Acute Kidney Injury Among Children Admitted With Viral Rhabdomyolysis

Acute Kidney Injury in Rhabdomyolysis: A 5-Year Children's Hospital Network Study

Rhabdomyolysis is a skeletal muscle injury that can cause myoglobinuria and acute kidney injury (AKI). Risk factors for AKI in children are not clearly understood with no standardized treatment guidelines for rhabdomyolysis. Our study explores factors associated with AKI and management of pediatric patients with rhabdomyolysis. Medical records from a children's hospital network over a 5-year period were retrospectively reviewed. The results are described with respect to the presence or absence of AKI. Of the 112 patients who met the inclusion criteria, AKI incidence was 7.1% (n = 8), with all affected patients having exertional etiology. The overall mean age was 13.5 years; patients without AKI were younger than patients with AKI (13.3 versus 17; p < 0.001). Using regression models for hypothesis generation, we found that patients with AKI were more likely to be older (OR = 1.44, 95%CI [1.11-2.19]; p = 0.03), have myoglobinuria (OR = 22.98, 95%CI [2.05-432.48]; p = 0.02), and have received intravenous bicarbonate (OR = 16.02, 95%CI [1.44-228.69]; p = 0.03). In our study, AKI was uncommon and associated with older age, myoglobinuria and bicarbonate treatment. Larger, prospective studies are needed to further understand AKI risk factors and optimal management of pediatric rhabdomyolysis.

Experience with carnitine palmitoyltransferase II deficiency: diagnostic challenges in the myopathic form

OBJECTIVES

Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive disorder of long-chain fatty acid oxidation. Three clinical phenotypes, lethal neonatal form, severe infantile hepatocardiomuscular form, and myopathic form, have been described in CPT II deficiency. The myopathic form is usually mild and can manifest from infancy to adulthood, characterised by recurrent rhabdomyolysis episodes. The study aimed to investigate the clinical features, biochemical, histopathological, and genetic findings of 13 patients diagnosed with the myopathic form of CPT II deficiency at Ege University Hospital.

METHODS

A retrospective study was conducted with 13 patients with the myopathic form of CPT II deficiency. Our study considered demographic data, triggers of recurrent rhabdomyolysis attacks, biochemical metabolic screening, and molecular analysis.

RESULTS

Ten patients were examined for rhabdomyolysis of unknown causes. Two patients were diagnosed during family screening, and one was diagnosed during investigations due to increased liver function tests. Acylcarnitine profiles were normal in five patients during rhabdomyolysis. Genetic studies have identified a c.338C>T (p.Ser113Leu) variant homozygous in 10 patients. One patient showed a novel frameshift variant compound heterozygous with c.338C>T (p.Ser113Leu).

CONCLUSIONS

Plasma acylcarnitine analysis should be preferred as it is superior to DBS acylcarnitine analysis in diagnosing CPT II deficiency. Even if plasma acylcarnitine analysis is impossible, CPT2 gene analysis should be performed. Our study emphasizes that CPT II deficiency should be considered in the differential diagnosis of recurrent rhabdomyolysis, even if typical acylcarnitine elevation does not accompany it.

Benign Acute Childhood Myositis in a Pediatric Patient Post Influenza B Infection

Benign acute childhood myositis (BACM) is a mild and self-limited sudden onset of lower extremity pain during or following recovery from a viral illness. It is characterized by difficulty walking due to severe bilateral calf pain, which usually resolves in three days. It is typically appreciated during times of large influenza outbreaks and epidemics. The most severe complication can be rhabdomyolysis without proper treatment and can lead to renal damage and potential renal failure. There are limited reported cases of BACM and therefore no clear guidelines in the treatment or management of the condition. This case is unique in the sense that the patient had leg pain the entire month prior to presentation in the absence of trauma or injury, and it is believed that the pre-existing myalgia may have been exacerbated by an upper respiratory infection (URI) that started a few weeks after the leg pain onset. In addition, this patient's creatine kinase peaked at over 13,000 U/L, which is three to five times higher than the average of other reported children with this condition. The patient is a five-year-old male who presented to the emergency department with bilateral leg pain and difficulty ambulating. His guardian reported that the leg pain began one month prior to presentation and worsened to the point where he could no longer ambulate, following a fever and cough that began one week prior to presentation. A respiratory viral panel was positive for influenza B, and initial creatine kinase (CK) levels were greater than 10,000. A diagnosis of BACM was made, and supportive care was initiated. BACM is an infrequent complication following a viral infection that is typically treatable with hydration management and routine CK monitoring. Symptoms of BACM are usually limited to muscle pain and weakness, but it can progress to rhabdomyolysis and renal failure if not managed properly. It is therefore crucial that physicians monitor CK values daily until a downtrend is noticed and symptoms begin to resolve.

Trends in Pediatric Rhabdomyolysis and Associated Renal Failure: A 10-Year Population-Based Study

OBJECTIVES

Rhabdomyolysis in children is a highly variable condition with presentations ranging from myalgias to more severe complications like acute renal failure. We sought to explore demographics and incidence of pediatric rhabdomyolysis hospitalizations and rates of associated renal failure, as our current understanding is limited.

METHODS

This was a retrospective analysis using the Healthcare Cost and Utilization Project Kids' Inpatient Database to identify children hospitalized with a primary diagnosis of rhabdomyolysis. Data were analyzed for demographic characteristics, as well as geographic and temporal trends. Multivariable logistic regression was used to identify characteristics associated with rhabdomyolysis-associated acute renal failure.

RESULTS

From 2006 to 2016, there were 8599 hospitalized children with a primary diagnosis of rhabdomyolysis. Overall, hospitalizations for pediatric rhabdomyolysis are increasing over time, with geographic peaks in the South and Northeast regions, and seasonal peaks in March and August. Though renal morbidity was diagnosed in 8.5% of children requiring hospitalization for rhabdomyolysis, very few of these patients required renal replacement therapy (0.41%), and death was rare (0.03%). Characteristics associated with renal failure included male sex, age greater than 15 years, and non-Hispanic Black race.

CONCLUSIONS

Though renal failure occurs at a significant rate in children hospitalized with rhabdomyolysis, severe complications, including death, are rare. The number of children hospitalized with rhabdomyolysis varies by geographic region and month of the year. Future studies are needed to explore etiologies of rhabdomyolysis and laboratory values that predict higher risk of morbidity and mortality in children with rhabdomyolysis.