  We consider an inflationary scenario in the holographic braneworld with a
cosmological fluid occupying the 3+1 dimensional brane located at the
holographic boundary of an asymptotic ADS$_5$ bulk. The contribution of the
boundary conformal field can be represented as a modification of Einstein's
equations on the boundary. Using these effective Einstein equations we
calculate the cosmological perturbations and derive the corresponding power
spectra assuming a general $k$-essence type of inflaton. We find that the
braneworld scenario affects the scalar power spectrum only in the speed of
sound dependence on the slow-roll parameters whereas there is no change in the
tensor power spectrum. This implies that the changes in the spectral indices
appear at the second order in the slow-roll parameter expansion.
