Colloids | Blood Volume Expanders | Albumin | Dextran | Hetastarch |

Colloids are mixtures of large molecules or particles that remain suspended in a liquid, rather than dissolving like crystalloids. In medical contexts, colloids are used as intravenous fluids to expand blood volume and support cardiac output. Types of colloids: 1. Albumin: Derived from human blood, albumin is a natural colloid that expands blood volume and supports cardiac output. 2. Hydroxyethyl Starch (HES): A synthetic colloid made from starch, HES is commonly used to expand blood volume. 3. Gelatins: Derived from animal collagen, gelatins are used as colloids in some countries. 4. Dextrans: Synthetic colloids made from glucose molecules, dextrans are used to expand blood volume. How do colloids work? Colloids work by: 1. Expanding blood volume: Colloids increase blood volume by drawing fluid into the bloodstream. 2. Supporting cardiac output: By expanding blood volume, colloids help maintain cardiac output and blood pressure. 3. Reducing fluid shift: Colloids help reduce fluid shift from the bloodstream to tissues, reducing edema. Advantages of colloids: 1. Rapid volume expansion: Colloids expand blood volume quickly, making them useful in emergency situations. 2. Longer duration of action: Colloids remain in the bloodstream longer than crystalloids, providing sustained volume expansion. Disadvantages of colloids: 1. Allergic reactions: Some patients may be allergic to colloids, particularly those derived from animal sources. 2. Coagulopathy: Colloids can affect blood clotting, increasing the risk of bleeding. 3. Cost: Colloids are generally more expensive than crystalloids. When to use colloids: 1. Hemorrhagic shock: Colloids are useful in emergency situations where rapid volume expansion is needed. 2. Sepsis: Colloids may be used to support cardiac output and blood pressure in septic patients. 3. Burns: Colloids can help manage fluid loss and support cardiac output in burn patients