Questions 1-20
You suspect a patient may have a pulmonary embolism. Which of the following would be the most appropriate recommendation for diagnosis of this condition? A- V/Q lung scan B- Bronchoscopy C- Shunt study D- Coagulation studies
A The best diagnostic test to determine whether a pulmonary embolism is present is the V/Q lung scan. (Application)
A 60-kg (132-lb) 52-year-old man is admitted to the ICU for the treatment of refractory hypoxemia. He is currently on VC-SIMV and pressure support of 10 cm H2O with an FiO2 of 0.60. Other pertinent data are below: ABGs: pH- 7.49 PaCO2- 30 torr PaO2- 59 torr Vitals: HR- 120/min RR- 12/min Spontaneous Vt- 400 mL Ventilator Vt- 500 mL PEEP- 5 cm H2O Total Respiratory Rate- 22/min Which of the following should the respiratory therapist recommend at this time? A- Increase the PEEP to 8 cmH2O B- Decrease the Vtto 400 mL C- Increase the FiO2 to 0.70 D- Increase the pressure support level to 15 cmH2O
A Refractory hypoxemia typically results from atelectasis, pneumonia, or pulmonary edema, whereby increasing oxygen levels do not correct the hypoxemia. Although the patient is hyperventilating, VT should not be decreased. The hyperventilation is a result of the low PaO2, therefore it should be increasing the PaO2 first is necessary. We should not exceed 60% oxygen to try to correct hypoxemia, so increasing the PEEP level is most appropriate. (Analysis)
The respiratory therapist palpates no pulse on a patient, but the ECG monitor shows QRS complexes on the tracing. The therapist should A- Begin cardiac compressions B- Get a STAT ABG C- Recommend defibrillation at 250 J D- Recommend cardioversion at 120 J
A Regardless of what the ECG monitor is recording, if the patient has no pulse, compressions must be started immediately. An example of this rare situation is electromechanical dissociation (EMD), also referred to as pulseless electrical activity (PEA), in which the ECG monitor does not reflect the actual mechanical activity of the heart. (Analysis)
The following data has been collected on a 75-Kg (165 lb) male patient receiving mechanical ventilation: Mode- SIMV Vt-600 mL Ventilator Rate- 4/min Spontaneous Rate- 20/min FiO20.35 pH- 7.29 PaCO2- 50 torr PaO2- 72 torr HCO3- 26 mEq/L BE +1 On the basis of this data, which of the following should the respiratory therapist recommend? A- Increase the ventilator rate to 8/min B- Increase the Vt to 650 mL C- Change to assist-control mode at a rate of 15/min D- Increase the FiO2 to 0.40
A This patient's increased PaCO2 level indicates hypoventilation, which can be reversed by increasing the minute ventilation. This can be accomplished by increasing the ventilator rate or VT, both of which are choices. We must assume the patient is being weaned from the ventilator based on the low ventilator rate (SIMV rate of 4). Weaning is accomplished as we reduce the ventilator rate and allow the patient to breathe more on his or her own. If the patient's PaCO2 begins to increase during weaning, we increase the rate, not the VT. The ventilator VT is at the maximum level of 8 mL/kg based on the patient's weight of 75 kg (8 x 75 = 600), therefore increasing the ventilator rate is the most acceptable choice. (Analysis)
A patient arrives in the emergency department after being pulled from a burning house. The respiratory therapist should recommend obtaining which of the following measurements to best determine the severity of the patient's smoke inhalation? A- HbCO B- PaO2 C- SpO2 D- Hb
A To best determine the severity of smoke inhalation, an HbCO level should be determined with a co-oximeter. The SpO2 value should never be evaluated on a patient suspected of CO poisoning because a pulse oximeter is not capable of determining what is bound to hemoglobin. Pulse oximeters work on the principle of spectrophotometry where lightweight probes direct filtered light of specific wavelengths through the skin or digit. The light absorbed differs for saturated and desaturated blood, whether it's saturated with oxygen or a combination of oxygen and carbon monoxide. Therefore, the reading will be erroneously high when HbCO is present. (Analysis)
The physician orders a 35% aerosol mask to be set up for a patient who requires an inspiratory flow of 42 L/min. What is the minimum flow rate to which the flowmeter must be set to meet this patient's inspiratory flow demands? A- 8 L/min B- 10 L/min C- 12 L/min D- 6 L/min
A- 8 L/min The air/O2 ratio for a 35% oxygen mixture is 5 : 1. To calculate total flow output from this device, add the ratio parts together and multiply by the liter flow: 6 × 6 = 36 L/min, 6 × 8 = 48 L/min, 6 × 10 = 60 L/min, 6 × 12 = 72 L/min. Total flow needed: 42 L/min. The minimum flow necessary is 8, giving a total flow of 48 L/min. (Analysis)
