Suspected acute compartment syndrome (adult limb)
Surgical emergency. Call the orthopaedic registrar or consultant early.
All Pathways
Orthopedic SurgeryEmergency
Acute Compartment Syndrome Management (AAOS 2025)
Acute Compartment Syndrome Management (AAOS 2025): Suspected acute compartment syndrome (adult limb) → At-risk patient: check hourly and keep a low thre...
Pathway Overview
19 steps
Algorithm Steps
19 total
01Start 02Action At-risk patient: check hourly and keep a low threshold
Know the causes. Any of these plus pain or swelling needs ACS assessment.
- Tibial shaft fracture (most common) or forearm fracture
- Crush injury or high-energy trauma
- Reperfusion after vascular repair or revascularisation
- Tight cast, splint or circumferential dressing
- Prolonged limb compression or immobilisation (e.g. overdose, long surgery, lithotomy position)
- Circumferential burn
- IV or IO fluid extravasation
- Anticoagulant or bleeding disorder
03Warning Unreliable exam (obtunded, sedated, nerve block) or child: monitor pressure
Pain may be absent. Children: rising analgesic need, anxiety and agitation are early signs; get paediatric orthopaedic advice.
- Obtunded or sedated: repeat or continuous compartment pressure until ACS is diagnosed or excluded
- Neuraxial or regional block may hide pain: examine often and/or monitor pressure
- Maintain perfusion; avoid hypotension
04Action Assess now and hourly: pain out of proportion, pain on passive stretch
ACS is a clinical diagnosis. A palpable pulse does NOT exclude it. Record each exam with the time.
- Pain out of proportion to the injury
- Pain on passive stretch of the compartment muscles
- Rising analgesic need (record dose and time)
- Tense, swollen compartment
- Paraesthesia or numbness (later sign)
- Weakness or paralysis (late sign; poor prognosis)
- Pallor and absent pulse are very late; pulses are usually present
05Action All patients: split the cast and release dressings now
Do this at once. It must not delay theatre when ACS is clear.
- Split the cast and padding down to skin; release all circumferential dressings
- Keep the limb at heart level; do not raise it (elevation lowers perfusion pressure)
- Correct hypotension
- Senior review; reassess within 30 minutes
06Decision Clear clinical ACS on a reliable exam?
Yes: go to the late-ACS check, then theatre. No, equivocal or exam unreliable: measure pressure.
- If Yes
07Decision Late or missed ACS with established irreversible damage?
Senior decision (two consultants). Time since onset or numbness alone does NOT prove it. If in doubt, decompress.
- If Yes
08Warning Late ACS with established necrosis: do NOT perform fasciotomy
Example: found down, long unknown duration, with myoglobinuria, renal failure and very high CK. Fracture: external fixation or cast that does not open the compartment.
- Two consultants decide and document; a small incision to check muscle viability may be reasonable; if muscle is dead, do not extend it
- Fasciotomy on dead muscle risks reperfusion injury, infection, sepsis and amputation
- Treat rhabdomyolysis: check potassium, CK and creatinine; IV fluids (heart failure or oliguric AKI: ICU or renal advice)
09Outcome Late ACS: non-operative care; amputation if limb not viable or sepsis
Senior team plan. Watch for hyperkalaemia, AKI and infection.
If No10Action Viable or uncertain tissue: emergency fasciotomy now
Decompress fully and immediately once ACS is diagnosed. Not for late ACS with established necrosis (senior decision).
- Open every involved compartment completely (leg: all 4, by the recommended two-incision technique)
- Crush or long ischaemia: check potassium before and after release; tell the anaesthetist (reperfusion hyperkalaemia)
- On an anticoagulant: plan reversal with the anaesthetist; do not delay decompression
- Debride dead muscle; record the viability of each compartment; leave the wounds open
- Forearm: volar incision; add a dorsal incision if the dorsal compartment stays tight
11Action If a long-bone fracture: stabilise it at the same operation
Operative fixation (external or internal) for initial stabilisation.
- Choose external or internal fixation by the soft tissues, contamination and the patient's condition
12Action After decompression: watch for reperfusion injury and rhabdomyolysis
Highest risk after crush, long ischaemia or late presentation.
- Check potassium, CK and creatinine; test urine for myoglobin (blood on dipstick)
- Monitor urine output hourly
- IV crystalloid to keep a good urine output (see rhabdomyolysis pathway); heart failure or oliguric AKI: fluid plan with ICU or renal team
- Treat hyperkalaemia at once (see hyperkalaemia pathway)
13Action Wound care: plastics review within 24 h; re-look within 72 h
Plan definitive closure or cover.
