Ch. 4 Test, Establishing the Need for Mechinical Ventilation Flashcards
Respiratory failure due to inadequate ventilation is known as which of the following?
a. Hypoxemic
b. Hypercapnic
c. Compensated
d. Chronic
ANS: B
Inadequate ventilation decreases the amount of carbon dioxide excreted by the lungs. This causes a buildup of carbon dioxide in the blood, which is hypercapnia.
DIF: 1 REF: pgs. 49-51
The underlying physiological process leading to pure hypercapnic respiratory failure is which of the following?
a. Ventilation/perfusion mismatch
b. Intrapulmonary shunting
c. Diffusion impairment
d. Alveolar hypoventilation
ANS: D
When a person cannot achieve adequate ventilation to maintain a normal partial pressure of carbon dioxide in the arteries (PaCO2), it is known as acute hypercapnic respiratory failure. Ventilation/perfusion (V/Q) mismatch, intrapulmonary shunting, and diffusion impairment lead to hypoxemic respiratory failure.
DIF: 1 REF: pgs. 49-51
A patient with an opiate drug overdose is unconscious and has the following arterial blood gas results on room air: pH 7.20; partial pressure of carbon dioxide (PaCO2) 88 mm Hg; partial pressure of oxygen (PaO2) 42 mm Hg; bicarbonate (HCO3-) 25 mEq/L. Which of the following best describes this patient’s condition?
a. Chronic hypoxemic respiratory failure
b. Chronic hypercapnic respiratory failure
c. Acute hypoxemic respiratory failure
d. Acute hypercapnic respiratory failure
ANS: D
A drug overdose will affect the patient’s central nervous system, knocking out the patient’s respiratory center. This will cause an increase in the partial pressure of carbon dioxide in the arteries (PaCO2). The alveolar hypoventilation is causing the low partial pressure of oxygen (PaO2). If this was a chronic hypercapnic respiratory failure the patient’s bicarbonate level would be elevated above the normal level.
DIF: 2 REF: pg. 50
Acute hypercapnic respiratory failure may be caused by which of the following?
a. Decrease fractional inspired oxygen (FIO2)
b. Pulmonary shunt
c. Respiratory muscle fatigue
d. Perfusion/diffusion impairment
ANS: C
A decreased fractional inspired oxygen (FIO2), pulmonary shunt, and perfusion/diffusion impairment will lead to acute hypoxemic respiratory failure. Respiratory muscle fatigue would decrease a patient’s ability to “move air” and would cause acute hypercapnic respiratory failure.
DIF: 1 REF: pg. 50
Hypercapnic respiratory failure due to increased work of breathing will be caused by which of the following?
a. Drug overdose
b. Myasthenia gravis
c. Asthma exacerbation
d. Pulmonary embolism
ANS: C
An asthma exacerbation is characterized by bronchoconstriction due to bronchospasm, edema, and inflammation of the airways. This increases the amount of work a patient must do to overcome the increase in airway resistance, thereby increasing the patient’s work of breathing. A drug overdose causes hypercapnic respiratory failure, but because of a reduced drive to breathe. Myasthenia gravis is a neuromuscular disease that may paralyze the ventilatory muscles, causing a patient to not be able to move air. A pulmonary embolism would increase dead space by blocking off perfusion to a part of the lung. This would cause acute hypoxemic respiratory failure.
DIF: 1 REF: pg. 50 (Box 4-2)
A postoperative patient complaining of dyspnea is found to have tachypnea and tachycardia, and is somewhat confused. Breath sounds reveal end inspiratory crackles in both lung bases. An arterial blood gas is drawn and reveals the following: pH 7.49; partial pressure of carbon dioxide (PaCO2) 33 mm Hg; partial pressure of oxygen (PaO2) 51 mm Hg; arterial oxygen saturation (SaO2) 87%; bicarbonate (HCO3-) 25 mEq/L while on a 30% air entrainment mask. The most appropriate respiratory therapy intervention includes which of the following?
a. Initiate noninvasive positive pressure ventilation (NPPV).
b. Initiate continuous positive airway pressure (CPAP) by mask.
c. Administer bronchodilator therapy.
d. Intubate and mechanically ventilate.
