CCRN Exam: Respiratory Questions with 100% Correct Answers 2023, Exams of Advanced Education

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CCRN Exam: Respiratory Questions

With 100% Correct Answers 2023

What is minute ventilation? What is the normal value for minute ventilation? - Correct Answer-Minute ventilation = Tidal Volume x Respiratory Rate Normal MV = 5-8 L/minute What is the optimal body position for ventilation? - Correct Answer-Upright sitting position - low Fowler's Why is high Fowler's not optimal for ventilation? - Correct Answer-High Fowler's position increases pressure of abdominal contents against the diaphragm, which decreases diaphragmatic excursion. Do you want the good or bad lung down? - Correct Answer-Want the GOOD lung DOWN = think of the effect of gravity on pulmonary perfusion Example: If you turn a patient with a right lung pneumonia to the right side (bad lung down), more blood goes to the right side and the patient may become hypoxic. (There is a decrease in blood flow past the alveoli due to the pneumonia.) What is dead space ventilation? - Correct Answer-The volume of air that does not participate in gas exchange What is anatomic dead space? - Correct Answer-2 mL/kg of tidal volume We all have this, it is normal. There is no gas exchange at the level of the nose down to the terminal bronchioles/alveoli. This area has air (ventilation), but no alveolar-capillary membrane. What is alveolar dead space? What is an example of alveolar dead space? - Correct Answer-Pathologic, non-perfused alveoli A pulmonary embolism causes alveolar dead space. There is air the alveolus, but no blood is available to that area to pick up the oxygen in the alveolus. What is physiologic dead space? - Correct Answer-Anatomic dead space + alveolar dead space What is V/Q ratio and what is the ideal lung unit (V/Q ratio number)? - Correct Answer- V/Q ratio = ventilation/perfusion ratio 4 L ventilation/min (V) ÷ 5 L perfusion/min (Q) = 0.8 normal V/Q ratio

A normal V/Q ratio is when there are no problems with either ventilation or perfusion, the patient will have normal gas exchange on room air. What does a negative V/Q scan tell us? - Correct Answer-Effectively rules out a pulmonary embolism What does an intermediate V/Q scan indicate? - Correct Answer-< 60% change of a pulmonary embolism Does not rule out a PE What does a low V/Q scan indicate? - Correct Answer-< 40% chance of a pulmonary embolism Does not rule out a PE What does a high probability V/Q scan indicate? - Correct Answer-97% chance of a pulmonary embolism What increases the specificity for pulmonary embolism with a low or intermediate V/Q scan? - Correct Answer-A positive D-dimer What is a shunt? - Correct Answer-An extreme V/Q mismatch A shunt is movement of blood from the right side of the heart to the left side of the heart without getting oxygenated What is an example of a normal physiologic shunt? - Correct Answer-Thebesian veins of the heart empty into the left atrium. This is why the normal SpO2 on room air is 95-99%; it cannot be 100% on room air due to this shunt. What is an example of an anatomic shunt? - Correct Answer-Ventricular or atrial septal defects What is an example of a pathologic shunt? - Correct Answer-ARDS: Acute respiratory distress syndrome Blood goes through lungs but does NOT get oxygenated, resulting in refractory hypoxemia What is the treatment for a shunt? - Correct Answer-Give O2 (usually 100%) Provide PEEP - increase alveolar recruitment, prevent alveolar collapse

What is PEEP and what does it do? - Correct Answer-Positive-end expiratory pressure Prevents expiratory pressure from returning to zero - keeps expiratory pressure POSITIVE

• Decreases surface tension of alveoli, preventing atelectasis
• Increases alveolar recruitment
• Increases driving pressure - extends time of gas transfer - allows decrease in FiO What is more diffusible - carbon dioxide or oxygen? - Correct Answer-Carbon dioxide is MUCH more diffusible than oxygen The thickening of the alveolar-capillary membrane affects the diffusion of oxygen rather than diffusion of CO2. Diffusion problems affect PaO2, but not PaCO2, since it is more diffusible. CO2 is transported in the body dissolved in the plasma, as bicarbonate, and attached to hemoglobin. Lung Sounds: Stridor is...and treatment could include.... - Correct Answer-High-pitched, crowing sound that occurs with an obstruction in the upper airway (trachea or larynx) Corticosteroids to reduce mucosal swelling Lung Sounds: Wheezing is...and treatment could include... - Correct Answer- Continuous high-pitched musical sounds; indicates narrowing of airways by spasm, mucous plug, or tumor Albuterol treatment (spasm), suctioning (mucous plug) Lung Sounds: Pleural friction rub is....and indicates... - Correct Answer-Loud, rough, scratching sound (both inspiration and expiration) Pleurisy Lung Sounds: Bronchial breath sounds sound like...and could also indicate... - Correct Answer-Loud, high-pitched, hollow sounds normally heard over the trachea and the large bronchi on expiration If heard in lung lobes = indicates pneumonia Lung Sounds: Decreased breath sounds indicate... - Correct Answer-Atelectasis Lung Sounds: Rhonchi sounds like...and indicates... - Correct Answer-Gurgles, moving in the large bronchioles and bronchi (large airways)

