Critical care - Nutritional therapy: Nursing

Nutritional therapy is an intervention used to meet nutrient requirements in critically ill patients who are unable to consume or tolerate oral nutrition or can’t digest or absorb food. The two main types of nutritional therapy are enteral nutrition and parenteral nutrition. As the nurse, you’ll provide patient-centered care while providing nutritional therapy to critically ill patients.

Now, enteral nutrition, also known as tube feeding, involves the delivery of temporary or long-term nutrition through a tube directly into the GI tract. This is indicated for patients who have some digestive function but are unable to consume adequate nutrients by mouth, like intubated patients, patients with nervous system disorders that impact chewing or swallowing, or patients with increased caloric needs due to major surgery or burns.

A common temporary route for enteral nutrition is through a nasogastric, or NG, tube which enters through the nose and goes into the stomach. For patients at increased risk of aspiration or with impaired gastric emptying, a small bowel feeding tube can be inserted directly into the small intestine.

On the other hand, if long-term or permanent enteral feeding is needed, a tube can be placed through a surgical opening in the abdominal wall and into the stomach, known as a gastrostomy tube, or G-tube. One common type of gastrostomy tube is the percutaneous endoscopic gastrostomy tube, also called a PEG-tube. Tubes can also be inserted into a part of the small intestine called the jejunum, known as a jejunostomy tube, or J-tube for short.

There are other conditions where a patient can’t digest and absorb any food via the GI tract, due to conditions like GI trauma or surgical procedures; as well as other illnesses, like intestinal cancer.

In these cases, parenteral nutrition is prescribed, where liquid nutrition, formulated based on the nutritional needs of the patient, is infused intravenously. The most common type of parenteral nutrition is total parenteral nutrition, or TPN where all nutrients, including protein, fat, minerals, electrolytes, water, and carbohydrates are delivered through a catheter into a large vein close to the heart, like the superior vena cava.

Since TPN can be corrosive to the peripheral veins, it must be administered using central venous access devices, like a peripherally inserted central catheter, or PICC line, or port.

Another type is peripheral parenteral nutrition, or PPN, where less calorically dense nutrition is delivered via peripheral veins. PPN is used less often due to risk of infection and phlebitis, or inflammation of the veins, but it can be indicated in the short term for patients without a central venous access device.

When caring for your critically ill patient receiving nutritional therapy, your goals of care include safely administering nutrition, monitoring for complications, and evaluating your patient’s ongoing nutritional status.

Begin by assessing your patient’s baseline nutritional status by recording their height and weight and calculating intake and output. Check their laboratory test results, including electrolytes, BUN, creatinine, and complete blood count.

Also auscultate their heart and lung sounds and assess for edema; and inspect for signs of malnourishment, such as skin breakdown, impaired wound healing, hair loss, and brittle nails.