Exam 1 Electrolytes Flashcards
Electrolytes effect what
the amount of water in your body
, the acidity of your blood (pH),
your muscle function,
and other important processes.
Sodium range
135-145 mmol/L
Hyponatremia- what happens to water balance
Excess body water compared to total body
– Patient not able to excrete excess water
– Patient looses more salt than water
Hyponatremia causes ***
Non-renal:
– Gastrointestinal: Diarrhea or Vomiting
– Transdermal: Heavy sweating
Renal:
– Thiazide diuretics
– Primary adrenal insufficiency
– Cerebral salt wasting
– Kidney disease
Additional hyponatremia causes
Third spacing
– Bowel obstruction, pancreatitis, sepsis or
•Muscle trauma
•Syndrome of Inappropriate Antidiuretic (SIADH)
•General anesthesia, nausea, pain, stress and
•medications
•Cancers (small cell carcinoma of the lung)
•Diseases of the lung (pneumonia)
•Central nervous system (subarachnoid hemorrhage)
•High water and low solute intake
– Primary polydipsia including MDMA (ecstasy)
– Anorexia
•Heart failure
•Liver failure
•Nephrotic syndrome
Clinical Manifestations: Acute(< 48 hours)
125-130 mmol/L hyponatremia
Nausea
Malaise
Acute clinical manifestations for hyponatremia 115-120 mmol/L
-Headache; lethargy; seizures; coma; respiratory arrest
Clinical Manifestations: Chronic (≥ 48 hours)
– 115-130 mmol/L hyponatremia
Fatigue, nausea, dizziness, gait disturbances, forgetfulness, confusion, lethargy, and muscle cramps
HYPERNATREMIA
•Clinical Manifestations:
158-180 mmol/L
– lethargy, weakness, and irritability, and can
progress to twitching, seizures, and coma
Hypernatremia
Above 180 mmol/L
– high mortality rate, particularly in adults
Hypernatremia treatment
–Hypertonic IVF
– Determine dietary intake and limit
Treat with dialysis, free water
K range
Normal 3.5-5.0 meq/L
- Oral/IV intake
- Stored in cells or excreted in urine
- Normal potassium intake 40-120 meq/day most of which is excreted in the urine.
HYPOKALEMIA
Causes:
•Decreased potassium intake •Increase entry of potassium into cells – Increased extracellular pH – Increased availability of insulin – Chloroquine intoxication •GI losses – Vomiting – Diarrhea – Feeding tube drainage/leakage – Chronic Laxative use/abuse
•Increased urinary sodium losses – Increased exchange sodium for potassium •Diuretics causing polyuria •Amphotericin B •Increased sweat losses •Dialysis/plasmaphoresis
HYPOKALEMIA S&S
Muscle weakness •Muscle cramps Below 2.5 meq/L •Rhabdomyolysis •Myoglobinuria •Cardiac arrhythmias
Fatigue, anorexia, muscle weakness, BP decrease, ileus development, decreased DTR,
Hypokalemia ecg changes
Depression ST segment; decrease in amplitude of the T-wave and an increase in the amplitude of the U wave.
HYPERKALEMIA S&S
•serum potassium concentration is ≥7.0 meq/L with chronic hyperkalemia or possibly at lower levels with an acute rise in serum potassium
•muscle weakness or paralysis
•cardiac conduction abnormalities and cardiac arrhythmias including :
sinus bradycardia, sinus arrest, slow idioventricular rhythms, ventricular tachycardia, ventricular fibrillation, and asystole
HYPERKALEMIA
•CAUSES:
•Reversible causes of renal insufficiency
– hypovolemia
– nonsteroidal anti-inflammatory drugs(NSAIDS)
– urinary tract obstruction (should also consider this in differentials)
– inhibitors of the renin-angiotensin-aldosterone system
•Dietary intake
HYPERKALEMIA TREATMENT
- Loop or thiazide diuretics (As long as the patient is not volume depleted!)