Mucus/fluid Lung Sounds: Crackles sound like...and indicates... - Correct Answer-Fine or course, more common during inspiration, can be heard of expiration Indicates secretions or fluid in the lung - intra-alveolar fluid or atelectasis What is PaO2? How is it measured? What is the normal value? - Correct Answer-Partial pressure of oxygen in arterial blood; amount of oxygen in the plasma Directly measured by arterial blood (ABG) Normal: 80-100 mmHg on room air <80 mmHg = hypoxemia What is SaO2? How is it measured? What is the normal value? - Correct Answer-The measurement of oxygen saturation in arterial blood; amount of oxygen bound to hemoglobin. Measures both functional and non-functional hemoglobin. Measured by a blood gas (ABG) Normal SaO2: 95-99% on room air What is SpO2? How is it measured? What is the normal value? - Correct Answer-Pulse oximetry reading of arterial blood, is a reflection of tissue oxygenation. Oxygen saturation in the arterial blood as measured by a pulse oximeter. Measures the oxygen saturation of only functional hemoglobin. SpO2 is an indirect measure of SaO Measured by pulse oximeter Normal Value: >90% on room air What is SvO2? How is it measured? What is the normal value? - Correct Answer-Mixed- venous oxygen saturation. It's the percentage of oxygen bound to hemoglobin in blood returning to the right side of the heart/returning to the lungs for reoxygenation. Most sensitive indicator of oxygenation at the cellular level. Direct measurement from pulmonary artery (PA Catheter/Swan Ganz) Normal value = 60-75%

What does a low SvO2 indicate? Potential causes? - Correct Answer-A low SvO indicates that the tissues are extracting a higher percentage of oxygen from the blood than normal. In other words, a decreased SvO2 indicates that the cardiac output is not high enough to meet tissue oxygen needs. Causes include decreased Hgb (anemia, hemorrhage, dilution), decreased SaO (hypoxemia), decreased perfusion (shock, arrhythmia), increased O2 demand (hyperthermia, shivering, pain, seizures) What does a high SvO2 indicate? Potential causes? - Correct Answer-Less tissue extraction of O High return of O2 is often an early indicator of pt status change Causes include increased O2 supply (FiO2 > need/hyperbaric oxygen), decreased O demands (hypothermia/anesthesia/neuromuscular blockade), or less effective O delivery and uptake by the cells (SEPSIS, curve shift/hyperthyroidism/severe liver disease) Difference between SvO2 and ScvO2? - Correct Answer-SvO2 > ScvO2 as it contains blood from both superior vena cava and inferior vena cava. SvO2 is obtained from PA catheter - SVC/IVC ScvO2 is obtained from a central line; estimates SvO2; contains predominately SVC blood (brain has higher O2 extraction) The normal level of Svo2 is 60% and Scvo2 is usually 2-3% lower than Svo2. This is because the lower half of the body extracts less oxygen and the brain extracts more oxygen than other organs of the body. What is CaO2? How is it measured? What is the normal value? - Correct Answer- Content of oxygen in the arterial blood; severe anemia may result in hypoxia; Hgb and SaO2 affect the CaO Calculated using the Hgb level and saturation level of the hemoglobin (SaO2) CaO2 = (Hgb x 1.39 x SaO2) + (PaO2 x 0.003) Normal CaO2 = 15-20 mL/100 mL blood What is DO2? How is it measured? What is the normal value? - Correct Answer- Delivery of oxygen to the tissue; best indicator of tissue oxygenation; takes into account cardiac output in addition to Hgb, SaO2/PaO2. Pump problems (heart) will decrease DO

CaO2 x CO x 10 900-1100 mL/min What is DO2I? How is it measured? What is the normal value? - Correct Answer- Oxygen Delivery Index. Takes into account body surface area (uses cardiac index instead of cardiac output). Normal oxygen delivery. CaO2 x (CI x 10) 600 mL/min/m^ What is VO2? How is it measured? What is the normal value? - Correct Answer-The volume of oxygen the body consumes; oxygen consumption, utilization. A reflection of venous oxygen reserve. (SaO2 - SvO2) x Hgb x 13.9 x CO 250-350 mL/min Low with septic shock = sepsis decreases O2 extraction and utilization; causes a decrease in the ability of the tissues to extract and use oxygen. What is the A-a gradient? How is it measured? What is the normal value? - Correct Answer-Alveolar-arterial gradient (A-a) Indicates if gas transfer is normal and, if not, how bad the V/Q mismatch or shunt is. Reflection of the process of diffusion across the alveolar-capillary membrane. PAO2 - PaO2 (%FiO2 x 715) - PaCO ÷ 0.8 - PaO A narrow A:a gradient is normal diffusion (<10 mmHg) A shift to the left on the oxyhemoglobin dissociation curve means... - Correct Answer- Hemoglobin wants to hold on to the oxygen molecules Hemoglobin Loves oxygen (L = left) Increased affinity for hemoglobin = easier for Hgb to pick up oxygen at the lung, but doesn't release it at the tissues as easily Conditions that cause a shift to the left results in a higher SaO2, but the tissues do not get needed O2 as readily