- Discuss with a plastic surgeon within 24 h of fasciotomy
- Re-look and debride within 72 h, or earlier if needed
- Negative pressure wound therapy may shorten time to closure and reduce skin grafting
- Close by delayed primary closure, gradual closure (e.g. vessel loops) or skin graft
14Outcome Compartments decompressed
Continue rhabdomyolysis checks and planned wound closure.
If No15Action Equivocal or unreliable exam: measure compartment pressures
Delta P = diastolic BP minus compartment pressure. Measure BP at the same time.
- Measure all suspected compartments with a validated device, near the fracture level
- Under general anaesthesia diastolic BP falls (mean 18 mmHg): delta P can be falsely low; compare with the pre-operative diastolic BP
- Repeated or continuous measurement is better than one reading
- No single absolute pressure defines ACS
16Decision Delta P 30 mmHg or less?
Yes: consultant decision on fasciotomy now. No: ACS unlikely now; keep monitoring.
- If Yes
17Action Delta P 30 mmHg or less: consultant decides on fasciotomy now
Combine the pressure with the clinical picture. Do not wait for late signs. If the consultant chooses to keep monitoring: hourly exam and repeat or continuous pressures; decide again at each check.
- A single low reading can overcall ACS; repeat if the picture is unclear and time allows
- Continuous monitoring: delta P below 30 mmHg for more than 2 hours was the fasciotomy threshold in the largest series
- Absolute pressure above 40 mmHg: consider urgent decompression
- At-risk patient with equivocal findings: fasciotomy is less harmful than a missed ACS
- Path rejoins step 07Shared downstream outcome
If No18Action Delta P more than 30 mmHg: ACS unlikely now; keep monitoring
One reading does not rule out ACS. ACS can still develop. Continue while the risk persists.
- Hourly clinical exam with documented findings
- Repeat or continuous pressure measurement
- Delta P falls to 30 mmHg or less, absolute pressure above 40 mmHg, or signs progress: consultant review for urgent fasciotomy
- Senior review of the plan
19Outcome ACS not present on serial assessment
Keep hourly checks while the risk persists. Any new sign: repeat pressure and senior review.
Guideline Source
AAOS Management of Acute Compartment Syndrome Evidence-Based Clinical Practice Guideline (2025 rapid update of the 2018 guideline)
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Adults only. Children: signs differ (rising analgesic need, anxiety, agitation); get paediatric orthopaedic advice.
- Evidence is limited; most AAOS statements are consensus. Pressure thresholds support, and do not replace, senior clinical judgement.
- Does not cover chronic exertional compartment syndrome.
- Foot and hand compartment syndrome: no consensus on management; follow local senior advice.
Contraindicated Populations
pediatric
Applicable Regions
USEUUKAUGlobal
AU: No national Australian guideline; AAOS and BOASt standards are used. Escalate to the on-call orthopaedic consultant; retrieval for remote sites without theatre access.
UK: BOASt Compartment Syndrome of the Extremities (updated July 2025): hourly assessment, immediate decompression, plastics discussion within 24 h, re-look within 72 h.
Version 2Next review: 2027-09-30
Next steps
Finish the workflow by opening the most relevant calculator, then convert the session into a live account when you are ready.
Related Resources
Frequently Asked Questions
What is the Acute Compartment Syndrome Management (AAOS 2025)?
The Acute Compartment Syndrome Management (AAOS 2025) is a emergency clinical algorithm for Orthopedic Surgery. It provides a structured decision tree to guide clinical decision-making, based on AAOS Management of Acute Compartment Syndrome Evidence-Based Clinical Practice Guideline (2025 rapid update of the 2018 guideline).
What guideline is the Acute Compartment Syndrome Management (AAOS 2025) based on?
This algorithm is based on AAOS Management of Acute Compartment Syndrome Evidence-Based Clinical Practice Guideline (2025 rapid update of the 2018 guideline).
What are the limitations of the Acute Compartment Syndrome Management (AAOS 2025)?
Known limitations include: Adults only. Children: signs differ (rising analgesic need, anxiety, agitation); get paediatric orthopaedic advice.; Evidence is limited; most AAOS statements are consensus. Pressure thresholds support, and do not replace, senior clinical judgement.; Does not cover chronic exertional compartment syndrome.; Foot and hand compartment syndrome: no consensus on management; follow local senior advice.. Individual patient factors may require deviation from these recommendations.
Get AI-Powered Analysis Alongside This Algorithm
In AttendMe.ai, the Acute Compartment Syndrome Management (AAOS 2025) appears automatically when your clinical question matches — alongside evidence from 3M+ peer-reviewed articles.
Try AttendMe Free