Which physiologic mechanism contributes to shock in peritonitis?

• A. Fluid shifts from the bloodstream into body tissues
• B. Intra-abdominal hemorrhage is typically present
• C. Severe pain causes systemic dilation of the vasculature
• D. Abdominal distention impairs cardiac contractions

Answer: (B)

Peritonitis can lead to shock primarily through a loss of circulating blood volume from intra-abdominal bleeding. When there’s bleeding into the abdominal cavity, the effective intravascular volume drops, reducing venous return to the heart and lowering cardiac output, which precipitates hypovolemic shock. Inflammation in the peritoneum does promote fluid shifts and edema, but the immediate, volume-depleting event that drives shock here is hemorrhage into the peritoneal space. The other options describe processes that can occur with peritonitis but are not the principal mechanism causing shock in this scenario.