Pressure ulcer Archives - Dr. Scott Rennie

The question comes up on almost every wound follow-up, and it is nearly always phrased the same way. What should I be eating to make this heal faster?

It is a good question. The answer patients get is usually a list of vitamins, which is mostly wrong, or a shrug, which is worse. There is real evidence here. It just does not point where the supplement aisle points.

A healing wound is a construction project

Closing a wound means building tissue. Collagen synthesis, angiogenesis, epithelial migration, immune cell proliferation. All of that runs on amino acids and calories, and the demand is above baseline for as long as the wound is open. A large or chronic wound raises resting energy expenditure meaningfully.

Which means the first question is not which supplement. It is whether the person is eating enough of anything at all. In older adults with a chronic wound, the answer is frequently no, and no capsule fixes an 1,100 calorie a day intake.

What glucose does to the machinery

Hyperglycemia interferes with wound healing at several points at once. Glycosylation impairs neutrophil and macrophage function, which stretches out the inflammatory phase instead of letting the wound progress to proliferation. Fibroblast activity falls. VEGF expression falls, so new vessels are slower to arrive. Matrix metalloproteinase activity rises, which means the collagen that does get laid down is broken down faster than it should be. Collagen density ends up lower.

Put underlying peripheral arterial disease on top and the wound has a supply problem as well as a manufacturing problem.

This is why I care about the A1c on a wound visit and not only on a diabetes visit. The same laceration on a person running an A1c of 11 and a person running a 6 is two different clinical situations, and only one of them is going to close on schedule.

An aside that patients find more persuasive than any of the biochemistry: the glucose control that matters for a wound is the control over the next several weeks, not the number on the day of the injury. That is actionable. It gives someone something to do about a wound that is already there.

The protein number

For adults with a pressure injury who are malnourished or at risk of it, the 2019 international guideline from EPUAP, NPIAP and the Pan Pacific alliance recommends 1.25 to 1.5 grams of protein per kilogram of body weight per day, with 30 to 35 kilocalories per kilogram per day for energy (1).

Those are the best-supported numbers in wound nutrition, and I use them as the floor for any significant open wound, not only pressure injuries. Most people are nowhere near them. A 70 kilogram adult needs roughly 88 to 105 grams of protein a day on that recommendation, and the typical intake I hear described on a video visit is half that.

Worth noting the overlap with the rest of my practice. When I start a patient on an incretin I ask for 1.6 grams per kilogram per day and strength training two to three times a week, because the risk on those drugs is lean mass loss. A patient on an incretin who also has a wound is being asked for the same thing for two different reasons, which makes the conversation easier rather than harder.

Arginine, and how good the evidence actually is

Arginine gets singled out because it is a substrate for nitric oxide and for proline, and proline goes into collagen. The 2019 guideline recommends a high-calorie, high-protein oral nutrition supplement fortified with arginine, zinc and antioxidants for adults with a stage 2 or greater pressure injury who are malnourished or at risk of malnutrition (1).

Read that recommendation carefully, because it is narrower than how it gets quoted. It is for a specific wound severity, in a specific nutritional context, and the arginine comes inside a fortified supplement rather than as arginine on its own (2). The trials behind it tested the whole formulation. Nobody has shown that arginine by itself, added to an adequate diet in a well-nourished person, does anything for a wound.

I have no objection to those supplements in the patients the guideline describes. I do object to a well-fed person with a healing surgical incision spending money on arginine capsules.

Vitamin C and zinc

Both are genuinely required for wound healing. Vitamin C is a cofactor for the hydroxylation steps in collagen synthesis, and frank scurvy produces wounds that will not close. Zinc deficiency impairs epithelialization.

None of that means supplementing someone who is not deficient helps. Reviews of vitamin and mineral supplementation in wound care keep landing in the same place: unclear benefit unless there is a confirmed or suspected deficiency, and no well-powered randomized trial showing that routine vitamin C or zinc speeds healing in replete patients (3).

So I correct documented deficiencies and I do not supplement reflexively. High-dose zinc in particular is not harmless; it interferes with copper absorption over time.

This is the part of the conversation patients like least, and I say it anyway.

What matters more than any of it

Smoking. Sørensen’s meta-analysis of surgical patients found substantially higher rates of wound complications and infection in smokers, and improvement with cessation before surgery (4). If a patient with a slow wound smokes, that is the highest-yield thing on the list, and it is not close.

Then perfusion. A wound on a limb without a decent pulse is a vascular problem wearing a dressing, and no amount of protein fixes it.

Then offloading and moisture balance, which are mechanical rather than nutritional and are where most home wound care goes wrong.

Nutrition belongs on the list. It belongs below those.

For patients

Eat more protein than you think you need while a wound is open. Aim for something in the range of 1.25 to 1.5 grams per kilogram of your body weight per day, which for most adults means adding a protein source to every meal rather than eating one large dinner. If you are diabetic, the wound is a reason to tighten control now, not later.

Skip the wound-healing supplement stack unless your clinician has found an actual deficiency. If you smoke, stopping will do more for that wound than everything else on this page combined.

For colleagues

Ask what people are eating before you reach for a supplement, and ask in grams rather than in general terms. The 1.25 to 1.5 g/kg recommendation is easy to quote and rarely translated into food for the patient, which is where it fails.

Check a zinc or vitamin C level if the history suggests deficiency, then treat what you find. Do not treat the wound with a multivitamin on principle.

And put smoking cessation at the top of the plan for any wound that is behind schedule, ahead of the dressing change conversation.

