Fluid and Electrolyte Balance in Heart Failure Patients

Fluid Management in Heart Failure

In patients with heart failure, a slightly dehydrated state is often preferred to prevent fluid overload.

• Patients are typically restricted to a maximum of 2 liters (or even 1 liter) of fluid intake per 24 hours. This includes all liquids such as water and coffee.

  • Encourage patients to space out their fluid intake throughout the day rather than consuming large amounts at once. This can help manage their fluid balance more effectively.

Input and Output (I/O) Monitoring

Accurate charting of a patient's fluid intake and output is crucial.

• Intake: Record all fluid intake, including oral fluids (e.g., milk cartons) and IV fluids (specifying the volume, e.g., 50 ml or 100 ml). Record all medications and fluids administered intravenously, including the specific type of fluid (e.g., normal saline, lactated Ringer's), the rate of infusion, and the total volume given.

• Output: Track fluid loss through urine (voiding), drains, etc. Record the volume (e.g., 200 cc of urine). In addition to urine and drains, track other sources of fluid loss such as emesis, liquid stool, and blood loss.
  Doctors review I/O records to determine if a patient is net negative (losing more fluid than they're taking in) or net positive (retaining fluid).

• Consistently monitor and document I/O to help health care providers make informed decisions.

Fluid Status Assessment

Doctors use the I/O measurements to assess a patient's fluid status and adjust treatment accordingly.

• 1 ounce of fluid is equivalent to 30 ml. Healthcare providers should correlate I/O data with other clinical assessments, such as daily weights, vital signs, and physical examination findings, to get a comprehensive picture of the patient's fluid status.

Vital Signs and Fluid Status

Vital signs can indicate fluid status, but they may not be the earliest indicators.

• Dehydration: May cause an increased heart rate and decreased blood pressure. Monitor patients at risk for dehydration, such as older adults, infants, and individuals with chronic illnesses, more frequently to detect changes early.

• Orthostatic Hypotension: A drop in blood pressure upon standing, as talked about previously. Educate patients about the signs and symptoms of orthostatic hypotension, such as dizziness, lightheadedness, and blurred vision, and advise them to rise slowly from a lying or sitting position to minimize the risk of falls.

Additional Assessment Techniques

• Mucosal Membranes: Assessed during health evaluations. Assess the oral mucosa for dryness, stickiness, or presence of fissures, which can indicate dehydration.

• Skin Tenting: Pinching the skin to see how quickly it returns to its normal position. Delayed return (tenting) can indicate dehydration. However, this may not be reliable in older adults due to decreased skin elasticity. Consider assessing skin turgor on the forehead or sternum in older adults, as these areas may be less affected by age-related changes in skin elasticity.

• Capillary Refill: Assesses peripheral circulation. Pressing on the nail bed to see how quickly color returns (normal is less than 3 seconds). Delayed capillary refill (greater than 3 seconds) suggests impaired circulation. The cold can affect the vessels, causing them to clamp up. Less blood flow to that periphery. This may cause some variation in testing. Ensure the patient is in a warm environment and avoid testing capillary refill on edematous or injured extremities to improve accuracy.

Sodium (Na)

• Normal Range: 135-145 mEq/L

Hyponatremia (Low Sodium, <135 mEq/L)

Hypervolemic Hyponatremia

Characterized by high fluid volume and low sodium concentration (dilution).

• Causes:

  • Excess water intake

  • Inappropriate ADH secretion (SIADH), causing water retention and sodium dilution

• Symptoms:

  • Headaches

  • Lethargy

  • Confusion

  • Muscle cramps

  • Cell edema

• Treatment: Address the underlying cause of excess fluid (e.g., manage SIADH to promote fluid excretion). Implement interventions to reduce fluid overload, such as fluid restriction, sodium restriction, and diuretic therapy, as prescribed by the healthcare provider.

Hypernatremia (High Sodium, > 145 mEq/L)

Can occur when water is lost without sodium, increasing sodium concentration.

• Mechanism: Cells become dehydrated as water moves out to balance the higher sodium concentration in the vessels, causing cell shrinkage.

• Symptoms:

  • Neuron shrinkage

  • Electrolyte imbalances, leading to neurological issues

• Causes:

  • Fluid overload (excess aldosterone secretion, leading to water and sodium retention)

  • Water loss without sodium loss (e.g., initial stages of sweating)

• Symptoms:

  • Dehydration

  • Thirst

  • Tachycardia

  • Oliguria (infrequent urination)

• Treatment: Administer fluids cautiously to avoid rapid shifts in sodium levels, and monitor serum sodium concentrations frequently during treatment.

Potassium (K)

• Normal Range: 3.5-5.0 mEq/L

• Potassium is crucial for cardiac function.

Hypokalemia (Low Potassium, <3.5 mEq/L)

Administering dextrose, a form of sugar, and insulin may lead to hypokalemia.

• Treatment: If hypokalemia is severe or symptomatic, administer intravenous potassium chloride (KCl) cautiously, monitoring serum potassium levels and cardiac rhythm closely.

Hyperkalemia (High Potassium, > 5.0 mEq/L)

• Causes:

  • Kidney failure

• Symptoms:

  • Numbness

  • Muscle cramps

  • Diarrhea

  • Cardiac changes (arrhythmias)

• Treatment:

  • In severe cases (>7.0), rapid intervention is necessary.

  • Administer dextrose and insulin to shift potassium from vessels into cells.

  • Use Kayexalate to excrete potassium through feces.

  • Dialysis for patients with kidney failure.

• Monitor serum potassium levels frequently, especially in patients with kidney failure or those receiving medications that can affect potassium balance, such as ACE inhibitors, ARBs, and potassium-sparing diuretics.

Calcium (Ca)

• Calcium is important for bone health, nerve function, and clotting.

• Parathyroid hormone (PTH) increases blood calcium levels by removing calcium from bones.

• Calcitonin decreases blood calcium levels by depositing calcium into bones.

• Calcium exists in free and albumin-bound forms.

Hypocalcemia (Low Calcium, <8.5 mg/dL)

• Symptoms: Neuromuscular excitability (e.g., muscle spasms, tetany), cardiac arrhythmias

Hypercalcemia (High Calcium, >10.5 mg/dL)

• Causes:

  • Hyperparathyroidism

  • Cancer

• Symptoms:

  • Muscle weakness (flaccidity)

  • Note: The symptoms for hypercalcemia are generally the inverse of those for hypophosphatemia.

Phosphorus

• Has an inverse relationship with calcium.

• High phosphate, low calcium

• Low phosphate, high calcium

Magnesium

• Magnesium levels tend to correlate with calcium levels.

• High calcium, high magnesium

• Low calcium, low magnesium

Fluid Volume Deficit

A client with a high temperature