Parenteral (Intravenous) Nutritional Therapy
“Optimizing medical therapy to allow adequate oral intake is the goal; however, that is not always achievable in patients with HG. The risks of enteral and parenteral nutrition (PN) may be less than those of chronic malnutrition and dehydration, especially in women with severe or prolonged symptoms.”
Kimber MacGibbon, RN
In women with hyperemesis gravidarum (HG) who become very malnourished or have a history of moderate to severe HG, parenteral nutrition may be initiated to ensure she receives adequate nutrition. Numerous vitamins and nutrients are depleted in only a few weeks, exacerbating her symptoms and making them more resistant to medical interventions.
Parenteral Nutrition (PN) not only addresses the chronic dehydration, but also the malnutrition. This reduces the risk of adverse fetal effects. PN may be administered centrally or peripherally. Central administration via a central line (most commonly a PICC line) or peripherally via a midline catheter.
- According to ASPEN, Peripheral Parenteral Nutrition (PPN) is contraindicated in those with severe weight loss, renal or liver compromise, large nutrient or electrolyte needs, or expected duration of PPN greater than two weeks.
- Central PN is recommended in patients receiving nutrition for more than a few weeks. Note that high body mass index patients losing weight still need nutrition to avoid life-threatening complications.
- Note: Chronic MVI and nutrient shortages create challenges for PN.
Central Vascular Lines (PICC)
Remember that many women have repeated fluid needs, so a longer dwelling central vascular access devices (CVADs) can preserve her veins. The American College of Obstetrics and Gynecology recommends enteral feedings before placing CVADs because of reported complication rates up to 66% in patients with HG. However, many studies find most enteral options are not tolerated by HG patients, especially those with refractory vomiting.
IMPORTANT: Prior to starting PN, a minimum of 100 mg of IV thiamin is critical and should continue daily. Assessment for signs of Refeeding Syndrome, thiamin deficiency, and Wernicke's encephalopathy should continue for at least 7-10 days or until lab values are stable and dietary intake is normal.
Parenteral Nutrition in HG
Medications vs. Parenteral Nutrition
While nutritional therapy is needed for some patients, clinicians must be aware of the possible life-threatening complications of catheter insertion as well as metabolic and infectious complications. Encouraging oral intake simultaneously with PN can decrease gastrointestinal atrophy and help meet nutritional needs. Due to pregnancy, some complications are more likely to occur and more likely to have adverse outcomes. However, these risks are estimated to occur in only a small percentage of those receiving parenteral nutrition according to recommended guidelines and protocols.
Prevention of Complications
Complications during pregnacy can be life-threatening for the mother and her child, so careful mangement is even more critical.
- Careful placement and management by highly skilled clinicians.
- Excellent training of home caregivers.
- Proactive monitoring and prevention strategies.
PN should be offered to hyperemetic women when aggressive medical management has failed, and the patient is at risk for malnutrition. The benefits usually outweigh the risks and intervention is crucial before serious complications develop.
- 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 PN 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 1-3 weeks, particularly in malnourished patients. Replacement is very important during pregnancy for mother and baby.
- 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 heart disease or kidney impairment, and during pregnancy to maintain uterine blood flow).
- Acid/base imbalance: Solution design must take into account acid/base status of patient, i.e. chloride, acetate etc.
- Liver 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 thiamin, cardiac arrhythmias, and congestive heart failure may result.
- 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 the 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.