ANS: B
This patient is showing signs and symptoms of hypoxemic respiratory failure due to post-operative atelectasis. This patient’s PaO2/FIO2 is below the critical value. Since the patient is still able to move air, intubation and mechanical ventilation, as well as noninvasive positive pressure ventilation (NPPV) are not appropriate at this time. This patient is not showing signs of increased work of breathing due to bronchospasm. Therefore, administering bronchodilator therapy is not appropriate. Initiating continuous positive airway pressure (CPAP) by mask will help to reverse the atelectasis and improve the patient’s oxygenation status.
DIF: 3 REF: pg. 50
A patient with inadequate oxygenation of the brain may display which of the following conditions?
- Confusion
- Excitement
- Somnolence
- Compliance
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 4 only
d. 3 and 4 only
ANS: B
Confusion and somnolence are neurological findings with severe hypoxemia, which shows that the hypoxemia has affected the patient’s brain. The brain requires approximately 3.3 mL of oxygen per 100 grams of brain tissue per minute. Initially, the body responds to lowered blood oxygen by redirecting blood to the brain and increasing cerebral blood flow. Blood flow may increase up to twice the normal flow but no more. If the increased blood flow is sufficient to supply the brain’s oxygen needs, then no symptoms will result. However, if blood flow cannot be increased or if doubled blood flow does not correct the problem, symptoms of cerebral hypoxia will begin to appear. These symptoms include restlessness, disorientation, headaches, lassitude, somnolence, confusion, delirium, blurred vision, etc.
DIF: 1 REF: pg. 51 (Table 4-1)
A 28-year-old man is admitted to the emergency department with suspected drug overdose. The patient is obtunded and slightly cyanotic. The arterial blood gas results obtained while the patient was breathing room air were: pH 7.24; partial pressure of carbon dioxide (PaCO2) 58 mm Hg; partial pressure of oxygen (PaO2) 52 mm Hg; bicarbonate (HCO3-) 24 mEq/L. The most appropriate interpretation of these results is which of the following?
a. Chronic respiratory failure
b. Hypoxemic respiratory failure
c. Hypercapnic respiratory failure
d. Acute orchronic respiratory failure
ANS: C
This arterial blood gas shows an uncompensated respiratory acidosis with moderate hypoxemia. A patient with chronic respiratory failure would show an elevated bicarbonate (HCO3-) due to the chronic respiratory failure. A patient with acute or chronic respiratory failure would have an elevated partial pressure of carbon dioxide in the arteries (PaCO2) that is higher than what the patient’s current HCO3- can compensate for. Hypoxemic respiratory failure will only show a decreased partial pressure of oxygen in the arteries (PaO2) unless the hypoxemia is so severe that the patient’s ventilation is compromised.
DIF: 2 REF: pg. x
The respiratory assessment of a 44-year-old female patient diagnosed with myasthenia gravis shows: vital capacity 475 mL, maximum inspiratory pressure (MIP) -18 cm H2O. The patient is 5 feet 6 inches tall and weighs 188 lbs. The most recent arterial blood gas on a 2 L/min nasal cannula is pH 7.32, partial pressure of carbon dioxide (PaCO2) 49 mm Hg, partial pressure of oxygen (PaO2) 77 mm Hg, arterial oxygen saturation (SaO2) 95%, bicarbonate (HCO3-) 24 mEq/L.The most appropriate recommendation for this patient is which of the following?
a. 50% air entrainment mask
b. Continuous positive airway pressure
c. Noninvasive positive pressure ventilation
d. Intubation and mechanical ventilation
ANS: D
The arterial blood gas result for this patient shows an acute respiratory acidosis. That along with a vital capacity of 7.4 mL/kg and the maximum inspiratory pressure (MIP) of -18 cm H2O point to the fact that this patient is also showing signs of muscle weakness that is progressively worsening. This requires prompt intubation and support to prevent acute respiratory failure. The 50% air entrainment mask and the continuous positive airway pressure (CPAP) will not provide support for this patient’s ventilatory problems. Noninvasive positive pressure ventilation (NPPV) is not appropriate for this patient because of the patient’s decreasing muscle strength.
