1. Which of the following statements is correct. A 1. Which of the following statements is correct? A. Rhabdomyolysis is caused by the breakdown of hemoglobin B. The diagnosis is confirmed by measuring urinary myoglobin levels C. Dark discolouration of the urine results from hypovolumia D. Status epilepticus is a cause of rhabdomyolysis

2. Which of the following condition is NOT a recognized cause of rhabdomyolysis? Paracetamol toxicity Tetanus Neuroleptic malignant syndrome Dermatomyositis

3. Regarding the management of rhabdomyolysis, which statements is/are correct? After crush injury, treatment should be started in hospital when the patient is fully monitored Normal saline 0.9% is an acceptable crystalloid to use There is no requirement for arterial blood gas analysis in an asymptomatic patient A urine output of 1ml/kg/hr is adequate

Rhabdomyolysis “Rhabdomyolysis was first reported in 1881, in the German literature” (Abbeele, Parker, 1985). “Rhabdomyolysis was first described in the victims of crush injury during the 1940-1941 London, England, bombing raids of World War II” (Craig, 2006).

Rhabdomyolysis Occurs in up to 85% of patients with trauma Rhabdomyolysis accounts for an estimated 8-15% of cases of acute renal failure. the overall mortality rate for patients with Rhabdomyolysis is approximately 5%, higher if MODS Rhabdomyolysis is more common in males than in females may occur in infants, toddlers, and adolescents

Rhabdomyolysis disintegration of striated muscle results in the release of muscular cell constituents into the extracellular fluid and the circulation major component released is myoglobin

Rhabdomyolysis massive amounts of myoglobin are released  the binding capacity of the plasma protein is exceeded myoglobin is then filtered by the glomeruli and reaches the tubules, where it may cause obstruction and renal dysfunction

Rhabdomyolysis syndrome characterized by muscle necrosis and the release of intracellular muscle constituents into the circulation creatine kinase (CK) levels are typically markedly elevated, and muscle pain and myoglobinuria may be present

Rhabdomyolysis severity of illness ranges from asymptomatic elevations in serum muscle enzymes to life-threatening disease associated with: extreme enzyme elevations electrolyte imbalances acute kidney injury

Rhabdomyolysis Source: (Muscle Anatomy & Structure, 2007) The sarcolemma is the cell membrane of a muscle cell. The membrane is designed to receive and conduct stimuli

Rhabdomyolysis dead muscle tissue may cause a large amount of fluid to move from the blood into the muscle, leading to hypovolemic shock  reduced blood flow to the kidneys.

Rhabdomyolysis

What Causes Rhabdomyolysis may result from a large variety of diseases, TRAUMA, or toxic insults to skeletal muscle hereditary myopathies

Rhabdomyolysis Traumatic Crush injury Entrapment Prolonged immobilization Electrical injury Excessive muscle activity: marathon running, status epilepticus, MH Heat related: heat stroke, neuroleptic malignant syndrome, rarely hypothermia

Rhabdomyolysis Non traumatic Ischemic insult Substance misuse: alcohol, cocaine, amphetamine, ecstacy Drugs: statins, fibrates, antipsychotics Toxins: carbon monoxide, heavy metals, snake venom Infection: tetanus, legionella, sepsis syndrome Electrolyte disorders: hypoK+, hypo/hyper Na+, hypocalcemia, hypophosphatemia, HONK, DKA< hypo/hyperthyroidism Autoimmune: dermatomyositis, polymyositis

Rhabdomyolysis Ranges from asymptomatic rise in CK -> hypovolumic shock with life threatening arrythmia Clinical Manifestations muscle tenderness myalgias muscle swelling & weakness DIC color of urine

Rhabdomyolysis Diagnosis Creatine Phosphokinase (CK) levels are very high – most sensitive indicator Serum/urine myoglobin test is positive Serum electrolytes imbalance: ↑ K+, urea, PO42- , Mg2+ ,↓ Ca2+ High anion gap metabolic acidosis due to lactic acidosis

