N6271 Electrolytes Lecture

Neurological signs of hyponatremia

mental status change, lethargy, siezures, decreased LOC

Normal lab values for magnesium

1.8-3.0 mg/dL

Normal lab value for sodium

135-145 mEq/L

Normal lab values for phosphorus

2.5-4.5mg/dL

Normal lab value for potassium

3.5-5 mEq/L

Normal lab values for calcium

8.5-10.5 mg/dL (serum)

Normal lab values for chloride

97-107 mEq/L

Lab value indicating hypomagnesemia

<1.8 mg/dL

Lab value defining hyponatremia

<135 mEq/L

Lab value indicating hypophosphatemia

<2.5mg/dL

Lab value indicating hypokalemia

<3.5 mEq/L

Hypocalcemic lab value for ionized calcium

<4.6 mg/dL

Lab value indicating hypocalcemia

<8.5 mg/dL

Lab value indicating hypochloremia

<97mEq/L

Lab value indicating hypercalcemia

>10.5 mg/dL

Lab value indicating hyperchloremia

>107mEq.L

Lab value defining hypernatremia

>145 mEq/L

Lab value indicating hypermagnesemia

>3.0 mg/dL

Lab value indicating hyperphosphatemia

>4.5mg/dL

Lab value indicating hyperkalemia

>5 mEq/L

A patient who is semiconscious presents with restlessness and weakness. The nurse assesses a dry, swollen tongue and a body temperature of 99.3°F. The urine specific gravity is 1.020. What is the most likely serum sodium value for this patient?

A.110 mEq/L; B.140 mEq/L; C.155 mEq/L; D.125 mEq/L

A client with pancreatic cancer has the following blood chemistry profile: Glucose, fasting: 204 mg/dl; blood urea nitrogen (BUN): 12 mg/dl; Creatinine: 0.9 mg/dl; Sodium: 136 mEq/L; Potassium: 2.2 mEq/L; Chloride: 99 mEq/L; CO2: 33 mEq/L. Which result should the nurse identify as critical and report immediately?

A.CO2; B.Sodium; C.Chloride; D.Potassium

A client has a serum calcium level of 7.2 mg/dl (1.8 mmol/L). During the physical examination, the nurse expects to assess:

A.Homans' sign; B.Hegar's sign; C.Trousseau's sign; D.Goodell's sign

Important considerations in potassium replacement therapies

ALWAYS VERIFY MOST RECENT LABS, Renal function, IV dose, NEVER GIVEN IV PUSH--DEADLY

Relationship between albumin and calcium

Albumin binds calcium, therfore in cases of weird calcium levels, albumin levels may be informative

Causes of hypomagnesemia

Alcoholism/withdrawal, parenteral nutrition/tube feeds, GI loss, loss of small bowel function, meds

Most symptoms of hyperphosphatemia are related to inverse relationship with __________.

Calcium

Most important consequence of hyperkalemia

Cardiac effects

The major anion of the extracellular fluid

Chloride

Causes of hypochloremia

Chloride produced in stomach, GI tube drainage, N/V, poor absorption, metabolic alkalosis, prolonged dextrose IV, diuretics, burns, fever

Fluid deprevation in those who cannot communicate thirst; hypertonic enteral feedings; watery diarrhea; burns; diabetes; excessive administration of bicarb

Common causes of hypernatremia

Clinical findings of hypermagnesemia

Depressed CNS/resp, low BP, N/V, lethargy, coma, cardiac arrest

Management of hypomagnesemia

Diet change, IV MgSulfate (NO BOLUS), PO MgOxide

Nursing management of hypercalcemia

Encourage mobility, adequate fluids

Causes of hyperkalemia

Excessive intake (esp renal impairment patients), Failure to excrete, Cell injuries, Addison's (hyperaldosteronism), Acidosis, Meds

True or false: minor potassium variations are not concerning

False: even minor variations in potassium are dangerous

Clinical findings in hypokalemia

Fatigue, anorexia, Nausea/vomiting, muscle weakness, leg cramps, decreased bowel motility, arrhythmias, increased sensitivity to digitalis, numbness/tingling, respiratory or cardiac arrest

Causes of hyperchloremia

Follows increased Na, loss of bicarb, and acidosis; increased intake, decreased loss (hyperparathyroidism, hyperaldosteronism, renal failure)

What is important to keep in mind regarding rates when administering IV therapy for hyponatremia?

Give slowly; giving lactated ringers or 0.9% NaCl too quickly can cause rapid water movement out of cells which can be dangerous

Medical management of hypermagnesemia

Hemodialysis (Mg free), Loop Diuretic with NaCl or LR, IV CaGluconate (antagonizes cardio/neuromusc effects)

Causes for artificial hyperkalemic labs

Hemolysis of sample, extreme leukocytosis/thrombocytosis, lab taken during IV potassium infusion

Alcohol withdrawl (specifically) is most commonly associated with which electrolyte deficiency?

