Ambulance Victoria CPGS Practice Test

Blood pressure is the vital sign most affected by shock due to its direct relationship with the body's circulatory system and the effectiveness of its ability to maintain adequate perfusion to the tissues. In cases of shock, there is a decrease in blood volume, heart function, or vascular tone, leading to impaired circulation. As a result, blood pressure typically drops, reflecting the body’s difficulty in maintaining adequate blood flow.

In contrast, while heart rate and respiratory rate can also respond to shock as compensatory mechanisms — increasing in response to stress and reduced perfusion — they may not change significantly or may even be variable depending on the individual's state. Temperature is generally less impacted in the immediate stages of shock and is typically a more delayed indicator of systemic issues. Understanding that blood pressure is a critical measure in assessing the severity of shock helps guide immediate interventions to restore perfusion and stabilize the patient.