From the Guidelines
For patients with acute kidney injury (AKI) and metabolic acidosis, the best fluid is typically a buffered crystalloid, such as lactated Ringer's solution or Plasma-Lyte, as it can help mitigate the risk of hyperchloremic acidosis and kidney injury associated with 0.9% saline 1. When managing patients with AKI and metabolic acidosis, it is essential to consider the potential risks and benefits of different fluid types. The use of 0.9% saline has been associated with hyperchloremic acidosis, renal vasoconstriction, and acute kidney injury (AKI) 1. In contrast, buffered crystalloids have been shown to be associated with a lower risk of major adverse kidney events (MAKE) compared to 0.9% saline 1.
Key considerations in fluid management for AKI and metabolic acidosis include:
- Avoiding the use of 0.9% saline due to its potential to cause hyperchloremic acidosis and kidney injury 1
- Using buffered crystalloids, such as lactated Ringer's solution or Plasma-Lyte, as the primary fluid for resuscitation 1
- Monitoring patients closely for signs of fluid overload, hypokalemia, and paradoxical CNS acidosis, particularly when using bicarbonate therapy 1
- Reserving bicarbonate therapy for severe acidosis (pH < 7.1) and using it judiciously to avoid complications 1
Overall, the choice of fluid for patients with AKI and metabolic acidosis should be guided by the principles of minimizing harm and optimizing kidney function, with a preference for buffered crystalloids over 0.9% saline 1.
From the Research
Fluid Management for Acute Kidney Injury (AKI) and Metabolic Acidosis
- The best fluid for managing AKI and metabolic acidosis is not explicitly stated in the provided studies, but certain fluids are associated with a higher risk of developing AKI and metabolic acidosis 2, 3.
- Hypertonic sodium chloride (NaCl) is associated with hyperchloremic metabolic acidosis, renal vasoconstriction, and increased risk of AKI 2.
- Patients receiving large volumes of intravenous hypertonic NaCl are at risk of developing hyperchloremia and AKI, with a higher risk if they receive more than 2055 mEq of chloride over 7 days 2.
- Metabolic acidosis is associated with a higher risk of AKI in patients with chronic kidney disease (CKD) 4, 3.
- Decreased carbon dioxide combining power (CO2CP) in venous blood is an independent risk factor for AKI and hospital mortality in non-respiratory patients 3.
Considerations for Fluid Selection
- The choice of fluid should take into account the patient's underlying condition, such as CKD or neurological injury 2, 4.
- The use of sodium acetate instead of NaCl may be considered to reduce the risk of hyperchloremic metabolic acidosis and AKI 2.
- The strong ion gap (SIG) and apparent strong ion difference (SIDa) values may be useful in predicting mortality in patients with metabolic acidosis and AKI 5.