From the A330 QRH
Unreliable Airspeed check ADR Procedure above FL 250:-
1/ A/P F/D off
2/ A/THR off
3/ PITCH/THRUST 5 deg/CLB
4/ Speedbrakes. Check retracted
5/ Level off for troubleshooting. Ie set about 2.5 nose up and 78% N1 or if you have time check the sev turb attitude and N1 from the QRH.