From the Guidelines
Hyperchloremia is primarily caused by excessive chloride intake, often due to the use of 0.9% saline for fluid resuscitation, as well as dehydration, certain medications, and kidney dysfunction, as evidenced by recent studies 1. The condition of hyperchloremia, characterized by elevated chloride levels in the blood, typically occurs when serum chloride exceeds 106-108 mEq/L. This condition often results from various factors, including:
- Dehydration
- Excessive chloride intake, such as from the use of 0.9% saline for fluid resuscitation, which can lead to hyperchloremic metabolic acidosis and electrolyte derangements 1
- Certain medications, such as diuretics
- Kidney dysfunction, which can impair the kidneys' ability to regulate electrolyte balance To address elevated chloride, the primary approach is to treat the underlying cause. For dehydration-related hyperchloremia, increasing fluid intake with water or balanced electrolyte solutions is recommended. If medication-induced, adjusting or discontinuing the causative agent (such as certain diuretics or IV fluids like normal saline) may be necessary. Recent studies have highlighted the importance of choosing the right type of fluid for resuscitation, with the Isotonic Solutions and Major Adverse Renal Events Trial (SMART) showing that the use of balanced fluids can reduce the risk of major adverse kidney events compared to 0.9% saline 1. For severe cases, especially with metabolic acidosis, sodium bicarbonate administration might be considered at doses of 50-100 mEq IV, titrated based on clinical response and laboratory values. Kidney dysfunction requires nephrology consultation and specific management based on the underlying condition. Hyperchloremia is clinically significant because chloride plays a crucial role in acid-base balance, fluid regulation, and nerve function. Excessive chloride can lead to metabolic acidosis, affecting multiple organ systems. Regular monitoring of electrolytes and kidney function is essential during treatment to ensure normalization of chloride levels and prevent complications.
From the Research
Causes of Hyperchloremia
The causes of hyperchloremia, or elevated chloride levels, can be attributed to various factors, including:
- Metabolic acidosis, which can be caused by increased endogenous acid production, accelerated loss of bicarbonate from the body, or a primary defect in renal acidification 2
- Dehydration, which can lead to water losses exceeding sodium and chloride losses, resulting in hyperchloremia 3
- Resorption of urine from an ileal conduit, as seen in a case report of a patient who underwent ileal conduit reconstruction 4
- Sepsis, which can lead to hyperchloraemia due to underlying diseases or medical interventions 5
- Normal anion gap metabolic acidosis, which can occur due to a variety of conditions, including distal renal tubular acidosis (RTA) or RTA of renal insufficiency 2
- Respiratory alkalosis, which can lead to a concomitant rise in chloride levels 3
Underlying Mechanisms
The underlying mechanisms of hyperchloremia involve alterations in the body's acid-base balance and electrolyte homeostasis, including:
- Changes in fluid balance, which can affect sodium and chloride concentrations 6
- Anion gap metabolic acidosis, which can lower bicarbonate concentrations but not chloride concentrations 6
- Strong ion difference (SID), which is the key pH regulator in the body and is affected by the difference between chloride and sodium concentrations 5