Electrolyte imbalances/acid-base disturbances

Sodium: Normal range

135-145 mEq/L

Sodium: Hyponatremia range

< 135

Sodium: Hyponatremia pathophysiology

too little in the blood → water moves into the cells → cells swell

Sodium: Hyponatremia causes

• Excess water intake (SIADH)

• Diuretics (thiazides esp.)

• GI loss (vomiting, diarrhea)

• Heart failure, cirrhosis

• Adrenal insufficiency

Sodium: Hyponatremia clinical manifestations

• Neurologic change (confusion (altered mental status)→ seizures if severe(status epilepticus))

• poor skin turgor, dry mucosa

• headache, decreased salivation

• orthostatic bp

• rapid pulse, decreased bp

• nausea, abdominal cramping

Sodium: Hyponatremia management

• Water restriction; replace with sodium as ordered

  • oral, nasogastric, or parenteral route

  • lactated ringers solution or isotonic saline

  • avoid increasing serum by >12 mEq/L in 24 hours

• monitor VS and neuro status (LOC, orientation)

• assess diet and intake

• ensure patient safety

Sodium: Hypernatremia range

> 145

Sodium: Hypernatremia pathophysiology

too much in the blood → water moves out of cells → cells shrink

Sodium: Hypernatremia causes

• fluid deprivation

• inadequate water intake

• excess sodium intake/ hypertonic fluids

• diabetes insipidus

• excessive sweating/fever

• tube feedings without adequate water

Sodium: Hypernatremia clinical manifestations

• thirst

• elevated body temperature

• swollen, dry tongue

• hallucinations

• lethargy

• restlessness

• hyperreflexia

• twitching

• N/V

• tachycardia/hypertension

Sodium: Hypernatremia medical management

gradual lowering of serum levels

infusion of hypotonic solution: 0.45% NaCl

or

infusion of hypotonic nonsaline solution (D5W)

• serum levels are decreased NO FASTER THAN 0.5 to 1 mEq/L/h to ALLOW sufficient time for readjustment through diffusion across fluid compartments

Sodium: Hypernatremia nursing management

• monitor for any neurological issues

• assess for abnormal losses of water or low water intake

• obtain medical history

• observe for any thirst or elevated body temperature

Potassium: normal range

3.5 - 5 mEq/L

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) clinical manifestations

hyponatremia: <135

hypoosmolality: <280

hypervolemia

weight gain

may be associated with lung cancer

serum sodium levels below 110-115; can cause severe and sometimes irreversible neurologic damage

Potassium is critical in:

resting membrane potential; balance essential to prevent cardiac dysrhythmias

Potassium: pathophysiology

• influences neuromuscular and cardiac function

  • alterations affect myocardial irritability and rhythm

  • osmotic integrity, acid base balance, kidney concentration, growth, energy, nerve impulse conduction and muscle excitability

Potassium: Hypokolemia range

<3.5

Potassium: Hypokalemia causes

• GI losses (vomiting, diarrhea, NG suction)

• Diuretics (common cause)

• metabolic alkalosis

• hyperaldosteronism

• poor dietary intake/starvation

• digoxin toxicity risk is high

Potassium: Hypokalemia clinical manifestations

severe: cardiac/resp arrest

prolonged: inability to concentrate urine, glucose intolerance
- dysrhythmias, fatigue, anorexia, muscle weakness, polyuria

Potassium: Hypokolemia ECG changes

flat T waves

Potassium: Hypokolemia medical management

preventive measures: increased dietary intakes and oral supplements

• foods high: fruits, vegetables, legumes, whole grains, milk, meat

IV replacement therapy if severe:

• potassium chloride, acetate, or phosphate

Potassium: Hypokolemia nursing management

• monitor at risk patients for early signs

  • fatigue, anorexia, muscle weakness, decreased bowel motility

• ECG monitoring for digitalis toxicity

• preventive measures

  • encourage this electrolytes rich foods

  • educate on laxative/diuretic misuse

  • monitor fluid I&O, ECG changes, ABG values

Potassium: Hyperkalemia range

>5.0

Potassium: Hyperkalemia pathophysiology

• common in an untreated kidney injury (kidneys are the main way to eliminate this electrolyte)

  • either from infection or excessive electrolyte intake

• hypoaldosteronism/addison disease

  • lack of aldosterone causes sodium loss and potassium retention (holds it)

