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When assessing the hemodynamic information for a newly admitted patient in shock of unknown etiology, the emergency department nurse will anticipate the administration of large volumes of Lactated Ringers (LR) when which one of the following occurs?

A.

The mean arterial pressure (MAP) is 50 mm Hg.

B.

Cardiac Out (CO) is 4 L/min

C.

Stroke volume 70 ml/beat

D.

The heart rate is 80 bpm.

Answer and Explanation

The Correct Answer is A

Mean arterial pressure (MAP) is a measure of the average pressure within the arteries during one cardiac cycle. It represents the perfusion pressure that drives blood flow to organs and tissues. In the context of shock, a MAP of 50 mm Hg is considered low and indicates inadequate tissue perfusion.
To improve tissue perfusion and restore blood pressure, the nurse would anticipate administering large volumes of intravenous fluids, such as Lactated Ringers (LR). Fluid resuscitation aims to increase intravascular volume and improve cardiac output, ultimately leading to improved tissue perfusion.
B. Cardiac Output (CO) is 4 L/min in (option A) is incorrect because Cardiac output represents the volume of blood pumped by the heart per minute. While a low cardiac output may require intervention, it does not specifically indicate the need for large volumes of fluid administration.
C. Stroke volume is 70 ml/beat in (option C) is incorrect because Stroke volume refers to the volume of blood ejected by the heart with each contraction. While stroke volume can be an important determinant of cardiac output, it alone does not indicate the need for large fluid volumes.
D. The heart rate is 80 bpm in (option D) is incorrect because: Heart rate is the number of heartbeats per minute. While the heart rate can impact cardiac output, it does not provide direct information about fluid resuscitation needs.
 


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Related Questions

Correct Answer is ["9"]

Explanation

  1. Doseinmcg/min=2mcg/kg/min×60kg=120mcg/min

    Convert this to mg/min since the concentration is in mg:

    120mcg/min=0.12mg/min120 \text{ mcg/min} = 0.12 \text{ mg/min}120mcg/min=0.12mg/min

  2. Determine the concentration of Dopamine:

    • Total amount of Dopamine: 200 mg in 250 mL of saline
    • Concentration:

    Concentration=200mg250mL=0.8mg/mL\text{Concentration} = \frac{200 \text{ mg}}{250 \text{ mL}} = 0.8 \text{ mg/mL}Concentration=250mL200mg​=0.8mg/mL

  3. Calculate the pump rate in mL/min:

    To find the rate in mL/min needed to deliver 0.12 mg/min:

    Pumprate=Desireddose(mg/min)Concentration(mg/mL)\text{Pump rate} = \frac{\text{Desired dose (mg/min)}}{\text{Concentration (mg/mL)}}Pumprate=Concentration(mg/mL)Desireddose(mg/min)​

    Pumprate=0.12mg/min0.8mg/mL=0.15mL/min\text{Pump rate} = \frac{0.12 \text{ mg/min}}{0.8 \text{ mg/mL}} = 0.15 \text{ mL/min}Pumprate=0.8mg/mL0.12mg/min​=0.15mL/min

  4. Convert the pump rate to mL/hour:

    Multiply by 60 to convert from mL/min to mL/hour:

    Pumprate=0.15mL/min×60min/hour=9mL/hour\text{Pump rate} = 0.15 \text{ mL/min} \times 60 \text{ min/hour} = 9 \text{ mL/hour}Pumprate=0.15mL/min×60min/hour=9mL/hour

So, you should set the pump to deliver Dopamine at a rate of 9 mL/hour.

Correct Answer is ["18"]

Explanation

Step 1: Convert the patient's weight from pounds to kilograms. 130 pounds ÷ 2.205 (1 pound = 0.453592 kilograms) ≈ 58.97 kilograms

Step 2: Calculate the total dosage of Dobutamine required per hour based on the weight-specific dose. 2.5 mcg/kg/min × 58.97 kg = 147.425 mcg/min

Step 3: Calculate the infusion rate (mL/hr) using the concentration of Dobutamine in the prepared solution. The solution contains 250 mg of Dobutamine in 500 mL, which means there are 250,000 mcg of Dobutamine in 500 mL. To determine the mL/hr, divide the required dosage (147.425 mcg/min) by the amount of Dobutamine in 500 mL (250,000 mcg) and multiply by 500 mL (volume of the solution).

(147.425 mcg/min ÷ 250,000 mcg) × 500 mL ≈ 0.295 mL/min

To get the mL/hr, we convert the rate from minutes to hours (60 minutes = 1 hour):

0.295 mL/min × 60 min/hr ≈ 17.7 mL/hr

Round the answer to the nearest whole number:

Approximately 18 mL/hr of Dobutamine should be administered to the patient.

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