Is chloride increased in dehydration?

From the Guidelines

Yes, chloride levels are typically increased in dehydration. When the body loses water through sweating, vomiting, diarrhea, or inadequate fluid intake, the concentration of electrolytes, including chloride, becomes more concentrated in the blood. This occurs because there is less fluid volume to dilute the electrolytes, resulting in a relative increase in chloride concentration. Normal serum chloride levels range from approximately 96-106 mEq/L, but during dehydration, these levels may rise above this range. The increase in chloride often occurs alongside elevations in sodium and blood urea nitrogen (BUN).

Key Points to Consider

• Dehydration leads to a decrease in fluid volume, causing an increase in electrolyte concentration, including chloride 1.
• Hyperchloremia is usually corrected by appropriate rehydration therapy with intravenous fluids or oral rehydration solutions, which restore proper fluid balance and dilute the electrolyte concentrations back to normal ranges.
• It's essential to consider the overall clinical picture and other electrolyte abnormalities when evaluating a patient's hydration status.
• The management of dehydration involves replacing lost fluids and electrolytes, and the choice of rehydration therapy depends on the severity of dehydration and the patient's clinical condition 1.

Rehydration Therapy

• Oral rehydration solutions (ORS) are recommended for mild to moderate dehydration, while intravenous fluids may be necessary for severe dehydration or when oral rehydration is not tolerated 1.
• The use of isotonic intravenous fluids, such as lactated Ringer's or normal saline, should be avoided in patients with hypernatremic dehydration, as they can exacerbate the condition 1.
• Water with dextrose (e.g., 5% dextrose) is a suitable alternative for rehydration in patients with hypernatremic dehydration, as it provides a low renal osmotic load and can help correct hypernatremia 1.

From the Research

Dehydration and Chloride Levels

• The relationship between dehydration and chloride levels is complex and can vary depending on the severity and type of dehydration.
• A study published in 2005 2 found that hypertonic dehydration is associated with an elevation of chloride >135 mmol/l in the vitreous humor, suggesting that chloride levels may be increased in dehydration.
• However, another study published in 2015 3 found no significant changes in chloride levels after intravenous rehydration in children with mild-to-moderate dehydration.
• Other studies have focused on the treatment of dehydration with different solutions, such as sodium chloride 0.9% and Lactated Ringer's solution 4, and the use of oral electrolyte solutions for the treatment of dehydrated calves 5.
• A study published in 1992 6 found that dehydration does not compromise the efficacy of hypertonic saline/dextran as a resuscitation treatment for hemorrhagic shock, but did not specifically examine the effect of dehydration on chloride levels.

Key Findings

• Chloride levels may be increased in hypertonic dehydration 2.
• Intravenous rehydration may not significantly affect chloride levels in children with mild-to-moderate dehydration 3.
• Different solutions, such as sodium chloride 0.9% and Lactated Ringer's solution, may be used to treat dehydration, but their effects on chloride levels are not well understood 4.