CHAPTER 3


EXPERT INSIGHT


Sodium disorders (hyponatremia and hypernatremia) are most commonly related to fluid imbalances (rather than sodium imbalances), and interdisciplinary collaboration as well as adjustments in PN fluid volume are likely warranted in these cases.


Potassium


Potassium is included in most PN solutions. Higher amounts may be required for individuals with significant GI losses or those receiving medications that reduce potassium levels (especially potassium-wasting diuretics). Lower amounts may be needed for patients with renal impair- ment, who are taking medications that increase potassium levels, or those receiving other sources of potassium. Like other electrolytes, it is important to consider trends in addition to absolute values when dosing potassium.19


potassium levels by approximately 0.1 mEq/ dL, although a patient’s clin- ical conditions and medications must be taken into account. No more than 10 mEq of potassium per 100 mL of PN solution may be provided. In addition, potassium may only be provided at a rate of 10 mEq/ h (for those without cardiac monitoring or with peripheral IV access) or 20 mEq/ h (for those with cardiac monitoring and central IV access).19-21 Appendix for monitoring and repletion strategies.


Refer to the


Chloride and Acetate Sodium and potassium are provided in PN solutions as part of either chlo- ride, acetate, or phosphate salts. Determining which salts to use is based on acid–base balance as well as the need for phosphate administration.


ƒ Chloride is the predominant salt used in PN solutions; however, excess amounts of chloride increase bicarbonate loss through the


kidneys and may contribute to metabolic acidosis.18


ƒ Acetate is a bicarbonate precursor and contributes to increases in serum bicarbonate levels; excess amounts may lead to meta-


bolic alkalosis.18


In general, adding 10 mEq of potassium will increase serum


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