1. Compartments, the Stryker, & You Consensus is P compartment > 30 mm Hg likely requires intervention ΔP = (DBP – P compartment ) measure of P perfusion Pts w/ P compartment 30) –Keeping extremity level w/ heart decreases limb MAP w/o increasing P compartment Ischemic injury is basis for CS –Supplement O 2 to increase pPO 2 –6 hrs ischemic time is currently accepted upper viability limit Myonecrosis assoc. w/ CS s/p envenomation is multifactorial fasciotomy may not prevent myonecrosis aggressive Rx w/ antivenom decreases limb hypoperfusion –consider delayed fasciotomy, if at all

2. Possible Etiologies Increased contents –Hematoma –Trauma fracture envenomation burns –Increased use exercise tetany seizure eclampsia –Edema nephrotic syndrome ischemia-reperfusion injury –Iatrogenic Orthopedic surgery Intraarterial drug injection Decreased volume –Hematoma –Trauma crush injury & entrapment compression during sleep/intoxication –Iatrogenic prolonged lithotomy MAST, casts, splints, dressings excessive traction in line tight closure of fascial defect IV infiltration

3. CompartmentSensoryMotorPainful Passive Motion Tenseness Forearm Dorsal Volar --- Ulnar / Median N. Digit Extension Digit Flexion Digit Extension Dorsal Forearm Volar Forearm Hand Interosseus---InterosseiAdd/Abduct MCPsDorsal Hand btwn MCPs Upper Arm Flexor Extensor Ulnar / Median N. Radial N. Biceps / Dist. Flexors Triceps / Forearm Ext. Elbow Extension Elbow Flexion Anterior Upper Arm Posterior Upper Arm Leg Anterior Sup. Posterior Deep Posterior Deep Peroneal N. --- Posterior Tibial N. Toe Ext. / Tib ant. Soleus / Gastroc. Toe Flex. / Tib post. Toe Flexion Foot Dorsiflexion Toe Extension Ant. Leg Calf Dist. Med. Leg (btwn Tib. & Achilles tendon) GlutealSciatic (rare) Gluteals, piriformis, tensor fascia lata Hip FlexionButtock FootDigital NervesFoot IntrinsicsToe Flex. / Ext.Dorsal / Plantar Foot

4. Open sterile assembly Place needle on tapered end of well chamber and syringe on opposite side Place assembly into monitor, clear side of well chamber up

5. Purge assembly of air –Injecting NS w/ Stryker at 45 0 Zero unit in position in which measurement will be taken Sterile prep of site Infiltrate local superficially Enter compartment perpendicularly, level w/ heart Inject ~ 0.3 of 1 cc saline Read measurement on display when equilibrates Re-Zero unit for each new measurement

6. Volar Compartment: btwn PL tendon & radial surface of ulna; depth 1-2 cm Enter compartments at junction of proximal & middle thirds of forearm

7. Dorsal Compartment: 1-2 cm lat to posterior aspect of ulna; depth 1-2 cm Mobile Wad Compartment: lateral to radius; depth 1-1.5 cm

8. Enter compartments at junction of proximal & middle thirds of lower leg Lateral compartment: posterior border of fibula; depth 1-1.5 cm

9. Deep posterior compartment: posterior to medial border of tibia in direction of posterior border of the fibula; depth 2-4 cm Superficial posterior compartment: posteriorly directly over center of gastrocnemius; depth 1-1.5 cm

10. Anterior compartment: 1 cm lateral to anterior tibial border; depth 1-3 cm CompartmentContentsEvaluation AnteriorDeep Peroneal N. Anterior Tibial Art. Dorsal Flex. Ankles & Toes Sensation at 1 st dorsal web space DP Pulse LateralSuperficial Peroneal (fibular) N. Foot Everters Sensation at dorsal foot Superficial posterior Sural N. Plantar Flex. of Ankle Sensation to lat. portion of inf. 1/3 of leg, lat. portion of 5 th digit Deep posterior Tibial N. Posterior Tibial & Peroneal Art. Plantar Flex. of toes Sensation to plantar foot PT Pulse

11. Additional Compartments Foot –Medial, Lateral, Interosseous Gluteal –18-G spinal needle –Depth 4-8 cm –Insert perpendicularly at point of max. tenderness

12. Improvised mercury or saline/sterile H 2 O manometers may also be zeroed & used to measure P compartment –Convert mmHg  cm H 2 O & back! References: –JR Roberts and J Hedges, eds. Clinical Procedures in Emergency Medicine, 4 th ed. Saunders; October 24, 2003. –CB Custalow. Color Atlas of Emergency Department Procedures, 1 st ed. Saunders; August 27, 2004.