Compartment Syndromes Rhabdomyolysis And Renal Failure

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Compartment Syndromes, Rhabdomyolysis, andRenal FailureGary Gaddis MD PhDMissouri Endowed Chair for Emergency MedicineSt. Lukes Hospital of Kansas City and the University of Missouri-Kansas CityKansas City, MO 641115th European Congress on Emergency MedicineMunich, GermanySeptember, 2008Overview of next 15 minutesA case will be presentedWe will review some relevant basic science to reinforce your understanding of important information about:Compartment SyndromesRhabdoymyolsisA few words about avoiding Renal FailureOpportunities for questions providedCaseChief Complaint: 22 year old married female medical student who recently finished a night shift, arrives to the Emergency Department with chief complaint of bilateral leg pain, mild bruising, and inability to actively or passively permit plantar flexion of the ankles.To do so causes extreme pain. CaseHistory of Present Illness: This student was on duty the prior evening and had returned home, exhausted. She fell asleep on her bed, on her back. She had NOT drank any alcohol nor taken any sleeping pills. She just driven home, walked into her bedroom, and laid on her bed, intending to then get up and change clothes. She simply fell asleep. Her legs were extended past the side of the bed.Relevant Physical Findings:Slight bruise on dorsum of each leg at mid-calf, posteriorly.The calf muscle tone is very elevated, and to squeeze her calves causes an increase of her already great pain.Unable to actively, or passively, plantar flex her anklesNormal pulses in feetCaseWhat test should we do?Numerically compare intra-compartment pressure (ICP) to capillary perfusion pressure (CPP) in the calf, and to mean arterial pressure (MAP):Measure a compartment pressuresee next slideMAP > CPP > Intra-Compartment Pressure This explains why loss of pulses is a LATE findinghttp://www.podiatrytoday.com/article/..%5CPODTD%5CHTML%5Cimages%5Cthumbs%5CPT.05.surgfig1tif.jpgMeasuringCompartmentPressureCaseWe find her muscular pressure in her calves is 45 mmHg.and she woke up this way, so it has probably been elevated for hours.The normal pressure is less than:Injury can occur with prolonged pressures over:(Her capillary perfusion pressure (CPP) is certainly lower than 45mmHg. CPP is much less than MAP; CPP is slightly greater than venous pressure)10 mmHg20 mmHgCaseHow many compartments does the leg have?What procedure does she need?4FasciotomyClinical symptoms and signs suggestive of compartment syndrome:First, deep pain in the compartmentEarliest symptom, almost always presentPain with active contraction or passive stretching of the muscles happens nextNext, hypesthesia because elevated compartment pressures compromise neurologic functionClinical symptoms and signs suggestive of compartment syndrome:Pallor and excessive coolness are late findingsPulselessness is a VERY LATE findingDont make the mistake of expecting to find compromised pulses in persons developing compartment syndrome!! MAP > CPPIschemia occurs when compartment pressure exceeds capillary perfusion pressure, and arterial pressure may remain sufficiently higher than compartment pressure, to permit good perfusion of structures distal to the compromised compartment!Clinical symptoms and signs suggestive of compartment syndrome:CaseYou become involved in this patients subsequent care in the ICUHer urine is not clear, nor yellow, nor red.It is very brown, dipstick suggests Hgb.Yet, her urine shows only 1-5 RBC/High Power FieldWhat does this imply?Where does this substance come from?What is happening?MyoglobinuriaSkeletal muscleMyoglobin leeches out of dyingskeletal muscle cells into lymph, then bloodCaseIn more detail:Skeletal muscle injury -> necrosisWhat is the cellular event at the muscle cell membrane?Creatine phosphokinase (CPK) and myoglobin are released from muscle as the membrane breaks downas are other intracellular contentsDisruption of sodium-potassium ATPase pump (and calcium transport)CaseMyoglobinuria presents a danger to her kidneys, a metabolite of myoglobin can cause them to fail.What substance is toxic to the kidney?Why is this compound present in urine?It is filtered in the kidney at the glomerulus, and is not reabsorbed in the collecting tubulesFerrihemateCaseWhat is the pathophysiology leading to renal failure and rhabdomyolysis after compartment syndrome?-Elevated compartment pressure causes cellular necrosis;-Failure of ATPase pump impacts electrolyte concentration; -Membrane breakdown causes loss of intracellular contents;-Intracellular contents travel via lymphatics to the venouscirculation;-One of the circulating cellular contents (myoglobin) whichis metabolized to ferrihemate becomes nephrotoxicCaseSome leading causes of rhabdomyolysis:Alcohol and drug abuse (Followed by prolonged loss of consciousness and rema