• acidosis

  • potassium moves from cells to ECF

Potassium: Hyperkalemia clinical manifestations

most significant effect: myocardium

• cardiac conduction disturbances

  • tachycardia → bradycardia → cardiac arrest

• muscle weakness

• arrhythmias

• flaccid paralysis

• intestinal colic

• irritability

• anxiety

Potassium: Hyperkalemia ECG changes

peaked T waves

Hyperkalemia raises resting potential toward threshold, which the cells then:

fire more easily

Potassium: Hyperkalemia medical management

CBIGKID

• calcium gluconate

• bicarbonate

• insulin

• glucose

• kayexalate/lokelma

• IV fluids

• dialysis (last resort for renal failure)

Potassium: Hyperkalemia nursing management

• monitor at risk patients

  • kidney disease, muscle weakness, arrhythmias, parasthesias, GI symptoms

• adhere to this electrolyte restriction

• avoid this electrolytes rich foods

  • fruits, vegetables, legumes, whole grains

• monitor serum potassium, BUN, creatinine, glucose, ABG values

Calcium: normal range

8.5 - 10.5 mg/dL

Calcium: Hypocalcemia range

<8.5

Calcium: Hypocalcemia causes

• hypoparathyroidism, surgical hypoparathyroidism

• pancreatitis

• acute kidney injury

• vitamin D deficiency

Calcium: Hypocalcemia clinical manifestations

• tetany

  • chvostek sign (facial muscle twitching)

  • trousseau sign (carpal spasm with BF cuff inflation

  • parasthesias around mouth

• seizures

• mental changes

• dyspnea

Calcium: Hypocalcemia medical management

acute/severe case: IV calcium salts

• calcium gluconate or calcium chloride

• monitor for digitalis toxicity

nutritional therapy

• vitamin D therapy

• calcium supplements in divided doses

• calcium-rich foods

  • milk products, green leafy vegetables, canned salmon

Calcium: Hypocalcemia nursing management

assess at risk patients

• seizure precautions for severe cases

• monitor airway for laryngospasm

Calcium: Hypercalcemia range

>10.5

Calcium: Hypercalcemia causes

• malignancies

• hyperparathyroidism

• immobilization

• thiazide diuretics

• vitamin A/D intoxication lithium

Calcium: Hypercalcemia clinical manifestations

• muscle weakness

• constipation

• polyuria

• dehydration

• confusion

Calcium: Hypercalcemia management

monitor at risk patients

• increase mobility, encourage fluids

• monitor cardiac rate/rhythm for ECG changes

Magnesium: normal range

1.8 - 3.0 mg/dL

Magnesium: Hypomagnesemia range

<1.8

Magnesium: Hypomagnesemia causes

• associated with hypokalemia and hypocalcemia

• chronic alcohol misuse

• GI loss (NG suct

• diuretics

• DKA

Magnesium: Hypomagnesemia clinical manifestations

• neuromuscular irritability

• positive chvostek/trousseau signs

• apathy, depression, agitation, confusion

• concurrent hypokalemia and hypocalcemia

Magnesium: Hypomagnesemia medical management

mild: correct diet

• green, leafy vegetables, beans, lentils, almonds

severe: IV magnesium sulfate

• monitor VS, urine output

• calcium gluconate for hypocalcemic tetany

• seizure precautions

Magnesium: Hypermagnesemia range

>2.6

Magnesium: Hypermagnesemia causes

• kidney injury/renal failure (aggravated by the electrolyte administration)

• DKA

• excessive administration

• overuse of antacids, laxatives

Magnesium: Hypermagnesemia clinical manifestations

CNS and neuromuscular depression

• respiratory depression

• coma

• heart block

• cardiac arrest

• flushing

• hypotension

• muscle weakness

• drowsiness

• dysrhythmias

Magnesium: Hypermagnesemia medical management

prevent by avoiding this electrolyte in kidney injury

• discontinue parenteral/oral electrolyte salts

emergency

• ventilatory support, IV calcium gluconate

• loop diuretics, sodium chloride, lactated ringers solution

Magnesium: Hypermagnesemia nursing management

monitor at risk patients

• VS, hypotension, shallow respirations

• arrhythmias, bradycardia, heart block

Phosphorus: normal range

2.5 - 4.5 mg/dL

More acidic =

lower pH value

More alkaline =

higher ph level

HCO3 is for:

metabolic

PCO2 is for:

respiratory

PCO2 normal range

35-45 mmHg

Respiratory acidosis range

pH: <7.35

PCO2: > 50mmHg

Respiratory alkalosis range

pH: >7.45

PCO2: < 24 mEq/L

Respiratory acidosis sign

impaired alveolar ventilation

Respiratory alkalosis sign

may be harbinger of serious conditions fever, hypoxemia, shock, sepsis, salicylate toxicity

