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.

It is important to note that TPPN/TPN is not a complete formula. Multivitamins and B complex are critical additions for women with HG to avoid potentially life-threatening complications. Sometimes insulin, anti-reflux medications, and other vitamins are also added.

IV bags surrounding baby

Parenteral Nutrition in HG

Once a woman with a normal body mass index loses over 5% of her body weight (preconception), intravenous vitamin supplementation is highly recommended, especially if she is continuing to have weight loss due to nausea and vomiting. It should be instituted earlier in women with preconception poor intake or low body mass index.

Once she loses 8-10% of her body weight or has been vomiting for more than a month, it is imperative that she receive nutritional intervention to replete her stores and prevent complications of deficiency, as well as regular fluids if she is also dehydrated.

Best practice is to administer nutrient replacement prior to depletion. Depending on severity, getting regular, scheduled infusions of fluids with added micronutrients and electrolytes as often as daily can reduce symptom severity and patient distress.

PN requires added vitamins and should be evaluated to ensure sufficient calories and nutrition based on her gestational age.

Medications vs. Parenteral Nutrition

While nutritional support is important, some physicians initiate home PN without having first attempted an adequate trial of antiemetic medications. Some physicians are reluctant to utilize newer medications with less safety data but are willing to offer PN which has a known history of complications which can be life-threatening.

Increasingly, drugs from the serotonin antagonist class (e.g. ondansetron, granisetron) are used in higher doses which may eliminate the need for PN and even repeated IV's. Beginning these medications at the onset of symptoms and increasing the dose as needed, then gradually weaning them in later pregnancy is an effective practice for many. Combining with medications in other classes often is necessary, as is a daily bowel regimen for women on serotonin antagonists. With symptoms better controlled, a mother is less miserable and will likely recover faster. This results in a net savings as the cost for additional physician visits, treatment of complications, PN, and repeated hospital visits may be reduced.

Potential Complications

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. 

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 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.

Adapted from and other sources.

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 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.

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