From the Guidelines
Lactic acid is not a reliable marker to assess dehydration from vomiting and diarrhea. While lactic acid levels can be elevated in severe dehydration due to poor tissue perfusion, they are not specific or sensitive enough for this purpose, as stated in the study by 1. Better assessments for dehydration include clinical signs, such as dry mucous membranes, decreased skin turgor, and sunken eyes, as well as vital signs like tachycardia, hypotension, and orthostatic changes. Additionally, urine specific gravity, BUN/creatinine ratio, and electrolyte abnormalities, particularly sodium, are more relevant indicators of dehydration.
Key Points to Consider
- Lactic acid is more useful for assessing tissue hypoperfusion in shock states, sepsis, or severe cardiac dysfunction rather than routine dehydration, as noted in the study by 1.
- In dehydration from vomiting and diarrhea, monitoring fluid status through clinical assessment, weight changes, urine output, and basic metabolic panels provides more relevant information for management decisions, as recommended by 1.
- Lactic acid may be falsely elevated due to other conditions and medications, further limiting its utility as a primary marker for dehydration assessment.
Clinical Guidelines
The Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea, as outlined in 1, recommend reduced osmolarity oral rehydration solution (ORS) as the first-line therapy for mild to moderate dehydration in infants, children, and adults with acute diarrhea from any cause. Nasogastric administration of ORS may be considered in infants, children, and adults with moderate dehydration who cannot tolerate oral intake.
Management Decisions
In managing dehydration from vomiting and diarrhea, it is essential to prioritize clinical assessment, weight changes, urine output, and basic metabolic panels over lactic acid levels, as these provide more accurate and relevant information for guiding treatment decisions, as supported by the studies 1.
From the Research
Dehydration Assessment
- Dehydration is a significant concern in patients with vomiting and diarrhea, and its assessment is crucial for effective management 2.
- Clinical signs and symptoms are commonly used to assess dehydration, but laboratory studies can also be useful in evaluating dehydration 2, 3.
Lactic Acid as a Marker
- Lactic acid levels can be elevated in patients with dehydration, particularly those with severe dehydration and tissue hypoperfusion 4, 5.
- However, lactic acidosis can have various etiologies, and its presence does not necessarily indicate dehydration 4, 5.
- Measuring lactate levels can be useful in assessing the severity of dehydration and guiding treatment, but it should be interpreted in the context of the patient's overall clinical presentation 4, 5.
Treatment of Dehydration
- Oral rehydration therapy is a common approach to managing dehydration in patients with vomiting and diarrhea 2, 6.
- Intravenous fluids, such as Ringer lactate or normal saline, may be necessary in severe cases of dehydration 6.
- The choice of fluid depends on the patient's clinical status, electrolyte levels, and other factors 6, 3.
Limitations of Lactic Acid as a Marker
- Lactic acid levels can be influenced by various factors, including medication, sepsis, and cardiac arrest 4, 5.
- The utility of lactate as a diagnostic or prognostic tool is limited by its nonspecificity and the presence of other potential causes of elevation 4, 5.
- Therefore, lactic acid should be used in conjunction with other clinical and laboratory parameters to assess dehydration and guide treatment 2, 3.