ABI 0.72 and an Order That Says 'Apply Compression'
Mrs. L, 74, has a 6 × 4 cm ulcer over the left medial malleolus present for 7 months. The left ankle is 26 cm in circumference versus 22 cm on the right, with 2+ pitting edema, hemosiderin staining, and lipodermatosclerosis. She smokes, has type 2 diabetes, and stops after one block with claudication. Left ABI is 0.72 (right 0.95), left toe pressure 42 mmHg, and TcPO2 28 mmHg. The wound bed is 60% pale yellow slough with dull granulation and moderate serous drainage; there is no odor. Pedal pulses are barely palpable. She lives alone, has no one to help her apply stockings, and her primary care note on the chart reads "apply compression."
1. Do you start compression as ordered? Justify your decision using the perfusion numbers, and state what the order does and does not settle.
Read the worked answer
Do not start standard high compression on the strength of that note. A written order tells you what was intended; it does not establish that the intent is safe.
Reading the perfusion data together:
- ABI 0.72 is moderate arterial impairment. High compression (30–40 mmHg multilayer) in this range can cause pressure necrosis, and the classic safe threshold for full compression is ABI ≥0.8.
- Toe pressure 42 mmHg is above the 30 mmHg floor but not comfortably so - it says healing is possible, not that the limb tolerates a tight bandage.
- TcPO2 28 mmHg is the most concerning number: below roughly 30 mmHg, tissue oxygenation is inadequate for reliable healing and compression tolerance is questionable.
- Claudication at one block, smoking, barely palpable pulses - this is not a venous ulcer with an incidental low reading. It is a mixed etiology ulcer with a hemodynamically significant arterial component.
- Note also that diabetes can falsely elevate ABI through medial calcinosis. That distortion makes a reading falsely high, so a reading of 0.72 is real disease, not artifact.
Conclusion: the correct next step is a vascular surgery referral for revascularization evaluation, not a compression wrap. Document the discrepancy between the order and the findings, and contact the prescriber with the specific numbers rather than a general objection. This ulcer is also 7 months old with 60% slough - compression alone was never going to close it.
2. The patient is going home alone in 3 days. What is your interim plan, what will you monitor, and what makes you stop?
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Interim plan (pending vascular review)
- Modified/light compression only, and only with clinician agreement. A short-stretch bandage applied at reduced tension to achieve roughly 20–25 mmHg is the usual compromise; a 40 mmHg system is not appropriate at these pressures.
- Elevation and edema control do real work on their own and carry no ischemic risk - build the plan around elevation when she is off her feet.
- Debride the 60% slough. Slough is a barrier to healing and a biofilm scaffold; dull, pale granulation in a chronic ulcer reflects a wound bed that has not been prepared. Coordinate conservative sharp or enzymatic debridement once perfusion is addressed.
- Smoking cessation and glycemic control are not side issues here; both directly limit the oxygen delivery that TcPO2 28 already shows is marginal.
- Adherence reality check: she lives alone and cannot apply stockings. Stockings are the wrong device for her. Arrange home health for wraps, or choose a system that a clinician reapplies on a schedule - a compression plan she cannot execute is not a plan.
Monitor at every visit: toe color and temperature, capillary refill, sensation, new or worsening pain (especially rest pain at night), and whether the wound bed deteriorates.
Stop immediately and escalate for: rest pain, pallor or cyanosis of the toes, cool toes, numbness or tingling, or a sudden increase in pain under the bandage. Remove the compression first, then call - do not leave it on to "see if it settles."
3. The evening nurse reports the toes look dusky and the patient now has pain at rest. What is your sequence of actions and your documentation?
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Sequence - remove the cause before you investigate it.
- Take the compression off immediately. Dusky toes plus new rest pain is limb-threatening. A bandage left on "to be assessed in the morning" can cost tissue.
- Assess and record: toe color, temperature, capillary refill, sensation, motor function, and a pain score with onset and character. Compare with the unaffected foot.
- Elevate to comfort level but do not add aggressive dependency - and if the foot improves with dependency rather than elevation, that itself is a sign of critical limb ischemia.
- Call the provider and vascular surgery now, reporting the ABI, toe pressure, and TcPO2 values along with the new findings.
- Do not reapply compression until the limb has been reassessed and a plan is documented by the clinician managing the vascular workup.
- Reassess perfusion and document the interval between removal and reassessment.
Document, at minimum: time the bandage was removed, exactly what was observed before and after removal, the pain score and change, who was notified with time and name, the orders received, and the patient's response. Avoid conclusory charting such as "bandage too tight" - describe the findings and let them speak. If the response is "keep it off and follow up Monday," escalate up the chain; the chart should show that you did.