Parenteral (Intravenous) Nutrition
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:
Aug. 09, 2006 |
