Plasma expanders play an essential role in treating hemorrhage and maintaining stable circulations in critically ill patients. These fluid solutions work to rapidly expand the circulatory plasma volume by drawing fluid into the vascular system from the interstitial spaces and cells. Their usage provides clinicians valuable time to address the underlying cause of hypovolemia while supporting adequate perfusion to vital organs.
Plasma expanders, also known as volume expanders or volume replacement solutions, are intravenous fluids administered to increase plasma volume and intravascular oncotic pressure. They function by acting as plasma substitutes in extracellular fluid, increasing the effective circulatory volume and circulating colloid osmotic pressure. The key classes are synthetic colloids like hydroxyethyl starches (HES) and gelatins along with crystalloid solutions such as saline. Each type has distinct properties affecting volume expansion duration and side effect profiles.
Synthetic colloids
Hydroxyethyl starches (HES) are synthetic starch derivatives that were widely used for plasma volume expansion until safety concerns arose. HES act by increasing oncotic pressure and prolonging expansion effects compared to crystalloids alone. However, they carry risks including kidney injury, bleeding complications, and allergic reactions. Related gelatin solutions offer shorter volume expansion windows but fewer adverse events. Both HES and gelatins must be used carefully in selected patients weighing risks versus benefits.
Crystalloid fluids
Saline (0.9% sodium chloride) is the most common crystalloid fluid used as a Plasma Expander. It provides a rapid yet short-lived increase in circulating volume by distribution throughout total body water. Other crystalloids like lactated Ringer’s solution aim to better mimic electrolyte composition of plasma. While safer than colloids, large volumes of crystalloids are required for equivalent effect and can cause fluid overload if given too quickly or in excess of losses.
Usage considerations
Critical factors in plasma expander selection and administration include the clinical scenario, desired volume expansion window, risks of fluid overload, and individual patient factors like kidney function and bleeding risk. Synthetic colloids provide the longest intravascular persistence but require more careful consideration. Crystalloids alone may suffice for mild-moderate hypovolemia if given in appropriate quantities over time. Goal-directed therapy maximizing clinical response and minimizing complications is paramount.
Monitoring safety and efficacy
When using any plasma volume expander, close monitoring of hemodynamic parameters, urine output, and labs is essential to gauge response and detect potential adverse effects or fluid overload early. Serial hematocrit, BUN, creatinine and electrolyte levels track fluid shifts and renal status. Following administration, urine output normalization, improved perfusion metrics, and stabilization of vital signs generally indicate adequate volume restoration and stable circulation have been achieved. Ongoing re-evaluation guides need for additional boluses or adjustment of fluid regimen.
Special situations and alternatives
In trauma or massive hemorrhage, plasma or packed red blood cells may restore volume more effectively than colloids alone due to replacement of clotting factors and oxygen transport capacity respectively. Albumin, freshly frozen plasma, or combinations with synthetic or natural colloids are options in these critical scenarios. For patients in hemorrhagic shock not yet candidate for transfusion, aggressive crystalloid resuscitation remains standard initial therapy. In septic shock, vasopressors to support blood pressure often complement plasma expander administration.
By expanding plasma volume and supporting cardiac preload, clinically indicated usage of plasma expanders such as colloids or crystalloids is a mainstay intervention to correct and maintain adequate circulation in hypovolemic states from hemorrhage, trauma, sepsis, or other causes. Careful selection, titrated dosing regimens, and vigilant monitoring safeguard against potential adverse effects. Each case requires individualized fluid resuscitation guided by ongoing re-evaluation of hemodynamic status and lab markers. Further research refines best practices for optimizing benefits and minimizing risks associated with these essential volume replacement solutions.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it