What are the maintenance fluids for treating lactic acidosis?

From the Guidelines

For patients with lactic acidosis, maintenance fluids should consist of isotonic crystalloids such as 0.9% normal saline, administered at a rate of 1-2 mL/kg/hour after initial resuscitation. Avoid lactated Ringer's solution as it contains lactate which could theoretically worsen lactic acidosis, though this concern is largely theoretical. The primary goal is to restore adequate tissue perfusion while addressing the underlying cause of lactic acidosis. Fluid therapy should be guided by frequent reassessment of volume status, with adjustments based on vital signs, urine output, and laboratory parameters.

Key Considerations

• In cases of severe acidosis (pH < 7.1), sodium bicarbonate may be considered at 1-2 mEq/kg IV over 1-2 hours, though its use remains controversial, as suggested by the Surviving Sepsis Campaign guidelines 1.
• Potassium supplementation may be necessary as acidosis correction can lower serum potassium levels.
• Monitoring should include serial lactate levels, arterial blood gases, electrolytes, and renal function tests every 4-6 hours.
• The most important aspect of management is treating the underlying cause, whether it's sepsis, tissue hypoxia, medication effects, or other conditions, as fluid therapy alone will not resolve lactic acidosis without addressing its primary etiology.

Fluid Management

• The use of crystalloid and blood products is essential for the management of patients with suspected acute mesenteric ischemia, as stated in the updated guidelines of the World Society of Emergency Surgery 1.
• In the postoperative period, intravenous fluid therapy is usually unnecessary beyond the day of operation, except for those undergoing upper gastrointestinal and pancreatic procedures, as recommended by the ESPEN expert group 1.
• Fluid restriction resulting in fluid deficit can be as detrimental as fluid excess, leading to decreased venous return and cardiac output, diminished tissue perfusion and oxygen delivery, and increased blood viscosity 1.

Guidelines and Recommendations

• The Surviving Sepsis Campaign guidelines suggest against the use of sodium bicarbonate therapy to improve hemodynamics or to reduce vasopressor requirements in patients with hypoperfusion-induced lactic acidemia with pH ≥ 7.15 1.
• The World Society of Emergency Surgery recommends fluid resuscitation with crystalloid and blood products in patients with suspected acute mesenteric ischemia 1.
• The ESPEN expert group recommends against the administration of early parenteral nutrition alone or parenteral nutrition in combination with enteral feedings in critically ill patients with sepsis or septic shock who can be fed enterally 1.

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. The amount of bicarbonate to be given to older children and adults over a four-to-eight-hour period is approximately 2 to 5 mEq/kg of body weight - depending upon the severity of the acidosis as judged by the lowering of total CO2 content, blood pH and clinical condition of the patient

The use of sodium bicarbonate for maintenance fluids in lactic acidosis is not directly addressed in the provided drug label. However, it provides guidance on the administration of sodium bicarbonate in metabolic acidosis, which may include lactic acidosis.

• The dose of sodium bicarbonate is approximately 2 to 5 mEq/kg of body weight over a period of 4 to 8 hours.
• Therapy should be monitored by measuring blood gases, plasma osmolarity, arterial blood lactate, hemodynamics, and cardiac rhythm 2. It is essential to approach this condition with caution and consider the potential risks and benefits of sodium bicarbonate therapy.

From the Research

Maintenance Fluids for Lactic Acidosis

• The use of maintenance fluids for lactic acidosis is not directly addressed in the provided studies, however, the treatment and management of lactic acidosis are discussed 3, 4, 5, 6, 7.
• According to the studies, the treatment of lactic acidosis focuses on addressing the underlying cause, such as sepsis or tissue hypoxia, and maximizing oxygen delivery to reduce tissue hypoxia 3, 4, 7.
• Buffering agents, such as sodium bicarbonate, have not been shown to improve outcomes in patients with lactic acidosis caused by shock 3, 4, 5.
• The administration of sodium bicarbonate may be considered in certain cases, such as severe acidemia with a pH < 7.2, but its use is not recommended as a routine treatment for lactic acidosis 4, 5.
• Other therapies, such as selective NHE1 inhibitors, may be considered in the future for the treatment of lactic acidosis, but further research is needed 4.

Key Considerations

• Lactic acidosis can be caused by various factors, including sepsis, tissue hypoxia, and medications 3, 4, 6, 7.
• The severity of lactic acidosis correlates with overall oxygen debt and survival 3.
• Lactate determinations may be useful as an ongoing monitor of perfusion as resuscitation proceeds 3.
• The treatment of lactic acidosis should focus on addressing the underlying cause and maximizing oxygen delivery to reduce tissue hypoxia 3, 4, 7.