At 4 AM, the hemodynamic monitor for a critically ill client in ...

[ETearle]

At 4 AM, the hemodynamic monitor for a critically ill client in the intensive care unit indicates that the client's mean arterial pressure is at the low end of the normal range; at 6 AM, the client's MAP has fallen definitively below normal. The client is
 
  A)
  pulmonary hypertension.
  B)
  left ventricular hypertrophy.
  C)
  organ damage and hypovolemic shock.
  D)
  orthostatic hypotension.

Question 2

Which of the following statements most accurately captures a principle of blood flow?
 
  A)
  With constant pressure, a small increase in vessel radius results in an exponential increase in blood flow.
  B)
  Blood flow is primarily determined by blood viscosity and temperature.
  C)
  Blood flows most quickly in the small diameter peripheral capillaries.
  D)
  Smaller cross-sectional vessel area is associated with lower flow velocity.

[fwbard]

Answer to Question 1

Ans:
C

Feedback:

The mean arterial pressure, which represents the average blood pressure in the systemic circulation, is a good indicator of tissue perfusion. Hospitalization and bed rest predispose to dehydration and low blood volume. Blood pressure normally follows a diurnal pattern in which pressures are highest in the morning. The fact that this client's MAP is falling at a time when it should be at its daily peak is the cause for grave concern; blood volume is likely low, and vital organs, which depend on adequate perfusion, are at risk.

Answer to Question 2

Ans:
A

Feedback:

Doubling the radius of a vessel is associated with a fourth-power increase in flow, provided pressure remains constant. Blood flow is primarily a function of blood pressure, resistance, and viscosity. The small size of capillaries is associated with quite slow velocity, given their large total combined cross-sectional area. Smaller cross-sectional area is associated with greater velocity.

[ETearle]

Excellent

[tkempin]

TYSM