For IV infusion of drugs (see course notes for more background information), we can assume that the volume delivery in the IV line of the ICU patient is too small to appreciably change the body fluid volume. Then Vbf may be taken as a constant and the differential equation for drug concentration in the plasma reduces to: [S]pl+Vbfkl+km[S]pl=VbfQin[S]lV After prolonged IV administration, a steady state has been reached a) What is the value of the steady state drug concentration [S]ss in the plasma? b) When the IV line is withdrawn and all inputs are zero, give an expression for the time course over which [S]pl will fall. Use [S]ss as the initial condition in your expression. Compare the fall of [S]pl in an adult with that of a child who has a Vbf only 0.2 of that for an adult. Consider kut and ks to be the same in the child and the adult. c) Suppose that the steady state condition is [S]ss=1.5mM, and the therapeutic threshold is 1.0 mM. The value of kl=0.3L/min;km=0.15L/min, and Ybf=50L in an adult and 10L in a child. After the IV line is withdrawn, how long does the drug remain above therapeutic concentration in the adult? In the child