Sonographic evaluation of muscle echogenicity for the detection of intensive care unit – acquired weakness

Background We compared the value of muscle echogenicity assessed by quantitative greyscale analysis (ImageJ) versus the qualitative Heckmatt scale (HS) in muscle ultrasound (MUS) to detect intensive care unit – acquired weakness (ICU-AW).

Methods MUS of eight skeletal muscles was performed at day 3 and 10 after ICU-admission. A Medical Research Council sum score (MRC-SS) <48 defined ICU-AW. The global mean greyscale score (MGS), the global mean z-score (MZS) and the global mean Heckmatt score (MHS) were calculated. The functional outcome after 100 days was assessed by the modified Rankin Scale (mRS) and the Barthel Index (BI).

Results We analysed 652 ultrasound images from 38 ICU patients (18 with and 20 without ICU-AW) and 10 healthy controls. Patients with ICU-AW had a higher MHS at day 10 compared to patients without ICU-AW (2.6 (0.4) vs 2.2 (0.4), p=0.006). The MHS at day 10 (cut-off 2.2) was superior in ROC analysis (AUC: 0.79, p=0.003, sensitivity 86%, specificity 60%) to detect ICU-AW compared to MGS and MZS. Only the MHS correlated with the MRC-SS (r=-0.45, p=0.004), the mRS (r=0.45; p=0.007) and the BI (r=-0.38, p=0.04) at day 100.

Conclusion Qualitative MUS analysis appears to be superior to software-based greyscale analysis of muscle echogenicity to detect ICU-AW.

Publikationsverlauf

Artikel online veröffentlicht:
20. Juni 2022