Sodium plays a critical role in the surgical stress response by stabilizing plasma sodium, maintaining extracellular fluid volume, and modulating the renin-angiotensin-aldosterone system (RAAS). These actions prevent complications such as hyponatremia, stabilize blood pressure, and ensure electrolyte homeostasis. Sodium is also essential for immune modulation, impacting macrophage and T cell responses within the interstitial microenvironment, which can enhance immune defense but may also exacerbate inflammation. Adequate sodium intake during surgery, often managed through intravenous fluids, helps optimize fluid and electrolyte balance, mitigate inflammatory responses, and support the RAAS for improved surgical outcomes.

 Mechanisms of Action and Benefits:

• Fluid and Electrolyte Balance: Sodium helps maintain extracellular fluid volume and osmotic balance, considered crucial during surgery to prevent hyponatremia and ensure blood pressure stability.
• RAAS Activation: The renin-angiotensin-aldosterone system is activated under surgical stress, leading to sodium retention and potassium excretion, supporting blood pressure and fluid balance.
• Immune Modulation: Sodium influences immune response by modulating macrophage and T-cell function, enhancing inflammatory response when needed but requiring balance to avoid excess inflammation.
• Supports Inflammatory Control: Proper sodium levels assist in controlling inflammation by supporting circulatory volume and tissue perfusion, aiding the body in managing the stress response effectively.

References:

1. Engquist A, Blichert-Toft M, Olgaard K, Brandt MR, Kehlet H. Inhibition of aldosterone response to surgery by saline administration. Br J Surg. 1978;65(4):224-227. doi:10.1002/bjs.1800650403
2. Strazzullo P, Leclercq C. Sodium. Adv Nutr. 2014;5(2):188-190. Published 2014 March 1.
3. https://www.msdmanuals.com/home/hormonal-and-metabolic-disorders/electrolyte-balance/overview-of-sodium-s-role-in-the-body accessed November 2024