A shift to the right on the oxyhemoglobin dissociation curve means... - Correct Answer- Hemoglobin releases the oxygen more easily to the tissues Hemoglobin Releases oxygen (R = right) Decreased affinity for hemoglobin = more difficult for the Hgb to pick up oxygen at the lung, but gives up oxygen easily at the tissue Conditions that cause a shift to the right result in a somewhat lower SaO2, but the tissues receive O2 more readily. A shift to the left on the oxyhemoglobin dissociation curve is caused by... - Correct Answer-Low temperature (hypothermia) Low 2, 3 DPG aLkaLosis (increased pH) Results in a higher SaO2, but the tissues do not get needed O2 as readily A shift to the right on the oxyhemoglobin dissociation curve is caused by... - Correct Answer-Increased temperature (hyperthermia) Increased 2, 3 DPG Acidosis (decreased pH) Results in a somewhat lower SaO2, but tissues receive O2 more readily On a normal midline curve on the oxyhemoglobin-dissociation curve, a SaO2 of 90% correlates with a PaO2 of... - Correct Answer-PaO2 = 60 mmHg correlates with an SaO2 of 90% What is 2,3-DPG? - Correct Answer-2,3-diphosphoglycerate An organic phosphate found in RBCs that has the ability to alter the affinity of Hgb for oxygen What causes a decreased 2,3-DPG? - Correct Answer-Hemoglobin holding onto oxygen Multiple blood transfusions of banked blood = banked blood does not have normal 2,3- DPG Hypophosphatemia Hypothyroidism Less oxygen available to tissues What causes an increased 2,3-DPG? - Correct Answer-Hemoglobin more readily releasing oxygen

Chronic hypoxemia (high altitudes, chronic HF) Anemia Hyperthyroidism More oxygen available to tissues Carbon monoxide poisoning symptoms - Correct Answer-Causes SEVERE hypoxia due to carbon monoxide binding with Hgb at a rate of 230x greater than it binds with oxygen Headache, dizziness, N/V, decreased LOC, coma Rarely seen: PE shock, confusion, focal neuro deficits, ataxia (impaired balance/coordination), seizure, cherry red lips Carboxyhemoglobin normal level - Correct Answer-0-5% Carboxyhemoglobin level often seen in smokers, truck drivers - Correct Answer-<15% Carboxyhemoglobin level that cause headaches, some confusion - Correct Answer-15- 40% Carboxyhemoglobin level resulting in loss of consciousness, Cheyne-Stokes respirations - Correct Answer-40-60% Carboxyhemoglobin level associated with mortality >50% - Correct Answer-50-70% Treatment of carbon monoxide poisoning - Correct Answer-100% FiO2 until symptoms resolve and carboxyhemoglobin level is < 10% Hyperbaric oxygen chamber, if available, generally within 30 minutes What is lung compliance? - Correct Answer-Degree of elasticity of tissue A decrease in compliance = increase resistance or stiffness What is static compliance? - Correct Answer-Measurement of the elastic properties of the lung How to measure static compliance? - Correct Answer-Tidal volume ÷ Plateau Pressure (minus PEEP) What is plateau pressure? How do you perform a plateau pressure? What is a normal plateau pressure? - Correct Answer-Pressure applied to the small airways and alveoli by positive pressure mechanical ventilation; the pressure inside the lungs when no air is moving - does not factor in airway resistance

Measured at end inspiration with inspiratory hold Used to calculate static compliance Normal plateau pressure typically < 10 cm H2O, but should be limited to a maximum of 30-35 cm H2O What limits plateau pressure results? - Correct Answer-External chest wall pressure may give false high results (i.e., pregnancy, obese patients, etc.) An increase in plateau pressure does what to compliance? What conditions cause elevated plateau pressures? - Correct Answer-An increase in plateau pressure will decrease compliance Lung conditions that stiffen the lungs = ARDS, pulmonary fibrosis, pneumonia What is dynamic compliance? - Correct Answer-Measurement of the elastic properties of the airways How to measure dynamic compliance? - Correct Answer-Tidal Volume ÷ Peak Inspiratory Pressure (minus PEEP) What is peak inspiratory pressure? What is a normal value? - Correct Answer-The highest level of pressure applied to the lungs during inhalation Normal PIP = ~20 cm H2O to < 40 cm H2O What causes an increase in peak inspiratory pressures? - Correct Answer-Airway resistance = secretions, bronchospasms, biting down on ETT, decreased lung compliance (lung pressures may transmit up to the airways) Normal static compliance and dynamic compliance? - Correct Answer-45-50 mL/cm H2O What does decreased compliance mean in terms of how the patient is breathing? - Correct Answer-A decrease in compliance increases the work of breathing. In status asthmaticus, the static compliance is _____ and the dynamic compliance is ____. - Correct Answer-Static compliance (lungs) would be normal Dynamic compliance would be low In ARDS, the static compliance is _____ and the dynamic compliance is ____. - Correct Answer-Static compliance would be low Dynamic compliance would be low (as the lung pressures may transmit up to the airways)