How do you manage acid-base balance in patients with Impaired renal function (kidney disease)?

From the Guidelines

Managing acid-base balance in patients with impaired renal function requires a multifaceted approach focusing on both treatment and prevention of metabolic acidosis, with the cornerstone of management including sodium bicarbonate supplementation and dietary modifications, as recommended by the KDIGO 2024 clinical practice guideline 1. The goal is to maintain serum bicarbonate levels above 22 mEq/L, with sodium bicarbonate supplementation typically starting at 650-1300 mg orally three times daily, and dosage adjustments based on serum bicarbonate levels. For severe acidosis (pH < 7.2 or bicarbonate < 12 mEq/L), intravenous sodium bicarbonate may be necessary. Dietary modifications are equally important, including:

• Reducing protein intake to 0.6-0.8 g/kg/day to decrease acid load
• Increasing consumption of fruits and vegetables which provide alkali precursors
• Avoiding medications that can worsen acidosis, such as NSAIDs and certain antibiotics Regular monitoring of electrolytes, bicarbonate levels, and kidney function is essential, with frequency determined by disease severity. Diuretics like furosemide (20-80 mg daily) may help manage volume overload while potassium-sparing diuretics should be used cautiously due to hyperkalemia risk, as suggested by the espen practical guideline on clinical nutrition in hospitalized patients with acute or chronic kidney disease 1. Additionally, lifestyle interventions such as maintaining a protein intake of 0.8 g protein/kg (weight)/d, restricting sodium intake to <2 g of sodium per day, and undertaking moderate-intensity physical activity for a cumulative duration of at least 150 minutes per week can be beneficial, as recommended by the 2020 kdigo clinical practice guideline on diabetes management in chronic kidney disease 1. These interventions are crucial because chronic metabolic acidosis accelerates kidney disease progression, causes bone demineralization, and promotes muscle wasting, while acute severe acidosis can lead to cardiac arrhythmias and hemodynamic instability. It is also important to educate patients about dietary adaptations regarding sodium, phosphorus, potassium, and protein intake, tailored to their individual needs, and severity of CKD and other comorbid conditions, as suggested by the KDIGO 2024 clinical practice guideline 1. Furthermore, increasing fruit and vegetable intake can yield more benefits than sodium bicarbonate supplementation alone, as shown in a study published in the American Journal of Kidney Diseases 1. Overall, a comprehensive approach to managing acid-base balance in patients with impaired renal function is essential to prevent complications and improve patient outcomes.

From the FDA Drug Label

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From the Research

Managing Acid-Base Balance in Patients with Impaired Renal Function

To manage acid-base balance in patients with impaired renal function, it is essential to understand the role of the kidneys in maintaining electrolyte and acid-base balance. The kidneys play a crucial role in regulating the body's internal environment, and their progressive loss of function can lead to various adaptive and compensatory changes [ 2 ].

Electrolyte Balance Disorders

Electrolyte balance disorders, such as water, sodium, and potassium imbalances, are common in patients with chronic kidney disease (CKD). Water balance disorders can manifest as nocturia and polyuria, while sodium balance disorders can lead to volume depletion or overload [ 2 ]. Potassium balance disorders can result in hyperkalemia, which can be life-threatening [ 2 ].

Acid-Base Disorders

Acid-base disorders, such as metabolic acidosis, are also common in patients with CKD. Metabolic acidosis can lead to bone demineralization, chronic hyperventilation, and muscular weakness [ 2 ]. Treatment of metabolic acidosis consists of administration of sodium bicarbonate and limitation of daily protein intake [ 2 ].

Dietary Management

Dietary management plays a crucial role in maintaining acid-base balance in patients with CKD. A diet rich in fruits and vegetables and low in animal-derived protein can help reduce net endogenous acid production [ 3 ]. Alkali therapy, such as oral administration of alkali salts, can also be effective in treating metabolic acidosis [ 3 ].

Key Considerations

Key considerations in managing acid-base balance in patients with impaired renal function include:

• Monitoring serum electrolyte levels regularly [ 2 ]
• Adjusting fluid intake to prevent water overload or depletion [ 2 ]
• Using diuretics to force natriuresis in volume overload [ 2 ]
• Limiting daily protein intake to reduce net endogenous acid production [ 2 ]
• Providing alkali therapy to treat metabolic acidosis [ 3 ]

Interconnected Relationships

The maintenance of acid-base balance is interconnected with other important physiological functions, such as cell energy metabolism and inflammation [ 4 ]. Understanding these relationships is essential for developing effective management strategies for patients with CKD.