Resumen: The definition of a consistent evolution equation for statistical hybrid quantum-classical systems is still an open problem. In this paper, we analyze the case of Ehrenfest dynamics on systems defined by a probability density and identify the relations of the nonlinearity of the dynamics with the obstructions to define a consistent dynamics for the first quantum moment of the distribution. This first quantum moment represents the physical states as a family of classically-parametrized density matrices ρˆ(ξ ), for ξ a classical point; and it is the most common representation of hybrid systems in the literature. Due to this obstruction, we consider higher order quantum moments, and argue that only a finite number of them are physically measurable. Because of this, we propose an effective solution for the hybrid dynamics problem based on approximating the distribution by those moments and representing the states by them Idioma: Inglés DOI: 10.1140/epjp/s13360-023-04266-w Año: 2023 Publicado en: European Physical Journal Plus 138, 7 (2023), 649 [14 pp] ISSN: 2190-5444 Factor impacto JCR: 2.8 (2023) Categ. JCR: PHYSICS, MULTIDISCIPLINARY rank: 31 / 110 = 0.282 (2023) - Q2 - T1 Factor impacto CITESCORE: 5.4 - Physics and Astronomy (all) (Q1) - Fluid Flow and Transfer Processes (Q2)