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Braden Scale (Pressure Injury Risk)の包括的な教育ガイドを準備中です。ステップバイステップの解説、数式、実例、専門家のヒントをお届けしますので、もうしばらくお待ちください。
The Braden Scale for Predicting Pressure Sore Risk is the most widely used validated tool for assessing a patient's risk of developing pressure ulcers (also called pressure injuries, decubitus ulcers, or bedsores). Developed by Barbara Braden and Nancy Bergstrom and published in Nursing Research in 1987, the Braden Scale evaluates six subscales that represent the key pathophysiological factors in pressure ulcer development: sensory perception (ability to respond meaningfully to pressure-related discomfort), moisture (degree to which skin is exposed to moisture), activity (degree of physical activity), mobility (ability to change and control body position), nutrition (usual food intake pattern), and friction and shear (degree to which skin is subject to friction and shear forces). The first five subscales are scored 1–4, and friction and shear is scored 1–3, giving a total possible score range of 6 to 23. Lower scores indicate higher risk: a score of 23 represents no risk (maximum function in all domains), while a score of 6 represents the highest possible risk. Clinical threshold cut-offs vary by setting and patient population, but general guidelines recommend: total score ≤18 = at risk of pressure ulcer; ≤16 = moderate risk; ≤13 = high risk; ≤10 = very high risk. Pressure ulcers affect approximately 2–3 million patients annually in the USA alone, carry significant morbidity (pain, infection, sepsis, prolonged hospitalisation), and are associated with increased mortality in already vulnerable patients. The Braden Scale guides targeted preventive interventions including repositioning frequency, pressure-redistributing mattresses and cushions, moisture management, and nutritional supplementation.
Braden Score = Sensory Perception (1–4) + Moisture (1–4) + Activity (1–4) + Mobility (1–4) + Nutrition (1–4) + Friction/Shear (1–3); Total 6–23; ≤18=at risk, ≤16=moderate, ≤13=high, ≤10=very high risk
- 1Step 1 — Sensory Perception: Score 1 (completely limited — no response to pain, or pain perception limited to most of body) to 4 (no impairment — responds to verbal commands, has no sensory deficit).
- 2Step 2 — Moisture: Score 1 (constantly moist — skin is kept moist almost constantly by perspiration, urine, etc.) to 4 (rarely moist — skin is usually dry, linen changed on routine schedule).
- 3Step 3 — Activity: Score 1 (bedfast — confined to bed) to 4 (walks frequently — walks outside room at least twice per day and inside room at least once every 2 hours during waking hours).
- 4Step 4 — Mobility: Score 1 (completely immobile — cannot make even slight changes in body position without assistance) to 4 (no limitations — makes major and frequent changes in position without assistance).
- 5Step 5 — Nutrition: Score 1 (very poor — never eats a complete meal, eats ≤1/3 of food offered, or receives nothing by mouth) to 4 (excellent — eats most of every meal, never refuses a meal, occasionally eats between meals, does not require supplementation).
- 6Step 6 — Friction and Shear: Score 1 (problem — requires moderate to maximum assistance in moving, complete lifting impossible, frequently slides in bed/chair, spasticity, contractures) to 3 (no apparent problem — moves in bed and chair independently and has sufficient muscle strength to lift completely during move).
- 7Step 7 — Calculate total and apply preventive care: Total 6–23. Score ≤18 = initiate prevention protocol (pressure-redistributing mattress, 2-hourly repositioning, skin inspection, nutritional assessment). Score ≤13 = high-specification foam/dynamic mattress; Score ≤10 = maximum pressure relief + wound care team referral.
Maximum prevention: dynamic air mattress, 2-hourly turning programme, protective dressings, nutrition optimisation, skin surveillance
Score 7 = very high risk. Every domain near minimum. ICU patients on vasopressors, sedation, and with incontinence represent the highest-risk group.
No specific pressure ulcer prevention interventions required; reassess if condition changes
Perfect score of 23. Ambulatory, continent, well-nourished patients with full mobility have no clinically significant pressure ulcer risk during admission.
High-specification foam or dynamic mattress; 2-hourly repositioning; nutritional supplement; protective heel offloading
Total 13 = high risk. Immediate post-operative period after hip surgery is a critical window for pressure injury development. Heels are particularly vulnerable.
