  The nonlinear theory of two-dimensional ion-acoustic (IA) solitary waves and
shocks (SWS) is revisited in a dissipative quantum plasma. The effects of
dispersion, caused by the charge separation of electrons and ions and the
quantum force associated with the Bohm potential for degenerate electrons, as
well as, the dissipation due to the ion kinematic viscosity are considered.
Using the reductive perturbation technique, a Kadomtsev-Petviashvili Burgers
(KPB)-type equation, which governs the evolution of small-amplitude SWS in
quantum plasmas, is derived, and its different solutions are obtained and
analyzed. It is shown that the KPB equation can admit either compressive or
rarefactive SWS according to when $H\lessgtr2/3$, or the particle number
density satisfies $n_0\gtrless 1.3\times10^{31}$ cm$^{-3}$, where $H$ is the
ratio of the electron plasmon energy to the Fermi energy densities.
Furthermore, the properties of large-amplitude stationary shocks are studied
numerically in the case when the wave dispersion due to charge separation is
negligible. It is also shown that a transition from monotonic to oscillatory
shocks occurs by the effects of the quantum parameter $H$.
