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BiPAP feeding



I am in a dilemma about what to do about feeding patients who require Non-Invasive ventilation. What is common practice?

Director A , Level 2 (JFICM) Rural NSW


Pretty much all the ones that really can't tolerate the time off the mask to eat get a fine bore NGT by day 2 if it is clear they aren't getting better in a hurry.  If I am conerned about their ability to tolerate feed they might get a size 14 sump NGT.

Director B, Level 2 (JFICM) Rural NSW


I don't think they should be allowed to eat. Our speech therapists did a study some years ago on patients with exacerbation of chronic airflow limitation and found (with barium swallow) that they all tend to swallow during inspiration rather than expiration.  That is their risk of aspirating was increased.

We only feed such patients (when they are on BiPAP) via a nasogastric tube, and only start this if the patient has been on BiPAP for more than 24 hours.  I prefer a proper NG tube, rather than a fine bore as I am
still worried about gastric insufflation.

Co-Director C Level 2 Metropolitan Sydney



As always some useful info Michael!

Some random thoughts:
I like your approach, and I agree the proper NG does inspire more confidence!  How confident are you that the NG does indeed keep the stomach decompressed?  I haven't noticed too many patients getting big
air filled stomachs with either tube much!

I wonder whether the incidence of NGT induced laryngeal dysfunction increases the risk of aspiration more than the increase due to the exacerbation of CAL you document...  hmmm...

I thought most people swallow in the gap between expiration and inspiration - this gap of course narrows or even disappears with tachypnoea and probably explains why it is so hard for patients with respiratory distress to eat at all...  of course, at the instant of swallowing the glottis is occluded so in theory the patient can neither inspire or expire "during the swallow".

Do the CAL patients revert to normal pattern swallowing once the exacerbation is over?

Director B, Level 2 (JFICM) Rural NSW



Hi John,

I'd agree, significant gastric insufflation is pretty uncommon in my experience too.  I guess my bias comes from training 15 years ago, when mask CPAP was just starting to be used with some frequency.  The
approach then was probably overcautious, but I have hung onto it as I haven't had any major catastrophes with it.

I'm sure that the presence of a nasogastric tube does affect swallow reflex (efficiency) in some patients but I think this is the lesser evil.

The swallow reversal in exacerbations of CAL does normalize when they have improved.  The respiratory physicians here incorporated this information in the clinical pathway (guideline) for managing CAL in our
hospital.  I think it states that patients are to be kept nil by mouth for 48 hours when admitted with an exacerbation.

You are correct, you normally swallow between inspiration and expiration, these people were swallowing after expiration and into inspiration.  I've got no idea why this might be other than it has something to do with the duration of their forced expiration and maybe the elevation in intrathoracic pressure that this causes.

Regards,Co-Director C Level 2 Metropolitan Sydney



John or Michael or anyone else.

I've long been fascinated by this term 'CAL' [small things amuse small minds] which seems to be a uniquely NSW term and is meaningless anywhere else in the world. I therefore pedantically use COPD which is the internationally accepted term and the only one overseas colleagues understand.

Does anyone know where on earth 'CAL' came from, why, and why we persist in being 'different'?

Staff Specialist Level 3 Metropolitan Sydney



Hi Ian,

I only use the term CAL because that is what seems to be popular in Sydney.  Elsewhere, I've heard it called COAD, COPD, and COLD.

I don't know for sure, but I think CAL may be a North American thing. The term certainly appears in a number of consensus statements from the American College of Pulmonology (or whatever it is called).

Personally I'd prefer to get back to basics and remove the shroud of accronyms from this condition and call it emphysema.

Regards,Co-Director C Level 2 Metropolitan Sydney