Classification of neurography in patients of Critical Illness Myopathy and Neuropathy (CRIMYN)

Introduction: Critical Illness Myopathy and Neuropathy (CRIMYN) frequently coexist with severe sepsis and is associated with prolonged weaning from mechanical ventilation and prolonged ICU length of stay. We aimed to classify different levels as well as patterns of impairment with regard to electrophysiological disturbandes in CRIMYN patients by cluster analysis.

Methods: 30 patients [pat.] with sepsis/SIRS were studied prospectively. Motor and sensory conduction studies were performed from six motor and four sensory nerves on a weekly basis from admission until discharge and finally after 6 months. A control group of 63 healthy persons was examined simultaneously at the same. Based on differences to reference values of 20 parameters (compound muscle action potential [CMAP], sensory nerve action potential [SNAP] and motor and sensor conduction velocity [NCV]) different patterns of electrophysiological disturbance were classified by cluster analysis.

Results: Four different clusters were identified: Cluster 1: normal values for CMAP, SNAP and NCV in all nerves (3 pat. and all test persons). Cluster 2: CMAP pathological at the lower extremities, the other parameters are normal (5 pat.). Cluster 3: CMAP, SNAP and sensor NCV at upper and lower extremities and motor NCV at lower extremities moderately pathological (12 pat.). Custer 4: Severe disturbances of CMAP, SNAP and NCV at upper and lower extremities (10 pat.).

Conclusion: Four different clusters of electrophysiological impairment can be identified in patients with sepis/SIRS, which enables further differentiation of the severity of neuromuscular disturbances in sepsis-associated organ failure. This might be used as a prognostic parameter and can be correlated with additional clinical and paraclinical parameters related to sepsis.