PHYSICS and ANESTHESIA

Question 1

Which of the following has the greatest effect on flow rate?

Answer 1

A. Increasing the radius of tubing
B. Decreasing the lengh of tubing
C. Viscosity
D. Pressure gradient

A. Increasing the radius of the tubing has the greatest effect on the flow rate. Doubling the radius of the IV catheter increases the flow rate by 16-fold

Question 2

Which of the following has the highest viscosity?

Answer 2

A. LR (Lactated)
B. Hetastarch
C. 5% Albumin
D. both B and C

C. 5% Albumin has viscosity of 40 centipose

Question 3

Which of the following statements regarding Poiseuille’s Law is TRUE?

Answer 3

A. The turbulent flow rate of fluids is described by Poiseuile’s Law
B. Decreasing the radius of the tubing has the greatest effect on the flow rate
C. In general, large bore peripheral IVs will deliver fluids rapidly than central venous catheters due to the shorter catheter length and large radius
D. flow rates are directly proportional to the length of the catheter

C. The Laminar flow rate is described in Poiseuille’s Law; Increasing the radius not decreasing. Flow rates are inversely proportional to the length of the catheter