A study of autonomic cardiovascular reflexes in elderly patients with pneumonia.

People recovering from pneumonia are often weak for no apparent reason. Clinical features such as postural hypotension, arrhythmia and syndrome of inappropriate ADH have, in other circumstances, been attributed to impaired autonomic function. The aim of this study was to see whether elderly patients with pneumonia had impaired autonomic cardiovascular reflexes and, if so, how long this persisted. We compared healthy elderly controls, elderly controls with trauma (fractured femoral neck) and elderly patients with pneumonia. Thirty-eight subjects were studied in a series of cardiovascular autonomic function tests. Results suggest that elderly people have a high prevalence of impaired cardiovascular autonomic reflexes in the immediate post-pneumonic phase, and that this improves significantly after six weeks, with a further improvement by six months. Elderly patients recovering from pneumonia are predisposed to the adverse effects of drugs and other factors which can further impair autonomic cardiovascular reflexes.