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