Hypomagnesemia

Causes of hypocalcemia

Hypoparathyroidism, Inadequate intake, hypoalbuminemia, malabsorption, renal failure, tissue injury, acute pancreatitis, massive transfusion, meds

Emergency therapies for hyperkalemia

IV CaGluconate, IV NaBicarb, IV insulin and hypertonic dextrose, IV furosemide, Dialysis

Medical management of hypocalcemia

IV calcium (chloride or gluconate), Vitamin D, oral calcium supplements, rule out hypomagnesemia

IV consideration in phosphorus replacement

Infiltration can cause necrosis

This electrolyte produces vasodilation in the peripheral cardiovascular system

Magnesium

The second most abundant intracellular cation

Magnesium (potassium is most abundant)

Causes of hypercalcemia

Malignancy or hyperparathyroidism (almost always), increased activity of osteoclasts, PTH producing tumor, Thiazide diuretics (slight increase), Vitamin D intoxication

EKG finding of hypokalemia

Moderate: flattened T wave; Extreme: Prominent U wave

Clinical findings in hypomagnesemia

Mostly neuromuscular, hyperexcitability with weakness, tremors, and athetoid movements, mood: apathy/depressive, torsade's

Clinical signs of hypernatremia

Neuro: restlessness, weakness, disorientation, delusions; Other signs: Thirst, dry swollen tongue, flushed skin, peripheral and pulm edema, increased deep tendon reflexes

Clinical findings in hypophosphatemia

Neurologic symptoms, tissue anoxia, muscle damage/weakness, Bruising/bleeding, bone changes (on x-ray)

Clinical findings of hypocalcemia

Neuromuscular hyperexcitability (tetany, trousseau's, Chvostek's), Siezures, Mental status changes, Prolonged QT, Dyspnea and stridor

What fraction of serum magnesium is bound to proteins?

One-third (1/3)

Causes of hypophosphatemia

Overexcretion, Underabsorption, Insufficient in diet, diabetic ketoacidosis, Resp. Alkalosis

Which hormones control serum calcium levels?

PTH and calcitonin

EKG findings of hyperkalemia

Peaked, Narrow T waves; ST depression, shortened QT, PR interval elongation and P wave loss; ventricular arrhythmias and cardiac arrest

The major intracellular electrolyte

Potassium

Medications for hyperkalemia

Potassium binders (binds for excretion)

The ultimate goal in the treatment/management of hypophosphatemia

Prevention

What is the relationship between calcium and phosphate?

Reciprocal (inverse)

Clinical findings of hypercalcemia

Reduced neuromusc excitability, severe thirst, excessive urination, mental status changes, shortened QT

Most common cause of hypermagnesemia

Renal failure

Most common cause of hyperphosphatemia

Renal failure

What is important teaching regarding potassium in patients trying to decrease sodium in their diets?

Salt substitutes are often high in potassium (50-60 mEq potassium/tsp)

Clinical findings of hyperkalemia

Skeletal muscle weakness, metabolic acidosis

The most abundant electrolyte in the ECF

Sodium

This elctrolyte plays a major role in water distribution in the body

Sodium

Major long term consequence of hyperphosphatemia

Soft tissue calcification

Why is hypermagnesemia rare?

The kidneys are efficient at secreting magnesium

Synrome associated with chemotherapy that can lead to hyperphosphatemia

Tissue lysis syndrome

True or False: Hyponatremia can be caused by both hypervolemia and hypovolemia

True: Hyponatremia can be casued by hypovolemia due to things such as vomiting, diarrhea, laxative abuse, burns, diuretics, and adrenal insufficiency; hypervolemia due to things such as Heart failure, liver disease, excess water intake, SIADH

True or false: Calcium chloride per IV dose has more calcium than calcium gluconate

True: check dose being given!

True of False: Hypochloremia rarely occurs without other electrolyte imbalances.

True: follos decreased Na and K, and metabolic alkalosis

True or False: Hypocalcemia may be asymptomatic

True: if ionized levels are normal hypocalcemia may be asymptomatic

True or False: clinical signs of hypernatremia are primarily neurological

True: restlessness & weakness; disorientation & delusions

True or False: always recheck extreme potassium levels before treating

True: unnecessary therapy can be deadly

Clinical findings for hypervolemic hyponatremia

edema, crackles, ascites, & JVD

The primary anion of the intracellular fluid

phosphorus

Clinical findings for hypovolemic hyponatremia

poor skin turgor, dry mucus membranes, headache, orthostatic hypotension, nausea,& abdominal cramping