NURSING 303 Chapter 9: Ventilatory Assistance ...QUESTIONS AND ANSWERS..100%

1. A patient has coronary artery bypass graft surgery and is transported to the surgical intensive care unit at noon. He is placed on mechanical ventilation. Interpret his initial arterial blood gas levels: pH 7.31 PaCO2 48 mm Hg Bicarbonate 22 mEq/L PaO2 115 mm Hg O2 saturation 99% a. Normal arterial blood gas levels with a high oxygen level b. Partly compensated respiratory acidosis, normal oxygen c. Uncompensated metabolic acidosis with high oxygen levels d. Uncompensated respiratory acidosis; hyperoxygenated ANS: D The high PaO2 level reflects hyperoxygenation; the PaCO2 and pH levels show respiratory acidosis. The respiratory acidosis is uncompensated as indicated by a pH of 7.31 (acidosis) and a normal bicarbonate level. No metabolic compensation has occurred. DIF: Cognitive Level: Analysis REF: pp. 178-179 | Box 9-2 | Box 9-3 OBJ: Describe methods for assessing the respiratory system, including physical assessment, interpretation of arterial blood gases, and noninvasive techniques. TOP: Nursing Process Step: Assessment MSC: NCLEX: Physiological Integrity 2. The physician orders the following mechanical ventilation settings for a patient who weighs 75 kg. The patient's spontaneous respiratory rate is 22 breaths/min. What arterial blood gas abnormality may occur if the patient continues to be tachypneic at these ventilator settings? Settings: Tidal volume: 600 mL (8 mL per kg) FiO2: 0.5 Respiratory rate: 14 breaths/min Mode assist/control Positive end-expiratory pressure: 10 cm H2O a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: D Assist/control ventilation may result in respiratory alkalosis, especially when the patient is breathing at a high rate. Each time the patient initiates a spontaneous breath—in this case 22 times per minute—the ventilator will deliver 600 mL of volume. DIF: Cognitive Level: Analysis REF: p. 197 OBJ: Relate complications associated with mechanical ventilation. TOP: Nursing Process Step: Evaluation MSC: NCLEX: Physiological Integrity 3. A patient’s ventilator settings are adjusted to treat hypoxemia. The fraction of inspired oxygen is increased from .60 to .70, and the positive end-expiratory pressure is increased from 10 to 15 cm H2O. Shortly after these adjustments, the nurse notes that the patient's blood pressure drops from 120/76 mm Hg to 90/60 mm Hg. What is the most likely cause of this decrease in blood pressure? a. Decrease in cardiac output b. Hypovolemia c. Increase in venous return d. Oxygen toxicity ANS: A Positive end-expiratory pressure increases intrathoracic pressure and may result in decreased venous return. Cardiac output decreases as a result, and is reflected in the lower blood pressure. It is essential to assess the patient to identify optimal positive end-expiratory pressure—the highest amount that can be applied without compromising cardiac output. Although hypovolemia can result in a decrease in blood pressure, there is no indication that this patient has hypovolemia. As noted, higher levels of positive end-expiratory pressure may cause a decrease, not an increase, in venous return. Oxygen toxicity can occur in this case secondary to the high levels of oxygen needed to maintain gas exchange; however, oxygen toxicity is manifested in damage to the alveoli. DIF: Cognitive Level: Analysis REF: p. 196 OBJ: Relate complications associated with mechanical ventilation. TOP: Nursing Process Step: Evaluation MSC: NCLEX: Physiological Integrity 4. The nurse is caring for a patient with an endotracheal tube. The nurse understands that endotracheal suctioning is needed to facilitate removal of secretions and that the procedure: a. decreases intracranial pressure. b. depresses the cough reflex. c. is done as indicated by patient assessment. d. is more effective if preceded by saline instillation to loosen secretions. ANS: C Suctioning is performed as indicated by patient’s assessment. Suctioning is associated with increases in intracranial pressure; therefore, it is important to hyperoxygenate the patient prior to suctioning to reduce this complication. Suctioning can stimulate the cough reflex rather than depress this reflex. Saline instillation is associated with negative physiological outcomes and is not recommended as part of the suctioning procedure; it does not loosen secretions, which is a common misperception. DIF: Cognitive Level: Comprehension REF: p. 193 | Box 9-7 | Nursing Care Plan OBJ: Discuss methods for maintaining an open airway. TOP: Nursing Process Step: Implementation MSC: NCLEX: Physiological Integrity 5. A 65-year-old patient is admitted to the progressive care unit with a diagnosis of community- acquired pneumonia. The patient has a history of chronic obstructive pulmonary disease and diabetes. A set of arterial blood gases obtained on admission without supplemental oxygen shows pH 7.35; PaCO2 55 mm Hg; bicarbonate 30 mEq/L; PaO2 65 mm Hg. These blood gases reflect: a. hypoxemia and compensated metabolic alkalosis. b. hypoxemia and compensated respiratory acidosis. c. normal oxygenation and partly compensated metabolic alkalosis. d. normal