PD261 - ASSOCIATION BETWEEN RECTUS FEMORIS ULTRASOUND AND NITROGEN BALANCE IN CRITICALLY ILL PATIENTS

PD261

ASSOCIATION BETWEEN RECTUS FEMORIS ULTRASOUND AND NITROGEN BALANCE IN CRITICALLY ILL PATIENTS

E. Garcia-Velasquez^1,*, O. Bolaños¹ on behalf of Susy Arelis López Laaz, Cecilia Arteaga-Pazmiño

¹Critical Care, Hospital Clinica San Francisco, Guayaquil, Ecuador

Rationale: Skeletal muscle loss is frequent in critically ill patients and is associated with worse clinical outcomes. While muscle ultrasound (MS) and nitrogen balance (NB) are both used in the critical care setting, their use remains controversial.

Methods: We conducted a retrospective cohort study including critically ill patients admitted between July and December 2025. MS was performed using a linear transducer within the first 48 hours of ICU admission. The distance from the anterior superior iliac spine to the superior border of the patella was measured, and the distal third of this length (right leg) was used as the insonation site. The difference in rectus femoris muscle thickness between day 1 and day 3 was also calculated. Nitrogen balance was measured on day 5.

A total of 58 patients met the inclusion criteria; however, only 14 had complete data for all predefined variables and were included in the final analysis (complete-case analysis).

Results: A total of 14 critically ill patients were included. The mean age was 56.0 ± 13.5 years, and 64.3% were male. The mean APACHE II score was 10.3, and the mean SOFA score was 2.4, indicating a population with moderate disease severity, while the mean NRS 2002  was 3.5. The mean rectus femoris ultrasound value was 1.01. The mean nitrogen balance was -6.3, reflecting an overall catabolic state. A moderate negative correlation was shown between RFM with nitrogen balance (ρ = - 0.403; p = 0.041).

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Conclusion: Rectus femoris ultrasound showed a moderate association with nitrogen balance, indicating a potential link with proteic catabolism.  However, due to the limitations of the study further research is needed to confirm its clinical utility for tailored nutritional therapy.

Disclosure of Interest: None declared