We think of vital signs as the most objective, reliable, and useful part of the physical exam. Not so for older people! For several reasons older people may not become tachycardic, febrile, or hypotensive when “they’re supposed to!”
- The CNS and CV ability to respond to beta-adrenergic stimulation is markedly decreased with age. Tachycardia may be minimal or absent with physiologic stress;
- The immune system produces fewer cytokines, leukotrienes and other inflammatory markers. A fever may be a very late response to infection (if at all). An infection can certainly exist even with a normal or low temperature;
- The peripheral vasculature is less elastic (“stiff pipes”). Hypotension does not develop until much later in a hypovolemic or septic situation;
- Medications can also alter vital signs. Half of all older people are on beta-blockers so it may not be possible to mount a tachycardia. Many older people take 4 gm of acetaminophen a day, further masking a fever;
- The lower metabolic rate and the fact that older ED patients are usually in bed mean that O2 Saturation is often in the normal range (>92%). A walk test, even brief, may reveal some important changes in saturation.
For example: You see an 80 year old afebrile, normotensive, sinus rhythm, Sat 95%, “Just not herself.”
- Could she have sepsis, pneumonia, peritonitis?