Skip to main content

Understanding Nutritional Optimization in Hyperbaric Oxygen Therapy

National Coverage Determination requires nutritional optimization for patients to receive hyperbaric oxygen therapy. These authors provide a guideline for how to assess nutrition and take a closer look at payers’ required elements of nutritional optimization.

Nutritional assessment and interventions are not straightforward. Sometimes, nutritional assessment and intervention are difficult even for seasoned hyperbaric oxygen therapy (HBOT) practitioners.

The National Coverage Determination (NCD) 20.29 for Hyperbaric Oxygen Therapy addresses nutrition in 4 words: “optimization of nutritional status.”1 The exact paragraph is transcribed below:

“The use of HBO therapy is covered as adjunctive therapy only after there are no measurable signs of healing for at least 30 days of treatment with standard wound therapy and must be used in addition to standard wound care. Standard wound care in patients with diabetic wounds includes: assessment of a patient’s vascular status and correction of any vascular problems in the affected limb if possible, optimization of nutritional status, optimization of glucose control, debridement by any means to remove devitalized tissue, maintenance of a clean, moist bed of granulation tissue with appropriate moist dressings, appropriate off-loading, and necessary treatment to resolve any infection that might be present.”1

The evaluation of nutritional status and performance of standard wound care have never been well-defined in a regulatory way. In addition, patients who come to hyperbaric clinics usually receive “advanced” wound care, not standard wound care. Vague regulatory verbiage leads to multiple interpretations. Any clinic can individually interpret the requirement for optimization of nutritional status to its liking. However, if Medicare and other payers disagree with that interpretation, they may withhold payment through post-treatment audits. In this article, we discuss relevant aspects related to payers’ required elements and suggest a structure that can be considered as guidance for nutritional assessments for every wound and HBOT patient.

A Closer Look at the Role of Nutrition in Wound Healing

Why is it important to perform nutritional assessments prior to and during the course of HBOT?

Nutritional assessments prior to, and during, the course of HBOT are of utmost importance for a successful treatment plan. From a clinical standpoint, nutrition plays a major role in wound healing.2,3 From a regulatory aspect, nutritional assessment and optimization allow hyperbaric programs to withstand eventual post-treatment audits, and meet insurers’ coverage requirements for HBOT. Nutritional assessments are also central elements of quality measures applicable to HBOT centers.  

Among patients receiving HBOT, patients with nonhealing wounds (e.g., diabetic foot ulcers and osteoradionecrosis) are most at risk of malnutrition.4 Malnourished patients do not have sufficient nutritional elements from which to build new tissue in order to heal a wound. Wound healing may be significantly delayed.2,3

A well-balanced diet includes adequate amounts of protein, carbohydrates, fluids, vitamins, and minerals.5 Especially for patients with wounds, proteins are essential, as proteins play an important role throughout the wound healing process and are major components of cells of the immune system (e.g., lymphocytes, leukocytes, phagocytes, monocytes, and macrophages). Protein is needed for production of collagen during the proliferative phase of the healing wound.6 Protein nutrition is responsible for maintaining a positive nitrogen balance, thus preventing muscle wasting and poor ATP production at the cellular level.

The NCD for Hyperbaric Oxygen Therapy (20.29) does not clearly define nutritional assessment.1,7 It is clear, however, that an assessment of nutritional status should be routinely performed on all patients seen in the HBOT program.

Since the NCD requires optimization of nutritional status to be part of standard wound care, documentation of nutritional status must be a part of every wound care and HBOT patient record. If this documentation is missing, provided services may be denied or funds recouped upon review by the Medicare Administrative Contractor (MAC).3

Factors That Prevent Nutritional Assessments In Practice  

Several factors may pose as obstacles that prevent clinicians from performing nutritional assessments. For instance, hyperbaric oxygen providers may not be aware that assessing patients’ nutritional status is a standard of care in wound management and HBOT. The Centers for Medicare and Medicaid Services (CMS) expects that patients’ nutritional status be assessed and managed appropriately but does not define exactly what that means.7 In certain cases, clinicians may shy away from performing nutritional assessments on their patients because of the perceived responsibility for managing newly diagnosed deficiencies or correcting abnormal laboratory findings. Or sometimes wound clinicians may feel like by performing nutritional assessments, they would be “stepping on other clinicians’ toes.”

