Doctora

EMERGENCIAS DIALITICAS EN PACIENTES CON FALLA RENAL

INJURIA RENAL AGUDA
INTRODUCTION — The management of patients with acute renal failure or acute
kidney injury (AKI) is principally supportive, with renal replacement therapy (RRT)
indicated in patients with severe kidney injury. Multiple modalities of RRT are
currently available. These include intermittent hemodialysis (IHD), continuousrenal
replacement therapies (CRRTs), and hybrid therapies, such as sustained lowefficiency dialysis (SLED). Despite these varied techniques, mortality in patients with
ARF remains high, greater than 50 percent in severely ill patients. (See "Renal and
patient outcomes after acute tubular necrosis".)
The initiation of RRT in patients with AKI prevents uremia and immediate death from
theadverse complications of renal failure. It is possible that variations in the timing of
initiation, modalities, and/or dosing may affect clinical outcomes, particularly survival.
However, there is a paucity of studies in which these issues have been addressed
directly.
The optimal timing, type of modality, and dosing strategy for patients with AKI who
require RRT will be reviewed here. Thedifferent modalities are discussed separately.
(See "Continuous renal replacement therapies: Overview" and "Continuous renal
replacement therapy in acute kidney injury (acute renal failure)"and "Continuous
venovenous hemodiafiltration: Technical considerations" and "Continuous
venovenous hemodialysis: Technical considerations" and"Sustained low efficiency or
extended daily dialysis".)
INDICATIONSFOR AND TIMING OF INITIATION OF DIALYSIS — Accepted
indications for renal replacement therapy (RRT) in patients with AKI generally
include:
 Refractory fluid overload
 Hyperkalemia (plasma potassium concentration >6.5 meq/L) or rapidly rising
potassium levels
 Signs of uremia, such as pericarditis, neuropathy, or an otherwise
unexplained decline in mental status
 Metabolic acidosis (pHless than 7.1)
 Certain alcohol and drug intoxications
As described in the next section, we suggest initiating dialysis prior to the
development of overt symptoms and signs of renal failure due to AKI.
(See'Timing' below.)
The likelihood of requiring RRT is increased in patients with underlying chronic
kidney disease in proportion to the degree of reduction in glomerular filtration rate(GFR) at baseline. This was illustrated in a study that compared the
prehospitalization estimated GFR (from the most recent serum creatinine) in 1746
hospitalized patients who developed dialysis-requiring acute kidney injury with that of
600,820 hospitalized patients who did not [1].
Compared to patients with an estimated baseline GFR greater than 60 mL/min per
1.73 m2, the risk of developingAKI requiring dialysis progressively and significantly
increased with the severity of underlying CKD. The adjusted odds ratios were 1.7,

4.6, and 20.4 for patients with stage 3 (estimated GFR of 30 to 59 mL/min per
1.73m2), 4 (estimated GFR 15 to 29 mL/min per 1.73m2), and 5 CKD (estimated
GFR less than 15 mL/min per 1.73m2), respectively. (See"Overview of the
management of chronic kidneydisease in adults", section on 'Definition and
classification'.)
Timing — Whether initiation of earlier or prophylactic dialysis offers any clinical or
survival benefit is unproven. We suggest initiating dialysis prior to the development of
symptoms and signs of renal failure due to AKI.
When introduced into clinical practice in the 1940s and early 1950s, RRT was used
to principally treat theadvanced symptoms of renal failure [2-4]. Although effective at
reversing the metabolic complications of renal failure, dialysis did not clearly lower
acute mortality [4]. Given the severity of illness and the lack of advanced critical care
medicine during this period, patients acutely died of complications such as infection,
bleeding, and other conditions.
In the 1950s, the concept of...