Hope you dont mind my five penneth...new to the site but a pre-retirement background in medical and psychiatric nursing.
Sometimes on over zealous "pulse taker" can quite easily collapse a distal pulse in an elderly person. Usually there are other signs and symptoms for impending problems ie, tingling in the fingers could herald a Raynauds phenomonen or a carpal tunnel syndrome would ellicit quite a degree of pain and swelling. Sclerosing of the artery could be another possibilty. The recieving end of the arterial flow...the hand would possibly give an indication in colour change,temperature and function etc.