A nurse is evaluating the central venous pressure (CVP) of a client who has sustained multiple traumas. Which of the following interpretations of a low CVP should the nurse make?
A.
Fluid overload
B.
Intracardiac shunt
C.
Hypovolemia
D.
Left ventricular failure
The correct answer and Explanation is :
The correct answer is C. Hypovolemia.
Central Venous Pressure (CVP) measures the pressure within the thoracic vena cava, near the right atrium of the heart, and is a reflection of venous blood return to the heart. It is often used as an indirect indicator of right ventricular preload, or the volume of blood filling the right ventricle. Normal CVP values typically range from 2 to 8 mmHg.
Interpretation of a Low CVP:
A low CVP suggests decreased venous return to the heart and is most commonly associated with hypovolemia (decreased circulating blood volume). Hypovolemia can result from significant fluid loss due to trauma, hemorrhage, dehydration, or excessive fluid loss through the skin (e.g., burns) or gastrointestinal system (e.g., vomiting, diarrhea). When the body loses a substantial volume of fluid, venous return to the heart is diminished, leading to a reduction in right ventricular filling pressure, which is reflected as a low CVP.
Other Options Explained:
- A. Fluid Overload: Fluid overload would result in increased venous return to the heart, which would elevate CVP. This condition is often seen in heart failure, kidney failure, or excessive intravenous fluid administration.
- B. Intracardiac Shunt: An intracardiac shunt, a congenital or acquired abnormality where blood flows between the chambers of the heart (e.g., atrial or ventricular septal defects), generally doesn’t directly cause a low CVP. However, it can lead to a variety of circulatory disturbances based on its severity.
- D. Left Ventricular Failure: This condition typically causes elevated CVP as it leads to backup of blood into the pulmonary circulation and eventually into the systemic venous system, raising the pressure in the veins.
In a client with multiple traumas, hypovolemia is a common concern due to the potential for significant blood loss. Hence, a low CVP should prompt the nurse to consider fluid resuscitation to restore circulating volume.