Exertional Rhabdomyolysis in a 21-Year-Old Healthy Woman: A Case Report

Do Intramuscular Temperature and Fascicle Angle Affect Ultrasound Echo Intensity Values?

PURPOSE

Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle "quality" with physical training, disuse, aging, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate experiments to investigate the effects of muscle temperature and fascicle angle, which are known to influence muscle tissue and sound wave properties and therefore affect EI.

METHODS

In experiment 1 ( n = 16, 28.0 ± 6.6 yr), vastus lateralis (VL) ultrasonographic images were acquired and intramuscular temperature continuously recorded for 15 min after 20 min of heating to 40.4°C ± 0.7°C using a microwave device. In experiment 2 ( n = 17, 30.2 ± 9.8 yr), VL sonographic images were obtained with the knee both fully extended (0°) and flexed to 90° and EI and fascicle angle measured post hoc . Fascicle movement was tracked during the passive knee flexion to ensure that sonographic images were obtained at the same muscle region. Knee flexion reduced muscle thickness, and we therefore reran analyses calculating EI using identical dimensions to minimize this effect.

RESULTS

EI decreased only immediately after the passive heating, and although a moderate, negative correlation was observed between EI and temperature ( rrm = -0.36), the effect of muscle temperature was small ( β = 0.97 (-1.89 to -0.06) per degree Celsius, P = 0.051). Nonetheless, EI increased as fascicle angle decreased, and a large, negative correlation ( rrm = -0.85) was observed; the effect of fascicle angle on EI was large ( β = 3.0 (-3.8 to -2.2) per degree, P < 0.01), and this was maintained when analyses were performed at a constant depth of the region of interest ( β = 3.5 (-4.4 to -2.7) per degree, P < 0.01).

CONCLUSIONS

These findings support the hypothesis that fascicle angle meaningfully affects VL EI but provides weak evidence of a temperature effect in vivo . Thus, acute fascicle angle alterations should be accounted for in studies using EI measurements, and longer-term studies should consider whether changes in EI might be partly explained by a change in fascicle angle.

Echo intensity as an indicator of skeletal muscle quality: applications, methodology, and future directions

PURPOSE

This narrative review provides an overview of the current knowledge of B-mode ultrasound-derived echo intensity (EI) as an indicator of skeletal muscle quality.

METHOD

PubMed and Google Scholar were used to search the literature. Advanced search functions were used to find original studies with the terms 'echo intensity' and/or 'muscle quality' in the title and/or abstract. Publications that conceptually described muscle quality but did not include measurement of EI were not a focus of the review.

RESULT

Importantly, the foundational premise of EI remains unclear. While it is likely that EI reflects intramuscular adiposity, data suggesting that these measurements are influenced by fibrous tissue is limited to diseased muscle and animal models. EI appears to show particular promise in studying muscular aging. Studies have consistently reported an association between EI and muscle function, though not all chronic interventions have demonstrated improvements. Based on the existing literature, it is unclear if EI can be used as a marker of muscle glycogen following exercise and nutritional interventions, or if EI is influenced by hydration status. Inconsistent methodological approaches used across laboratories have made comparing EI studies challenging. Image depth, rest duration, participant positioning, probe tilt, and the decision to correct for subcutaneous adipose tissue thickness are all critical considerations when interpreting the literature and planning studies.

CONCLUSION

While some areas show conflicting evidence, EI shows promise as a novel tool for studying muscle quality. Collaborative efforts focused on methodology are necessary to enhance the consistency and quality of the EI literature.

Mining and visualizing high-order directional drug interaction effects using the FAERS database

Background

Adverse drug events (ADEs) often occur as a result of drug-drug interactions (DDIs). The use of data mining for detecting effects of drug combinations on ADE has attracted growing attention and interest, however, most studies focused on analyzing pairwise DDIs. Recent efforts have been made to explore the directional relationships among high-dimensional drug combinations and have shown effectiveness on prediction of ADE risk. However, the existing approaches become inefficient from both computational and illustrative perspectives when considering more than three drugs.

