Diagnosis:

• There is no consensus on the definition of hyperkalemia, some define it as any K level > 5, and some as any K level ≥ 5.5 meq/L.

• All patients with hyperkalemia should get an immediate 12-lead EKG.

• If the EKG is normal or similar to the baseline EKG, as some patients may have abnormal EKG to start with, is there any reason for the patient to have hyperkalemia:
  • Renal failure
  • Potassium supplements
  • Drugs known to cause hyperkalemia

• If no EKG changes and no reason for the patient to develop hyperkalemia, then the potassium should be rechecked before any treatment is provided.

• Potassium concentration can be artificially high secondary to:
  •  Hemolysis in the blood tube related to the blood drawing techniques.
  • Severe leukocytosis (WBC>50K)
  • Thrombocytosis (Plt >1M).

• If there’s any Hyperkalemia-related EKG, initiate treatment immediately, this is a true hyperkalemia

Hyperkalemia-induced EKG changes:

• Wide complex tachycardia.
• STEMI elevation mimicking STEMI.
• Bradyarrhythmias: High-grade AV blocks, sinus bradycardia, high-grade AV block with slow junctional and ventricular escape rhythms, slow AF.
• BBB and fascicular blocks.
• Peaked T wave.
• P wave widening/flattening, PR prolongation.
• Sine waves.
• Any bizarre-looking EKG or an EKG with changes that don’t make sense should make you think of hyperkalemia.
• Hyperkalemia-induced EKG changes don’t necessarily appear in chronological order, and not necessarily all of them appear.

The severity of hyperkalemia:

• Severe:
  • The presence of Hyperkalemia-induced EKG changes regardless of K level.
  • K => 6.5 meq/L
• Moderate:
  •  K 6 – 6.4 meq/L
• Mild:
  •  K 5.5-5.9 meq/L

Management

• All hyperkalemia patients should placed on telemetry.
• The first step of the management in all hyperkalemic patients, regardless of the severity of Hyperkalemia, is to:
•  Discontinue any potassium supplements including oral, IV, or TPN
• Screen the patient’s medications and stop any medication known to cause hyperkalemia like:
  • Heparin
  • ACE/ARBs
  • K-sparing diuretics
  • Antibiotics (trimethoprim, pentamidine, ketoconazole, IV penicillin G-potassium)
  • NSAIDs
  • Nonselective beta-blockers (e.g., labetalol).
  • Calcineurin inhibitors (cyclosporine, tacrolimus)
  • Digoxin toxicity, succinylcholine.
• The second step is to provide IV calcium for cardiac stabilization when indicated.
• The third step is to shift K intracellularly when indicated
• The fourth step is to eliminate K through the renal route with diuretics or hemodialysis.

The management of mild hyperkalemia

• For Hemodialysis patients, just have nephrology dialyze them.
• For Non-HD patients, a watchful approach is reasonable as long as all sources of potassium are discontinued, and repeat K level in 12-24 hours.
• A more aggressive approach is to give 1-2 doses of IV loop diuretics like furosemide, and then check K 6-12 hours after that.

The management of moderate Hyperkalemia

• For HD patients, have them dialyzed the same day.
• For non-HD patients, eliminating potassium with an IV loop diuretic should be performed:
  •  1-2 doses of IV furosemide (40-80 mg) can be used.
  • Recheck K in 6-8 hours.
  • Monitor urine output

• The patient’s volume status must be assessed before giving IV loop diuretics:
  • Hypovolemic patients should be resuscitated with IVF first, then given IV loop diuretics second.
  • Euvolemic patients should receive IV loop diuretic first followed by IVF to replace the lost volume.
  • Hypervolemic patients should only receive IV loop diuretics.

• Isotonic solution should be used for fluid resuscitation, the patient’s HCO3 level determines the type of isotonic solution:
  • LR or plasmalyte if HCO3 >= 22
  • HCO3 drip If HC03 < 22, HCO3 drip will help restore volume and also it will shift K intracellularly and improve renal K excretion.
• Please avoid using NS in hyperkalemia, NS can lead to normal gap acidosis which can worsen hyperkalemia.
• LR isn’t contraindicated in hyperkalemia, the amount of K in lactated ringer solutions is very small.
• In IVF resuscitation, the fluids should be infused rapidly, this includes HCO3 drip which can be given as fast as 500-1000 ml/hour.

