Many real-world medical applications require timely actions to be taken in time pressured situations. Existing approaches to dynamic decision modeling have provided relatively efficient methods for representing and reasoning, but the process of computing the optimal solution has remained intractable. A major reason for this difficulty is the lack of models that are capable of modeling temporal processes and dealing with time-critical situations. This paper presents a formalism called the time-critical dynamic influence diagram that provide the capability for both temporal and space abstraction. To deal with the time criticality, we exploit the concept of space and temporal abstraction to reduce the computational complexity and propose an anytime algorithm for the solution process. We illustrate through out the paper, the various approaches with the use of a medical problem on the treatment of cardiac arrest.