Pressure-redistributing cushion; hourly observation; repositioning q2–3h; continence care; nutritional review
Score 16 = moderate risk. Moderate risk patients benefit from targeted interventions. The combination of impaired mobility + incontinence + reduced activity drives risk.
Hospital admission pressure ulcer risk screening for all adult inpatients to guide mattress, positioning, and skin care decisions. This application is commonly used by professionals who need precise quantitative analysis to support decision-making, budgeting, and strategic planning in their respective fields
ICU pressure injury prevention bundle implementation — daily Braden scoring drives equipment prescribing and turning schedules. Industry practitioners rely on this calculation to benchmark performance, compare alternatives, and ensure compliance with established standards and regulatory requirements
Nursing home and care home resident assessment to prioritise pressure-redistributing equipment allocation. Academic researchers and students use this computation to validate theoretical models, complete coursework assignments, and develop deeper understanding of the underlying mathematical principles
Surgical theatre pre- and post-operative assessment to detect patients requiring immediate pressure relief from standard theatre tables. Financial analysts and planners incorporate this calculation into their workflow to produce accurate forecasts, evaluate risk scenarios, and present data-driven recommendations to stakeholders
NHS pressure ulcer prevention audits using Braden documentation rates and scores as quality indicators. This application is commonly used by professionals who need precise quantitative analysis to support decision-making, budgeting, and strategic planning in their respective fields
ICU and Prone Positioning
ICU patients placed prone for ARDS management (prone ventilation) are at extreme pressure injury risk, particularly to the face, chest, anterior chest wall, genitalia, knees, and toes. A standard Braden protocol must be supplemented with specific prone-positioning skin bundles including face cushions, genital padding, and 2-hourly head rotation. Prone patients should have Braden scored at a minimum as very high risk (≤10) during prone intervals.
Patients on Vasopressors
Vasopressors (noradrenaline, adrenaline, vasopressin) cause peripheral vasoconstriction, critically reducing skin perfusion. Even short-term high-dose vasopressor use can cause ischaemic pressure injuries within hours of direct pressure. Vasopressor-dependent patients on standard mattresses without supplementary pressure relief are at extreme risk. Dynamic air mattresses and minimum 2-hourly turns are mandatory.
Bariatric Patients
Morbidly obese patients (BMI >40) have disproportionately high pressure loads at bony prominences and skin fold areas, and often cannot reposition independently. Standard hospital mattresses have weight limits (typically 135–200 kg) that bariatric patients may exceed. Bariatric-specific mattresses (wider, higher weight limits) and bariatric handling equipment are required. The Braden scale slightly underestimates risk in this population.
Heel Pressure Injuries
Heel pressure injuries are the second most common pressure ulcer site and are frequently missed or underestimated. Even short periods of heel pressure (e.g., 2 hours during surgery) can cause deep tissue injury not visible on initial examination. All patients with mobility scores ≤2 on Braden should have prophylactic heel offloading using specifically designed heel protection boots, foam wedges under the calf, or splinting.
| Subscale | Score 1 (Highest Risk) | Score 4 (Lowest Risk) |
|---|---|---|
| Sensory Perception | Completely limited — unresponsive to pain | No impairment — responds normally |
| Moisture | Constantly moist — skin almost always wet | Rarely moist — skin usually dry |
| Activity | Bedfast — confined to bed | Walks frequently — outside room 2x/day+ |
| Mobility | Completely immobile — no position changes | No limitations — changes frequently |
| Nutrition | Very poor — eats ≤1/3 of food; NPO | Excellent — eats most meals; no supplements |
| Friction/Shear (1–3) | Problem — requires maximal assist; slides | No apparent problem — moves independently |
How often should the Braden Scale be reassessed?
NICE recommends Braden (or equivalent) assessment on admission, within 6 hours of hospital admission for high-risk patients (elderly, immobile, post-operative), and reassessment every 24–48 hours or whenever clinical status changes significantly. In ICU, daily reassessment is standard. In nursing homes, weekly reassessment with every-shift skin inspection is typical. The process involves applying the underlying formula systematically to the given inputs.
What is the clinical threshold for the Braden Scale?
