Acute renal failure secondary to myoglobinuria

Acute Renal Failure (ARF) secondary to rhabdomyolysis and myoglobinuria was seen in four patients. In three, this was secondary to trauma and the fourth patient had an inflammatory myositis. All 4 patients had total recovery of renal function.

Vascular and myofibrillar lesions in acute myoglobinuria associated with carnitine-palmityl-transferase deficiency

A case of severe exercise-induced myoglobinuria in a 14-year-old boy suffering from a carnitine-palmityl-transferase (CPT) defect is reported. Biopsies of the forearm muscle were examined using light and electron microscopy in the acute and recovery phases of the illness. The first biopsy showed the presence of scattered foci of necrosis where necrotic fibres with occasional disruptions of the basal lamina were seen around injured capillaries. Various degrees of damage and different stages of evolution were found in these foci, which also contained regenerating muscle fibres. In the second biopsy, performed 2 weeks later, most of the fibres displayed a normal structure. Necrosis was no longer present. However, in some areas perivascular fibrosis was prominent, the fibres were small and irregularly shaped, and their nuclei often centrally located. These data strongly suggest that circulatory disorders and ischaemia, brought about by premature acute metabolic imbalance, could be involved in the development of exercise-induced myolysis observed in CPT deficiency. The risk of fibrous cardiomyopathy in these patients is pointed out.

Reactive oxygen metabolites in toxic acute renal failure

We have examined the role of reactive oxygen metabolites (ROM) in gentamicin nephrotoxicity and in glycerol-induced acute renal failure, a model for myoglobinuric acute renal failure. Several agents which affect mitochondrial respiration have been shown to enhance the generation of hydrogen peroxide. Based on gentamicin's ability to alter mitochondrial respiration both in vitro and in vivo we postulated that gentamicin may enhance the generation of ROM by renal cortical mitochondria. Gentamicin, in a dose-dependent fashion, enhanced hydrogen peroxide production by rat renal cortical mitochondria as measured by the decrease in scopoletin fluorescence. At the highest concentration of gentamicin tested (4.0 mM), the rate of hydrogen peroxide generation was markedly increased from 0.17 +/- 0.02 to 6.21 +/- 0.67 nmol/mg/min. We next demonstrated that hydroxyl radical scavengers and an iron chelator provide a marked functional and histological protection in gentamicin-induced acute renal failure in rats. Hydroxyl radical scavengers and the iron chelator deferoxamine also protected renal function in glycerol-injected rats, a model for acute renal failure due to muscle injury. Although these data suggest that ROM may be important mediators of toxic renal injury, in vivo generation of ROM by kidney in normal and pathological states has not been previously examined. Aminotriazole (AT) irreversibly inactivates catalase only in the presence of hydrogen peroxide and previous studies have shown that AT-mediated inhibition of catalase in a sensitive measure of in vivo changes in the hydrogen peroxide generation. Using this method, we have demonstrated the in vivo generation of hydrogen peroxide under normal conditions and enhanced generation of hydrogen peroxide in rats treated with gentamicin or glycerol.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of mannitol on myoglobinuric acute renal failure: functional, biochemical, and morphological assessments

This study was undertaken to explore the protective influence of mannitol against the glycerol model of myohemoglobinuric acute renal failure. Three hypotheses were tested: (1) mannitol confers cytoprotection by acutely blunting renal hypoperfusion, thereby improving tubular cell energetics; (2) as an hydroxyl radical (OH.) scavenger, mannitol mitigates Fe-driven lipid peroxidation and, hence, decreases tubular cell necrosis; and (3) mannitol prevents intrarenal heme pigment trapping, decreasing cast formation. Rats were injected with 50% glycerol (10 mL/kg im), followed immediately by an iv mannitol (1.25 mL/100 g over 1 h) or sham infusion. Mannitol induced a brisk diuresis (approximately 5.7 mL/2 h; approximately 35 mg of heme protein excreted), whereas glycerol controls were anuric. Mannitol did not significantly increase postglycerol RBF (2.8 mL/min), and it paradoxically worsened cellular energetics, halving cortical ATP concentrations at 1 h. However, this adverse effect on ATP was transient, correlating with active diuresis. Glycerol did not induce convincing in vivo lipid peroxidation (malondialdehyde; conjugated diene assay), and mannitol did not block Fe-driven in vitro lipid peroxidation of isolated brush border membrane vesicles. Na benzoate, an OH. scavenger, conferred no in vivo or in vitro protection. However, Na2SO4, not an OH. scavenger, reproduced the diuretic and in vivo protective effects of mannitol. Purified myoglobin infusion (35 mg) largely negated the beneficial action of mannitol. It was concluded that mannitol confers functional but not cytoprotection against the glycerol acute renal failure model, it acutely worsens renal bioenergetics, and its protective influence is probably due to a diuretic, not an antioxidant, effect.

