IV Potassium Administration

IV potassium may be required in patients with marked hypokalemia. However, it should be used with extreme caution. Boluses of potassium may cause severe and potentially fatal rhythm disturbances, so careful monitoring is required. Infiltration of potassium salt-containing solutions can cause severe chemical burns and skin sloughing; thus, central access is important for more concentrated solutions. When possible, oral potassium is preferable to IV potassium. Remember that serum potassium is "the tip of the iceberg", with the majority of the body's potassium stored in cells. Equilibration with serum levels may take several days, so slow replacement is preferable if the patient is stable.

The following guidelines are general in nature. Individual medical centers are likely to have a standing policy with regard to IV potassium administration, and practioners are urged to review those policies before infusing IV potassium.

Procedure
Rational and Key Points
1.  Obtain documented laboratory value prior to drug administration A normal serum potassium level is 3.5 to 5.5 mEq/L.  Maintenance intravenous solutions are designed to maintain a normal range of serum potassium.  Intermittent dose infusions (bolus) of potassium (KCl) are ordered in hypokalemic states where the serum potassium is less than 3.5 mEq/L.
2.  Obtained order from physician.  Order must include: dosage in mEq/kg; rate of infusion; type of solution or diluent; and total volume to administer. Potassium orders should not be accepted if not properly written.  Potassium dosage 2 to 5 mEq/kg/day.
3.  KCl concentrations according to type of IV access.  Concentrations up to a maximum of: 
 
Peripheral Line 80 mEq/L -= 0.08 mEq/cc
*Umbilical Line 1000 mEq/L = 1 mEq/cc in PICU only
Central Line 200 mEq/L = 0.2 mEq/cc on general pediatric ward
Central Line 1000 mEq/L = 1 mEq/cc in PICU only.
 
KCl is stocked in a concentration of 2 mEq/cc.  Never administer potassium by IV push or undiluted.  
 
Example:  If a patient is ordered to receive 10 mEq of KCl via peripheral access, KCl must be further diluted in a total of 125 cc of IV fluid.
*For an umbilical line to be considered central, the tip of the catheter must be above the diaphragm, otherwise treat line as a peripheral line (confirm by x-ray).
4.  All pediatric patients require a cardiac monitor if the infusion of KCl is given over less than 4 hours regardless of the rate, dose or concentraton. Rarely is there a need to administer potassium over less than 4 hours, but on occasion in a critically ill, fluid restricted, hypokalemic patient, KCl may be delivered over 1 hour. 
 
 
Example: 

Cardiac monitor: 0.1 to 1 mEq/kg/hour 
but 
No monitor: 0.5 to 1 mEq/kg over 4 hours.

 
5.  The usual potassium bolus dose for critically ill, fluid restricted, hypokalemic PICU patients is 0.5 to 1 mEq/kg/dose administered over 1 hour.  On the general pediatric ward, 0.5 to 1 mEq/kg over 4 hours. If the patient is more than 40 kg, the maximum amount of potassium that may be given is 40 mEq per dose (This is the maximum adult dose regardless of weight).
Example: 

A 10 kg patient with a central line in the PICU is ordered for 10 mEq KCl.  10 mEq is 5 cc, therefore the KCl is further diluted with 5 cc of diluent for a total volume of 10 cc to be delivered over 1 hour.  Dose equals 1 mEq/kg/dose.  The maximum amount of KCl that this patient can receive in one dose is 10 mEq.

 
6.  All bolus doses of KCl should be administered via a syringe pump.  If volume is greater than 60 cc, infusion should be via a 570 IVAC pump.  After KCl dose is properly diluted, pruse fluid through tubing so infusion can begin immediately.  Tubing should be properly labeled during infusion.  After potassium infusion is complete, flush with standard IV solution over appropriate amount of time. By purging the fluid through the tubing, the infusion can begin immediately.  Tubing should be labeled appropriately, to avoid accidental bolus of medication.  Remember, potassium remains in the tubing post bolus, therefore standard IV solution should be infused at an appropriate rate to clear the tubing of potassium.
7.  Patient in cardiac monitors should be closely monitored for: 
  • EKG changes (i.e., peaked T waves, tachycardia progressing to bradycardia, arrythmias-- V-tachycardia or V-fibrillation; hypotension, heart block, or cardiac arrest.
  • Musculoskeletal: muscle weakness or flaccid paralysis.
  • CNS: Hyperreflexia progressing to weakness and mental confusion.
With hyperkalemia, EKG changes are common.  It is imperative that the nurse observe for these changes and notify M.D. immediately.
8.  Monitor intake and output closely.  If urine output starts to decrease, notify M.D. immediately.  A serum potassium level may be warranted. Remeber to account for volume of fluid administered to a patient on flowsheet.  Potasssium is excreted via the kidneys, therefore a decrease in urine output could increase serum potassium.
9.  Document on appropriate medication record 
  • Amount of drug
  • Administration Route
  • Time and Date
When administering potassium, make sure concentration and dilution does not exceed stated parameters.
10.  Document any adverse effects in the patients condition on the flow sheet, including who was notified, intervention(s) taken, and outcome after intervention.
11.  If KCl is administered via a peripheral intravenous line, assess IV site for: redness, swelling, and tenderness prior to and during infusion q 30 minutes.  If any of these signs are present prior to infusion, do not infuse.  If sign(s) are noted during infusion, stop infusion immediately and obtain another site for access.  Attempt to aspirate catheter.  If unable to aspirate, do not flush, remove catheter.  If infiltration occurs administer wydase (see policy). KCl extravasation can be very severe.  Pain at catheter site or phlebitis may be your only sign of an impending infiltrate.  If IV is questionable, do not infuse KCl bolus or stop infusion if already begun.
12.  If line needs to be interrupted during infusion, aspirate at least 2 cc of blood and discard to prevent rapid infusion of KCl A bolus of KCl can cause cardiovascular collapse.
13.  If patient can tolerate enteral feedings, oral potassium should be considered.  For administration of oral potassium, the physician should include the same information as IV administration in the written orders. Oral potassium absorbs well from the GI tract.  Further dilution of oral potassium is required prior to administrationAdverse reactions: nausea, vomiting, diarrhea, or abdominal cramping.
14.  A verbal order for the admnistration of KCl should not be taken (*see individual hospital policies).
15.  After admnistration of any potassium (KCl) bolus, a serum potassium must be obtained within 30 to 60 minutes.  Do not repeat a bolus dose until the result is obtained form the lab, and the physician is notified. A serum potassium may be obtained before 30 minutes, but may be falsely low.  Blood obtained by peripheral stick or ABG (if patient has an arterial line) is the preferable method.  A serum potassium obtained by heel stick may be falsely elevated, and a peripheral stick warranted for accuracy.
 

References:

Children's National Medical Center (1995-1996).  Choy, F & Carnegie, L (Eds.).  Pediatric Drug Therapy and Formulary Handbook 634:476-479. 

Hamill, RJ, Robinson, LM, Wexler, HR, Moote, C.  1991.  Efficacy and safety of potassium infusion therapy in hypokalemic critically ill patients.  Critical Care Medicine 19(5):694-699. 

Khilnani, P.  1992.  Electrolyte abnormalities in critically ill children.  Critical Care Medicine 20(2):241-250. 

Takemoto, CK, Hodding, JH, Kraus, DM (1996-1997).  Pediatric Dosage Handbook, 3rd. Ed, 562-564. 
 

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Last modification: November 6, 2001