Rhabdomyolysis NSG 530

Instructions

Here is the case study for week 10.

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A 28-year-old male presents to the primary care office for evaluation of left calf pain, swelling, and redness. He reports that this started one day ago and worsened today. He ran a 27-mile marathon 2 days ago and traveled for 3 hours in a car today. He reports slight pain on walking and a swollen red calf. He took Ibuprofen 600 mg twice today without relief. The patient reports being an experienced runner, running 3-5 miles daily. He trained for the marathon for 4 months. The patient also reports a history of exercise-induced asthma and uses albuterol sulfate HFA as needed.

On physical exam, the patient appears in good health T 99 P 68 R 18 BP 118/78 wt. 175 lb, height 72 in. BMI 23.1. Heart rate is regular without murmurs, rubs, or gallops. Lungs clear bilaterally. HEENT WNL. Strength lower extremities +5 and DTRs + 2. Left calf erythematous, edematous, warm, and tender on palpation. Pulses 3+.

Two possible diagnoses were considered: deep vein thrombosis (DVT) and rhabdomyolysis.
Stat ultrasound of the left leg to rule out DVT was ordered and read as normal
CBC WNL
Creatine Kinase (CK) 23,000 U/L (normal 24-170 U/L)
BUN and Creatinine WNL
A diagnosis of rhabdomyolysis was made.

• Discuss the pathophysiology of acute renal failure in rhabdomyolysis.

Solution

Case Study

Rhabdomyolysis (RM) is an illness that can result in detrimental health impacts on the patient. In the provided scenario, the patient presented to the clinic with complaints of left calf pain, swelling, and redness. Further examination revealed that the patient had rhabdomyolysis. According to Esposito et al. (2018), rhabdomyolysis may occur due to extreme physical activity, trauma, drugs and alcohol, and other situations. The patient is an athlete who runs between 3-5 miles daily. This could be the reason why the patient developed rhabdomyolysis.

This week’s discussion focuses on the pathophysiology of acute renal failure in rhabdomyolysis. According to Esposito et al. (2018), acute kidney injury occurs in 10-40% of patients experiencing severe rhabdomyolysis. The primary mechanism of acute renal failure in patients diagnosed with rhabdomyolysis is the leakage of myoglobin into the circulation. Kwiatkowska et al. (2020) stated that intracellular fluid is often released, after muscle damage, and sequestrated into the extracellular spaces. This situation leads to a reduced intravascular volume that provides a signal to activate the renin-angiotensin-aldosterone system (RAAS), which reduces renal blood flow, henceforth.

Increasing concentration of myoglobin leads to cytotoxic and destructive effects on the nephron (Kwiatkowska et al., 2020). This incident also leads to the accumulation of iron in the proximal tubules associated with intratubular obstruction, as well as, proximal tubular cell injury (Esposito et al., 2018). A reaction occurs between free iron and peroxide compounds to form reactive oxygen species (ROS) that have a negative impact on tubular integrity. Uric acid is often released, at the same time, by other muscle components into the circulatory system, forming deposits of crystals and causing intratubular impediment.

Another mechanism involved in the pathophysiology is referred to as lipid membrane components peroxidation. This happens after reacting with a ferryl form of myoglobin (redox-cycling), which leads to metabolic acidosis that increases myoglobin toxicity (Kwiatkowska et al., 2020). Metabolic acidosis and resulting aciduria may worsen tubular damage. Further tubular damage happens because myoglobin dissociates into globin and ferrihemate, at low urinary pH, which has a direct nephrotoxic effect (Esposito et al., 2018). Once patients are diagnosed, they should be queried about their history of any unusual physical activity, prolonged immobilization, trauma, and other situations that are related to the disease.

References

Esposito, P., Estienne, L., Serpieri, N., Ronchi, D., Comi, G. P., Moggio, M., & Rampino, T. (2018). Rhabdomyolysis-associated acute kidney injury. American Journal of Kidney Diseases, 71(6), A12-A14. https://doi.org/10.1053/j.ajkd.2018.03.009
Kwiatkowska, M., Chomicka, I., & Malyszko, J. (2020). Rhabdomyolysis–induced acute kidney injury–an underestimated problem. Wiad. Lek, 73(11), 2543-2548. https://doi.org/10.36740/WLek202011137

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