Parenteral (Intravenous) Nutritional Therapy
After several weeks of vomiting, mothers with hyperemesis
can become very malnourished, yet this may not be realized
by health professionals who only see them periodically. This
is especially true if they are above their ideal body weight
prior to pregnancy. TPPN (Total Peripheral Parenteral
Nutrition)
or TPN (Total Parenteral Nutrition) may be ordered to ensure
she receives adequate nutrition. TPPN supplies many more
nutrients than basic IV fluids, and may be given in a regular
(peripheral) IV in the arm. However, the IV will typically
only last for a few days and will then need to be replaced
at another location.
TPN supplies most of her daily nutritional
requirements and is usually given through a catheter called
a PICC line placed in the forearm, or a central venous line
placed in the neck/shoulder area. Local anesthetic is given
during the procedure. These catheters are much longer and
the end point is in the heart. This allows very concentrated
nutrients to be given without damage to the smaller blood
vessels of the arms.
It is important to note that TPPN/TPN
is not a complete formula. Added multivitamins are very important
in women with HG to avoid nutritionally-related complications.
Management of HG with Parenteral Nutrition
Once she loses over 5% of her pre-pregnancy body weight, nutritional therapies should be discussed, especially if she is continuing to have significant nausea, vomiting, and weight loss. At a minimum, IV home therapy with added vitamins should be administered after a few weeks of frequent vomiting. Blood tests can determine deficiencies long before you will see them. Encourage her physician to give her replacement multivitamins.
"According to the American Medical Association (AMA), the physician should not await the development of clinical signs of vitamin deficiency before initiating vitamin therapy.
Patients with multiple vitamin deficiencies or with markedly increased requirements may be given multiples of the daily dosage for two or more days as indicated by the clinical status." aaiPharma®
Once she loses 8-10% of her body weight or has
been vomiting for
more than a month, it is imperative
that
she
receive
support to replace the many nutrients she has lost and
to maintain her hydration. TPPN or TPN is the next choice
for
ongoing replacement. Dehydration perpetuates the vomiting
cycle, as do nutritional deficiencies.
If nutritional support
is not offered and/or she is not responding to anti-vomiting
medications, a second opinion with a specialist may be
needed. She may need you to do this for her as it is very
difficult
to think clearly and advocate for yourself when you are
ill. See our Referral
Network for
tips on finding a doctor experienced in treating HG.
Medications v. Parenteral Nutrition
While nutritional support is important, some physicians initiate home TPN without having first attempted an adequate trial of antiemetic medications and may not adequately consider the risks of TPN. Serious complications are possible when central venous lines are placed, as well as metabolic and infectious complications. These are usually due to insertion techniques, improper care of the IV site or line, or inadequate monitoring of her metabolic and nutritional status with blood tests. However, these problems are estimated to occur in only a small percentage of women with HG, even when TPN is given at home.
Before TPN is begun, consideration should be given to aggressive anti-vomiting medications and home IV therapy with vitamins, which do not put her at risk for any life-threatening complications. A growing number of women report that drugs from the serotonin antagonist category (e.g. Zofran, Anzemet, Kytril) have been used in higher doses (and early in pregnancy) in their subsequent pregnancies, eliminating the need for TPN and even IV's in some cases. Many physicians (and midwives) are not familiar with the use of these drugs during pregnancy, and are reluctant to offer them in adequate doses to give mothers relief from incessant vomiting. Feel free to refer her health professionals to our site for assistance, or find a physician up-to-date on caring for mothers with hyperemesis.
Potential Complications of Parenteral Nutrition: | |
Metabolic complications: | |
Hyperglycemia | Most common metabolic complication of parenteral nutrition. Related to rate of dextrose infusion, concentration, level of stress, etc. May cause hypertriglyceridemia which may cause pancreatitis. Close monitoring is important during pregnancy, esp. if using glucocorticoid therapy. |
Hypoglycemia | Most commonly related to abrupt discontinuation of TPN without tapering, especially with high dextrose concentrations. |
Essential fatty acid deficiency | May result from parenteral nutrition regimen devoid intravenous fat administration. May occur in as little as 2 weeks, particularly in malnourished patients. Replacement is very important during pregnancy. |
Electrolyte imbalance | Inadequate or excess administration of electrolytes in parenteral nutrition solutions. Losses due to vomiting should be accounted for. |
Fluid volume disturbances | Volume deficit or volume overload (particularly important in patients with renal impairment and during pregnancy to maintain uterine flow). |
Acid/base imbalance | Solution design must take into account acid/base status of patient, i.e. chloride, acetate etc. |
Hepatic complications | Such as steatosis, possibly due to excessive carbohydrate administration. |
Refeeding syndrome | The metabolic cascade of events that takes place when a malnourished patient is refed. Hypophosphatemia, hypokalemia, hypomagnesemia, body-fluid disturbances, vitamin deficiencies such as thiamine, cardiac arrhythmias, and congestive heart failure may result. |
Mechanical complications: | |
Catheter related | Pneumothorax, vessel damage, thrombosis, occlusion, catheter breakage, infection, etc. |
Infection | Fever, pain, redness at site. |
Site related | Pain, inflammation, or redness, drainage. |
Air embolism | A result of air being introduced into catheter. |
Delivery device related | Most commonly device failure. |
Septic complications | Patients with indwelling access devices and a compromised immune system are at high risk for catheter related sepsis. |
Adapted from www.nyschp.org, www.medscape.com and other sources.
Updated on: Sep. 15, 2022