oxygenation and uncompensated respiratory acidosis. ANS: B The PaO2 of 65 mm Hg is lower than normal range (80-100 mm Hg), indicating hypoxemia. The high PaCO2 indicates respiratory acidosis. The elevated bicarbonate indicates metabolic alkalosis. Because the pH is normal, the underlying acid-base alteration is compensated. Given the patient’s history of chronic pulmonary disease and a pH that is at the lower end of normal range, it can be determined that this patient is hypoxemic with fully compensated respiratory acidosis. DIF: Cognitive Level: Analysis REF: pp. 181-182 | Box 9-2 | Box 9-3 OBJ: Describe methods for assessing the respiratory system, including physical assessment, interpretation of arterial blood gases, and noninvasive techniques. TOP: Nursing Process Step: Assessment MSC: NCLEX: Physiological Integrity 6. A patient’s status worsens and needs mechanical ventilation. The pulmonologist wants the patient to receive 10 breaths/min from the ventilator but wants to encourage the patient to breathe spontaneously in between the mechanical breaths at his own tidal volume. This mode of ventilation is called: a. assist/control ventilation b. controlled ventilation c. intermittent mandatory ventilation d. positive end-expiratory pressure ANS: C The intermittent mandatory ventilation mode allows the patient to breathe spontaneously between breaths. The patient will receive a preset tidal volume at a preset rate. Any additional breaths that he initiates will be at his spontaneous tidal volume, which will likely be lower than the ventilator breaths. In assist/control ventilation, spontaneous effort results in a preset tidal volume delivered by the ventilator. Spontaneous effort during controlled ventilation results in patient/ventilator dyssynchrony. Positive end-expiratory pressure (PEEP) is application of positive pressure to breaths delivered by the ventilator. PEEP is an adjunct to both intermittent mandatory and assist/control ventilation. DIF: Cognitive Level: Application REF: p. 198 OBJ: Describe types and modes of mechanical ventilation. TOP: Nursing Process Step: Implementation MSC: NCLEX: Physiological Integrity 7. A patient’s endotracheal tube is not secured tightly. The respiratory care practitioner assists the nurse in taping the tube. After the tube is retaped, the nurse auscultates the patient’s lungs and notes that the breath sounds over the left lung fields are absent. The nurse suspects that: a. the endotracheal tube is in the right mainstem bronchus. b. the patient has a left pneumothorax. c. the patient has aspirated secretions during the procedure. d. the stethoscope earpiece is clogged with wax. ANS: A The endotracheal tube can become dislodged during repositioning and is likely in the right mainstem bronchus. It is important to reassess breath sounds after the retaping procedure. A pneumothorax would also result in diminished or absent breath sounds; however, it is not associated with repositioning the endotracheal tube. Aspiration may occur during the procedure but would be manifested in changes in chest x-ray, hypoxemia, etc. The stethoscope is not a factor. DIF: Cognitive Level: Analysis REF: p. 193 | Box 9-7 | Nursing Care Plan OBJ: Formulate a plan of care for the mechanically ventilated patient. TOP: Nursing Process Step: Evaluation MSC: NCLEX: Physiological Integrity 8. A mode of pressure-targeted ventilation that provides positive pressure to decrease the workload of spontaneous breathing through the endotracheal tube is: a. continuous positive airway pressure. b. positive end-expiratory pressure. c. pressure support ventilation. d. T-piece adapter. ANS: C Pressure support (PS) is a mode of ventilation in which the patient’s spontaneous respiratory activity is augmented by the delivery of a preset amount of inspiratory positive pressure. Positive end-expiratory pressure provides positive pressure at end expiration during mechanical breaths, and continuous positive airway pressure provides positive pressure during spontaneous breaths. The T-piece adapter is used to provide oxygen with spontaneous, unassisted breaths. DIF: Cognitive Level: Comprehension REF: pp. 199-200 OBJ: Describe types and modes of mechanical ventilation. TOP: Nursing Process Step: Implementation MSC: NCLEX: Physiological Integrity 9. Neuromuscular blocking agents are used in the management of some ventilated patients. Their primary mode of action is: a. analgesia. b. anticonvulsant. c. paralysis. d. sedation. ANS: C Neuromuscular blocking agents cause respiratory muscle paralysis. They do not have sedative, analgesic, or anticonvulsant effects. DIF: Cognitive Level: Comprehension REF: pp. 212-213 OBJ: Formulate a plan of care for the mechanically ventilated patient. TOP: Nursing Process Step: Implementation MSC: NCLEX: Physiological Integrity 10. One of the early signs of the effect of hypoxemia on the nervous system is: a. cyanosis. b. restlessness. c. tachycardia. d. tachypnea. ANS: B Decreased oxygenation to the nervous system may result in restlessness and agitation—early signs of hypoxemia. Cyanosis is a late sign. Tachycardia and tachypnea may occur, but CNS changes tend to occur earlier