Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Nephrology PPT 3 Electrolyte Imbalance Lecture Notes
Electrolyte Imbalance
Sodium and Water abnormalities
? Hyponatremia- S.Na < 135 meq/l.
? Hypernatremia- S.Na > 145 meq/l.
Tools for evaluation of Hyponatremic patient
? History
Idea about obvious cause and Volume status
? Physical examination
? Lab tests
? S. Osmolality
? U. Osmolality
? Urine electrolytes (Na+, K+, Cl-)
? Response to Isotonic saline volume expansion
Hypernatremia
? S.Na+ > 145 meq/l
? reflects serum hyperosmolarity
? In the normal man, total body water is approximately 60% of body
weight (50% in women and obese individuals). With hyponatremia or
hypernatremia, the change in total body water can be calculated from
the serum Na+ concentration by the following formula:
? Water excess = 0.6W X ( 1 ? [Na+]obs/140 )
? Water deficit = 0.6W X ( [Na+]obs/140 ? 1)
? obs is observed sodium concentration (in mmol/l) and W is body
weight (in kilograms).
Hyperkalemia
? S.K+ > 5.5 meq/L
Hypokalemia
? S.Potassium < 3.5 meq/l
Treatment
? Potassium replacement can be given through the intravenous (IV) or oral
(PO) route.
? Oral or enteral administration is preferred if the patient can take oral
medication and has normal GI tract function.
? When potassium is given intravenously, acute hyperkalemia can occur if
the IV rate is too rapid and can cause sudden cardiac death.
? IV replacement can be given safely at a rate of 10 mmol KCl/h.
? IV administration of 20 mmol KCl typically increases the serum potassium
by about 0.25 mmol/l.
? If more rapid replacement is necessary, 20 or 40 mmol/h can be
administered through a central venous catheter, but continuous ECG
monitoring should be used under these circumstances.
This post was last modified on 07 April 2022