Which of the following findings is most indicative of a retroperitoneal bleed?

• A. Drop in hematocrit
• B. Increase in hematocrit
• C. Normal vital signs
• D. Stable hemoglobin

Answer: (A)

The main idea here is that hidden or occult bleeding often reveals itself most reliably through a fall in hematocrit. When blood leaks into the retroperitoneal space, red blood cells are lost from the circulating volume, and over time the proportion of red cells in the blood decreases. This drop in hematocrit reflects actual blood loss even if the patient’s blood pressure or pulse remains temporarily stable due to compensatory mechanisms. An increase in hematocrit would point away from bleeding (it suggests hemoconcentration or dehydration). Normal vital signs can occur despite ongoing retroperitoneal bleeding, and hemoglobin can lag behind hematocrit changes, so a stable hemoglobin is not as sensitive an indicator early on.