Plasma expanders are used in :
**Core Concept**
Plasma expanders are colloidal or crystalloid solutions used to increase the volume of plasma in the circulatory system, thereby improving blood pressure and cardiac output. They are particularly useful in hypovolemic shock, burns, and severe trauma. The primary mechanism of plasma expanders involves increasing the intravascular volume, which in turn enhances blood flow to vital organs.
**Why the Correct Answer is Right**
Plasma expanders work by increasing the oncotic pressure within the vasculature, which attracts more fluid from the interstitial space into the bloodstream. This process is mediated by the movement of water and electrolytes across the capillary endothelium, ultimately leading to an increase in cardiac preload and stroke volume. The most commonly used plasma expanders include albumin, hydroxyethyl starch (HES), and dextran solutions.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incomplete and does not provide a valid answer choice.
**Option B:** Although plasma expanders may be used in sepsis, this option is too broad and does not accurately capture their primary indication.
**Option C:** Plasma expanders are not typically used to treat cardiac failure; rather, they are used to support the circulation in cases of hypovolemia.
**Clinical Pearl / High-Yield Fact**
When selecting a plasma expander, it is essential to consider the patient's underlying fluid status, the severity of the shock, and the potential for complications such as volume overload or coagulopathy.
**Correct Answer:** D. Plasma expanders are used in hypovolemic shock.