Question

A child has been admitted to the pediatric unit with gastroenteritis. Which laboratory finding indicates the child is dehydrated? A. Elevated reticulocyte count B. Elevated white blood cell counts C. Decreased urine-specific gravity D. Elevated hemoglobin and hematocrit

Short answer

The laboratory finding indicating dehydration is D. Elevated hemoglobin and hematocrit.

Step-by-step solution

Understanding Gastroenteritis and Dehydration

Gastroenteritis often leads to dehydration because of the loss of fluids through diarrhea and vomiting. Dehydration will cause the body's blood volume to decrease, leading to a higher concentration of cells and substances within the blood.

Evaluating the Options

We must look for a lab finding that indicates a higher concentration of substances in the blood due to decreased blood volume. This can be reflected in various blood parameters.

Analyzing Laboratory Results for Dehydration

An elevated reticulocyte count (option A) generally indicates increased red blood cell production. Elevated white blood cell counts (option B) could be a response to infection, not necessarily indicative of dehydration. Decreased urine-specific gravity (option C) would suggest dilute urine, not dehydration. Elevated hemoglobin and hematocrit (option D) levels would indicate a higher concentration of red blood cells due to reduced plasma volume, which is a sign of dehydration.

Identifying the Correct Answer

Given these analyses, the laboratory finding that indicates dehydration is elevated hemoglobin and hematocrit (option D), as they reflect the increased concentration of red blood cells in the blood.

Key concepts

Understanding Gastroenteritis

Gastroenteritis, commonly referred to as the stomach flu, is an inflammation of the gastrointestinal tract, involving both the stomach and the small intestine. It often presents with symptoms of diarrhea, vomiting, abdominal pain, and sometimes fever. The illness can be caused by a variety of factors including viruses, bacteria, and parasites.

These symptoms lead to the rapid loss of fluids and electrolytes from the body, which if not properly managed, can result in dehydration. Dehydration in this context is the body's loss of water and salt, which are both critical for normal function. It's particularly concerning in pediatric patients because they have a smaller reserve of bodily fluids compared to adults, which makes them more vulnerable to the effects of fluid loss. For children with gastroenteritis, prompt fluid replacement, often with oral rehydration solutions, is vital to prevent dehydration and its complications.

Recognizing Pediatric Dehydration

Dehydration in children can be difficult to diagnose based on symptoms alone, especially in very young children who may not be able to communicate their needs effectively. However, there are certain signs and laboratory findings that can point towards dehydration. The clinical signs may include dry mucous membranes, decreased tear production, reduced urine output, sunken eyes, and lethargy.

In severe cases, children may present with more alarming signs such as rapid breathing, a rapid heart rate, and cold, discolored hands and feet. Healthcare professionals closely monitor these signs and often turn to laboratory tests for a more precise assessment of a child's hydration status.

Interpreting Laboratory Findings for Dehydration

Laboratory tests play a crucial role in confirming dehydration and assessing its severity. Common lab findings indicating dehydration include elevated hemoglobin and hematocrit levels, as seen in the provided exercise. These levels rise as the plasma portion of the blood decreases while the number of red blood cells remains relatively constant; a condition known as hemoconcentration.

Additionally, urine-specific gravity can be evaluated. An elevation in urine-specific gravity indicates that the kidneys are conserving water to mitigate the effects of dehydration, producing more concentrated urine. This is contrary to the exercise's option C, where a decreased urine-specific gravity would suggest otherwise. Electrolyte imbalances such as elevated serum sodium are also commonly observed with dehydration. By analyzing these lab values, healthcare practitioners can decide on the best course of action to rehydrate the child and address any underlying conditions causing the gastroenteritis.