Closing the Gap: How to Provide Protein without Increasing Total Calories

Advances in Skin & Wound Care, Jul/Aug 2004 by Posthauer, Mary Ellen

Mr R is an 86-year-old patient admitted to a nursing facility after a below-knee amputation. Besides the surgical wound, he also has a Stage IV pressure ulcer on his coccyx. His diagnosis includes diabetes mellitus, chronic obstructive pulmonary disease, hypertension, and a cerebrovascular accident with expressive and receptive aphasia. he has been receiving continuous oxygen, tube feedings, and the appropriate medications to control his medical conditions.

Clinicians have been treating Mr R's coccyx wound with normal saline. Bacitracin with zinc was applied to the red healthy tissue; necrotic tissue was removed and packed with a gauze dressing. After a modified barium swallow, the speech language pathologist determined that it was not clinically safe for Mr R to advance to oral intake.

Because his wounds exhibited little healing progress, the dietitian was asked to review Mr R's nutritional status.

Time to Intervene

The dietitian determines that Mr R is receiving adequate calories and fluids per his requirements and can to tolerate additional volume. His weekly weights are level and within the adjusted range for his amputation. However, his protein needs are not being met based on the status of his wound and his prealbumin level of 9 mg/dl (which indicates moderate depletion).

Protein is responsible for the synthesis of enzymes involved in wound healing and cell multiplication, as well as collagen and connective tissue synthesis. The current recommendation for protein intake for stressed patients ranges from 1.2 to 1.5 g/kg/day. Higher protein intakes are associated with improved wound healing in patients with pressure ulcers.1-2 Although the optimum protein range has not been established, a range of 1.5 to 2.0 g/kg/day has been associated with wound healing.3 Intake beyond 2.0 g/kg/day can affect renal and hepatic function.4

To meet Mr R's increased protein needs, the dietitian recommends a high-nitrogen, cnzyme-hydrolyzed, tryptophan-fortified collagen liquid protein that mixes well with the water flush, will not clog the feeding tube, and provides 15 grams of protein per ounce. As with other protein products, predigesting proteins facilitate absorption in the gastrointestinal tract, thus making the amino acids more bioavailable. One ounce of the liquid product twice daily provides the protein needed to meet Mr R's additional requirements.

The product contains the essential amino acids and is enriched with arginine at a level of 8.5 grams/100 grams of protein and glutamine at 11 grams/100 grams of protein. Arginine is a substrate for nitric acid and regulates nucleic acid synthesis. Nitric acid production activates wound macrophages, which are rich sources of growth factors, cytokines, bioactive lipid products, and proteolytic enzymes necessary for the healing process.5-7

The increased level of arginine promotes its own conversion to ornithine, a precursor to prolinc that is incorporated into collagen.8-10 After 3 weeks of additional protein intake, Mr R's wounds begin to decrease in size and demonstrate signs of healing.

Role of Modular Protein

The need to increase protein without increasing total caloric intake is often a challenge for the dietitian or health care professional. In addition to patients like Mr R, obese patients are ideal candidates for modular protein. Although they may need increased protein, they should not receive the high-calorie supplements designed for undernourished patients with wounds.

Clinicians should become familiar with the various types of powdered and liquid supplements that provide protein and moderate calories to patients with wounds. Factors to consider when selecting such supplements include:

* protein source

* grams of protein per serving

* number of servings to meet protein requirement

* taste, if taken orally

* ease in mixing

* ability to mix into hot/cold products

* cost per gram of protein.

Modular protein products may have a soy, whey, casein, or egg white composition. Or they may have a hydrolyzed collagen and casein base or a hydrolyzed collagen base fortified with tryptophan, which is considered a high-quality protein that contains the essential amino acids required for growth and wound healing. Most commercial powdered products provide 5 to 7 grams of protein per serving, versus 10 to 15 grams of protein per ounce of the liquid products.

To evaluate the available products, dietitians should meet with their facility's wound care team, as well as with wound care patients. Results can be incorporated into a facility's nutrition protocol for wound healing, which would include monitoring the total nitrogen intake and the hydration status. Commercial products currently on the market include ArgiMent (National Nutrition Inc), Arginaid and Beneprotein (Novartis), Hi-ProCal (Hormel), ProMod (Ross/Abbott), ProSource (National Nutrition Inc), ProSure (Ross/Abbott), and Pro-Stat101 (Medical Nutrition, Inc).

References

1. Chernoff R, Milton K, Lipschitz E, et al. The effect of a high protein formula on decubitus ulcer healing in long-term tube fed institutionalized patients. JADA 1990; Oct suppl;A-130.