Ultrasonographic quantification of muscular mass thickness in patients of intensive care unit

Purpose

The aim of this study is to assess the degree of change of upper-arm skeletal muscle thickness in patients of Intensive Care Unit (ICU) and to propose a new method for quantifying this change.

Methods

The thickness of upper-arm biceps was measured twice in 16 female patients (mean age 61.63 ± 8 years) and in 27 male patients (mean age 50.7 ± 9 years) during an ultrasonographic scan by the same ultrasonographer. A 10 MHz frequency, linear high resolution transducer was held longitudinal to the biceps muscle in the place of maximum thickness. All subjects were patients of ICU (13 with multi trauma, 4 with brain injuries, 11 with cerebral sroke, 8 with respiratory insufficiency, 3 with tetraparesis C3-C4 fracture, 3 with hypoxemic engephalopathy and 1 with septic shock) hospitalized for 18.88 ± 3 days. Throughout hospitalization all patients were in parenteral nutritional support with 1800–2400 Kcal/day intake and were also under physical therapy for 60 min/day. Creatine phosphokinase (CPK), Aldolase (Ald) and Albumin (Alb) levels were recorded twice. First measurement was done when patients entered the study and second when they left ICU. Ultrasonographic scans were performed at the same periods of time. Ten of our patients were not under muscle relaxant or drug depression muscle treatment, meanwhile all the others were under muscle relaxant treatment for 4 ± 2, days and under drug depression muscle treatment for 7 ± 3 days.

Results

During the period of our study CPK levels decreased from 2301.26 U/l (mean value, with maximum level 20 000 U/l and minimum level 20 U/l) to 251.21 U/l (mean value, with maximum level 850 U/l and minimum level 30 U/l). Ald levels decreased from 10.39 U/l (mean value, with maximum level 21.15 U/l and minimum level 3.5 U/l) to 7.59 U/l (mean value, with maximum level 18.6 U/l and minimum level 3 U/l), Alb levels decreased from 33.07 g/l (mean value, with maximum level 41.15g/l and minimum level 26 g/l) to 29.56 g/l (mean value, with maximum level 35 g/l and minimum level 24g/l). Fifteen patients showed an increase of 2.714 g/l of the Albumin levels and 28 other patients showed a decrease of 7 g/l of the Albumin levels. Muscle thickness decreased from 2.51 cm (mean value, with maximum level 3.75 cm and minimum level 1.48 cm) to 2 cm (mean value, with maximum level 2.19 cm and minimum level 1.19 cm)

Conclusion

We conclude that long term ICU hospitalization is associated with a gradual decline (0.03 cm/day) in muscular mass. This decline is not CPK, Ald, Alb or physical therapy-dependent.