Deißler et al. in their article (1) raise awareness within the medical profession of the important topic of dehydration in older patients, for which they deserve thanks. We have two comments to add to the carefully researched article.

Firstly, it seems to us that in principle, no hard objective criteria exist for the anticipatory detection of dehydration, not even in terms of pathology or anatomy. In sum, it is always a combination of the following factors that enable the—ultimately retrospective—diagnosis:

• A constellation that predisposes to dehydration (among others, increased [pathophysiological] fluid losses or diuretic treatment, insufficient fluid intake)

• Symptoms consistent with dehydration

• Improvement to dehydration by increasing the fluid balance.

Secondly, we remind readers of a method that we regularly use in our hospital for clinically assessing a patient’s volume status—namely, the filling level of the jugular veins.

In this setting, these veins are not to be considered as peripheral in the sense of the article by Deißler et al., but—like the inferior vena cava—as sufficiently central. When considering a separate superior inflow congestion (for example, goiter), only the same limitations apply as in the sonographic determination of the filling level of the inferior vena cava.

In this setting, a jugular pulse at the level of an imaginary horizontal line through the center of the clavicle shows (intravasal) euvolemia. If the filling level is lower, hypovolemia is present. If it is higher then hypervolemia is present—independently of the tilt of the upper body.

This technique was possibly not included in the article because the scientific literature does not include any systematic studies of the association between jugular pulse and fluid balance.

The question of a patient’s hydration status in the above-mentioned sense remains largely pragmatic. We still think, however, that the technique we explained is valuable, because this simple clinical aid can also be used to sensitize nursing staff to the problem of dehydration.