Serum myoglobin

Mild rhabdomyolysis (which differs from that in myoglobinuric acute renal failure patients), and serum levels of creatine phosphokinase (CPK) and myoglobin, which are normal or slightly increased (less than 7 times the reference value for serum myoglobin, and less than 9 times the reference value for CPK). 

CPK less than 9 times and serum myoglobin less than 7 times the reference values... 

Serum myoglobin (ng/ml) CPK (U/l) Myoglobinuria Kidney biopsy Hypouricemia... 

The serum myoglobin level (Fig. 51) was lOOng/ml or less in most patients ( = 42), and exceeded 300ng/ml in only 4 patients. The mean was 1.6 1.3 times higher than the reference value. No values were more than 7 times higher than the reference... 

Fig. 51. Serum myoglobin levels in patients 50 100 150 200 250 300 >300 (ng/ml) with ALPE...

Type II muscle fibers (white muscle, fast muscle) (Table 6) contribute to rapid muscle contraction by using energy obtained from stored ATP, and ATP production from creatine phosphate and anaerobic glycolysis of glycogen. However, the myoglobin content of these fibers is low [144,145], which may lead to less marked increases in serum myoglobin and creatine phosphokinase (CPK) in patients with ALPE. 

We enrolled five members of the Kanazawa Medical University Soccer Team (including one member with a history of ALPE) in order to examine changes in serum creatinine, serum myoglobin, and CPK before and after a match. There were no differences in the levels of change in these three parameters regardless of the presence or absence of a history of ALPE (Fig. 66). We did not investigate creatinine clearance. 

ALPE frequently developed after anaerobic exercise, and caused severe loin pain, nausea/vomiting, and slight fever without dark urine. Furthermore, the serum myoglobin and CPK levels were normal or slightly increased, and delayed computed tomography (CT) showed wedge-shaped contrast enhancement. 

The following issues, including the etiology, remain to be clarified (a) the pathogenesis of ALPE, (b) the prevention of relapse, and future exercise guidance, (c) why delayed CT shows patchy contrast enhancement even in the recovery phase, (d) whether or not patchy renal vasoconstriction persists for 1-2 weeks, (e) why a contrast medium is present in the kidney for 72 h maximum, (f) the association between ALPE and disorders of type II muscle fibers, (g) the reasons for the less marked increases in serum myoglobin and creatine phosphokinase (CPK), and (h) why ALPE frequently develops in patients with renal hypouricemia. 

Plotz J, Braun J. Serummyoglobin nach Wiederholungsgaben von Succinylchohn und der Einfluss von Dantrolen. [Serum myoglobin following intermittent administration of succinylcholine and the effect of dantrolene. Clinical studies of children in halothane anesthesia.] Anaesthesist 1985 34(10) 513-15. 

A 73-year-old man took an unknown number of theophylline modified-release tablets and furosemide 40 mg tablets. He developed a tachydysrhythmia, vomiting, and restlessness. His maximum theophylline concentration was 67 pg/ml and he had hypokalemia (2.8 mmol/1) and hyponatremia (123 mmol/1). The maximum creatine kinase activity was (32 mol/1 [sic]) and the serum myoglobin concentration was 3789 pg/l. He was treated with oral activated charcoal, continuous venovenous hemodialysis, intravenous potassium and sodium chloride, forced diuresis, and continuous intravenous meto-prolol, and survived without sequelae. 

EN99 Gorus, F.K., Van Blerk, M., Huyghens, L. and Maes, V. (1992). Analytical and clinical evaluation of CK-MB on Abbott IM, Comparison with CK-MB activity and serum myoglobin in patients with or without myocardial infarction. Clin. Chem. 38, 975, Abstr. 174. 

Grenadier E, Keidar S, Kahana L, Alpan G, Marmur A, Palant A. The roles of serum myoglobin, total CK, and CK-2 isoenzymes in the acute phase of myocardial infarction. Am Heart J 1983 10 408-16. 

We have defined the ability to identify affected individuals as sensitivity and the ability to recognize unaffected individuals as specificity and can express these abilities as percentages or decimal fractions. A perfect test would exhibit both a sensitivity and specificity of 1001 or 1.0. Tests are rarely perfect. It would be rather unusual for a test to exhibit a sensitivity and a specificity of lOOX at the same time. Often we hear or read that a particular test has a particular sensitivity or specificity. In reality, as noted with radar and serum myoglobin, there isn t just one sensitivity or specificity for a test, but rather a continuum of sensitivities and specificities. 

A 71-year-old woman took sertraline 50 mg/day for depression and 2 months later was found to have markedly increased creatine kinase, lactate dehydrogenase, and aspartate aminotransferase activities and serum myoglobin concentration. These abnormalities resolved within 1 week of sertraline withdrawal, but recurred dramatically 2 weeks after re-introduc-tion of sertraline. Once again, everything resolved after withdrawal of sertraline. She was successfully treated with escitalopram without recurrence of the biochemical disturbances. 

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