The original Braden validation used ≤16 as the threshold for risk in a hospital setting, with sensitivity 83% and specificity 64%. However, different thresholds apply in different settings: ≤18 is used for elderly care facilities; ≤16 for acute care; ≤13 for ICU; and ≤10 for critical care. NICE CG179 and many guidelines use ≤18 as the universal alert threshold requiring preventive intervention.
How does the Braden Scale compare to the Waterlow Score?
The Waterlow Score is the main alternative used in UK healthcare settings, while Braden is more commonly used in North America. Both assess similar domains of pressure ulcer risk but use different scoring conventions: Braden is reverse scored (lower = more risk; higher = less risk), while Waterlow is forward scored (higher = more risk). Both tools have comparable predictive validity. Some trusts use one; some use both.
What are the most important Braden subscales for predicting pressure ulcers?
Activity and mobility subscales are the strongest individual predictors of pressure ulcer development — immobile, bedfast patients are at dramatically higher risk. Moisture (particularly urinary incontinence causing skin maceration) and sensory perception (particularly pain insensitivity preventing self-repositioning) are next most important. Nutrition plays a significant role in wound healing capacity even if less predictive of ulcer development.
Does a high Braden score rule out pressure ulcer risk?
Not entirely. Braden predicts population-level risk but cannot guarantee individual patients are safe. Additional risk factors not captured by Braden include: peripheral vascular disease, dark skin (harder to detect early erythema), previous pressure ulcer history, anaemia, oedema, and critical illness medications (vasopressors causing peripheral vasoconstriction). Clinical skin inspection remains essential regardless of score.
What pressure redistribution devices are recommended at different risk levels?
At risk (≤18): high-density foam overlay on standard hospital mattress. Moderate risk (≤16): high-specification foam mattress (e.g., ROHO, Repose). High risk (≤13): dynamic air alternating pressure mattress (APM). Very high risk (≤10): continuous low-pressure or lateral rotation mattress; protective foam dressings on bony prominences; consider pressure-relieving operating table pads. This is an important consideration when working with braden pressure ulcer calculations in practical applications.
Is nutrition management part of pressure ulcer prevention?
Yes — malnutrition significantly impairs skin integrity and wound healing capacity. MUST (Malnutrition Universal Screening Tool) should be completed alongside Braden assessment. Patients at nutritional risk require dietitian referral. Protein supplementation (1.2–1.5 g/kg/day) is recommended for at-risk patients. Zinc, vitamin C, and arginine-containing supplements have evidence for wound healing in established pressure ulcers.
What are the most common pressure ulcer sites?
In supine patients: sacrum (35–40% of all pressure ulcers), heels (30%), occipital scalp (common in ICU). In sitting patients: ischial tuberosities, coccyx. In lateral lying: greater trochanter, medial knees, malleoli, ear. In prone-positioned patients (ICU): face, chest, genitalia. Heel pressure ulcers are often underestimated and should be prevented with heel offloading boots or foam wedges.
プロのヒント
Remember the Braden mnemonic SMANMF: Sensory, Moisture, Activity, Nutrition, Mobility, Friction. Scores are INVERSE to risk — lower = more risk, higher = less risk. A score of 6 is maximum risk (worst on every subscale) and 23 is minimum risk (best on every subscale). The activity subscale is particularly powerful — a bedfast patient (activity = 1) almost always requires a minimum of high-specification foam mattress regardless of other subscale scores.
ご存知でしたか？
Barbara Braden and Nancy Bergstrom developed the Braden Scale in 1987 as part of their doctoral and post-doctoral work at Creighton University. At the time, no validated pressure ulcer risk tool existed, and nurses used clinical intuition alone — with highly variable and unreliable results. The Braden Scale has now been translated into over 30 languages and used in studies on six continents. It remains the most validated pressure ulcer risk tool nearly 40 years after its creation — a testament to the rigour of its original development.
参考文献
- ›Braden B, Bergstrom N — A Conceptual Schema for the Study of Etiology of Pressure Sores (Rehabil Nurs 1987)
- ›NICE CG179 — Pressure Ulcers: Prevention and Management (2014, updated 2023)
- ›EPUAP/NPUAP — Prevention and Treatment of Pressure Ulcers: Clinical Practice Guidelines (2019)
- ›National Wound Care Strategy — NHS England (2023)
- ›LITFL Braden Scale Pressure Ulcer Risk