Transcript Potassium Repletion: IV vs PO

POTASSIUM REPLETION:
IV VS. PO
STEPHANIE SINGSON, PGY2
OUTLINE
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Introduction
Evidence
Guidelines
When to use IV vs. PO
Study Question
Study Results
Discussion
Summary
INTRODUCTION
• Normal serum potassium level: 3.5 and 5.0 mmol/L.
• The daily minimum requirement of potassium is
considered to be approximately 1600 to 2000 mg
(40-50 mmol or mEq).
• More than 20% of hospitalized patients have
hypokalemia (K < 3 .5 mmol/L).
EVIDENCE
• Thomas (1983): The risk of early ventricular fibrillation
in acute myocardial infarction is increased in
patients with serum potassium less than 3.9 mmol/L.
• Leier et al (1994): Serum potassium in heart failure
should be maintained between 4.5-5.0 mmol/l to
minimize the risk of sudden cardiac death.
WHY DO WE REPLETE
K TO 4.0?
• Consensus Guidelines for Potassium Replacement in
Clinical Practice. JAMA, 2000.
• “Patients with heart disease are often susceptible to
life-threatening ventricular arrhythmias […] Such
arrhythmias are associated with heart failure, left
ventricular hypertrophy, myocardial ischemia, and
myocardial infarction (both in the acute phase and
after remodeling)”
• “Maintenance of optimal potassium levels (at least
4.0 mmol/L) is critical in these patients and routine
potassium monitoring is obligatory.”
APPROPRIATE USE OF IV
• Guidelines for the treatment of hypokalemia
recommend the use of oral agents at a moderate
dose, typically between 40 and 200 mmol per day.
• IV potassium preparations are recommended for
treatment of severe cases (K < 2.5) or in
symptomatic patients.
STUDY QUESTION
• What percentage of patients on UCI wards had
their potassium repleted with an IV preparation
while on a diet?
METHODS
• Charts reviewed of all inpatient medicine patients
on Teams A-G for potassium administered on 2/122/13.
• Documented level of K, amount and formulation of
K given on all patients with active oral or tube
feeding orders.
• Contacted UCI inpatient pharmacy for prices on
the various potassium formulations most commonly
used on wards.
COST OF COMMONLY USED
FORMULATIONS
• At UCI Medical Center the cost of IV KCl is almost 34x times more than oral KCl.
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Potassium chloride 10meq tab: 35 cents
Potassium chloride 20meq oral solution: 56 cents
Potassium chloride IV 20meq vial: $2.25
Potassium phosphate IV 4.4meq vial: $16.92
RESULTS
Potassium level
Diet
IV
PO
Both
3.5
Yes
x
3.1
Yes
3.1
Yes
3.4
Yes
3.2
Yes
x
80meq
3.3
Yes
x
40meq
3.3
Yes
x
40meq
3.3
Yes
3.2
Yes
3.8
Yes
x
30meq
3.4
Yes
x
40meq
3.9
Yes
3.0
Yes
x
40meq
3.3
Yes
x
40meq
3.4
Yes
x
80meq
3.6
Yes
x
40meq
3.2
Yes
3.4
yes
2.4
Yes
3.5
Yes
x
40meq
3.4
Yes
x
20meq
3.6
Yes
x
20meq
3.1
yes
40meq
x
x
60meq
40meq
x
40meq
x
60meq
x
40meq
x
40meq
x
x
x
x
Amount given
60meq
40meq
80meq
40meq
RESULTS
• 24 patients on medicine wards had their potassium
repleted between 2/12-2/13
• All 24 patients had an active diet order: PO or NG
tube feeds
• 9/24 patients were repleted with IV potassium only
• 12/24 patients were repleted with PO potassium
only
• 2/24 patients were repleted with both IV and PO
potassium
• 45.8% of patients received IV potassium while on a
diet
UNNECESSARY COSTS
• 370 mEq of IV potassium given to floor patients on a
diet
• $41.62 spent on IV potassium/ 24 hours
• Extrapolated annual cost: $15,193
DISCUSSION
• Is IV better than PO?
• Is IV faster than PO?
• 10 meq/hr via peripheral line
• Has a discharge ever been delayed because the IV
K order is going to take at least 4 hours to
complete?
LIMITATIONS
• Small sample size n=24
• Unclear why residents chose IV vs PO. A detailed
chart further for EKG changes, symptoms or other
manifestations that would be considered a “severe
case” was not done.
SUMMARY
• Current guidelines recommend K repletion to 4.0 in
patients with heart disease.
• Oral potassium chloride is the preferred agent for
repletion if patient is tolerating a diet.
• Use IV potassium for severe symptomatic cases.
• IV potassium costs 3-4x more than PO.
• Consider adding an additional step on Quest for
potassium repletion options. For example, a box to
check off:
Is IV Potassium indicated
SOURCES
• Cohn JN, Kowey PR, Whelton PK, Prisant L. New Guidelines for Potassium
Replacement in Clinical Practice: A Contemporary Review by the National
Council on Potassium in Clinical Practice. Arch Intern Med. 2000;160(16):24292436. doi:10.1001/archinte.160.16.2429.
• Hemstreet B, Stolpman N et al. Potassium and Phosphorus Repletion in
Hospitalized Patients: Implications for Clinical Practice and the Potential Use of
Healthcare Information Technology to Improve Prescribing and Patient Safety.
Curr Med Research and Opinion.
• Leier CVDei Cas LMetra M Clinical relevance and management of the
major electrolyte abnormalities in congestive heart failure: hyponatremia,
hypokalemia, and hypomagnesemia. Am Heart J. 1994;128564- 574
• Macdonald JE, Struthers AD. What is the optimal serum potassium level in
cardiovascular patients?. J Am Coll Cardiol. 2004;43(2):155-161.
doi:10.1016/j.jacc.2003.06.021.
• Thomas RD. Ventricular fibrillation and initial plasma potassium in acute
myocardial infarction. Postgraduate Medical Journal 1983;59(692):354-356.
• UCI pharmacy
THANKS!