Which one of the following sets of ABG measurements would indicate compensated respiratory acidosis? A- pH 7.42, PCO2 39 torr, PO2 87 torr, HCO3 26 mEq/L, BE -1 B- pH 7.37, PCO2 58 torr, PO2 60 torr, HCO3 31 mEq/L, BE +8 C- pH 7.25, PCO2 61 torr, PO2 75 torr, HCO3 26 mEq/L, BE +1 D- pH 7.26, PCO2 60 torr, PO2 68 torr, HCO3 26 mEq/L, BE 0
B A blood gas level is considered compensated when both the PaCO2 and HCO3− are abnormal and the pH level is normal. Respiratory acidosis is caused by an elevated PaCO2, which drops the pH to below normal levels. If the patient's lungs are not ventilated better to decrease the PaCO2, the HCO3− levels in the blood begin to increase (renal compensation), which increases the pH toward normal. When the pH reaches the normal range, it is called fully compensated. The most common example of this type of blood gas level is the patient with severe COPD who has chronic retention of CO2 and remains in a constant state of compensation. (Application)
Failure to hyperoxygenate a patient on a ventilator before ET suctioning may result in A- Hypocapnea B- Hypoxemia C- Bradycardia D- Hypertension
B It is important during ET suctioning that the PaO2 be maintained within a normal range. This requires increasing the oxygen percentage during the procedure. Failure to hyperoxygenate may cause hypoxemia, resulting in cardiac arrhythmias. Bradycardia may occur as a result of vagal stimulation. (Application)
After a patient has received bronchodilator therapy, the respiratory therapist attempts to perform nasotracheal suction on the patient. As the catheter enters the oropharynx, the following ECG waveform is observed on the ECG This ECG pattern is most likely the result of which of the following? A- Hypoxemia B- Vagal nerve stimulation C- Hypercapnia D- Excessive suction pressure
B The ECG strip indicates sinus bradycardia, which results from vagal stimulation from suctioning. The vagus nerve runs through the oropharynx. When the vagus nerve is stimulated, bradycardia and hypotension result. Thus, a catheter placed in the oropharynx during suctioning may elicit this response. Hypoxemia may also result in bradycardia, but with the catheter in the oropharynx, hypoxemia is unlikely. (Application)
Tracheal secretions tend to dry out in an intubated patient when inspired air has which of the following characteristics? A- 50 mg of particulate water/L of gas B- An absolute humidity of 24 mg/L of gas C- 44 mg of particulate water/L of gas D- A water vapor pressure of 47 mmHg
B When air that is not fully saturated at body temperature is delivered to an intubated patient, a humidity deficit exists, and secretions get thicker because of lack of inspired water. The inspired air must contain 44 mg H2O per liter of gas or exert a water vapor pressure of 47 mm Hg to be fully saturated at body temperature. (Analysis)
The most reliable method of determining whether the lungs of a patient receiving mechanical ventilation are getting stiffer and harder to ventilate is by measuring the A- Dynamic lung compliance B- Static lung compliance C- Spontaneous Vt D- PaO2
B When lungs get stiffer and harder to ventilate, greater pressure is required to move the same volume of air. Because peak inspiratory pressure increases when RAW increases (e.g., when airway secretions are present or water is in the ventilator tubing), this pressure does not reflect how stiff the lungs actually are. We determine the plateau or static pressure by holding the volume in the patient's lungs for 1 to 2 s. This pressure closely relates to alveolar pressure. PEEP (if used) is subtracted from the plateau pressure and this number is divided into the VT. The results determine how compliant the lungs are. (Application)
To most effectively increase a sedated, paralyzed patient's alveolar minute ventilation while the patient is on volume-controlled ventilation in the assist-control mode, you would recommend increasing which of the following? A- Inspiratory flow B- Ventilator rate C- Vt D- PEEP
C Alveolar minute ventilation = (VT - VD) × respiratory rate It represents the volume actually reaching the alveoli per minute. It takes into account anatomic dead space (VD), which is approximately 1 mL/lb of body weight. Anatomic VD is that portion of the airway where no gas exchange occurs. If a patient's alveolar minute ventilation is to be increased, the VT must be increased. If only the ventilator rate is increased, the same VT is delivered, even though the minute ventilation (VT × RR) increases. (Recall)
The physician has ordered O2 to be administered to an active 3-year-old with an SpO2 of 86%. Which of the following delivery devices would you recommend for this patient? A- O2 hood B- Simple O2 mask C- 1- to 2-L/min nasal cannula D- Air-entrainment mask
