\documentclass[a4paper,10pt]{article}
\usepackage[latin1]{inputenc}
\usepackage[italian]{babel}
\usepackage[T1]{fontenc}
\usepackage{pslatex}
\usepackage{tikz}
\usepackage{pgfkeys}

\pgfkeyssetvalue{/dnd/item/acp}{0}
\pgfkeyssetvalue{/dnd/item/name}{test}
\newcommand{\Item}[1]{%
\pgfqkeys{/dnd/item}{acp=0,name=test,#1}%
Name: \pgfkeysvalueof{/dnd/item/name}
ACP: \pgfkeysvalueof{/dnd/item/acp}
}

\begin{document}
\Item{name=prova}

\Item{name=altro,acp=12}
\end{document}