Despite the existing barriers, nutrition should be discussed at every wound visit. Since nutrition is a critical component of the wound healing process, it is imperative that providers begin questioning their patients at the initial consultation and weekly thereafter. Collaboration among the wound care team, primary care physician, and registered dietician can be seamless if a simple system is in place to communicate among the parties. This may be a phone call, text message, quick face to face encounter, or telemedicine.8

How Can Clinicians Conduct Nutritional Assessments For HBOT?  

Conducting nutritional assessments for wound and hyperbaric patients can be efficient and meaningful depending on the systems that have been implemented at the wound and hyperbaric center. Many clinics have electronic health records that contain mandated questions such as height, weight, and calculated body mass index (BMI). Although these parameters are important, they are only a piece of the puzzle.

Providers should begin by asking questions during the initial consultation, such as:

• How would you describe your diet?
• What did you have for breakfast today?
• How many servings of fruit and vegetables do you have each day?
• How often do you eat meat or protein?
• Have you unintentionally lost or gained weight in the last 3 months?

A standardized nutrition tool can be extremely effective in identifying a patient’s current nutritional state. The tool should be completed by staff at the initial consultation and then every 30 days (as required by Medicare), or as needed. If there is any significant change in the patient’s health status, the intervention should be repeated. The free Mini Nutritional Assessment by the Nestlé Nutrition Institute is one such screening tool. This validated tool takes only a few minutes to complete and can identify patients who are at risk for malnutrition. Results from the screening can be instrumental in encouraging the provider to consult with a registered dietician for identified deficits.9

Laboratory Screening For Nutrition

In addition to the formal nutritional consultation, certain laboratory tests may provide additional information:

• Complete blood count with differential
• Complete metabolic panel (which includes albumin and serum protein levels)
• Erythrocyte sedimentation rate
• C-reactive protein
• Pre-albumin level
• 25-hydroxy vitamin D

These tests look at the body’s ability to mount a response to wounding, the presence of inflammation, renal and liver function, and short- and long-term protein nutrition.

Alternative Assessments for Patients with Chronic Kidney and/or Liver Disease

For patients with chronic kidney disease (CKD), a registered dietitian and nephrologist should be involved in the nutritional plan. Increasing protein intake in these patients may lead to increased protein waste products in the blood. This may have an effect in response to dialysis or ammonia products in liver disease.

For patients with diabetes, it is critical to assess nutritional status as it interfaces with immune function, malnutrition, glycemic control, and weight loss. Of note, there have been no randomized controlled trials that link HbA1c and wound healing. There is a paucity of randomized controlled trials comparing nutritional variations of wound healing in the patient with diabetes.

During the healing process, the body needs increased amounts of calories, protein, vitamins A and C, and, sometimes, elemental zinc. As a result, providers need to promote wound healing through better nutrition, starting on the day of the initial consultation. It takes an integrated approach involving endocrinology, nephrology and a registered dietician (RD) to improve clinical outcomes.7 Medicare Part B may cover medical nutrition therapy (MNT) services and certain related services for patients with diabetes complicated by chronic kidney disease, or for patients who have had a kidney transplant in the last 36 months.10

When To Take Action And Intervene

Upon identifying nutritional deficits or risks in patients during consultation or weekly follow-up, the provider may decide to manage these deficits or risks through counseling and education. Providers can provide nutritional handouts that outline the best foods to eat, healthy snacking and supplementation with vitamins and amino acids.

Some nutritional intervention can be started by encouraging protein consumption, such as eggs, meats, nuts, cheese or liquid supplements. Some patients may choose to mix peanut butter with dry, powdered milk (another source of increased protein). A number of powder/liquid supplements have been introduced specifically for wound care patients, but there have been no randomized controlled trials to show that powder or liquid micro-nutrients are beneficial in healing chronic wounds.

In general, a multivitamin and mineral supplement is an appropriate nutritional intervention.9 In many instances, it is difficult for patients to consume a balanced diet that meets these needs, and wound repair may require additional amounts or specific vitamins and minerals. These deficits are best replaced by supplements as needed.

