15.1 Evaluating Treatment Effectiveness
Key Takeaways
- Reassess for deterioration at every dressing change, and take comparable measurements on a defined interval, commonly weekly.
- The PUSH tool scores length times width, exudate amount, and tissue type using the worst tissue present; it is an NPIAP scale, not a WOCNCB-owned instrument.
- About 20 to 40 percent area reduction at 2 to 4 weeks is a commonly cited venous-ulcer research rule of thumb, not an official cut score.
- Serial wound photographs require consent plus the same distance, lighting, and position, and they never replace centimeter measurements.
- A stalled or worsening wound requires a plan change; repeating the same orders is not evaluation.
Evaluating a wound plan is not a courtesy visit. It is the moment you decide whether the current dressing, offloading, compression, debridement, and teaching are actually changing tissue. This OpenExamPrep section prepares CWCN candidates to treat reassessment as a clinical decision, not a charting ritual. A plan that looked reasonable on Monday can be the wrong plan by the next dressing change if pain, odor, size, or perfusion have moved the wrong way.
When to look again
Two clocks run at once.
At every dressing change, inspect for deterioration: spreading erythema, new necrosis, unexpected odor after cleansing, a jump in pain, dressing strike-through hours too early, or a cool, dusky margin. Those findings cannot wait for a scheduled weekly measurement.
At defined intervals, usually weekly length × width × depth in the same position with the same method, you judge trajectory. Daily measuring of a stable wound adds noise; skipping measurement for a month hides failure. Many wound programs graph weekly area so a stall is visible instead of remembered as "it looked about the same."
Reassessment also includes the person attached to the wound: edema, glucose, nutrition, device fit, sleep, caregiver skill, and whether supplies actually arrived. A foam that works in the clinic fails if the patient never received the second box.
What effectiveness looks like
Healing is not a vibe. Look for smaller surface area and depth over successive weeks; healthier tissue with less slough or eschar and more granulation and epithelium; exudate that the dressing can contain without macerating the periwound; edges that are attached and advancing rather than rolled (epibole) or undermining further; pain that is stable or falling rather than a new ischemic or infectious pattern; and function—the patient can wear the compression, keep the heel off the mattress, or allow a family member to change the dressing. If those signals are absent, you do not congratulate the plan for being consistent. You change it.
The PUSH tool: a common scale, not a board-owned instrument
The Pressure Ulcer Scale for Healing (PUSH) Tool 3.0 was developed by the National Pressure Ulcer Advisory Panel, now the National Pressure Injury Advisory Panel (NPIAP). It is a widely used healing scale in clinical practice. It is not a WOCNCB-owned instrument. Using PUSH in this guide does not create any official relationship among OpenExamPrep, NPIAP, and WOCNCB. CWCN items may still expect you to know what the scale captures and how a falling total score is interpreted.
PUSH scores three parameters and adds them:
| Parameter | How it is scored | What a worsening subscore means |
|---|---|---|
| Length × width | Greatest length (head to toe) × greatest width (side to side) in cm², then mapped to a 0–10 surface-area category. Do not guess; use a centimeter ruler and the same method every time. | The wound is enlarging or failing to contract. |
| Exudate amount | None = 0, light = 1, moderate = 2, heavy = 3 | Drainage is increasing; moisture balance or inflammation may be off. |
| Tissue type | Closed = 0, epithelial = 1, granulation = 2, slough = 3, necrotic tissue = 4. Score the most severe tissue present, not the majority tissue. | Dead or slough tissue is persisting or returning. |
Total score ranges from 0 to 17. A total of 0 means the ulcer is closed. Compare totals over time: a falling score supports healing; a flat or rising score is a stall or deterioration. PUSH does not capture depth, undermining, or tunneling, so it never replaces a full wound description. Directions on the original tool also warn: do not guess area, and always use the same measurement method.
Worked PUSH example
A sacral pressure injury measures 2.2 cm × 1.8 cm (about 4.0 cm²), has moderate exudate, and shows mostly granulation with a rim of adherent slough. Surface area near 4.0 cm² maps to the PUSH 3.1–4.0 cm² category (subscore 6). Exudate moderate = 2. Tissue type = slough (3), because the worst tissue present is what you score. Total = 11. Next week, if area is 3.0 cm² (subscore 5), exudate is light (1), and only granulation remains (2), total = 8. The drop is the clinical message, not a single snapshot.
Percent area reduction as a research rule of thumb
For venous leg ulcers, published cohorts often treat about 20–40% percent area reduction (PAR) at 2–4 weeks as a signal that the wound is on a healing trajectory. Calculate PAR as:
PAR = (baseline area − current area) ÷ baseline area × 100
Example: week 0 area 5.0 × 4.0 cm = 20.0 cm². Week 4 area 4.0 × 3.2 cm = 12.8 cm². Reduction = 7.2 cm². PAR = 36%. That value sits inside the commonly cited 20–40% window.
Teach this as a research rule of thumb, not an official cut score, not a payer law, and not a WOCNCB threshold. Studies use slightly different percentages and time windows—some emphasize roughly 30–40% at 4 weeks; consensus-style venous-ulcer pathways often flag less than about 20–30% reduction by 4–6 weeks as a reason to reassess compression quality, adherence, infection, and mixed arterial disease. If PAR is near zero despite what you believed was good compression, the plan is not working.
Photographs that can be compared
Serial photos help the next clinician—and you in four weeks—see change. They do not replace measurements.
- Obtain informed consent (or follow the facility photography policy for patients who cannot consent) and store images in the designated electronic record location, not a personal phone album.
- Use the same distance, lighting, and patient position. Include a ruler in the frame. Shoot perpendicular to the wound when anatomy allows.
- Date, location, and laterality belong in the caption or metadata.
- Avoid identifying features when policy requires de-identification.
- Do not let a pretty photo hide a missing centimeter measurement.
Changing cameras, standing closer one week and farther the next, or using a harsh flash that washes out slough makes "improvement" impossible to judge. The photo protocol is a measurement method, just as the ruler is.
Clinic scenario: Ms. Patel's medial-malleolus ulcer
Ms. Patel, 71, has a left medial-malleolus venous ulcer. Four weeks ago the area was 12.0 cm². Today it is 11.4 cm² (PAR about 5%) with heavier exudate and a new sweet odor after cleansing. The foam dressing and a 20 mmHg "light" wrap have not changed. The incorrect reflex is to reorder the same products because she is used to them. The correct reflex is to treat the trajectory as a failed plan: confirm arterial status, upgrade compression if perfusion allows, address bioburden and edema, and set a new review date. A 5% PAR at 4 weeks is not a 20–40% research-range signal.
If there is no progress, do not keep the same plan
Stalled size, a rising PUSH total, new odor, or extending maceration means at least one major element—debridement, infection control, moisture balance, offloading, compression, a perfusion work-up, or education—must change. "Continue current treatment" is the trap answer when the numbers have not moved. Evaluation without modification is just watching the wound fail in slow motion.
A home-health nurse is starting a serial photo file for a venous ulcer. Which practice makes later images useful for judging treatment effect?
A venous ulcer measured 6.0 × 5.0 cm (30 cm²) at week 0. At week 4 it is 5.8 × 4.9 cm (about 28.4 cm²) with unchanged compression and the same foam. Percent area reduction is about 5%. What is the best evaluation decision?
A pressure injury is 70% granulation and 30% adherent slough. Using PUSH tissue-type rules, which score should be assigned?
When should the wound nurse reassess treatment effectiveness?