Rhabdomyolysis serum CK begins to rise within 2 to 12 hours following the onset of muscle injury and reaches its maximum within 24 to 72 hours decline is usually seen within three to five days of cessation of muscle injury

Rhabdomyolysis CK has a serum half-life of about 1.5 days and declines at a relatively constant rate of about 40 to 50 percent of the previous day’s value patients whose CK does not decline as expected, continued muscle injury or the development of a compartment syndrome may be present

Rhabdomyolysis Diagnosis Urinalysis may reveal protein and be positive for hemoglobin without evidence of red blood cells on microscopic examination Urine myoglobin test is positive

Rhabdomyolysis Lab Values elevated muscle enzymes (CK) hyperkalemia hyperphosphatemia hypocalcemia

Rhabdomyolysis Complications Early: severe hyperkalemia may lead to arrythmia and cardiac arrest, especially in association with profound hypovolumia, hypocalcemia and acidosis Early to late: compartment syndrome, hepatic dysfunction Late: AKI, DIVC, hypercalcemia during recovery period

Rhabdomyolysis Treatment volume replacement treat electrolyte abnormalities protect renal perfusion alkalinization of urine treat underlying cause (fasciotomy etc)

Rhabdomyolysis early and aggressive fluids (hydration) may prevent complications by rapidly remove myoglobin out of the kidneys. administer isotonic crystalloid fluids (Normal Saline) give as much fluid as you would give a severely burned patient.

Rhabdomyolysis studies of patients with severe crush injuries resulting in Rhabdomyolysis suggest that the prognosis is better when prehospital personnel provide FLUID RESUCITATION!

Use of bicarbonate and mannitol therapy is recognized however observational data suggest that they provide NO additional clinical benefit to volume expansion with crystalloid Fluid should be titrated to achieve urine output of 200-300ml/hr Administration of both 0.9% NaCl & isotonic sodium bicarbonate (1.26%) is acceptable to avoid a worsening hyperchloraemic metabolic acidosis

Rationale for bicarbonate and mannitol therapy Aim for urinary pH > 6.5 This potentially prevents precipitation & degradation of myoglobin in the urinary tubules Also helpful in management of hyperkalemia and acidosis No effect on the development of AKI, need for dialysis or death

Rhabdomyolysis if urinary flow is >20 mL/hour add mannitol to the intravenous alkaline solution providing an increase in urine output is demonstrated following a test dose suggested test dose is 60 mL of a 20 percent solution of mannitol administered intravenously over three to five minutes

Rhabdomyolysis if urine output increases by at least 30 to 50 mL/h above baseline levels in response to the test dose, 50 mL of 20 percent mannitol (1 to 2 g/kg per day [total 120 g], may be given at a rate of 5 g/hour. mannitol is contraindicated in patients with oliguria

Rhabdomyolysis The outcome varies depending on the extent of kidney damage. Source: Silberber, 2007

Acute Renal Injury

RRT Indication: Established AKI Refractory hyperkalemia and acidosis Unususal for fluid overload to be an indication The prognosis of renal failure secondary to rhabdomyolysis is good with renal function usually returning to normal within 3 months.

Summary Common in ICU setting Patients may have few symptoms, so high level of suspicion should be maintained Serum CK is the most sensitive indicator Initiate fluid resuscitation immediately Treat acute hyperkalemia Monitor for complications including compartment syndrome Serial CK measurement Renal replacement therapy may be required

References Oxford journals: Continuing education in Anesthesia, Critical Care & Pain (CEACCP) Anaesthesia tutorial of the week 198 (TOTW) ICU bedside handbook Tan Tock Seng Hospital

Marathon, CrossFit & rowing has been associated with rhabdomyolysis Thank you Marathon, CrossFit & rowing has been associated with rhabdomyolysis