What is the primary defense mechanism of the conducting airways? 

What type of acid-base imbalance results from hypoventilation? 

Which of the following control the inhibitory neurons that switch off the inspiratory ramp signal?  Select all that apply. I. pneumotaxic center II. apneustic center III. pulmonary stretch receptors

Which of the following are absolute contraindication for HBO therapy.   I. ischemic skin flap II. thermal burns III. cerebral edema IV. congenital heart defects dependent on a patent PDA V. untreated pneumothorax

Primary safety concerns in the application of hyperbaric oxygenation include which of the following?   I. sudden decompression II. electrical fires III. CO2 accumulation

Why is barotrauma a common complication in HBO therapy? 

According to Fick’s first law of diffusion, which of the following will allow more diffusion to occur?  I. increased thickness of the membrane II. increase surface area III. diffusion constant IV. increased pressures gradient

What type of flow-volume loop is expected with tracheomalacia? 

Which tracheal injuries are associated with endotracheal intubation?  Choose all that apply.

You have a patient breathing room air with an arterial PaO2 of 90 mm Hg. Assume that barometric pressure is 760 mm Hg, FiO2 is 21 %, and PaCO2 is 40 mm Hg.  What is the A – a gradient? Round to the nearest whole number.