electrolyte: potassium

what is potassium critical for?

skeletal and cardiac muscle function

how are the levels of potassium influenced?

acid base balance, sodium and magnesium levels

what is the relationship between sodium and potassium?

• sodium and potassium have an inverse relationship with each other

• when serum sodium increases, serum potassium decreases

• when the kidneys hang on to sodium, they excrete potassium (and vice-versa)

• sodium and potassium are not cool with each other

describe the pathophysiology behind hypokalemia

1. deficit potassium intake (rare)

2. excessive potassium excretion

   • increased aldosterone levels lead to sodium (and water) retention

     • since sodium and potassium have an inverse relationship, there is increased renal excretion of potassium in the urine. in response to the fluid volume loss (vomiting, diarrhea, severe burns, etc.) and conditions that cause hyperaldosteronism aldosterone increases

   • vomiting

     • loss of stomach acid can lead to metabolic alkalosis (high blood pH level)

     • the body needs to raise its acidity which is done by having potassium move into cells and swap with hydrogen (will move into the blood)

     • this will fix the plasma pH level but it will lead to decreased serum potassium concentrations

   • diuretic medications

3. shift from extracellular to intracellular space

   • in response to metabolic alkalosis

   • treatment of diabetic ketoacidosis with insulin

     • the mechanisms of insulin getting access to the cell is the mechanisms by which potassium can enter the cell

     • this means that glucose cannot get into the cell which will lead to hypokalemia

what are the clinical manifestations of hypokalemia

• bradycardia

• fatigue, muscle weakness or spasms, depressed or absent deep tendon reflexes

• serum pH abnormalities

• organ dysfunction (body systems)

  • nervous system

  • pulmonary

  • cardiovascular

  • gastrointestinal

  • renal

  • integument

  • musculoskeletal

what is done for clinical management of hypokalemia?

• replace orally if mild and asymptomatic

• IV if severe and symptomatic or NPO

  • NEVER AN IV PUSH, this will result in death

• treat underlying conditions and related fluid and electrolyte imbalances

• reevaluate manifestations and lab data

describe the pathophysiology of hyperkalemia

• renal failure

  • unable to regulate potassium levels through the excretion of urine

• deficit of aldosterone

  • makes you hold onto urine

  • if you have a deficit then you will be excreting a lot of sodium leading to the retention of potassium

• “potassium-sparing” diuretics

  • makes you pee but will spare the potassium and make you hold onto it

• leakage of intracellular potassium into extracellular fluids

• displacement of potassium from cells by prolonged or severe acidosis (often seen in uncontrolled diabetes/severe hyperglycemia)

what are the clinical manifestations of hyperkalemia?

• bundle branch block (BBB; can cause chest pain, palpitations, nausea/vomiting, dyspnea), then ventricular fibrillation (collapse, loss of consciousness, absent pulses); then cardiac arrest (absent cardiac activity, death)

• fatigue, muscle weakness/paralysis, depressed or absent deep tendon reflexes

• acid/base imbalance (tachypnea)

• organ dysfunction (body systems)

what is the clinical management of hyperkalemia?

• glucose and insulin

• treat underlying conditions and related fluid and electrolyte imbalances

• reevaluate manifestations and lab data

describe the pathophysiology behind a chloride imbalance

endocrine, renal, liver dysfunction: associated with fluid and sodium imbalance

what is hyperCl-

a form of metabolic acidosis

what is hypoCl-

a form of metabolic alkalosis

what are the functions are chloride

1. serum osmolarity

2. acid base balance

3. inverse relationship with bicarbonate

what is the clinical management of chloride imbalance

• stop Cl- based fluids

• treat underlying conditions and related fluid and electrolytes imbalances

• reevaluate manifestations and lab data

• consult endocrine, nephrology