Organ perfusion depends on mean arterial pressure. All are true regarding mean arterial pressure except:

Variables influencing MAP are blood volume, cardiac output, and vascular tone.

If blood volume increases, MAP increases.

If cardiac output increases, MAP increases.

If the vascular bed increases in diameter, the MAP increases.

Answer and Explanation

The Correct Answer is D

Rationale:

A. This statement is correct. Blood volume provides the fluid needed to fill the vascular system, cardiac output determines the flow of blood, and vascular tone (the degree of constriction or dilation of blood vessels) regulates resistance. Together, these factors determine the MAP that drives blood through organs.

B. Blood volume is directly related to MAP. An increase in circulating volume, such as from fluid administration, raises venous return to the heart, increasing stroke volume and cardiac output, which subsequently increases MAP. Conversely, hypovolemia lowers MAP and reduces organ perfusion.

C. Cardiac output is the product of heart rate × stroke volume. When cardiac output increases, more blood is pumped into the arterial system per minute, raising arterial pressure and MAP. This is why interventions that improve cardiac output, such as fluids or inotropes, are used in shock to maintain MAP and perfusion.

D. This statement is incorrect. When the vascular bed dilates (vasodilation), systemic vascular resistance decreases. Because MAP is determined by MAP = CO × SVR (systemic vascular resistance), a decrease in resistance lowers MAP if cardiac output remains the same. Vasodilation can occur in conditions like septic shock, leading to hypotension despite normal or even elevated cardiac output. In contrast, vasoconstriction increases resistance and raises MAP.

Nursing Test Bank

Test Bank #1: RN Pharmacology Exams Test Bank #2: RN Medical-Surgical Exams Test Bank #3: RN Fundamentals Exams Test Bank #4: RN Maternal-Newborn Exams Test Bank #5: RN Anatomy and Physiology Exams Test Bank #6: RN Obstetrics and Pediatrics Exams Test Bank #7: RN Fluid and Electrolytes Exams Test Bank #9: RN Adult Health Test Bank #10: RN Dosage Calculation Test Bank #11: RN Community Health Exams Test Bank #12: RN Psychology Exams Test Bank #13: RN Nursing Care Of Children Test Bank #14: RN Foundations of Nursing Exams

Get 100+ Naxlex Exit Exams for $79 Try Naxlex NCLEX-RN (14 Day Free-Trial)

Naxlex Comprehensive Predictor Exams

Exam #1: RN Comprehensive predictor 2023 proctored exam Exam #2: Ati rn vati comprehensive predictor proctored exam Exam #3: Ati Rn Comprehensive Predictor Proctored Exam 2023 Exam #4: Rn Comprehensive Predictor 2023 Proctored Exam - St. Joseph Exam #5: RN Comprehensive Predictor Proctored Exam (National U CA San Diego) Exam #6: Ati rn comprehensive predictor 2023 retake proctored exam Exam #7: RN Hesi Exit Proctored Exam Exam #8: Hesi RN Exit proctored exam Exam #9: Hesi rn exit proctored exam Exam #10: Hesi Rn compass exit B proctored exam

Free Nursing Study Resources

Correct Answer is C

Explanation

Rationale:
A. Applying a heating pad is not appropriate. Heat may increase tissue metabolism and oxygen demand, potentially worsening ischemia. It does not relieve the underlying problem of compartment syndrome caused by circumferential burns.

B. Elevating the leg may slightly reduce edema, but in circumferential burns with compromised perfusion, elevation alone is insufficient. Delay in intervention can result in permanent tissue damage.

C. Notify the physician and prepare for a fasciotomy is the correct action. Circumferential burns can cause circumferential eschar and compartment syndrome, where swelling increases pressure within the burned area, restricting blood flow to distal tissues. Signs such as delayed capillary refill and weak or absent pulses detectable only by Doppler indicate impaired circulation and impending tissue ischemia. A fasciotomy is a surgical procedure that releases pressure in the affected compartment to restore perfusion and prevent permanent damage or loss of the limb.

D. Observing the patient and waiting is unsafe. Delaying intervention in the presence of compromised circulation can result in irreversible tissue necrosis, nerve damage, or limb loss.

A. Assess the capillary refill. B. Check pupillary response to light. C. Evaluate chest expansion. D. Assess pulses.

Correct Answer is C

Explanation

Rationale:
A. Assessing capillary refill evaluates peripheral perfusion but does not take priority over airway and breathing assessment. It is important for circulation assessment but comes after ensuring adequate ventilation.

B. Checking pupillary response provides information about neurological status and potential brain injury, but neurological assessment is not the first priority in trauma unless airway or breathing is compromised.

C. Evaluating chest expansion addresses airway and breathing, which are the first priorities according to the ABCs (Airway, Breathing, Circulation). Multiple injuries from trauma can compromise ventilation due to rib fractures, pneumothorax, or flail chest. Ensuring effective chest expansion and oxygenation is critical to prevent hypoxia and further organ injury.

D. Assessing pulses evaluates circulation and is important in trauma care, but it is secondary to airway and breathing assessment. Hypoxia poses a more immediate threat to life than reduced peripheral perfusion in the early stages of trauma management.

View Question and Answer

Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.

Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today

Organ perfusion depends on mean arterial pressure. All are true regarding mean arterial pressure except:

Nursing Test Bank

Naxlex Comprehensive Predictor Exams

You are caring for a patient with circumferential burns on his right leg. You note that the capillary refill in his right big toenail is not as brisk as it was 2 hours ago and that the pedal and tibial pulses are only noted by Doppler. What is your best plan of action?

Correct Answer is C

Explanation

The nurse in trauma unit has received report on a client who has multiple injuries following a motor vehicle crash. Which of the following actions should the nurse plan to take first?

Correct Answer is C

Explanation

You have just received the change-of-shift report in the burn unit. Which client requires the most immediate assessment or intervention?

Shock can result from all of the following except:

A client has a high risk for sepsis-induced shock. Which of the following changes in the client's status should the nurse immediately report to the physician?

Administering Dopamine (Inotropin) at 2 mcg/kg/minute results in:

The critical care nurse is preparing to initiate an infusion of a vasoactive medication to a patient in shock. The nurse knows that vasoactive medications are given in all forms of shock. What is the primary goal of this aspect of treatment?