- IV NaCl (If volume depleted)
- Dialysis
Bicarbonate is what
Co2
BICARBONATE(CO2)
•normal range arterial
7.35- 7.45
Bicarbonate serum range
22-28 meq/L
•Acid-base balance is maintained by
pulmonary and renal excretion of carbon dioxide
METABOLIC ACIDOSIS S&S
- Chest pain, palpitations, headache, altered mental status, decreased visual acuity, nausea, vomiting, abdominal pain, muscle weakness, bone pains, Kussmaul respirations ( Rapid deep breathing)
- Extreme acidemia leads to neurological and cardiac complications
METABOLIC ALKALOSIS
•CAUSES:
Kidney ‘s are unable to excrete the excess bicarbonate, usually because of volume depletion
- the desire to retain sodium prevents the excretion of bicarbonate, which would have to occur as sodium or potassium bicarbonate to maintain electroneutrality
- Loop diuretic therapy (Lasix, Torsemide, Bumex)
- Loss of gastric secretions emesis/NG suction
METABOLIC ALKALOSIS S&S
Slowed breathing which can lead to Apnea
•Cyanosis
•Nausea, vomiting, and diarrhea
•Irritability, twitching, confusion, and picking at bedclothes.
•Rapid heart rate, irregular heart beats, and a drop in blood pressure
•Severe cases can lead to convulsions and coma.
MAGNESIUM range
•Normal 1.8-2.5 mg/Dl
Magnesium regulated by what
Parathyroid hormone
Diet
Kidneys
Magnesium competes with
Calcium
an excess of one can lead to excretion of the other.
HYPOMAGNESEMIA
•CAUSES:
•Magnesium intake is less than renal excretion
•Alcoholism
•Poor nutritional intake or malabsorption disease
– Celiac sprue, short bowel syndrome
•Diuretics
•Magnesium-wasting agents
– Amphotericin B, cisplatin, cyclosporin, pentamidine
•Chronic diarrhea
•Chronic use of omeprazole and other PPI
•Uncontrolled Diabetes Mellitus/Hyperglycemia
•Increased calcium intake can cause decrease in Mg absorption
HYPOMAGNESEMIA S&S
Hypocalcemia (40-60% due to diuresis/diarrhea) •Abnormal eye movements •Convulsions/muscle spasms/cramps •Muscle weakness •Anorexia •Refractory Hypokalemia •Cardiac arrest •Coma/death
Increased nm activity/ irritability
HYPERMAGNESEMIA
•CAUSE:
Impaired renal function •Ingestion of magnesium -Epsom salts – accidental poisoning •laxative abuse •Magnesium Citrate / Milk of Magnesia
HYPERMAGNESEMIA S&S
•Can result in Hyperkalemia
•
CNS depression,
somnolence, bradycardia, increased QRS duration, decreased deep tendon reflexes, paralysis
•4.0 mEq/L mg- conduction
hyporeflexia
> 5.0 mEq/L mg conduction
prolonged atrioventricular conduction
•>10 mEq/L mg conduction
omplete heart block
•> 13.0 mEq/L mg conduction
Cardiac arrest
PHOSPHORUS
•Normal range
2.4-4.1 mg/dL
Ph absorbed through
Small intestine
Phosphorus stored in
Bone
Phosphorus regulated by
Kidney regulates to keep homeostasis
– Excess excreted in the urine
•85% phosphorus is found in
Bone
Phosphorus main function
formation of bones and teeth
•
Phosphorus assists with
Assists with using protein for growth, maintenance and repair of cells and tissues
•Works with B vitamins to support – Kidney function – Muscle contractions – Normal heartbeat – Nerve signaling
HYPOPHOSPHATEMIA
CAUSES:
Decreased net intestinal absorption – Inadequate intake – Medications interfering with absorption (antacids with Mg or Aluminum, niacin) – Steatorrhea or chronic diarrhea – Vitamin D deficiency or resistance
Increased urinary phosphate excretion
– Primary and secondary hyperparathyroidism
– Vitamin D deficiency or resistance
– Hereditary hypophosphatemia rickets
HYPOPHOSPHATEMIA
?
