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Potassium,
parenteral administration
Large doses/sudden infusions of
parenteral potassium can cause cardiac arrest. Therefore, potassium
infusions should be closely monitored by physicians, nurses, and the
pharmacy.
To prevent inadvertent administration of dangerous amounts of
concentrated potassium, all parenteral potassium preparations dispensed
by the pharmacy will be diluted. KCl to be administered via central
line or added to a buretrol will be diluted to a concentration of 1 mEq/5mL
(0.2 mEq/mL.) KCL to be administered via peripheral iv will be diluted
to a concentration of 1 mEq/12.5mL (0.08 mEq/mL.)
In the NICU,
hypokalemia can usually be slowly corrected by adjusting the amount of
K+ in the maintenance IV fluids or TPN running continuously over 24
hours. In cardiac babies, particularly babies on digoxin, serum
potassium concentrations must be closely monitored and hypokalemia
promptly corrected due to the risk of arrhythmias.
Potential ways
to increase potassium intake in the hypokalemic patient
-
For mild
hypokalemia, the potassium concentration (in mEq/kg) in the patient’s
daily TPN or IVF should be increased. Alternatively, in the patient
receiving full enteral nutrition, diluted oral potassium supplements
may be added to feeds.
-
For patients with more severe hypokalemia whose
electrolyte intake needs to be increased before new TPN could be
ordered, small amounts of additional potassium may be added to the
buretrol.
WizOrder
allows for either 1 or 2 mEq of
additional KCl to be added to 100mL in the buretrol (thereby
increasing the amount of potassium in the fluid by either 10 or 20 mEq/L.)
When ordering, the physician should specify the diluent in which the
pharmacy should send the KCl (D5W, D10W, D20W, or NS.) The dose will
arrive in 5 – 10 ml of volume respectively and should be added by the
nurse to 95 or 90 ml in the buretrol to achieve the appropriate
concentration. The buretrol should then be carefully labeled with the
new amount of potassium infusing.
-
Rarely, for
life-threatening hypokalemia, a potassium bolus infusion (“K-run”) may
be considered. The dose is 0.5 mEq/kg (maximum dose of 10 mEq)
running no faster than 0.5 mEq/kg/hr (minimum infusion time over 1 – 2
hours). Again, the pharmacy will dispense the dose diluted to either
1 mEq/5mL for a central infusion or 1 mEq/12.5mL for a peripheral
infusion. Due to
the potential for serious complications with K-runs, correction of
hypokalemia by adding potassium to the buretrol is preferred.
Attending approval is required before ordering a K-run.
MAXIMUM CONCENTRATIONS OF POTASSIUM IN INFUSIONS
|
TYPE OF
INFUSION |
MAXIMUM
AMOUNT OF KCL |
|
Central TPN |
200 mEq/L |
|
Peripheral TPN or IVF |
80 mEq/L |
|
Rapid
Infusion (K run) |
10 mEq/ 50mL |
Resolved at the Collaborative Pathways meeting 4/21/03. |