Background Aims: The present study investigates the influence of low-dose and short-term administration of corticosteroids and muscle relaxants on the muscular mass (MM) in hemiplegic ICU patients, with the aid of ultrasonography (U/S). Methods: Thirty-seven patients hospitalised in the ICU for 18.6 +/- 3.6 days, were included in the study. Sixteen patients did not receive either drug (group A), five patients received dexamethasone (24 mg/day) for 4 days (group B), eight patients received dexamethasone (24 mg/day) for 4 days and atracurium (0.3-0.6 mg/kg/h) for 2.8 +/- 0.4 days (group C), whereas eight other non-hemiplegic ICU patients comprised the control group. MM was measured in cm by U/S and serum Albumin (ALB, g/l) at the first and the tenth ICU hospitalisation day. The corresponding differences (DeltaMM, DeltaALB) were compared between the four groups of patients. Results: MM and ALB decreased significantly in all groups. AMM was significantly higher in group C in comparison to all other groups, while AMM was also higher in group B, when compared to the control and A groups. DeltaALB did not show significant inter-group differences. A MM was significantly related to patients' age (r=0.41, P=0.001). Conclusions: Muscular atrophy of the ICU hemiplegic patients is significantly influenced by the synchronous treatment with muscle relaxants and corticosteroids at low doses and for short term. This myopathy should be taken into account for the better prognosis and the safer outcome of the patient and U/S is suitable for accurate and non-invasive monitoring of MM. (C) 2002 Published by Elsevier Science Ltd.