What factor contributes to elevated specific gravity in burn patients post-injury?

In patients who have experienced burns, elevated specific gravity is primarily influenced by dehydration and reduced kidney perfusion. Following a significant burn injury, the body often undergoes a profound inflammatory response, leading to fluid loss through the compromised skin barrier. This loss can result in hypovolemia, which is characterized by a decrease in plasma volume.

As dehydration sets in, the kidneys respond to conserve water, which increases the concentration of urine. This concentration is reflected in a higher specific gravity value. Reduced kidney perfusion occurs due to the overall decrease in circulating blood volume, making the kidneys less able to filter and excrete waste effectively.

In contrast, increased glomerular filtration rate would typically indicate better kidney function and hydration status, leading to a lower specific gravity. Fluid overload from intravenous administration usually results in a dilutional effect, leading to a lower specific gravity as well. Lastly, stable body fluid levels would suggest normal hydration and kidney function, which would not contribute to elevated specific gravity.