Hypodermoclysis - subcutaneous rehydration

#KYJ- Hypodermoclysis

Do you have much experience with this procedure? Let's break it down.
Hypo = below
Dermo =skin
Clysis = to flood or inundate with fluid.

Hypodermoclysis is commonly called Subcutaneous rehydration.
It is a simple procedure that requires the insertion of a cannula (usually a butterfly) into the subcutaneous space, then infusion of an isotonic fluid eg normal saline or Hartmann's.

It was developed for use to rehydrate vomiting children, but has been used in all ages so successfully that it is a common rehydration strategy in debilitated elderly.

As an alternative to IV the other rock star is Intraosseous (IO) infusion; so why would you use Hypodermoclysis over IO?
It's all about  speed.  If fluid resuscitation is urgent then IO is your alternative to IV; but in the stable mild-moderately dehydrated patient, too nauseated to keep down oral fluids, subcutaneous infusion at 20ml/kg over an hour is a fair approach.

In children Insert 25 Butterfly into subcutaneous tissue between the shoulder blades.  In adults, the abdomen is a good site.
There is no hard and fast rule but the age old saying , "pinch up an inch" suggests that anywhere you can pinch up an inch of tissue, AND secure the butterfly safely,  is fair game.

Don't go bigger than 25g.  The sc tissue absorbs fluid at a rate that is constant, so a bigger gauge cannula won't achieve anything- it doesn't hydrate them faster and just causes swelling to increase discomfort.

Premed ?
Topical anaesthetic creams like EMLA or Angel cream are kind and effective.

Some clinicians use a premed of Hyaluronidase  150units S/C.
This temporarily dissolves (painlessly) the connective tissue glue membrane (Hyaluronic acid) that bonds skin to fat.  It accelerates fluid absorption up to 5 times faster.  Consider it.

What to expect.
Inflammation is expected, so some swelling and pinkish penumbra around the injection site are normal.  It shouldn't be hot to the touch, or itchy or painful, so if these latter  symptoms are present, then consider resiting.

Rate- 20ml/kg over an hour is well tolerated and once rehydrated , and nausea/vomiting eases, reattempt oral rehydration.

Secure with occlusive film dressing and leave it in up to 24 hours if needed.