DIF: 3 REF: pgs. 53, 58
Which of the following values are indicative of acute respiratory failure and the need for ventilatory support?
- Maximum inspiratory pressure (MIP) = – 25 cm H2O
- Dead space to tidal volume ration (VD/VT) = 0.4
- Vital capacity (VC) = 8 mL/kg IBW
- pH = 7.20
a. 1 and 2 only
b. 2 and 3 only
c. 3 and 4 only
d. 1 and 4 only
ANS: C
The critical values for the parameters listed are: maximum inspiratory pressure (MIP) -20 to 0, dead space to tidal volume (VD/VT) 0.3 to 0.4, vital capacity (VC)
A 46-year-old male presents to the emergency department with a chief complaint of shortness of breath. Physical assessment reveals: pulse 102, blood pressure 138/80, respiratory rate 25 with accessory muscle use, and breath sounds are decreased with bilateral inspiratory and expiratory wheezing with a prolonged expiratory phase. The peak expiratory flow rate is 100 L/min. The immediate action by the respiratory therapist should include which of the following?
a. Intubate and mechanically ventilate.
b. Administer oxygen via nonrebreather mask.
c. Administer continuous bronchodilator therapy.
d. Initiate noninvasive positive pressure ventilation.
ANS: C
It would be inappropriate at this time to intubate this patient because he is still moving air, as evidenced by his respiratory rate and breath sounds (although he may be tiring). Noninvasive ventilation is not appropriate for the same reasons. An arterial blood gas is necessary to establish the need for mechanical ventilation. This patient appears to be having an asthma exacerbation, as evidenced by his bilateral wheezing with a prolonged expiratory phase. The patient would probably benefit from oxygen therapy. However, the immediate problem and cause for alarm is his severe airflow obstruction, as evidenced by his breath sounds and peak expiratory flow rate (PEFR). Therefore, the most appropriate answer is to administer continuous bronchodilator therapy.
DIF: 3 REF: pgs. 54, 55
A 64-year-old female patient having an acute exacerbation of chronic obstructive pulmonary disease (COPD) was admitted to the hospital yesterday. During rounds today the respiratory therapist finds the patient to be difficult to arouse and has the following physical findings: heart rate 102, respiratory rate 23 shallow and slightly labored, breath sounds are bilaterally decreased with rhonchi in both bases. The patient has a frequent, but weak cough. The respiratory therapist draws an arterial blood gas with the following results on a 2 L/min nasal cannula: pH 7.52, partial pressure of carbon dioxide (PaCO2) 30 mm Hg, partial pressure of oxygen (PaO2) 45 mm Hg, arterial oxygen saturation (SaO2) 86%, bicarbonate (HCO3-) 24 m Eq/L. The most appropriate action is which of the following?
a. Intubate and mechanically ventilate.
b. Increase the nasal cannula to 4 L/min.
c. Administer incentive spirometry.
d. Begin noninvasive positive pressure ventilation.
ANS: B
It would be inappropriate to intubate or use noninvasive positive pressure ventilation (NPPV) on this patient at this time because the patient is able to move air, as evidence by the partial pressure of carbon dioxide (PaCO2) of 30 mm Hg in the arteries. This patient might benefit from lung expansion therapy. However, she would not be able to cooperate to perform the incentive spirometry properly because she is difficult to arouse. The patient would benefit from an increase in oxygen therapy by increasing the nasal cannula flow to 4 L/min since her partial pressure of oxygen in the arteries (PaO2) is 45 mm Hg on 2 L/min nasal cannula. When the 2 L/min is estimated to be approximately 28% oxygen the PaO2/FIO2 is 161. This is a critical value. This patient would also benefit from bronchial hygiene therapy to mobilize the retained secretions.