C An active 3-year-old generally tolerates a cannula much better than any kind of mask and is too large for an O2 hood. (Recall)
The following data has been collected on a patient receiving continuous mechanical ventilation: 1:00pm 3:00pm Delivered Vt: 600 mL 600 mL Peak airway pressure: 44 cmH2O 52 cmH2O Static airway pressure: 25 cmH2O 33 cmH2O Inspiratory flow: 40 L/min 40 L/min PEEP: 5 cmH2O 5 cmH20 Which of the following is the best interpretation of these data? A- The peak airway pressure increased as a result of increased airway resistance B- The patient's lung compliance is improving C- The peak airway pressure increased as a result of decreased lung compliance D- The patient's dynamic compliance is increasing
C Notice that while peak inspiratory pressure increased, the static airway pressure increased as well. Static pressure closely resembles alveolar pressure. An increasing static pressure is a sign that it is taking more pressure to ventilate the lung; therefore, lung compliance is decreasing. In this question, if the PIP would have increased with no increase in the static pressure, then choice A would have been the correct answer. When airway resistance increases because of airway secretions, water in the ventilator tubing, or bronchospasm, PIP increases, but static pressure remains unchanged. (Analysis)
A 70-kg (154-lb) male patient is receiving mechanical ventilation. The respiratory therapist notes the patient's SpO2 drops from 97% to 86%. The right lung is expanding more than the left, with clear breath sounds on the right but absent breath sounds on the left. The patient's ET tube is taped at the 29-cm mark at the lip. Which of the following should the respiratory therapist do at this time? A- Advance the ETT 2 cm B- Recommend an immediate chest X-Ray C- Withdraw the tube to the 24-cm mark D- Obtain immediate ABG levels
C The ET tube should be positioned 2 to 6 cm above the level of the carina. That means the ET tube should be at the 21- to 25-cm mark at the teeth. In this question, the tube is at the 29-cm mark and the patient has decreased breath sounds in the left lung, which indicates the tube is in the right mainstem bronchus and must be withdrawn. (Application)
A patient is receiving volume-controlled ventilation, and the low-pressure alarm suddenly sounds. The corrective action is to: A- Suction the patient B- Begin manual ventilations C- Determine whether the patient is disconnected from the ventilator D- Increase the flow
C The low-pressure alarm will sound if there is a leak in the ventilator tubing or around the ET-tube cuff, the patient is disconnected from the ventilator, or the low-pressure alarm is set too high. Suctioning the patient could be indicated if the high-pressure alarm is triggered. (Analysis)
A premature 3-week-old infant is receiving 2 l/min of 02 via nasal cannula and has a PaO2 of 43 torr and a PaCO2 of 40 torr. The respiratory therapist should recommend which of the following? A- Initiate CPAP of 4 cm H2O and 50% 02 B-Increase the cannula flow to 5 L/min. C- Intubate and institute mechanical ventilation D- Increase the cannula flow to 2 L/min
D A PaO2 of 43 torr represents hypoxemia. The normal PaO2 for an infant is 50-70 torr. Increasing the cannula flow by 1 L/min is the most appropriate choice to return the PaO2 to normal. With a normal PaCO2 of 40 torr, mechanical ventilation is not indicated. (Analysis)
A peripheral lung mass is to be biopsied. Which of the following procedures should be recommended to obtain the tissue sample? A- Bronchoalveolar lavage (BAL) B- Fiberoptic bronchoscopy C- Rigid Bronchoscopy D- Electromagnatic navigational bronchoscopy (ENB)
D ENB is diagnostic tool that combines conventional bronchoscopy with virtual bronchoscopy that allows bronchoscopic instruments to reach peripheral lung areas that traditional fiberoptic bronchoscopes can't reach. (Analysis)
The ability of the patient to follow instructions would be indicated by which of the following? A- Awareness of time B- Ability to feed himself C- Orientation to person D- Performance of tasks when asked
D If the patient is able to perform simple tasks when asked, this best determines his or her ability to follow instructions. This is important before administering an incentive spirometry or IPPB treatment, which requires the patient to be able to follow instructions well or the treatment will not be effective. (Recall)
It is important to monitor plateau pressure in a patient receiving mechanical ventilation because it best reflects A- ICP B- PaO2 C- PaCO2 D- Lung compliance
D Lung compliance is determined by dividing the VT by the plateau pressure. (Application)