Although costly, there are a number of packaged dietary and protein supplements such as L-arginine, glutamine and other micronutrients. L-arginine has several functions including accelerating insulin secretion, stimulating protein regeneration and promoting the transport of amino acids into the cells. L-arginine is a component of nitric oxide that increases blood flow and oxygen to the wound, and thus increases collagen formation and reduces inflammation.11,12 Glutamine, an amino acid, supports the immune system and collagen production and can be synthesized by almost all tissues in the body.

How Can Nutritional Assessment Be Documented?

Assessment of nutritional status and optimization should be documented in the patient’s health record by the provider at the time of the initial consultation and at least once every 30 days, per CMS. The minimum documentation should include:

• Food/nutrition-related history
• Anthropometric measurements such as height/weight, BMI, and weight history
• Biochemical data, medical tests and procedures such as laboratory data and testing
• Nutrition-focused physical findings such as physical appearance, evidence of muscle wasting, history of poor appetite, and swallowing function
• Client history: personal, medical and family history, alternative medicine use and social history
• Results from the nutritional screening tool and any referrals to clinic or hospital nutritionist

Templates and checklists provided by clinical and reimbursement decision support systems such as WoundReference and/or embedded in electronic health systems can help reinforce appropriate documentation.


Nutritional optimization is a commonly overlooked element that is essential to successful patient outcomes in HBOT, both from clinical and reimbursement perspectives. Documentation of nutritional assessment, status, plans, and outcomes should be part of the HBOT patient record.

Tiffany Hamm is an Advanced Certified Hyperbaric Registered Nurse, Certified Wound Specialist and Co-Founder, Chief Nursing Officer of WoundReference, Inc., and Principal Partner with Midwest Hyperbaric LLC.

Jeff Mize is a Registered Respiratory Therapist, Certified Hyperbaric Technologist, Certified Wound Care Associate and Co-Founder, Chief Clinical Officer of WoundReference, Inc, and Principal Partner with Midwest Hyperbaric LLC.  

Elaine H. Song is a plastic surgeon, and Co-Founder and CEO of WoundReference, Inc.

Eugene R. Worth is an anesthesiologist, wound care and hyperbaric physician, and Advisor and Editor of WoundReference, Inc.


Tiffany Hamm, BSN, RN, ACHRN, CWS; Jeff Mize, RRT, CHT, CWCA; Elaine Horibe Song, MD, PhD, MBA; and Eugene R. Worth, MD, M.Ed., FABA, ABPM/UHM

1. National Coverage Determination (NCD) for Hyperbaric Oxygen Therapy (20.29). Available at Accessed August 21, 2017.
2. Quain AM, Khardori NM. Nutrition in wound care management: A comprehensive overview. Wounds. 2015;27(12):327-335.
3. Hamm T, Mize J. Nutritional screening for wound care and hyperbaric oxygen therapy. WoundReference. Available at Accessed August 8, 2019.
4. See HG, Tan YR, Au-Yeung KL, Bennett MH. Assessment of hyperbaric patients at risk of malnutrition using the Malnutrition Screening Tool - a pilot study. Diving Hyperb Med. 2018;48(4):229-234.
5. Aviles F, Munoz N, Smith K. What the experts say about nutrition, diabetes and wounds. Today’s Wound Clinic. Available at Published July 3, 2019. Accessed August 8, 2019.
6. Collins N, Friedrich L. Appropriately diagnosing malnutrition to improve wound healing. Today’s Wound Clinic. 2016;10(11):10–13.
7. Gelly H. Nutritional assessment & prior authorization of hyperbaric oxygen therapy. Today’s Wound Clinic. 2016;10(11):25,31.
8. Song E. What is new in 2019 for Telehealth and Telemedicine? WoundReference. Available at Published January 11, 2019. Accessed August 8, 2019.
9. Collins N. Diabetic foot ulcers and nutrition: making the connection. Today’s Wound Clinic. 2019;13(7):10–15.
10. Medical Nutrition Therapy Insurance Coverage. Available at Accessed August 7, 2019.
11. Bath PM, Krishnan K, Appleton JP. Nitric oxide donors (nitrates), L-arginine, or nitric oxide synthase inhibitors for acute stroke. Cochrane Database Syst Rev. 2017;4:CD000398.
12. Witte MB, Barbul A. Role of nitric oxide in wound repair. Am J Surg. 2002;183(4):406-412.

Back to Top