DIF: 3 REF: pgs. 55, 56
A 55-year-old male with acute dyspnea is admitted to the hospital. He is alert and oriented. His physical examination reveals: heart rate (HR) 120 and regular, blood pressure (BP) 146/88, temperature 38° C, respiratory rate (RR) 28 shallow and labored. Breath sounds are decreased throughout with fine late crackles on inspiration, chest expansion is decreased in both bases. The patient is not coughing. The arterial blood gas (ABG) on room air is: pH 7.52, partial pressure of carbon dioxide (PaCO2) 30 mm Hg, partial pressure of oxygen (PaO2 ) 42 mm Hg, Hb-O2 80%, bicarbonate (HCO3-) 24 mEq/L. This patient is retired after working in a steel factory for 38 years and he has a 50 pack-year history of smoking. The most appropriate action for the respiratory therapist to take is which of the following?
a. Intubate and initiate positive pressure ventilation.
b. Initiate noninvasive positive pressure ventilation.
c. Administer oxygen via a high flow nasal cannula.
d. Initiate bronchodilator and mucolytic therapy.
ANS: C
According to the arterial blood gas (ABG) this patient is able to move air as evidenced by a partial pressure of carbon dioxide (PaCO2) of 30 mm Hg (respiratory alkalosis); therefore intubation and artificial ventilation are not necessary. The patient does not require noninvasive positive pressure ventilation (NPPV), because he is breathing. The patient does not seem to have evidence of requiring a bronchodilator and mucolytic. The patient does, however, have moderate hypoxemia. Since the patient is not a carbon dioxide (CO2) retainer, a high concentration of oxygen may be applied in the form of high flow nasal cannula.
DIF: 3 REF: pgs. 55, 56
A 28-year-old female was admitted last night for weakness and what appears to be ascending muscle paralysis. The patient is alert and oriented. Physical findings reveal: pulse 96, regular; blood pressure (BP) 134/83; temperature 37° C; respiratory rate (RR) 24 shallow with bilateral decrease in air entry, and no adventitious breath sounds. The patient’s arterial blood gas (ABG) results on room air are: pH 7.46; partial pressure of carbon dioxide (PaCO2) 39 mmHg; partial pressure of oxygen (PaO2) 80 mmHg; Sat 97%; bicarbonate (HCO3-) 26 mEq/L on room air. The most appropriate suggestion that the respiratory therapist should make for this patient includes which of the following?
a. Vital capacity every two hours
b. Continuous positive airway pressure
c. Noninvasive positive pressure ventilation
d. Peak expiratory flow rate y
ANS: A
Although this patient is suffering from a neuromuscular disease, the patient’s arterial blood gas results are within normal limits and therefore do not warrant the use of continuous positive airway pressure (CPAP) or noninvasive positive airway pressure (NPPV). Peak expiratory flow rate is most frequently used to assess airway resistance for patients with acute asthma. This patient requires frequent monitoring to assess her respiratory muscle strength, and that would be within the vital capacity.
DIF: 3 REF: pgs. 53, 54
An 80-year-old female with a diagnosis of pneumonia was admitted to the hospital 2 days ago from a nursing home. The patient is responsive only to painful stimuli. She has a peripheral IV and a feeding tube in place. Physical examination reveals: pulse 98 bpm, respiratory rate 24 and shallow, blood pressure 100/48, and temperature 39.2° C. Auscultation reveals decreased breath sounds with crackles in the bases. The patient has an occasional weak, nonproductive cough. Arterial blood gas on NC 4 L/min is pH 7.42, partial pressure of carbon dioxide (PaCO2) 38 mmHg, partial pressure of oxygen (PaO2) 40 mm Hg, arterial oxygen saturation (SaO2) 76%, bicarbonate (HCO3-) 24 mEq/L. A portable chest x-ray shows patchy basilar infiltrates in both lungs. The most appropriate action to take at this time is which of the following?
a. Intubate and initiate mechanical ventilation.
b. Administer a bronchodilator and mucolytic.
c. Initiate noninvasive positive pressure ventilation.
d. Change the nasal cannula to a nonrebreather mask.
ANS: D
According to the arterial blood gas (ABG) this patient has a normal acid-base balance, therefore intubation and artificial ventilation are not necessary. The patient does not seem to have evidence of requiring a bronchodilator and mucolytic. The patient does not require noninvasive positive airway pressure ventilation (NPPV), because he is breathing. The patient does, however, have severe hypoxemia that warrants a high oxygen concentration.
DIF: 3 REF: pg. 56