The management  of severe Hyperkalemia 

• The management of severe hyperkalemia consists of:
  • Cardiac stabilization with IV calcium
  • Shifting K intracellularly
  • K elimination from the body
• Remember the chronicity factor, The more chronic the hyperkalemia is the less worrisome it is. A hemodialysis patient whose K is chronically elevated around 6 and has a K of 7 is far less worrisome compared to a patient who has an acutely elevated K of 7, the latter will require immediate treatment, while the first one, may only require a HD session and K restriction.

Cardiac stabilization with IV Calcium:

• IV calcium is available as calcium gluconate or calcium chloride.
  • Peripheral access: 3 grams IV calcium gluconate over 10 minutes.
  • Central access: 1 gram IV calcium chloride over 10 minutes, or slow IV push.
• IV Calcium only lasts for about 30-60 minutes, so we may need to give multiple doses for persistent, dangerous arrhythmias (e.g. ongoing bradycardia with hypoperfusion). Remember Hyperkalemia is more dangerous than hypercalcemia.

Potassium shifting:

Insulin

•  shifts K intracellularly, it must be given IV. please don’t give it SQ.
• We typically give 10 units of IV regular insulin followed by 2 amps of D50 if BS <180, and one amp if BS 180-250, it’s always safer to go in the hyperglycemia rather than hypoglycemia side. Make sure to continue monitoring blood sugar to catch any hypoglycemia early.
• The insulin-induced potassium shift lasts for ~4-6 hours and may need to be repeated if there is a delay to definitive therapy (e.g., diuresis or dialysis).

Beta-2 agonists

• Shift K intracellularly, albuterol or salbutamol are the main ones here, I typically use albuterol if the patient is unstable where I am throwing everything to bring the K down.
• Albuterol-induced K shift is small and lasts for ~2-4 hours.
• You have to give a big dose of 10-20 mg via nebulizer to see this effect, small doses don’t work.
• Epinephrine can be useful in patients with critical hyperkalemia who are hypotensive or bradycardic.

NaHCO3 drip

• • Can help restore volume, shift K intracellularly, and promote K renal excretion
  • It has to be given as a drip, bicarb amps should be avoided because they are hypertonic which can osmotically drive K extracellularly worsening hyperkalemia.
  • It should be used only if there’s metabolic acidosis (HCO3 < 22) and the patient is euvolemic or hypovolemic.
  •  It should be avoided in patients who are volume-overloaded.

• NAHco3 drip cab infused rapidly at 500-1000 ml/hour if used for volume resuscitation.

Elimination of K from the body

• HD patients will require emergent HD.
• In non-HD patients we should give a challenge of an aggressive diuretic regimen,, volume status should be assessed first:
• Hypovolemic patients should be resuscitated with IVF first, then given IV loop diuretics
• Euvolemic patients should receive IV loop diuretic first followed by IVF to replace the lost volume
• Hypervolemic patients should only receive IV loop diuretic
• An isotonic solution should be used for fluid resuscitation, the patient’s HCO3 level determines the type of isotonic solution:
• LR or plasmalyte if HCO3 >= 22
• HCO3 drip if HC03 < 22, HCO3 drip will help restore volume and also it will shift K intracellularly and improve renal K excretion
• In critically ill patients a cocktail of diuretics (Furosemide + Chlorthalidone + Acetazolamide) can be tried:
  • Furosemide 80 mg IV + Chlorothalidone 500 mg IV + Acetazolamide 500 mg IV.
  • The patient should start producing a large amount of urine, if minimal response, call nephrology and prepare for HD.
  • Monitor electrolytes closely every 2-4 hours
  • I don’t recommend using this cocktail if the patient isn’t closely monitored, if the patient is on the floor we may give a high dose of furosemide of 120-200 and again make sure to monitor electrolytes closely.
• Fludrocortisone can be tried here in severe hyperkalemia if recent ACE/ARB use also if recent NSAID or beta-blocker use or adrenal insufficiency 01-0.2 mg po x1.
• Potassium binders like Kayexalate (Sodium polystyrene) or Batiromer have no role in the management of acute hyperkalemia. If a GI binder is to be used, Sodium zirconium 10 mg PO TID can be used.