Avaliação ultrassonográfica da musculatura do quadríceps e diafragma de pacientes com sepse

Abstract

Introduction: Septic patients frequently present exacerbated catabolism, persistent systemic inflammation, and loss of skeletal muscle mass, impacting nutritional status, functionality, and prolonging intensive care unit (ICU) stay. Muscle assessment may help characterize these changes, with ultrasonography (US) being a promising tool as it is non-invasive, reproducible, and applicable at the bedside. Serial ultrasonographic measurements of quadriceps muscle thickness, specifically the rectus femoris, as well as diaphragmatic excursion, and the adductor pollicis muscle thickness (EMAP) measured with a skinfold caliper, allow monitoring of muscle degradation and support the definition of therapeutic strategies. Objective: To serially assess quadriceps, rectus femoris, and diaphragm musculature by ultrasonography, and EMAP with caliper in patients with sepsis or septic shock admitted to the ICU. Methods: Prospective observational study conducted between February 2024 and February 2025 in two ICUs of the Hospital das Clínicas of UFMG. Adult patients diagnosed with sepsis or septic shock were included, excluding cases with severe edema, amputations, controlled mechanical ventilation, use of neuromuscular blockers, or expected early death (<24h after inclusion). Evaluations were performed at study inclusion (D1), 72h after the first assessment (D2), and on the seventh day after the first assessment (D3). Clinical and nutritional data were collected (global leadership initiative on malnutrition – GLIM, sequential organ failure assessment – SOFA, microbiological results and blood cultures), in addition to clinical outcomes. Quadriceps, rectus femoris, and diaphragmatic excursion were assessed using ultrasound, while EMAP was measured with a caliper. Data were analyzed longitudinally with appropriate statistical tests for repeated measures. Results: Of the 247 patients screened, 43 were included in this study. Median age was 64 (55–74) years, 58.1% were male, and 51.2% presented malnutrition at study admission. Median (Q1–Q3) ICU length of stay was 9 (6–12) days and hospital stay was 16 (11–34) days. The EMAP thickness decreased by 15.6% (D1–D2) and 28.1% (D1–D3) (p <0.001); quadriceps: decreased by 31.8% (D1–D2) and 42.6% (D1–D3) (p <0.001); rectus femoris: decreased by 25.4% (D1–D2) and 43.0% (D1–D3) (p <0.001). No significant reduction in diaphragmatic excursion was observed during the evaluated days (p = 0.74). Quadriceps loss between D1 and D2 was positively correlated with ICU length of stay (r = 0.345; p = 0.032), and simple linear regression indicated that variation in quadriceps thickness explained 11.9% of the variability in ICU length of stay (F(1,37) = 4.984; p = 0.032). Other muscles showed no significant association with clinical outcomes. Conclusion: Muscle loss in septic patients occurs significantly and early, in the quadriceps and especially in the rectus femoris, as well as in EMAP, during the first seven days of sepsis. Ultrasonography proved to be a safe, practical, and effective method for serial muscle assessment, allowing identification of early deterioration associated with prolonged ICU stay. Muscle mass monitoring may contribute to therapeutic strategies and improved clinical outcomes in these patients. Keywords: Sepsis; Septic Shock; Ultrasonography; Quadriceps; Rectus Femoris; Diaphragm; EMAP; ICU