38Is Doppler needed? No. Compression is sufficient. Color can sometimes help identify vessels.Doppler can give false normals:eg non-occlusive DVT has normal augmentation.
39Doppler flow info: Augmentation: - squeeze the calf and blood rushes past the probe- implies no obstruction between calf and probeRespiratory phasicity:- flow stops on inhale, goes on exhale- implies no obstruction up in pelvis