Polyneuropathy of critically ill patients (critical illness polyneuropathy – CIP) and critical illness myopathy (CIM) were till recently relatively omitted nosological units. Recent works indicates their relatively frequent incidence in patients in a critical condition at intensive care units along with the concurrent presence of multiorgan failure (MOF). The objective of the authors’ work who present their own group of 25 patients with clinically significant muscular weakness is to make readers familiar with electromyographic findings (EMG) which indicate the frequent concurrent incidence of CIP and CIM. It is however difficult to differentiate these units by standard EMG methods. A new possibility how to differentiate them is the method of direct muscle stimulation. Assessment of the correct diagnosis is essential for assessment of an adequate prognosis and ensuing period and intensity of treatment.

        Key words: polyneuropathies and myopathies of critically ill patients, direct muscle stimulation, multiorgan failure