Convexity

 

Articles Included:

·        Facts About Convexity

·        Convexity

 

Facts About Convexity

By  Bob Baumel, Stillwater-Ponca City UOA Newsletter

Edited by Chicago's North Suburban Chapter UOA

 

A convex pouching system is designed to improve the peristomal seal by increasing the depth of  the faceplate.  This is done in order for the appliance to conform to the peristomal skin contour more continuously. 

 

The following are indications for use:

 

·        A flush stoma

·        A retracted stoma

·        A stomal at or near skin level

·        Peristomal creases and wrinkles

·        Liquid drainage getting on the skin

·        A high output stomal effluent

·        A protruding or flabby abdomen

·        Frequent pouching system changes caused by leakage

 

The following are contraindications for use:

 

·        Pyoderma Gangrenosum

A chronic non-infective eruption of spreading, undermined ulcers showing central

healing, with diffuse dermal neutrophil infiltration; often associated with ulcerative colitis.

·        Caput Medusa (peristomal varices)

Varicose veins radiating  from the umbilicus.  Dilated ciliary arteries girdling the corneoscleral limbus in rubeosis iridis.

·        Pressure ulcers

A lesion on the surface of the skin caused by superficial loss of tissue, usually with inflammation.  May be cause by an ostomy belt, or convex insert putting stress on the skin causing ulceration.

·        Mucocutaneous separation

Relating to mucous membrane and skin; denoting the line of junction of the two at the orifice.  In our case the separation of the skin from the stoma.

·        Crohn's ulceration

Ulceration caused from Crohn's disease.

·        Malignant ulceration

Ulceration caused from cancer.

 

Products and devices to achieve convexity include:

 

·        Convex Insert:  A pre-sized plastic ring for use in the flange of a two-piece system.

·        Barrier Rings or Strips:  A moldable product used to create convexity.

·        A Convex Wafer:  A skin barrier manufactured with built-in convexity.               

 

It should be noted that an ostomy belt is usually worn to provide additional support when using any convex product.  There are also differing degrees of depth available in convex products such as: shallow, normal and deep.

 

The person who has a need for a convex product should be able to maintain peristomal skin in  excellent health; comfort and satisfaction with the pouching system; increased pouching system wear time; a more cost effective stomal management system.

 

There are certain consideration when using a convex system:

 

·        Convex pouching systems should be fitted by an ET nurse and evaluated regularly.

·        Convex products leave an imprint on the skin.

·        Convex barriers may be less flexible.

·        Convex products generally cost more, but should be a better value because of the

increase wear time leading to less frequent pouch changes.

                       

Patients are encouraged to see their ET nurse if there are any stomal changes, bumps, cuts bruises or bleeding; if peristomal skin changes occur such as: irritations, rash, color changes, bleeding, pain, itching or lesions;  if there is continued and frequent leakage of the pouching system.

 

Convexity

By Loree Siebert, RNET

 

What is convexity?  Who needs it?  Unfortunately, many of us have less than a perfect stoma—for many reasons.  The less perfect the stoma, the more difficult it is to obtain a good pouch seal.

 

Convexity is the adaptation of a barrier or faceplate so that it protrudes the stoma.  The use of convexity is commonly indicated when: one is unable to maintain a pouch seal for an acceptable length of time or when persistent skin irritation occurs even without leakage.

 

Stomas that are flush—level with the skin—or peristomal skin with irregular contours frequently result in the stomal discharge undermining the barrier.  A pouching system that incorporates convexity may help to eliminate the undermining and improve pouch adherence.  Naturally, there are always those individuals who have their own unique problems and need the help and guidance of an ET nurse. 

 

Many manufacturers have people on staff to work with you.  Also, many suppliers are experts in solving these types of challenges.  They have people who have talked to hundreds of people with issues just like you.  They may have a simple solution for a problem that is causing you considerable concern, pain, lessened quality of life, etc.

 

It was not too long ago that people with problem stomas requiring convexity were forced to use re-useable faceplates and pouches.  Now, there are several ways of achieving convexity:  The addition of an insert into a two-piece system.  Or, one may also use a barrier that is manufactured with build-in convexity.  These are available in one- and two-piece systems.

 

There are numerous manufacturers of high quality disposable products that have built convexity into the flange and/or the barrier itself.  Several companies even offer varying depth of convexity—shallow, medium or deep.

 

If your stoma is less than perfect, and you find you are often troubled with skin breakdown or pouching adherence problems, it may prove fruitful to pursue obtaining a couple of samples from a manufacturer.  After you try them, you may find they greatly improve the satisfaction you receive from your ostomy system.   

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