Physiologic Response to Exercise or Rhabdomyolysis? Creatine Phosphokinase Elevation in 16 Asymptomatic Firefighters.

BACKGROUND We present a case series of 16 trainee firefighters who presented to the Emergency Department with elevated creatine phosphokinase levels of greater than 14 000 units per liter 3 days after the initiation of intense aerobic exercise. All 16 patients were diagnosed with exercise-induced rhabdomyolysis and were mostly asymptomatic. While exercise-induced rhabdomyolysis often affects untrained individuals who abruptly initiate strenuous exercises, our patients were all physically well-trained and maintained an active training regimen. In review of this unusual case series, we assess the patients' risk factors for exercise-induced rhabdomyolysis and the complications of their elevated creatine phosphokinase levels despite their asymptomatic presentations. CASE REPORT We focus on the exercise routine, hospital admission, and course of treatment for 4 of the 16 patients who gave written consent to participate in the study. Therapy was targeted towards intravenous fluids and the lowering of creatine phosphokinase levels. Patients 1, 2, 3, and 4 were discharged when creatine phosphokinase levels decreased by 17%, 40%, 39%, and 40%, respectively. CONCLUSIONS Given the differing guidelines for diagnosis, treatment, and discharge for asymptomatic exercise-induced rhabdomyolysis, it was unclear if this was a physiologic or pathologic response to exercise, if hospital admission was indicated, and the extent to which creatine phosphokinase had to decrease for discharge. Our aim is to: 1) determine recommendations to prevent muscle injury following exercise, 2) distinguish between physiologic response to exercise and clinically significant muscle damage, and 3) and recommend a course of treatment given asymptomatic presentation.

Radiopacity of sodium zirconium cyclosilicate on CT imaging.

A patient who post-operatively develops hyperkalemia is treated with sodium zirconium cyclosilicate (Lokelma®), a novel agent used for the treatment of non-life-threatening hyperkalemia with reduced side effects as compared with its predecessors. On CT imaging of the chest, abdomen, and pelvis, a radiopaque fluid is noticed despite the patient not having received any oral or intravenous contrast nor any medications or supplements that may appear radiopaque. Based on previous CT imaging of zirconium-based tooth implants and their radiopaque appearance on images, it is hypothesized that the sodium zirconium cyclosilicate that the patient was administered is the explanation of the radiopacity on CT imaging. We performed an in-vitro experiment to confirm that Lokelma is radiopaque to support our hypothesis. It is important to fully understand the differential of what may cause different appearances on imaging as well as to eliminate potential sources of artifact prior to imaging, or alternatively, to potentially be able to use medications with known radiopaque properties as alternatives to contrast agents.

Variability in response to hepatitis B vaccine in hemodialysis patients.

BACKGROUND: Hemodialysis patients are exposed to blood and blood products more than the general population and are also at higher risk for hepatitis B (HB) contamination. For these reasons, it is highly recommended that this patient population gets the HB vaccine. The efficacy of the vaccine is measured by measuring titers of antibody in the serum of the patient. A minimum titer of 10 mIU/mL is considered to be a response. The conversion rate in hemodialysis patients ranges from 50% to 80%, as compared to the general population where the conversion rate is over 95%. As opposed to the general population, end-stage renal patients on hemodialysis do not always respond to the vaccine. The main objective in this study was to try to identify factors that may hinder the response. Correction of these factors in the future may help non-responders. METHODS: This was a retrospective chart review at a single hemodialysis center to compare the laboratory and clinical differences between responders and non-responders. Inclusion criteria are hemodialysis patients who received the HB vaccine and patients with concomitant hepatitis C. Exclusion criteria are patients who refused the vaccine and patients who did not complete the vaccine course. RESULTS: There are a total of 108 subjects included in the study, out of which 44 (42.3%) are responders to the HB vaccine. A multivariate logistic regression was performed using the statistically significant risk factors as identified by the univariate logistic regression, including age range, albumin, hemodialysis vintage, vascular access and diabetes status. The results from the multivariate logistic regression show that advanced age (P = 0.005) and diabetes status (P = 0.003) are found to be strong independent risk factors of responder status. The type of vascular access (AVF or other types) is also marginally statistically significant (P = 0.05). CONCLUSIONS: In this retrospective chart review comparing HB vaccine in responders versus non-responders, we found that advanced age and a history of diabetes are independent risk factors in predicting responder status.

Severe oxalosis with systemic manifestations.

UNLABELLED: Ethylene glycol toxicity can have various clinical presentations with different organ system involvements. These presentations are independent of the level of toxicity. We describe a 31 years old male who presented with ethylene glycol toxicity manifesting as anuric renal failure who subsequently developed neurological sequela of its toxicity. Ethylene glycol is known to be metabolized to various metabolites and is ultimately converted to oxalate which results in crystal deposition the renal parenchyma causing renal failure. Oxalate deposition can occur in various organs including the nervous system as seen in our patient. The majority of patients do not recover from severe oxalosis despite the supportive care of hemodialysis in removing the parent compounds. Despite severe oxalosis, our patient was fortunate enough to be left with minimal neurological sequelae, and eventually was able to cease hemodialysis treatments. KEYWORDS: Ethylene glycol; Oxalate; Oxalosis; Glyoxylic acid.

Correlation between glycated hemoglobin and mean plasma glucose in hemodialysis patients.

BACKGROUND: Since the half-life of red blood cells (RBCs) is shorter in hemodialysis patients, the value of glycated hemoglobin (HbA1c) as a marker of glycemic control in patients with diabetes on hemodialysis has recently been questioned. It is thought that it is not a good marker of mean plasma glucose (MPG) over a 3-month duration. In our current study, we evaluate whether monthly HbA1c values is a better marker of glycemic control than HbA1c every 3 months. METHOD: We performed a cross-sectional analysis of a retrospective cohort of 152 patients with diabetes who presented to two hemodialysis units in NYC. Patients had weekly predialysis glucose levels checked over the last 3 months, and HbA1c values were checked every 3 months. Data collection spanned a 6-month time frame from August 2008 to January 2009. RESULTS: We found no difference in the correlation between HBA1c/mean plasma glucose (MPG) over the last month (MPG1m) and HbA1c/mean plasma glucose (MPG) over the last 3 months (MPG3m; r = 0.57 and r = 0.53, respectively; P = 0.212). Using multivariate analysis, reticulocyte count and weekly erythropoietin dose were found to independently and inversely effect the correlations HbA1c/MPG1m and HbA1c/MPG3m. CONCLUSION: The value of HbA1c in hemodialysis for monitoring glycemic control is limited in the setting of a high reticulocyte count (>2%) and a high weekly erythropoietin dose. Checking HbA1c monthly versus every 3 months is not a better approximation of glycemic control in hemodialysis patients.