Introduction:
Rhabdomyolysis is a complex medical condition involving rapid dissolution of damaged or injured skeletal muscle. Common causes of rhabdomyolysis include direct traumatic injury, drugs, toxins, infection and prolonged bed rest. Exertional heat stroke (EHS) is a medical emergency frequently associated with exertional rhabdomyolysis (ERM). High temperatures combined with high humidity levels can impair the body's ability to dissipate heat, impaired thermoregulation which can leads to inflammation and eventually multiorgan failure including severe rhabdomyolysis. EHS is common especially in young patient who involved in exertional strenuous activity under hot and humid weather. We reported two cases of bimodal rhabdomyolysis with acute kidney injury (AKI) secondary to ESH.
Methods:
Case 1
17-year-old overweight boy with no known medical illness brought in to emergency department unconscious , requiring intubation after running for 3.5km in a fun run. He had brief seizure before collapsed. He was found to have profuse sweating and warmth to touch upon arrival to the emergency department.
Blood investigation showed impaired liver and kidney function with serum creatinine kinase (CK) of 812 IU/L, therefore was diagnosed as severe rhabdomyolysis with multiorgan failure secondary to exertional heat stroke. His CK raised from 812 IU/L to >42670 IU/L ( unmeasurable) level within 4 days. He was supported with continuous renal replacement therapy initially and followed by 5 session of hemodialysis with high-flux dialyzer before his condition improved and able to be extubate and transferred to normal ward after 9 days in ICU.
Unfortunately he was intubated again and transferred back to ICU the next day because he developed sudden onset of shortness of breath failed the non-invasive ventilator support. His CK rebound from 8689 IU/L to >42670 IU/L and creatinine also raised from 531 IU/L to 836 IU/L requiring dialysis support. His CK started to come down and kidney function started to improve after 11 session of haemodialfiltration before able to stop dialysis support and discharge home after total 37 days of hospital stay. His kidney function has normalised during outpatient follow-up.
Case 2
22 years old military trainee with no known medical illness developed generalized tonic clonic seizures after completed his 11 hours training including 2.4km run. Upon presentation, he had hypotension requiring inotropic support, unstable supraventricular tachycardia requiring cardioversion and intubation for status epilepticus requiring ICU admission. He was diagnosed to have heat stroke with multiorgan failure. He required sustained low efficiency dialysis for worsening AKI and rhabdomyolysis, CK increased from 15179 IU/L to > 42670 IU/L (unmeasurable level) and serum creatinine raised from 250mmol/L to 417mmol/l. He was transferred to normal ward after that, however his condition deteriorated and had to readmitted to ICU due to respiratory distress and worsening rhabdomyolysis. His CK level rebound from 6819 IU/L to 33000 IU/L. We started hemodialysis support with high-flux dialyzer x1, followed by Teranova dialyzer for four sessions before his condition stabilized. He continued to improve after that and his creatinine normalized upon discharged. His total hospital stay was 41 days.
Results:
We report 2 very severe rhabdomyolysis cases secondary to EHS. Both involved young and fit patient who presented with neurological manifestations (seizure) requiring intubation and multiorgan involvement including AKI requiring dialysis support in ICU. Both cases took about 2-4 days to reach first peak CK (till unmeasurable level in both cases). They responded quickly to initial treatment including intensive hydration and haemodialysis and was able to transferred to normal ward within a week (between 5-8 days). However both cases had their CK level rebounded to second peak within 7 to 11 days requiring further dialysis support. Fortunately both cases make good recovery with their kidney function returned normal level eventually.
AKI in rhabdomyolysis can be due to deposition and occlusion of renal tubules by Tamm-Horsfall protein forming cast nephropathy, therefore intravenous hydration with or without alkalinisation of urine remains main important management in severe rhabdomyolysis. We used haemodialfiltration as dialysis modality for the first case and Theranova dialyzer for the second case.
Conclusions:
Severe rhabdomyolysis can leads to AKI which need early dialysis if did not respond to initial medical therapy such as intensive hydration. Bimodal rise in CK is not common but few case report had shown similar findings. Therefore, patient still need close monitoring of kidney function and CK level after initial treatment response to watch out for CK rebound as some may have bimodal rhabdomyolysis which require timely intervention again including dialysis support as reported in this 2 cases. In rhabdomyolysis cases, usage of medium cut off dialyzer become a relevant option for dialysis modality due to specific needs for clearing myoglobulin and other large middle molecule in short duration as compared to standard high flux dialyzer and this might help reducing the severity and duration of AKI and improving overall renal recovery.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.