Diagnosis of ICU-acquired muscles weakness. On daily clinical examination in the ICU, cognitive function needs to be assessed. Glasgow coma scale (GCS) should be assessed on admission of trauma patients; sedation and agitation level should be evaluated, and delirium screening should be conducted. In patients able to follow commands, manual muscle testing should be conducted, and a normal score (of ≥ 48 using the medical research council scale, 0 to 5, six muscle groups, bilateral testing) and absence of a focal motor deficit confirm the absence of ICU-acquired muscle weakness. Impaired mental status or a low MRC score dictate additional diagnostic workup for ICU-acquired muscle weakness that includes blood tests, point-of-care testing (train-of-four ratio), as well as a spontaneous awakening trial. Persistent neurologic deficit triggers advances imaging of the brain, and electrophysiologic testing (EMG, measurement of nerve conduction velocity) may be considered in patients with persistent, severe muscle weakness of unclear mechanism. CAM = Confusion Assessment Method; CT= computed tomography; EMG = electromyogram; ICU = intensive care unit; MRC = Medical Research Council scale; NMBA = neuromuscular-blocking agent.