Complications risk low among hospitalized patients with spin-induced exertional rhabdomyolysis

Management of hospitalized individuals with spin-induced exertional rhabdomyolysis (SER) includes hydration, oral analgesia, and basic laboratory investigations, according to a Singapore study, noting that the risk of complications in these patients is low.

“SER patients without risk factors for complications can be considered for hospital-at-home management with bed rest, aggressive hydration, and early outpatient review,” said the researchers, who conducted a review for those admitted to Singapore General Hospital from 1 March 2021 to 31 March 2022.

All admitted patients with a diagnosis of rhabdomyolysis, raised creatinine kinase (CK) level, or elevated CK level with a history of spin-related physical exertion were included. Those without a history of exertion, with a history of nonspin-related exertion, or with a peak serum CK <1,000 U/L were excluded.

Ninety-three patients (mean age 28.6 years, 71.0 percent female, mean body mass index 25.0 kg/m²) made it to the final analysis, of whom 81 (87.1 percent) were first-time spin participants. All patients had muscle pain, 68 (73.1 percent) dark urine, 16 (17.2 percent) muscle swelling, and 14 (15.1 percent) muscle weakness. [Ann Acad Med Singap 2023;52:356-363]

Of the participants, 80 (86.0 percent) had admission CK of >20,000 U/L. Mean creatinine among patients upon admission was 59.6 µmol/L. Mean intravenous (IV) hydration received was 2,201 mL/day, oral hydration was 1,217 mL/day, and total hydration was 3,417 mL/day. One patient (1.1 percent) presented with acute kidney injury (AKI), which was resolved the following day with IV hydration.

Previous studies suggested a cutoff value of CK >20,000 U/L for inpatient management. In the current study, 86.0 percent of patients had CK >20,000 U/L at presentation but did not develop complications following IV hydration. Moreover, 89.2 percent had a mean peak CK >20,000 U/L. [Curr Sports Med Rep 2021;20:169-178; Pediatr Emerg Care 2010;26:864-866]

“Quantifying the exact value of CK would allow more research to be done to adjust the thresholds for admission and increased risk of developing complications,” the researchers said.

“In addition, when assessing the necessity for inpatient management, the number of days to presentation needs to be taken into consideration as CK levels may take up to 7 days to peak depending on the type of exercise,” they added. [Muscle Nerve 2012;45:356-362; Int J Sports Med 1989;10:69-80; Phys Sportsmed 2020;48:179-185]

Notably, the mean number of days needed for CK to fall below 20,000 U/L was 7.9 days postexertion. In the current study, 17 patients (18.3 percent) were discharged with CK >20,000 U/L, all of whom were given a follow-up appointment within 1 month. Thirteen patients attended their follow-up appointment, and all of them had a downward trend in CK.

“CK and myoglobin levels individually have been shown to have no correlation with AKI or mortality, although higher admission CK levels are associated with a longer length of stay (p<0.01),” the researchers said. [Med Sci Sports Exerc 2006;38:623-627; Clin Chem 2009;55:2190-2197; Clin Chem 2009;55:2190-2197]

“Hence, persistently high CK levels should not be a contraindication to patients’ discharge as long as the patient has improved symptomatically and does not have any complications,” they added.