HCO3 normal range

22-26 mEq/L

Metabolic acidosis range

pH: <7.35

HCO3: < 22mEq/L

low pH, low HCO3

Metabolic alkalosis range

pH: >7.45

HCO3: >26 mEq/l

high pH, high HCO3

Uncompensated

only the main problem is abnormal

ex:

pH: 7.25 (low)

PCO2: 40 (normal)

HCO3: 18 (low)

Partially compensated

system is trying to fix it but the pH is still abnormal

ex:

pH: 7.30 (low)

PCO2: 30 (low)

HCO3: 18 (low)

Fully compensated

normal pH, but PCO2 and HCO3 is abnormal

ex:

pH: 7.36 (normal)

PCO2: 30 (low)

HCO3: 18 (low)

Isotonic IV solution

total electrolyte content between 250 and 375 mEq/L

stays in the ECF (cells stay about the same)

Hypotonic IV solution

total electrolyte content less than 250 mEq/L

into the cell (cells swell)

Hypertonic IV solution

total electrolyte content greater than 375 mEq/L

out of the cell (cells shrink)

Hypotonic IV solutions

• D5W

• 0.45% NaCl (1/2 NS)

• D5 0.45% NaCl

Isotonic IV solutions

• 0.9% NaCl (NS)

• D5 0.9% NaCl (D5NS)

• Lactated Ringers (LR)

Hypertonic IV solution

3% NaCl

For decreased capillary colloidal osmotic pressure, check:

• albumin

• serum calcium (may be falsely low)

Obesity creates a greater risk for dehydration in people because:

Adipose cells contain little water because fat is water repelling

Expect changes in osmolarity with: INCREASE

• hypernatremia

• water deprivation/dehydration

• diabetes insipidus

• hyperglycemia

• hyperosmolar hyperglycemic state (HHS)

• diabetic ketoacidosis (DKA)

• excessive sodium administration

• severe diarrhea

• extensive burns

• mannitol administration

• increased BUN/uremia

Expect changes in osmolarity with: DECREASE

• hyponatremia

• excessive water intake

• SIADH

• hypotonic fluid administration

• primary polydipsia

• adrenal insufficiency

• severe hypothyroidism

• renal failure with impaired water handling

BNP and NT-pro BNP levels are used in which diagnosis and management?

heart failure and cardiac dysfunction

Hypovolemia: contributing factors

loss of water and electrolytes

• vomiting, diarrhea, fistulas, fever, excess sweating, burns, blood loss, gastrointestinal suction, and third-space fluid shifts

decreased intake

• anorexia, nausea, and inability to gain access to fluid

diabetes insipidus and uncontrolled diabetes

Hypovolemia: signs/symptoms

• acute weight loss

• decreased skin turgor

• oliguria

• concentrated urine (less water, more waste/electrolytes, darker)

• capillary filling time prolonged

• low CVP

• low BP

• high pulse

• flattened neck veins

• dizziness, weakness

• thirst, confusion

Hypovolemia: labs indication

• increased hemoglobin/hematocrit

• increased serum/urine osmolality

• increased BUN/creatinine

• increased urine specific gravity and osmolality

• decreased urine sodium

Hypervolemia: contributing factors

compromised regulatory mechanisms

• kidney injury, heart failure, cirrhosis

excess administration. of sodium-containing fluids

fluid shifts

prolonged corticosteroid therapy, severe stress and hyperaldosteronism augment fluid volume excess

Hypervolemia: signs/symptoms

• acute weight gain

• peripheral edema and ascites

• vernacular JVD

• crackles

• elevated CVP

• shortness of breath

• increased BP, bounding pulse

• increased RR

Hypervolemia: labs indication

• decreased hemoglobin/hematocrit

• decreased serum and urine osmolality

• decreased urine sodium and specific gravity

BUN to serum creatinine ration for FVD

>20:1

BUN normal range

7-20

Creatinine normal range

0.6-1.2