From what I've just read, it is possible for a person to change and maintain their own TPN?

Re:  Yes.  Most home TPN consumers are independent with all aspects of catheter care and TPN management.  Some even draw their own blood.  The procedures are taught by a home nurse when someone first goes home.  Eventually,  the person becomes the expert and performs all of their own care.  By cycling the TPN overnight (See blog "Time Off") consumers can return to work, travel, and participate in most any activity. 

My son is on the TPN, He was a victim of carjacking in July 09, gunshot wound in stomach, he's been on the TPN for at least 4 months now the doctor is sending him to a specialist regarding jaundice from tpn bag, he will visit a hepatologist on January 7, 2008, my question is even though his liver isn't in any danger at the time but the doctor is concern, he's young at 22 years old don't drink never have don't smoke basically a healthy young active man before this all happened. He worked and played a lot of basketball.

I am sorry that your son is a victim of violent crime. Recovery and stabilization of TPN can take months, but your son should eventually be able to resume a job and non-contact sports.
Liver complications are associated with long term (greater than two weeks) TPN.  Various factors contribute to elevation of bilirubin in the bloodstream, which is what causes jaundice, or yellowing of the eyes and skin.  These factors include altered anatomy, gallbladder sludge, intestinal bacterial overgrowth, overfeeding of fats (intralipids) or calories, and non-cycled/24 hour TPN.  It is a good idea to consult with a hepatologist and rule out non-TPN related liver problems.  Once that is done, manipulation of the TPN regimen along with medications to treat the GI tract can be tried to reduce the bilirubin and liver enzyme levels.    
It is important to address this issue soon, as you are doing, to maintain a healthy liver.
Our goal at Nutrishare is to reduce complications and improve quality of life for the home TPN consumer.  Please keep me posted on your son's progress and feel free to contact me with any additional questions.

So what do you do if you live alone, and don't really have anyone you know that can take over care?

Sarah,
Of course, when you live alone it is more of a challenge to find someone that can help you with TPN. Often, you have casual friends,  but not anyone available who you trust with your private medical matters. An option could be a nursing agency, if you qualify for visits. They are usually on call for emergency situations. Another option is connecting with Oley Foundation (support group for home enteral and parenteral nutrition) www.oley.org. They may have other consumers in your area that may have helpful suggestions about back up care, or even perhaps you could share back up with someone else.  Lastly, sometimes there just isn't anyone available.  Writing down your medical history and TPN protocols in a journal that goes with you during travel or hospital admissions would be very helpful to medical staff in case of an emergency.

My wife just began TPN therapy.  What is the approximate cost of daily program with home health agency, suupies and TPN bag?

I am not able to give you an actual $$ amount for home TPN.  Private insurances, Medicare, and Medicaid programs reimburse at different rates based on volume, % amino acids, and additives.  A HMO might reimburse on a flat daily rate, other insurances bundle the supplies with the related therapy, and some may itemize. Nursing agencies bill depending upon the state you live in and how many hours spent in the home. Some nursing visits are classified with different rates depending upon the level of care provided.

I am a registered dietitian, I've been trying to find some research about holding lipids if a patient's triglycerides are high.  What is the cut off point of holding lipids.  And how long can a person go without lipids before developing EFA deficiency.  What is the amt needed to prevent this?

According to the ASPEN Nutrition Support Practice Manual 2nd Ed.,2005, lipids should be held in adult patients with a triglyceride level greater than 500 mg/dL or in the presence of lipemic serum.  It is unclear how long an individual can go before developing EFAD.  Patients with a higher body fat % may be able to go longer than someone who is underweight.  Early research suggests that a hospitalized patient may develop EFAD in 2 weeks. The amount of lipid needed in an adult patient on TPN without enteral suppplementation is 20% 250 ml 1-2 times per week.