Pre test physiology of one lung ventilation

Which of the following can increase pulmonary vascular resistance?

• Septicemia

• Systemic hypoxia

• Positive end-expiratory pressure (PEEP)

• All of the above

Which of the following statements is TRUE regarding changes seen when a patient is positioned in the lateral decubitus position?

• Blood flow to the nondependent lung is significantly greater than it is to the dependent lung.

• The distribution of blood flow is turned by 180 degrees compared with the supine position.

• An awake, spontaneously breathing patient will demonstrate poor ventilation–perfusion matching in the dependent lung.

• Ventilation in the dependent lung is greater than in the nondependent lung.

• The nondependent hemidiaphragm is displaced higher into the chest.

A patient undergoing a right thoracotomy with one-lung ventilation is given vecuronium bromide and is placed in the left lateral

decubitus position. The following statements are true EXCEPT:

• Thirty-five percent of the cardiac output participates in gas exchange in the left lung.

• Hypoxic pulmonary vasoconstriction reduces blood flow to the nondependent hypoxic lung by 50%.

• The patient's functional residual capacity (FRC) is reduced by receiving vecuronium bromide.

• One-lung ventilation causes a right-to-left shunt through the nonventilated lung.

All of the following antagonize hypoxic pulmonary vasoconstriction EXCEPT:

• Pulmonary hypertension secondary to pulmonary embolism

• Epinephrine

• Mitral stenosis

• Infection

• Propofol

Which of the following sympathomimetic drugs are β2 -selective and typically produce minimal cardiac effect from β1 -stimulation?

• Albuterol

• Terbutaline

• Metaproterenol

• Epinephrine

The right lung, in the upright position

• is the smaller of the two

• has a single fissure

• has three lobes

• receives 45% of total lung blood flow

• is less frequently involved in aspiration

  compared to the left

During awake, closed chest ventilation in the

lateral decubitus position

• the lung relationships are the same as in

  the semirecumbent position, i.e., the

  apex is in zone 1 and the bases are in zone 3

• ventilation is highest at the apex

• perfusion is greater in the nondependent lung

• compliance is unequal in the two lungs

• the nondependent lung receives most of

  the tidal ventilation

In surgical cases requiring lung isolation

• Measurement of tracheal width from a posteroanterior chest radiograph is of no

  use in selecting the size of a double-lumen tube (DLT)

• More frequent use of left-sided DLT is based on the anatomy of

  tracheobronchial tree

• Uniform ventilation to all lobes is most likely achieved by a right-sided DLT

  because it has a ventilation slot in the bronchial tube

• Fiber–optic confirmation of correct DLT placement is not required if you have

  good clinical confirmation

Which of the following statements is false regarding ventilation/perfusion

relationship in a lateral decubitus position during spontaneous ventilation ?

• The ventilation /perfusion matching is preserved

• Contraction of dependent hemidiaphragm is more efficient

• Dependent lung is on a more favorable part of the compliance curve

• The lower lung receives less ventilation and more perfusion than the upper lung

Which of the following statements is not true regarding lower lung syndrome?

• It is caused by excessive fluid administration in a lateral decubitus position

• It increases intrapulmonary shunting

• It is gravity-dependent transudation of fluid in to the dependent lung

• It is due to volutrauma caused during

  one-lung ventilation