Can sepsis-associated acute kidney injury (AKI) present with metabolic alkalosis?

Sepsis-Associated Acute Kidney Injury Typically Presents with Metabolic Acidosis, Not Alkalosis

Sepsis-associated acute kidney injury (AKI) typically presents with metabolic acidosis rather than alkalosis, due to the underlying pathophysiology of sepsis and renal dysfunction.

Pathophysiology of Sepsis-Associated AKI

• Sepsis is characterized by systemic inflammation, microcirculatory dysfunction, and cellular metabolic reprogramming that leads to acute kidney injury through multiple mechanisms 1
• The metabolic hallmark of AKI in sepsis includes protein catabolism, altered amino acid metabolism, peripheral insulin resistance, and impaired lipid clearance 2
• These metabolic derangements typically result in metabolic acidosis due to:
  • Tissue hypoperfusion leading to lactic acidosis 2
  • Impaired renal acid excretion due to kidney dysfunction 2
  • Inflammatory mediators affecting cellular metabolism 2

Acid-Base Disturbances in Sepsis and AKI

• Sepsis-induced hypoperfusion commonly leads to lactic acidosis, not alkalosis 2
• The KDIGO guidelines specifically address the management of metabolic acidosis in AKI, indicating its prevalence in this condition 2
• The Surviving Sepsis Campaign guidelines recommend against the use of sodium bicarbonate therapy for hypoperfusion-induced lactic acidemia with pH ≥ 7.15, highlighting that acidosis (not alkalosis) is the common acid-base disturbance in sepsis 2

Rare Instances of Alkalosis in Sepsis-AKI

• While metabolic alkalosis can occur in critically ill patients, it is not the typical presentation of sepsis-associated AKI 3
• Metabolic alkalosis in critically ill patients is often iatrogenic or due to other concurrent conditions such as:
  • Excessive administration of bicarbonate-containing fluids 4
  • Diuretic therapy 4
  • Massive gastric fluid losses through vomiting or nasogastric drainage 5
  • Hypokalemia 5

Clinical Implications and Management

• Proper identification of the acid-base disturbance is crucial for appropriate management of sepsis-associated AKI 2
• In sepsis-associated AKI, management should focus on:
  • Treating the underlying sepsis with appropriate antimicrobials 2
  • Maintaining adequate renal perfusion with fluids and vasopressors 2
  • Using crystalloids rather than colloids for fluid resuscitation 2
  • Considering renal replacement therapy for severe metabolic derangements 2

Monitoring and Prevention

• Regular monitoring of acid-base status is essential in patients with sepsis-associated AKI 2
• Prevention strategies should focus on:
  • Early recognition and treatment of sepsis 6
  • Avoiding nephrotoxic medications when possible 6, 7
  • Maintaining adequate renal perfusion 2
  • Appropriate fluid management to prevent both hypovolemia and fluid overload 2

Conclusion

While metabolic alkalosis can occasionally occur in critically ill patients, sepsis-associated AKI typically presents with metabolic acidosis due to the underlying pathophysiology of sepsis and impaired renal function. Proper identification and management of acid-base disturbances are crucial for optimizing outcomes in these patients.