Ideal Dry Weight in Dialysis Patients are we there Yet?

Letter to the Editor

One of the difficult tasks to achieve in hemodialysis patients is the ideal dry weight; hence many definitions had evolved during the past few decades.

As early as Hemodialysis began; dry weight was an objective to reach during the evolving therapy. In 1967 Thomson et al, define dry weigh as reduction of BP to hypotensive levels during ultra filtration and not associated with other obvious causes [1]. During 1980th the definition have changed to a more aggressive approach states that dry weight is the weight obtained at the conclusion of a regular dialysis treatment below which the patient is more often will become symptomatic and might go into shock, such an aggressive approach have been abandoned with more rationale definitions in 1990th where again maintain normotensive without antihypertensive medications in between dialysis session marking the ideal dry weight in spite of possible salt and fluid retention [2].

In 2009, Sinha and Agarwal proposed a definition that combines subjective and objective measurements; “The lowest tolerated post dialysis weight achieved via a gradual change in post dialysis weight at which there are minimal signs or symptoms of hypo- or hypervolemia & the patient can remain normotensive until the next dialysis without antihypertensive medication” [3].

Still however some patients develop hypotension while not achieving dry weigh and manifestations of intravascular volume depletion still can occur in patients with volume overload.

Ideal Dry weight then can be achieved when patients having: Shortest post-dialysis recovery time, Least intradialytic hypotension episodes, Longest patient survival, Fewest cardiovascular and cerebrovascular events and hospitalizations, Fewest hypovolemiarelated access thrombosis, and fewest post-dialysis falls [3].

Predialysis hypertension is a major problem and escalation of antihypertensive medications is a usual approach by many nephrologists, however achieving the ideal dry weight and gradual increase in patient ultra filtration till a euovolemic status achieved play a major rule in controlling hypertension in hemodialysis patients.

On the other hand patients developing hypotension or postural drop in blood pressure post dialysis especially if symptomatic with dizziness, easy fatigability, somnolence is a strong indicator of the need to elevate dry weight to a higher target at which such symptoms and findings disappear.

Different approaches have been developed to assess the target dry weight with either clinical or non-clinical procedures as illustrated in (Figure 1).

    

    

    Figure 1:  The target dry weight with either clinical or non-clinical procedures.