Methods

We proposed an efficient approach to estimate the directional effects of high-order DDIs through frequent itemset mining, and further developed a novel visualization method to organize and present the high-order directional DDI effects involving more than three drugs in an interactive, concise and comprehensive manner. We demonstrated its performance by mining the directional DDIs associated with myopathy using a publicly available FAERS dataset.

Results

Directional effects of DDIs involving up to seven drugs were reported. Our analysis confirmed previously reported myopathy associated DDIs including interactions between fusidic acid with simvastatin and atorvastatin. Furthermore, we uncovered a number of novel DDIs leading to increased risk for myopathy, such as the co-administration of zoledronate with different types of drugs including antibiotics (ciprofloxacin, levofloxacin) and analgesics (acetaminophen, fentanyl, gabapentin, oxycodone). Finally, we visualized directional DDI findings via the proposed tool, which allows one to interactively select any drug combination as the baseline and zoom in/out to obtain both detailed and overall picture of interested drugs.

Conclusions

We developed a more efficient data mining strategy to identify high-order directional DDIs, and designed a scalable tool to visualize high-order DDI findings. The proposed method and tool have the potential to contribute to the drug interaction research and ultimately impact patient health care.

Availability and implementation

http://lishenlab.com/d3i/explorer.html

The effects of training status and exercise intensity on exercise-induced muscle damage

BACKGROUND

Individuals participating in exercise beyond their level of fitness may be at higher risk for exercise-induced muscle damage, however the impact of training status on muscle damage development is not well understood. The purpose of this study was to measure skeletal muscle damage and soreness after five days of high and low intensity exercise in previously trained and untrained individuals.

METHODS

Eighteen males and females (9 trained and 9 untrained) completed five consecutive days of high intensity (HI) exercise and five consecutive days of low intensity (LI) exercise. Blood was drawn at the initial visit and after completion of each exercise intensity period.

RESULTS

CK was elevated post exercise for both groups during both intensities, but was greater in trained vs. untrained (HI: 203.6 vs. 143.4 IU/L and LI: 156.4 vs. 109.3 IU/L; P<0.01). Myoglobin was significantly higher after exercise for both groups (P<0.01) and was higher following high vs. low intensity in trained (P<0.01), but not untrained (P=0.052). Untrained experienced soreness following one day of high intensity exercise vs. after 3 days in trained participants (P=0.04, P=0.02).

CONCLUSIONS

The current study suggests that high intensity exercise results in greater muscle damage in both trained and untrained individuals vs. low intensity exercise. However untrained participants experience more pain and with earlier onset and should therefore take caution when beginning exercise programs that require consecutive sessions of high intensity exercise.

Exertional rhabdomyolysis in a 21-year-old healthy man resulting from lower extremity training: A case report

RATIONALE

The incidence exercise-induced rhabdomyolysis is increasing in the healthy general population. Rhabdomyolysis can lead to the life-threatening systemic complications of acute kidney injury (AKI), compartment syndrome, and disseminated intravascular coagulopathy.

PATIENT CONCERNS

A 21-year-old man had bilateral lower limb pain and soreness, dark brown urine after lower exremity training. Laboratory results showed that creatinine kinase (CK) and myoglobin (Mb) increased to 140,500 IU/L and 8632 μg/L respectively, with elevated liver enzymes, Scr, and proteinuria.

DIAGNOSES

Exercise-induced rhabdomyolysis with AKI.

INTERVENTIONS

The patient was hospitalized and treated with vigorous hydration and sodium bicarbonate for 6 days.

OUTCOMES

After 6 days of treatment, the patient had a significant decrease in the CK and Mb levels. His renal function returned to normal. His laboratory tests had completely normalized during 2-week follow-up.

LESSONS

Exercise-induced rhabdomyolysis can cause serious complications such as AKI. Delayed diagnosis can be critical, so timely manner should be taken to achieve a favorable prognosis.