[Myoglobinuria and the kidney]

The relationship between myoglobinuria and acute renal failure is analyzed patho-histologically in five autopsy cases of rhabdomyolysis and acute renal failure. The presence of myoglobin urinary casts was not a common finding, but various tubular damages due to factors other than myoglobin deposition were observed. These findings suggest that in addition to the toxic effect of myoglobin or its derivatives, preexistent or simultaneous renal or extrarenal tissue damages participate in the development of acute renal failure.

[Myoglobinuria and acute renal failure]

Clinical and experimental studies on the development of myoglobinuria-associated acute renal failure (ARF) were reviewed. ARF developed in 30% of the cases of rhabdomyolysis. Rhabdomyolysis-associated ARF accounted for 5-10% of all ARF. The presence of dehydration or hypotension at the presentation of rhabdomyolysis seems to be a risk factor in the development of rhabdomyolysis-associated ARF. ARF occurred more frequently in the rhabdomyolysis caused by sepsis or burns. Glycerol-induced ARF in rats or rabbits has been studied to investigate the pathogenesis of myoglobinuria-associated ARF. The early decrease in inulin clearance (Cin) in glycerol-induced ARF was dependent upon the decrease in renal blood flow, but the decrease in Cin in the late phase could not be attributed to the decrease in renal blood flow. Diminished glomerular permeability and cast formation might play important roles in the decrease in Cin in the late phase of glycerol-induced ARF.

Occult ischaemic necrosis of skeletal muscle associated with renal failure

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Hemofiltration in myoglobinuric acute renal failure

The frequency of myoglobinuric renal failure is estimated between 8 and 20%. Despite early onset of therapy often the use of renal substitution by hemodialysis or hemofiltration is required. This study of the clinical course of nine patients with myoglobinuric acute renal failure reveals continuous arterio-venous hemofiltration (CAVH) to have an effective clearance for myoglobin. Thus, the time until recovery of renal function as well as the frequency of secondary complications in rhabdomyolysis induced acute renal failure can be distinctly reduced.

[Rhabdomyolysis caused by severe sepsis: discussion on its role in the development of acute renal failure]

Rhabdomyolysis was evaluated by measurement of total creatine kinase (CK) and lactic dehydrogenase (LDH) in 19 patients with severe sepsis; 12 developed acute renal failure (Group B) and 7 did not (Group A). Results were compared to 7 patients with trauma (Group C) and 6 patients with chronic renal failure and minor infections (Group D). CK was higher (p less than 0.005) in Group B than in A. Results in Group C were similar to those in A. Elevation of CK correlated to increases in creatinine (r = 0.655, p less than 0.005). CK levels of Group D patients were lower than those of Group B. Blood pressure, lactate and pO2 were similar in both groups but thrombopenia was noted in Group B patients. Our results suggest that rhabdomyolysis and thrombopenia play a role in the development of renal failure in patients with severe sepsis.

Recurrent myoglobinuria and HIV seropositivity: incidental or pathogenic association?

There have been few cases of polymyositis in patients with AIDS, and polymyositis is rarely a cause of myoglobinuria. We studied a 20-year-old homosexual man with recurrent myoglobinuria. He was asymptomatic between episodes. Each episode was accompanied by muscle pain, limb weakness, high serum levels of creatine kinase, and pigmenturia. Muscle biopsy showed active necrosis without inflammation or abnormalities of glycolytic or other energy-generating enzymes. Antibodies to HIV were present in serum. Clinical evidence of AIDS has not developed in 2 years. Recurrent myoglobinuria may be another consequence of HIV infection.

