatric age group. Remember that 30% of all normal people have a probe patent foramen ovale.
3.   A small amount of air in the epidural space may form a small bubble around one of the nerve roots. Subsequent LA solution will be prevented by this bubble from accessing the nerve root leading to patchy block or root sparing

The reason why we persist with LORT- AIR is because if we use saline to identify the space
Then thread the catheter in
And then find some liquid in the catheter then we are in a dilemma
Is this liquid the saline we instilled or CSF due to catheter entering the sub-arachnoid space
To evaluate this doubt we could use
1.   Temperature of the returning liquid
2.   Precipitation with freshly prepared Thiopentone solution
3.   Use of Glucose strips

I think it is this doubt that makes us persist with a technique we are so well used to – LORT – AIR

Given the scientific evidence I think the youngsters must be encouraged to switch to LORT- SALINE
right from the beginning of their anaesthetic careers



Thanks for the instant response.
The site was running dry, no one writing.
That is why I put the controversial point.
Yes, I always use NS, but I still, like air, and now I am no more ashamed of announcing it.
I knew that there will be scintific reply within 2 days. I got it.
Regards, and welcome back.


I find it better to use air for thoracic epidurals and saline for lumbar epidurals.
I use continuous LOR technique, I find early loss of fluid occurring with the saline technique as you are pushing especially elderly people with lax tissue.

Therefore I prefer saline technique in young( mostly needing labour analgesia)
In thoracic epidural with slightest appearance of fluid I do not want to proceed any further, all these make me prefer saline technique for Thoracic epidurals and saline for lumbar epidurals.




i use air and have no experience with saline.. ;)


I use NS almost exclusively but am not dogmatic about it noting at least the theoretical advantages of air.  I find the "aspiration test" problematic as the one time I threaded a catheter through the dura I had not been able to aspirate CSF into the catheter.  I depend heavily on the TD with epi and go slow.  As to one poster's note of "losing NS early due to lax tissue in the elderly", my perception is that this occurs in the interspinous ligament which is noticeably less dense than the LF.