A patient has a systolic/diastolic blood pressure of 130/70 mmHg and a cardiac output of 5 L/min. What is his total peripheral resistance?
**Core Concept**
Total peripheral resistance (TPR) is a measure of the resistance offered by the systemic circulation to blood flow. It is an important determinant of blood pressure and is calculated by dividing the mean arterial pressure (MAP) by the cardiac output (CO). TPR is a critical parameter in understanding the hemodynamic profile of a patient, especially in conditions like hypertension, shock, and heart failure.
**Why the Correct Answer is Right**
To calculate TPR, we can use the formula: TPR = MAP / CO. Given that the patient's MAP is approximately 100 mmHg (average of systolic and diastolic pressure) and the cardiac output is 5 L/min, we can plug these values into the formula to calculate the TPR. The correct answer is derived from this calculation.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not provided, skipping this option.
* **Option B:** This option is incorrect because it does not provide a valid calculation for TPR. Without the correct values or formula, it's impossible to determine the TPR.
* **Option C:** This option is incorrect because it does not take into account the correct formula or values for calculating TPR. Without considering the MAP and CO, the TPR cannot be accurately determined.
* **Option D:** This option is incorrect because it does not provide a valid calculation for TPR. Like Option B, it lacks the necessary information or formula to determine the TPR.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that TPR is a dynamic parameter that can change in response to various factors, such as changes in blood volume, cardiac output, or vascular tone. This understanding is crucial in managing patients with hypertension, heart failure, or shock, where TPR plays a critical role in determining the patient's hemodynamic status.
**Correct Answer: C. 20 dyn·s·cm^-5.**