Basic Concepts of Fluid and Electrolyte Therapy

Recovery
The first signs of recovery from oliguric AKI may be an increase in
urine output. Alternatively recovery may be heralded by a reduction in
the rise in the daily serum creatinine followed by a plateau in its value
prior to a fall. Recovery from AKI can result in a polyuric state in some
patients with the production of large urine volumes until the capacity
of the renal tubule to concentrate urine returns. There must therefore
be careful attention to the patient’s volume status and fluid requirements.
Patients can be at risk of developing a free water deficit which manifests
as hypernatraemia and requires an increased intake of water
(intravenous 5% dextrose if unable to take water orally). Failure to
address the free water deficit promptly will not only slow renal recovery
but will also put the patient at risk of neurological complications.
Another potential complication is the development of hypokalaemia,
which requires appropriate therapy due to the risk of cardiac arrythmias
and ileus. A balanced crystalloid containing potassium is recommended
in this clinical context. If further potassium is required consider
infusing dextrose saline (4%/0.18%) with added potassium
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