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How important is nutritional assessment in hyperbaric oxygen therapy? 

One of the keys to a successful patient outcome is assessing nutritional status. If the patient is malnourished, there is insufficient nutritional substrate from which to build new tissue to heal a wound.[1] One out of three patients treated at hyperbaric services can be at risk of malnutrition. 

Patients receiving hyperbaric oxygen therapy (HBOT) for non-healing wounds (e.g., diabetic foot ulcers - DFUs) and osteoradionecrosis are most at risk of malnutrition.[2] 

The definition of a nutritional assessment in the National Coverage Determination NCD 20.29 for Hyperbaric Oxygen Therapy [3] is vague. Although an assessment of nutritional status should be routinely performed on all patients seen in the outpatient wound clinic, the protocol is not well defined. Many times the patient’s nutritional evaluation and management is directed back to the primary care or referring physician. 

NCD 20.29 states: "For diabetic wounds of the lower extremity, 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".[3] Standard wound care in patients with diabetic wounds includes optimization of nutritional status.[4] Since the NCD requires this to be part of conservative care, documentation of nutritional status must be a part of the wound care and HBOT patient record. If this documentation is missing, the services may be denied post payment and funds recouped upon review by your Medicare Administrative Contractor (MAC).

How is optimization of nutritional status defined?

The requirements are not well defined by the NCD or any of the MACs (i.e., WPS, Novitas, Noridian). However, we suggest that laboratory documentation of nutritional status include: albumin, transferrin, and/or pre-albumin levels, with vitamin and trace mineral levels as clinically indicated. Also, since inflammation alters the levels of these markers, C-reactive protein may be of use in interpreting results.


Protein deficiencies are thought to contribute to poor healing rates. Proteins play the most important role throughout the entire wound-healing process. Cells of the immune system (e.g. lymphocytes, leukocytes, phagocytes, monocytes, and macrophages) are mainly comprised of proteins and are necessary to initiate a healthy inflammatory response in the healing process. An adequate supply with proteins is necessary for consistent wound healing. Because collagen is the protein that is produced mainly in the healing wound, a lack of protein decreases the synthesis of collagen and the production of fibroblasts.[5] 

According to the NCD 20.29, patients with DFUs require 30 days of optimization of all parameters.[3] Using this timeframe, transferrin and prealbumin levels would show the greatest changes in the time period that is being reviewed (see Table 1 below).

Table 1. Protein laboratory markers and their half-life and normal ranges



14-20 DAYS

3.5 to 5.5 g/dL


8-9 DAYS

Adults: 20%-50%


2-3 DAYS

18-36 mg/dL

The initial intervention should consist of oral nutritional supplements such as high protein/high-calorie food items (e.g. eggs, meats, nuts, cheese, and prepackaged dietary supplements that include arginine, glutamine, and/or hydroxyl-methyl-buterate HMB).

Patients who are unable to adequately increase their protein consumption by simple oral nutritional supplements should be considered for tube feedings or parenteral nutritional support. Evaluation by a registered dietitian should be considered if there is an inadequate response to first-line oral interventions.

The body creates protein waste products when it ingests protein. In healthy kidneys, millions of nephrons filter waste products. If a patient has chronic kidney disease (CKD), the kidney loses the ability to remove protein waste. This waste builds up in the blood instead of being flushed out into the urine. Patients with CKD should consult their nephrologist or a registered dietician before increasing protein intake. 

Patients who live with diabetes and experience delayed wound healing should balance optimization of nutrition with glycemic control. A multidisciplinary approach may be necessary to achieve clinical outcomes. Wound Centers should strive to develop a systematic approach to optimizing nutritional status in patients starting with the initial evaluation and reassessing at 30 day intervals. 

Key takeaways

One of the keys to a successful patient outcome in HBOT is assessment of nutritional status. Malnutrition screening should be part of routine patient assessment in order to ensure patients receive timely nutritional intervention. 

NCD 20.29 requires optimization of nutritional status to be part of conservative care thus documentation of nutritional status, plan and outcomes must be part of the wound care and HBOT patient record.


The WoundReference Hyberbaric Oxygen Therapy Knowledge Base features reimbursement and clinical guidelines, protocols and tools to promote high standards of patient care and operational safety within the hyperbaric program, including comprehensive topics related to Patient Care in HBOT.  WoundReference Curbside Consult gives you actionable, specific answers from our multidisciplinary advisory panel in a timely manner. More topics and tools on nutrition in wound care HBOT will be released soon. 


  1. Wild Thomas, Rahbarnia A, Kellner M, Sobotka L, et al. Basics in nutrition and wound healing; Nutrition 26 . 2016;.
  2. See HG, Tan YR, Au-Yeung KL, Bennett MH et al. Assessment of hyperbaric patients at risk of malnutrition using the Malnutrition Screening Tool - a pilot study. Diving and hyperbaric medicine. 2018;volume 48(4):229-234.
  3. CMS. National Coverage Determination (NCD) for Hyperbaric Oxygen Therapy (20.29) . 2017;.
  4. Gelly H, et al. Today’s Wound Clinic . 2016;.
  5. Collins N, Friedrich L, et al. Appropriately Diagnosing Malnutrition to improve wound healing; Today’s Wound Clinic . 2016;.
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