CERTIFIED RESPIRATORY THERAPIST EXAM 3-8 100 QUESTIONS AND ANSWERS RATED A+ WITH COMPLETE SOLUTIONS Assessment of a 28-year-old trauma patient reveals diminished breath sounds, asymmetrical chest expansion, severe chest pain, and an SpO2 of 90%, despite receiving oxygen via cannula at 5 L/min. These findings are most consistent with what diagnosis? - B). Pneumothorax Both viral pneumonia and pleural effusion can be ruled out as correct answers as they are related to trauma. Breath sounds, though diminished, can be heard, and chest expansion, though asymmetrical, is present; both of these are not consistent with a complete airway obstruction. The physical assessment is consistent with the correct answer, pneumothorax. A 23-year-old firefighter is admitted with suspected smoke inhalation. You place him on a nonrebreathing mask. What is the most appropriate method of monitoring his oxygenation? - B). COoximetry In the case of smoke inhalation, carbon monoxide (CO) binds to the hemoglobin molecule in place of oxygen. Neither ABGs, pulse oximetry, or calculation of A-a gradient will indicate how much oxygen is bound to hemoglobin. Any victim of suspected smoke inhalation must be monitored with CO-oximetry. The ratio of lecithin to sphingomyelin, or L/S ratio, is a test to determine fetal lung maturity. Such a test may be done in the later stages of pregnancy, and the values will initially be noted in the lab results section of the mother's medical record. Approximately what ratio is associated with the onset of mature surfactant production? - A). 2:1 The lecithin to sphingpmyelin ratio, or L/S ratio, is used to determine fetal lung maturity. Generally, this ratio reaches 2:1 (twice as much lecithin as sphingomyelin) near week 35 of gestation, which corresponds to the onset of mature surfactant production. The L/S ratio will generally be noted in the lab results section of the mother's medical record. Sputum culture and sensitivity would be indicated in the evaluation of which of the following clinical conditions? - B). Bacterial pneumonia Sputum culture and sensitivity are used to identify microorganisms and their most appropriate drug therapy. Bacterial pneumonia is the obvious infectious process in the choice of answers. You measure an oxygen concentration of 55?ing delivered by an air-entrainment mask set to deliver 31% oxygen. - C). Check the entrainment ports. Because air-entrainment masks mix air and oxygen at a constant ratio, an alteration in the delivered oxygen concentration could result only from an alteration in the mixing ratio. Since jet size (for a given adapter) is fixed, the problem must be with the entrainment ports. Obstruction of the entrainment ports will decrease air entrainment and raise the delivered oxygen concentration. Which of the following is the approximate total output flow delivered from a 35% air-entrainment mask operating at 8L/min? - B). 48L/min To compute the total output flow delivered by an air-entrainment device, multiply the sum of its ratio parts by the input flow. A 35% air-entrainment mask mixes air and oxygen at a fixed 5:1 ratio; thus (5+1) x 8 = 48 L/min You observed that the reservoir bag on a patient receiving O2 at 10 L/min does not deflate at all when the patient inspires. What to do first. - C). Check the mask for a snug fit. If a nonrebreathing mask reservoir bag does not deflate at all when the patient inspires, either the flow is higher than needed, there are large inspiratory air leaks (around the mask or through the exhalation valves), or the inspiratory valve is jammed. The most common cause is large air leakage, which can easily be corrected by making sure that the mask is fit comfortably tight to the patient,s face.