The use of muscle ultrasound to detect critical illness myopathy in patients with sepsis: an observational cohort study

Critical illness myopathy (CIM) has negative impact on patient outcomes. We aimed to explore the diagnostic value of bedside ultrasonography for early identification of CIM in septic patients and its correlation with other diagnostic methods. This prospective observational study included 40 ICU patients diagnosed with sepsis on admission or within 48 h later according to the third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). They were evaluated using muscle ultrasound, electrodiagnostic and clinical muscle assessment (Medical Research Council, MRC) at two time points, the first was between days 2 and 5 and the second was between days 10 and 15. There was significant deterioration of neuromuscular function between the two evaluation points demonstrated by decline in MRC, abnormal nerve conduction and electromyography (EMG) and increased muscle echogenicity on ultrasonography (P ≤ 0.001). Sepsis-Related Organ Failure Assessment (SOFA) score significantly correlated with different neuromuscular assessment tools. MRC had significant correlation with myopathic EMG (P ≤ 0.001, r = − 0.869) and increased muscle echogenicity (P ≤ 0.001, r = − 0.715). Abnormal ultrasonographic muscle architecture had sensitivity of 100%, specificity of 75% and positive likelihood ratio of 4 in detecting muscle dysfunction compared to myopathic EMG. Bedside peripheral muscle ultrasound echogenicity grade could be used as an additional screening test in ICU septic patients for early detection of CIM.