Studies of mechanisms and protective maneuvers in myoglobinuric acute renal injury

To explore why urine pH affects myoglobin (M)-induced renal injury, rats were infused with M under aciduric (NH4Cl) or alkalinuric (KHCO3) conditions with or without additional solute loading. Acute renal M retention (R) was highly pH dependent (pH 5.77, 68% R; pH 6.45, 49% R; pH 8.0, 28% R), the % R positively affecting the severity of renal injury (azotemia, proximal tubular necrosis, M casts, medullary vascular congestion, assessed 3 and/or 24 hours later). However, nonreabsorbable, nonalkalinizing salts (SO4) equiosmolar to KHCO3 decreased M retention to 21% and produced comparable functional/morphologic protection as HCO3. Equiosmolar reabsorbable salt (NaCl) did not decrease M retention (67%) or confer significant protection. M, when suspended in urine, but not in 0.45% NaCl, was highly acid precipitable (73% versus 10%). Electrophoretic/solubility studies indicated that M, not hematin, precipitated. M infusion did not decrease renal cortical soluble thiol groups (principally glutathione) or raise malondialdehyde concentrations at a time that tubular damage was apparent. Neither deferoxamine nor 2 hydroxyl radical scavengers (dimethylthiouria, Na benzoate) conferred significant functional/morphologic protection. These results indicate that aciduria promotes myoglobinuric-renal injury by acutely trapping M within the kidney, not by causing hematin formation. HCO3 protects by increasing urinary M solubility and by providing nonreabsorbed solute, both facilitating its excretion. Fe-stimulated hydroxyl radical formation does not appear to be necessary for M to cause renal damage.

Exertional rhabdomyolysis and acute renal failure following the Army Physical Fitness Test

Rhabdomyolysis and myoglobinuric acute renal failure may occur following strenuous exercise and may be more common in less physically conditioned persons. A case of moderately severe acute renal failure after the exercise involved in a routine Army Physical Fitness Test (APFT) is described. This level of exertion, which is universally applied to Army personnel, should be recognized as a potential etiology of rhabdomyolysis. Prospective studies may help define the exact risk to renal function provided by the APFT.

Myoglobinuria exacerbates ischemic renal damage in the dog

The effects of intramuscular glycerol on ischemic acute renal failure was investigated in dogs. Anesthetized dogs received a bilateral 120-min renal artery obstruction (RAO) alone, RAO plus 5 ml/kg of 50% glycerol or RAO plus 5 ml/kg of 75% glycerol. Control groups received the glycerol injection, but not RAO. Renal histopathology was minimal in dogs receiving glycerol alone. In RAO dogs, those receiving 50% glycerol showed diffuse acute tubular necrosis (ATN), while those receiving 75% glycerol had severe ATN with extreme mortality. Changes in serum creatinine, creatinine clearance, and fractional excretion of sodium were consistent with the histopathologic changes. We conclude that myoglobinuria, of a degree insufficient to cause renal failure itself, can interact with renal ischemia to significantly exacerbate the renal damage produced.

Rhabdomyolysis: computed tomography findings

Computed tomography scans were performed on two patients who presented with clinical rhabdomyolysis and acute renal failure secondary to myoglobinuria. Localized muscle swelling with patchy focal areas of low attenuation were demonstrated. Computed tomography may be helpful to clarify the nature and extent of the muscle injury in the appropriate medical setting.

Fatal rhabdomyolysis associated with hyperosmolar diabetic decompensation

A patient is described who developed fatal acute rhabdomyolysis in association with hyperosmolar diabetic decompensation. The delay in making the diagnosis of acute rhabdomyolysis may have contributed to the outcome as the use of dantrolene may be of benefit in such patients.

Myoglobinuric renal failure in a newborn after traumatic delivery

Fetal and neonatal asphyxia is the main cause of transient or acute renal failure (ARF) in neonates. Rhabdomyolysis and subsequent myoglobinuria have been rarely reported in neonates. We describe a case of ARF in a newborn infant in whom asphyxia, birth trauma and hypovolemic shock precipitated rhabdomyolysis which contributed to ARF.

Polymyositis with myoglobinuria in pregnancy: a report and review of the literature

A pregnant patient developed fulminant polymyositis with myoglobinuria after terbutaline and magnesium sulfate tocolysis. Her response to prednisone was dramatic. Rapid relapse occurred after inadvertent postcesarean dose reduction. Our patient again responded to increased prednisone. She and her twin babies are well.