Clinical Anesthesia | Physics and Monitoring

Question 1

What are orifice, turbulent, and laminar flows?

Answer 1

Orifice - occurs where gas flows through region of severe constriction.

Laminar - when gas flows down parallel sided tubes at rate less than critical.

Turbulent - gas flow exceeds critical velocity

Question 2

A 58-year-old patient has severe shortness of breath and “wheezing.” On examination, it is found that the patient has inspiratory and expiratory stridor. Further evaluation reveals marked extrinsic compression of the midtrachea by a tumor. The type of airflow at the point of obstruction within the trachea is:

A. Laminar flow
B. Orifice flow
C. Undulant flow
D. Stenotic flow
E. None of the above

Answer 2

Answer: B. Orifice flow
*Orifice flow occurs when gas flows through a region of severe constriction such as described in this question.

A. Laminar flow
*Laminar flow occurs when gas flows down parallel-sided tubes at a rate less than critical velocity

C. Undulant flow and D. Stenotic flow are not real things

Turbulent flow: When the gas flow exceeds the critical velocity, it becomes turbulent