What fluids are used to treat a patient with lactic acidosis?

From the Guidelines

For patients with lactic acidosis, balanced crystalloid solutions like lactated Ringer's or Plasma-Lyte are generally preferred over normal saline (0.9% NaCl). Initial fluid resuscitation should begin with 30 mL/kg of balanced crystalloids, administered rapidly for patients with hypoperfusion or shock. Normal saline can worsen acidosis due to its high chloride content, potentially exacerbating the existing acidemia. Despite its name, lactated Ringer's is appropriate even in lactic acidosis because the lactate it contains is metabolized to bicarbonate, helping to correct acidosis rather than worsen it 1. The primary goal of fluid therapy is to improve tissue perfusion and oxygen delivery, addressing the underlying cause of lactic acid production.

Some key points to consider when managing lactic acidosis include:

• Avoiding the use of sodium bicarbonate therapy to improve hemodynamics or reduce vasopressor requirements in patients with hypoperfusion-induced lactic acidemia with pH ≥ 7.15, as suggested by the Surviving Sepsis Campaign guidelines 1
• Monitoring plasma electrolytes and correcting any derangements according to standard guidelines, such as those from the Advanced Paediatric Life Support guidelines 1
• Considering the use of sodium bicarbonate as an adjunct therapy in cases of severe acidosis (pH < 7.1) that is compromising cardiac function, although its use remains controversial 1

It's essential to note that the management of lactic acidosis should be guided by hemodynamic monitoring, with careful attention to avoid volume overload, especially in patients with cardiac or renal dysfunction. The most recent and highest quality study, the Surviving Sepsis Campaign guidelines from 2017 1, provides the best evidence for guiding fluid management in patients with lactic acidosis.

From the FDA Drug Label

In metabolic acidosis associated with shock, therapy should be monitored by measuring blood gases, plasma osmolarity, arterial blood lactate, hemodynamics and cardiac rhythm. Bicarbonate therapy should always be planned in a stepwise fashion since the degree of response from a given dose is not precisely predictable Initially an infusion of 2 to 5 mEq/kg body weight over a period of 4 to 8 hours will produce a measurable improvement in the abnormal acid-base status of the blood. In cardiac arrest, a rapid intravenous dose of one to two 50 mL vials (44.6 to 100 mEq) may be given initially and continued at a rate of 50 mL (44. 6 to 50 mEq) every 5 to 10 minutes if necessary (as indicated by arterial pH and blood gas monitoring) to reverse the acidosis. In less urgent forms of metabolic acidosis, Sodium Bicarbonate Injection, USP may be added to other intravenous fluids

The fluid to use in a patient with lactic acidosis is Sodium Bicarbonate Injection, USP, which can be administered intravenously. The dose is approximately 2 to 5 mEq/kg of body weight over a period of 4 to 8 hours. It can be added to other intravenous fluids. Therapy should be monitored by measuring blood gases, plasma osmolarity, arterial blood lactate, hemodynamics, and cardiac rhythm 2.

From the Research

Fluid Management in Lactic Acidosis

• The choice of fluid in patients with lactic acidosis should be guided by the cause of hypovolemia, cardiovascular state, renal function, serum osmolality, and coexisting acid-base and electrolyte disorders 3.
• Lactated Ringer's infusate should not be given in patients with severe metabolic alkalosis, lactic acidosis with decreased lactate clearance, or severe hyperkalemia 3.
• Crystalloids are the preferred solution for the resuscitation of patients with severe sepsis and septic shock, with balanced crystalloids being a potential alternative to normal saline 4.
• The use of normal saline is implicated with the development of hyperchloremic metabolic acidosis and renal vasoconstriction, making balanced solutions a better choice 3.
• Sodium bicarbonate therapy for lactic acidosis remains controversial, with some studies suggesting its use in severe acidemia, but others recommending against it due to lack of evidence and potential adverse effects 5, 6.

Key Considerations

• Lactate clearance and vasopressor use seem to be predictors for mortality in severe sepsis patients with lactic acidosis 6.
• The pathophysiology of lactic acidosis is complex and involves increased production or decreased removal of L-lactic acid, highlighting the need for a comprehensive understanding of the biochemical and metabolic basis of the condition 7.
• The choice of fluid should be individualized based on the patient's specific needs and clinical context, taking into account the potential risks and benefits of different fluid types 3, 4.