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Flashcards in Rhabdomyolysis Deck (27)
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1
Q

Rhabdomyolysis definition

A

Destruction of skeletal muscles that results in injury to myocytes and membranes releasing intracellular contents into blood.

2
Q

2 Broad Causes of rhabdomyolysis

A

Direct damage to the skeletal muscle

Depletion of ATP within the myocyte due to damaged ATP pumps.

Both results in unregulated intracellular calcium which leads to eventual necrosis and death of muscle cells

3
Q

Intracellular contents released into blood stream from rhabdomyolysis

A

Myoglobin

Potassium and phosphorus

enzymes: CK, AST, ALT, LDH, Aldolase

All will be elevated in rhabdomyolysis

4
Q

Specific causes of rhabdomyolysis

A

Trauma, crush or compression syndrome/injury’s

Excessive muscle contraction: causes failure of sarcolemma sodium/potassium ATP pumps.

Statin medications

restrained psychiatric patients

Drug abuse: specifically alcohol, sedatives and sympathomimetic meds.

Bites that inject venom.

Influenza virus (In children)

Metabolic and genetic disorders.

5
Q

Statin medications

A

Meds that lower lipid levels

Class of HMG-CoA reductive inhibitors that block the production of coenzyme Q.

Disrupts ETC and leads to ATP disruption which once ATP is depleted can cause rhabdomyolysis

6
Q

Sympathomimetic medications

A

Cocaine, amphetamines, methamphetamines, PCP

Medications that cause agitation and increase demands on the cell and depletion of ATP.

7
Q

Other Signs and symptoms

A

Muscle pain

Weakness

Red brown urine

8
Q

Creatinine kinase

A

Enzyme responsible for reversible transfer of terminal phosphate group of ATP to generate phosphocreatinine.

In rhabdomyolysis, serum CK levels are At least 1500 units/L but can be way higher like 5000.

Isotopes can tell you where the damage is.

CK-MM: skeletal muscle

CK-BB: brain tissues

CK: MB: heart muscle

9
Q

Myoglobin

A

Functional oxygen reservoir similar to hemoglobin but in muscle cells and higher affinity for oxygen.

Elevated levels rise within 1 hour of rhabdomyolysis.

10
Q

Complications of rhabdomyolysis

A

Can lead to the following

Acute kidney injury/failure

Electrolyte derangements : specifically hyperkalemia MOST SIGNIFICANT

Compartment syndrome

Disseminated intravascular coagulation resulting in severe bleeding.

11
Q

Testing for myoglobin levels

A

Urine dipstick

  • easy and quick method of checking for possible rhabdomyolysis
  • reports high levels of blood with no red blood cells being present on microscopy. Indicates myoglobin in urine
12
Q

Signs of hyperkalemia on an EKG

A

Spiking of T waves

widening of the QRS complexes

flattening of the P waves

13
Q

Treatment of rhabdomyolysis

A

IV fluids with 1-2 liters of saline

Monitor enzymes, urine output and electrolytes

14
Q

Compartment syndrome

A

Increased pressure (usually via compression) within non-expendable compartments within the body surrounded by fascia.

When compartment pressure is higher than capillary perfusion pressure, tissue hypoxia occurs.

Histamine is released to try and compensate with increases blood flow, but also increases leakage of proteins and increases the pressure even further.

15
Q

Risks of compartment syndrome

A

Severe trauma

Open fractures

Vascular injury

leg/tibia fractures are the most common cause of compartment syndrome

16
Q

Symptoms of compartment syndrome

A

Pain that is out of proportion with physician findings
Most reliable early non physical sign

Paresthesias in Nerve distribution

Pallor and diminished pulses

Progression to lack of pulses (implies compressed blood supply and nerves which leads to necrosis if unchecked).

17
Q

5 P’s in compartment syndrome

A

Pain

Paresthesia

Pallor

Pulselessness

Paralysis

18
Q

Most reliable physical sign of compartment syndrome

A

Difference between diastolic BP and compartment pressure is less than 30mm

(Diastolic pressure - compartment pressure = less than 30 (requires fasciotomy)

19
Q

Volkmanns contracture

A

Compartment syndrome caused usually by a Supracondylar fracture of elbow. Results in hand loss of function.

20
Q

Exertional Rhabdomyolysis

A

Depletion of ATP causes inflammation which damages myocytes

-caused by exercise induced inflammation

Myocytes release potassium, myoglobin and creatine kinase

21
Q

Exertional compartment syndrome

A

Muscle swelling causes increased interstitial pressure. Impairs microcirculatory perfusion.

Causes muscle damage and pain

Induces a self-propagating cycle (body’s natural response to compartment syndrome is to increase the pressure via histamine and dilating blood vessels to try to get blood to the affected area.)

22
Q

Poikilothermia

A

Found in compartment syndrome.

Distal end of the limb = cold
Proximal end of the limb = hot

23
Q

Fasciotomy

A

Treatment for compartment syndrome. Relives pressure and is required to save the limb most of the time.

24
Q

Alcohol and ethanol

A

Direct toxicity to uncles and can cause prolonged immobilization when passed out

Same goes with sedatives and hypnotic medications

25
Q

Renal failure

A

Complication of rhabdomyolysis due to accumulation of Uric acid and myoglobin in the nephrons

  • dehydration, heat stress and trauma can all contribute to increased renal failure by decreasing blood flow through kidney
26
Q

Normal compartment pressure

A

0-10 mmHg

Once you hit 30 mmHg, blood circulation becomes impaired and compartment syndrome is likely.

Diastolic- compartment pressure = <30 mmHg is compartment syndrome 100%

27
Q

Treatment of compartment syndrome

A

Fasciotomy, IV fluids and do not elevate the limb.