Is the history and physical exam reliable for the detection of hypervolemia?
The history and physical exam is neither sensitive nor specific for diagnosing hypervolemia. No one exam finding or historical feature is 100% accurate in the determination of volume status. There may be false negatives. A patient with kidney disease or heart failure may not have crackles or edema on exam, yet have significant extracellular volume expansion. Moreover, a patient may have no dyspnea by history, yet still harbor significant pulmonary congestion. Nor are certain physical exam findings entirely specific for hypervolemia (false positives). For instance, a patient may have edema related to venous stasis or pulmonary crackles from atelectasis despite intravascular effective arterial volume depletion. Some physical exam signs are technically challenging and have variable interoperator reliability. Obesity, valvular heart disease, and impaired right heart function make interpretation of jugular venous distention contentious. These difficulties have led to the proliferation of innumerable techniques to aid in assessment of volume status.