Acute movement of extracellular phosphate into the cells
Refeeding Syndrome: increased insulin secretion, particularly during refeeding after starvation anorexia
Acute respiratory alkalosis
Hungry bone syndrome
HYPOPHOSPHATEMIA S&S
- Loss of appetite
- Anemia
- Muscle weakness
- Bone pain
- Rickets in children/Osteomalacia in adults
- Increased susceptibility to infection
- Numbness and tingling in extremities
- Difficulty walking
HYPERPHOSPHATEMIA
•CAUSES:
Phosphate entry into the extracellular fluid exceeds the rate at which it can be excreted
•Tumor lysis syndrome
•Muscle necrosis (rhabdomyolysis)
•Lactic acidosis
•Diabetic ketoacidosis (or severe hyperglycemia alone)
•Ingestion of a large amount of phosphate containing
laxative
Most commonly seen with pts with CKD, also seen with hyperparathyroidism, also associated with hypocalcemia, DKA, injuries that cause muscle damage, high levels of vit D
HYPERPHOSPHATEMIA S&S
- Muscle cramps
- Tetany
- Perioral numbness or tingling
- Bone and joint pain
- Pruritus
- Rash
Normal total calcium
8.5-10.5 mg/dL
•Normal ionized calcium
4.65-5.25 mg/dL
•Factors that influence the calcium concentration
– Parathyroid hormone
– Vitamin D
- Calcium ion
– Phosphate
CORRECTED SERUM CALCIUM
Ca = Serum Ca + 0.8 * (Normal Albumin – Patient Albumin)
•Example:
Serum Ca = 10mg/dL; Albumin 2.0 g/dL
Normal Albumin = 4 g/dL
Corrected Ca = 10 + ( 0.8 (4-2))= 10 + 1.6
= 11.6 mg/dL
If Ca abnormal,
look at albumin levels
If albumin low, do a corrected Ca level
Half ca bound by protein, half unbound
so after being corrected, you may have normal ca
Calcium has inverse relationship to
Phosphorus
HYPOCALCEMIA
•CAUSES:
•Hypoparathyroidism– Ineffective action in the kidney, bone and intestine to normalize the calcium
- Post surgical (parathyroid glands or thyroid gland)
•Hyperparathyroidism (secondary)– PTH is increased in response to low serum calcium concentrations, in an attempt to mobilize calcium from kidney and bone and to increase 1,25-dihydroxyvitamin D production.
•Chronic hypocalcemia occurs when these actions are inadequate to restore the serum calcium to normal.
HYPOCALCEMIA
•CAUSES:
Vitamin D deficiency – Poor intake or malabsorption – Reduced exposure to UV light •Hyperphosphatemia •Acute kidney injury with increased phosphorous intake (oral/enema) •Rhabdomyolysis or tumor lysis
HYPOCALCEMIA S&S
•Neuromuscular irritability •Cardiac – Prolonged QT interval – Hypotension – Heart failure – Arrhythmia
HYPOCALCEMIA S&S
Chronic
– Ectopic calcifications – Extrapyramidal signs – Parkinsonism – Dementia – Subscapular cataract – Abnormal dentition – Dry skin
HYPOCALCEMIA TREATMENT
- Normalize magnesium
- Correct PTH
- Normalize phosphorous
HYPERCALCEMIA
•CAUSES:
- Accelerated bone reabsorption
- Excessive gastrointestinal absorption
- Decreased renal excretion of calcium
~ primary hyperparathyroidism and malignancy are the most common, accounting for greater than 90% of cases
~calcium Values above 13 mg/dL are most likely what
Malignancy
HYPERCALCEMIA S&S
•<12 mg/dl
– asymptomatic, – nonspecific symptoms such as constipation, fatigue, and depression.
Hypercalcemia s/s
12 to 14 mg/dL
– may be well-tolerated chronically
– acute rise to these concentrations may cause marked symptoms, including polyuria, polydipsia, dehydration, anorexia, nausea, muscle weakness, and changes in sensation
•>14 mg/dL
– progression of the above symptoms
HYPERCALCEMIA TREATMENT
•12-14 mg/dl asymptomatic or mildly symptomatic (eg,
Constipation)– does not require immediate treatment.
•> 14 mg/dL– Requires treatment regardless of symptoms
