What vital sign pattern is typical in heat exhaustion?

What vital sign pattern is typical in heat exhaustion?

• A. Tachycardia, hypotension, and dehydration
• B. Hypothermia and bradycardia
• C. Normotension with bradycardia
• D. Hypertension with tachycardia only

Answer: (A)

In heat exhaustion the body loses fluids through sweating, which reduces circulating blood volume. To keep blood flow to essential organs, the heart speeds up, so tachycardia is common. The reduced volume can cause blood pressure to drop, leading to hypotension, and the patient will appear dehydrated. This combination—tachycardia with dehydration and hypotension—best matches the typical pattern seen in heat exhaustion. Other patterns don’t fit as well: hypothermia with bradycardia would point away from heat-related illness; normotension with bradycardia is unlikely since heat exposure and dehydration tend to raise heart rate; hypertension with tachycardia only doesn’t reflect the volume depletion seen in heat exhaustion. Also, core temperature in heat exhaustion is usually normal or only mildly elevated, unlike the marked fever of heat stroke.

In heat exhaustion the body loses fluids through sweating, which reduces circulating blood volume. To keep blood flow to essential organs, the heart speeds up, so tachycardia is common. The reduced volume can cause blood pressure to drop, leading to hypotension, and the patient will appear dehydrated. This combination—tachycardia with dehydration and hypotension—best matches the typical pattern seen in heat exhaustion.

Other patterns don’t fit as well: hypothermia with bradycardia would point away from heat-related illness; normotension with bradycardia is unlikely since heat exposure and dehydration tend to raise heart rate; hypertension with tachycardia only doesn’t reflect the volume depletion seen in heat exhaustion. Also, core temperature in heat exhaustion is usually normal or only mildly elevated, unlike the marked fever of heat stroke.