Hyperkalemia

Transcellular shifts

• Acidosis, insulin defic. (DM), p-blockers. dig intox.. massive cellular necrosis (tumor lysis, rhabdo. ischemic bowel), hyperkalemic periodic paralysis (Na channelopathy) Decreased GFR

• Any cause of oligo- or anuric acute renal failure or any cause of end-stage renal disease Normal GFR but with i renal K excretion

• Normal aldosterone function (TTKG >7)

i EAV (K excretion limited by 1 distal Na delivery & urine flow): CHF. cirrhosis excessive K intake: in conjunction with impairment in K excretion or transcellular shift

• Hypoaldosteronism (TTKG <7): same as etiologies of Type IV RTA

1 renin: diabetic nephropathy. NSAIDs, chronic interstitial nephritis. HIV normal renin. I aldo synthesis: 1° adrenal disorders. ACEI. ARBs, heparin i response to aldosterone meds: K-sparing diuretics.TMP-SMX. pentamidine, calcineurin inhibitors tubulointerstitial disease: sickle cell. SLE. amyloid, diabetes Clinical manifestations

• Weakness, nausea, paresthesias, palpitations

• ECG: peaked T waves, i PR interval. T QRS width, sine wave pattern. PEA Workup

• Rule out pseudohyperkalemia (IVF with K. hemolysis during venipuncture. T pit or WBC)

• Rule out transcellular shift

• If normal GFR. calculate transtubular potassium gradient (TTKG) - (U* Pk) (U«m P«™)

TTKG >7 normal aldosterone function TTKG <7 — hypoaldosteronism

Treatment of Hyperkalemia

Intervention

Dose

Onset

Comment

Calcium gluconate Calcium chloride*

1-2 amps IV

few min

transient effect stabilizes cell membrane

Insulin

reg. insulin 10 U IV

15-30

transient effect

1-2 amps DwW

min

drives K into cells

Bicarbonate

1-3 amps IV

15-30

transient effect

min

drives K into cells in

exchange for H

02 agonists

albuterol 10-20 mg inh. or 0.5 mg IV

30-90

min

transient effect drives K into cells

Kayexalate1

30-90 g PO PR

1-2 h

1 total body K exchanges Na for K in gut

Diuretics

furosemide -40 mg IV

30 min

I total body K

Hemodialysis

1 total body K

'calcium chloride contains more calcium and is typically reserved for use in codes 'increased risk of intestinal necrosis with postoperative ileus

'calcium chloride contains more calcium and is typically reserved for use in codes 'increased risk of intestinal necrosis with postoperative ileus

• Rote of onset important to note when establishing a treatment plan

• Calcium helps prevent cardiac complications; should be initial Rx. esp. if ECG As

• Insulin, bicarbonate, and 02 agonists should follow to i plasma K

• Treatments that eliminate total body K essential as other Rxs will wear off with time;

kayexalate • diuretics may be effective in many cases, but emergent hemodialysis should be considered in life-threatening situations

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