The Bottom Line

Wounds heal on protein, calories and blood flow, in something like that order, and they stall on high glucose and tobacco. The guideline numbers worth remembering are 1.25 to 1.5 grams of protein per kilogram per day and 30 to 35 kilocalories per kilogram per day. Arginine and antioxidant supplements have a real place, in malnourished patients with stage 2 or worse pressure injuries, and almost nowhere else. Vitamin C and zinc are worth correcting when they are low and worth skipping when they are not. If you fix only one thing on this list, fix the smoking.

Sources

1. European Pressure Ulcer Advisory Panel, National Pressure Injury Advisory Panel and Pan Pacific Pressure Injury Alliance. The Role of Nutrition for Pressure Injury Prevention and Healing: 2019 International Clinical Practice Guideline recommendations. https://cdn.ymaws.com/npiap.com/resource/resmgr/The_Role_of_Nutrition_for_Pr.pdf

2. Chu AS, Delmore B. Arginine: What You Need to Know for Pressure Injury Healing. Adv Skin Wound Care. 2021;34(12):630-636. PMID 34807894. https://pubmed.ncbi.nlm.nih.gov/34807894/

3. Indian Health Service National Pharmacy and Therapeutics Committee. Formulary Brief: Nutritional Supplements in Wound Healing. https://www.ihs.gov/sites/nptc/themes/responsive2017/display_objects/documents/guidance/NPTC-Formulary-Brief-NutritionalSupplementsinWoundHealing.pdf

4. Sørensen LT. Wound healing and infection in surgery. The clinical impact of smoking and smoking cessation: a systematic review and meta-analysis. Arch Surg. 2012;147(4):373-383. PMID 22508785. https://pubmed.ncbi.nlm.nih.gov/22508785/

5. Armstrong DG, Boulton AJM, Bus SA. Diabetic Foot Ulcers and Their Recurrence. N Engl J Med. 2017;376(24):2367-2375. PMID 28614678. https://www.nejm.org/doi/10.1056/NEJMra1615439

I am Scott Rennie, DO, board certified in Family Medicine and Obesity Medicine. I practice entirely by telemedicine, licensed in all 50 states. Most of my work now is weight loss, metabolic health and menopause care. If this was useful, Start here lists what I write about now.

A patient came in to see me today with a sore on his heel that’s been bothering him for the past few months. He’s diabetic and has lost feeling in the bottom of his feet. He’s had these pressure sores in the past but has trouble getting them to heal up.

Pressure sore: An area of skin damaged by pressure, such as sitting or lying in one position for a long period. They are also called bedsores. They are most common where bone sits near the surface of the skin: the hips, elbows, ankles, and back or buttocks. The skin and soft tissue become damaged because not enough oxygenated blood reaches the area to support healing, usually because the soft tissue is compressed between the surface and the hard bone beneath.

Appearance: The sores change in appearance depending on how long they have been present and how much damage has been done. At the start, the sore looks like a small red patch of skin. If it is not treated, the skin breaks down and a hole or crater forms, which is what we call an ulcer.

Stage 1: The skin is intact without ulceration, but when you press on it the color does not change the way it should. Healthy tissue is pink, and pressing on it with a finger blanches it, with the pinkness returning within a couple of seconds. That does not happen in damaged skin at this stage, and the area may look darkly pigmented.

Stage 2: There is an open, shallow ulcer with a red-pink base. Blisters may be present, either intact or ruptured.

Stage 3: Structures beneath the skin such as fat may be exposed, but at this stage you should not see bone, tendon or muscle.

Stage 4: Bone, tendon and muscle may be visible in the base of the ulcer.

People at risk: Some patients are far more likely than others to develop pressure sores.

Patients who cannot move well because of a medical problem. They may sit or lie in one position for a long time and need help repositioning so the skin does not break down.
Older people, who often move less and whose skin is thinner and more fragile.
Patients with diabetes or nerve problems in their feet, who may not feel a pebble in a shoe or pressure building against the foot.
Patients in the hospital or a nursing home, who are at especially high risk because several of these factors stack: increased age, reduced mobility, and other complicated medical problems.

Prevention: Several things lower the chance of developing pressure sores.

Repositioning the patient’s body every two hours so no one area of skin stays crushed, pinched or under pressure.
Putting pillows between the ankles and knees to reduce pressure on the skin over those bony areas.
Raising the head of the bed when the patient is lying on their side to reduce pressure on the hip bone.
Using special foam or soft mattresses that reduce pressure over the areas that bear the most load.

For patients in wheelchairs:

Use a cushioned seat if possible to prevent pressure on the sacrum.
Tilt forward or to the side every hour to release pressure on the seat.
If the ankles or heels press against the chair, use foam padding to protect against sores.
Check the skin regularly for signs of pressure or ulceration.

Treatment: Pressure sores are treated differently depending on the stage and how severe the skin damage is.

If there is mild erythema, treatment is generally offloading the area by reducing the time it spends compressed, through repositioning and pillows to cushion it. We also use transparent films over the ulcers to protect them.
In patients with diabetes, keeping blood sugars under good control is very important. Elevated blood sugars impede wound healing.
If there is dead or dying skin or soft tissue, it often needs to be removed to help prevent infection.
Special bandages may be needed to keep the healing tissue moist while preventing maceration from being too moist. The dressings we use can be expensive.
Antibiotics may be prescribed if there is a wound infection.
Medication for pain may also be prescribed.

There are scoring tools to grade pressure and track healing. These help for patients who return for repeat visits to a wound care clinic or their primary care provider and need their progress graded. Clinical features examined include:

Amount of exudate
Skin color surrounding the wound
Peripheral tissue swelling
Peripheral tissue firmness around the wound
Amount of granulation (healing) tissue
How much epithelialization is present

It’s important to optimize the nutritional status of patients with wounds. Patients with stage 3 and stage 4 ulcers in particular need enough protein and calories to heal.

Dr. Scott Rennie

Tag: Pressure ulcer

Why Won’t My Wound Heal?