Intracompartmental Pressure Monitor

Aka: Intracompartmental Pressure Monitor, Compartment Pressure

1. Indications
   1. Compartment Syndrome
   2. Exertional Compartment Syndrome
2. Contraindications
   1. Entry at infected skin or Burn Injury
   2. Coagulopathy (relative contraindication)
3. Equipment
   1. Needles: 18 gauge
      1. Smaller gauge (22 to 25) may be used without an effect on pressure reading accuracy
      2. Side-ported needle or
      3. Indwelling slit catheter or wick catheter
         1. Indicated for continuous pressure monitoring
         2. Consider in patients trending toward Fasciotomy or those unable to communicate
      4. Avoid simple needle (lower accuracy)
   2. Hand-held monitor
      1. Compartment Pressure Monitor (e.g. Stryker Instrument)
4. Technique
   1. Practice sterile technique
      1. Sterile gloves
      2. Skin Preparation (e.g. Hibiclens)
      3. Sterile drape
   2. Local Anesthetic
      1. Lidocaine 1% to raise a small wheal at skin surface
      2. Deeper Anesthetic injection may affect pressure reading
   3. Preparation
      1. Position affected limb at heart level
      2. Prepare measurement kit
         1. Screw kit prefilled syringe onto diaphragm
         2. Place syringe and diaphragm into measurement device
      3. Purge air from device
         1. Hold device at 45 degrees above floor plane
         2. Apply pressure to syringe plunger
      4. Turn device on
      5. Calibrate the device, zeroing at level of limb immediately prior to skin entry
   4. Fluid filled 18 gauge (or 22 to 25 gauge) needle inserted perpendicularly (90 degrees) into compartment
      1. Infuse Normal Saline in small volume (0.1 to 0.3 ml)
      2. Compress compartment proximal or distal to the needle to confirm expected pressure change
   5. Obtain measurement for each compartment of concern
      1. Check pressure at level of Fracture
      2. Obtain all measurements with either patient supine or prone
      3. Lower leg
         1. Check pressure at proximal to middle third of lower leg (unless Fracture dictates site)
         2. Patient supine for all compartment measurements except the superficial posterior compartment
         3. Check anterior and deep posterior Compartment Pressures at minimum
            1. Anterior Compartment: 1 cm lateral to anterior tibia and 2 cm insertion depth
            2. Deep Posterior Compartment: Posterior to tibia from medial approach to 3 cm depth
         4. Ideally, check the other 2 lower extremity Compartment Pressures
            1. Lateral Compartment: Needle perpendicular to posterior aspect of fibula
            2. Superficial Posterior Compartment: Patient prone, needle to either side of midline
   6. Repeat measurement at up to every 1-2 hours as needed
   7. Precautions
      1. Avoid excess fluid infusion (raises Compartment Pressure, False Positive)
      2. Control needle depth and insertion site
      3. Control extremity position during measurement
5. Interpretation
   1. Normal Compartment Pressure <10 mmHg
   2. Traumatic Compartment Syndrome Criteria
      1. Tissue pressure exceeds >30 mmHg (Fasciotomy for pressure >30-45 mmHg)
      2. Delta Pressure (Diastolic pressure - Tissue pressure) <30 mmHg
   3. Exertional Compartment Syndrome Criteria
      1. Readings only valid if Exercise reproduces symptoms
      2. Resting tissue pressure exceeds 10 to 15 mmHg
      3. Pressure 5 minutes post-Exercise over 15 to 25 mmHg
6. Complications
   1. Infection
   2. Soft Tissue Injury (nerve, vessel)
   3. Inaccurate measurement
7. References
   1. Blythe, Gray and Delasobera (2018) Crit Dec Emerg Med 32(7):3-9
   2. Warrington (2021) Crit Dec Emerg Med 35(11): 25
   3. Warrington (2017) Crit Dec Emerg Med 31(5): 21