Ventilators NCLEX

Ventilators NCLEX Leave the first rating Students also studied Terms in this set (61) Science MedicineEmergency Medicine Save NCLEX Acute Respiratory Failure an...22 terms EmSayPreview ARDS nclex questions 33 terms almachengray Preview Mechanical Ventilation NCLEX quest...20 terms haannahsonPreview NCLEX 100 term akr A patient has coronary artery bypass graft surgery and is transported to the surgical intensive care unit at noon and is placed on mechanical ventilation. Interpret the initial arterial blood gas levels

pH: 7.31

PaCO2: 48 mm Hg

Bicarbonate: 22 mEq/L

PaO2: 115 mm Hg

O2 saturation: 99%

• Normal arterial blood gas levels with a high oxygen

level

• Partly compensated respiratory acidosis; normal

oxygen

• Uncompensated metabolic acidosis with high oxygen

levels

• 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.

The provider orders the following mechanical ventilation settings for a patient who weighs 75 kg. The patient's spontaneous respiratory rate is 22 breaths/min. Which 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

• Metabolic acidosis
• Metabolic alkalosis
• Respiratory acidosis
• Respiratory alkalosis

ANS: D

Assist/control ventilation may result in respiratory alkalosis, especially when the patient is breathing at a higher rate that the ventilator rate. Each time the patient initiates a spontaneous breath—in this case 22 times per minute—the ventilator will deliver 600 mL of volume.A patient's ventilator settings are adjusted to treat hypoxemia. The fraction of inspired oxygen is increased from 0.6 to 0.7, 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?

• Decrease in cardiac output
• Hypovolemia
• Increase in venous return
• 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.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

• decreases intracranial pressure.
• depresses the cough reflex.
• is done as indicated by patient assessment.
• is more effective if preceded by saline instillation.

ANS: C

Suctioning is performed as indicated by patient assessment. Suctioning is associated with increases in intracranial pressure; therefore, it is important to hyperoxygenate the patient before 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.A 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:

• hypoxemia and compensated metabolic alkalosis.
• hypoxemia and compensated respiratory acidosis.
• normal oxygenation and partly compensated

metabolic alkalosis.

• normal oxygenation and uncompensated respiratory

acidosis.

ANS: B

The PaO2 of 65 mm Hg is lower than normal range (80 to 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.

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 between the mechanical breaths at his own tidal volume.This mode of ventilation is called

• assist/control ventilation.
• controlled ventilation.
• intermittent mandatory ventilation.
• 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.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

• the endotracheal tube is in the right mainstem

bronchus.

• the patient has a left pneumothorax.
• the patient has aspirated secretions during the

procedure.

• the stethoscope earpiece is clogged with wax.

ANS: A

The endotracheal tube can become dislodged during repositioning and is likely to be 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 the chest x-ray or by hypoxemia, for example. The stethoscope is not a factor.A mode of pressure-targeted ventilation that provides positive pressure to decrease the workload of spontaneous breathing through the endotracheal tube is

• continuous positive airway pressure.
• positive end-expiratory pressure.
• pressure support ventilation.
• 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.The primary mode of action of neuromuscular blocking agents is

• analgesia.
• anticonvulsant.
• paralysis.
• sedation.

ANS: C

Neuromuscular blocking agents cause respiratory muscle paralysis. They do not have sedative, analgesic, or anticonvulsant effects.One of the early signs of hypoxemia on the nervous system is

• cyanosis.
• restlessness.
• agitation.
• tachypnea.

ANS: B

Decreased oxygenation to the nervous system may result in restlessness and agitation—early signs of hypoxemia. Cyanosis is a late sign. Tachypnea may occur, but CNS changes tend to occur earlier. Agitation is not usually seen with hypoxemia.The amount of effort needed to maintain a given level of ventilation is termed

• compliance.
• resistance.
• tidal volume.
• work of breathing.

ANS: D

Work of breathing is the amount of effort needed to maintain a given level of ventilation. Compliance is a measure of the distensibility, or stretchability, of the lung and chest wall. Resistance refers to the opposition to the flow of gases in the airways. Tidal volume is the volume of air in a typical breath.

Which of the following devices is best suited to deliver 65% oxygen to a patient who is spontaneously breathing?

• Face mask with non-rebreathing reservoir
• Low-flow nasal cannula
• Simple face mask
• Venturi mask

ANS: A

Face masks with reservoirs (partial rebreathing and non-rebreathing reservoir masks) provide oxygen concentration of 60% or higher. The addition of the reservoir increases the amount of oxygen available to the patient during inspiration and allows for the delivery of concentrations of 35% to 60% (partial rebreather) or 60% to 80% (non-rebreather), depending on the flowmeter setting, the fit of the mask, and the patient's respiratory pattern. The high-flow nasal cannula, not the traditional low-flow models, can provide higher flows. The simple face mask can deliver flows up to 60%. The Venturi mask allows better regulation of oxygen concentration and generally does not deliver more than 60% oxygen.A patient is being mechanically ventilated in the synchronized intermittent mandatory ventilation mode at a rate of 4 breaths/min. His spontaneous respirations are 12 breaths/min. He receives a dose of morphine sulfate, and his spontaneous respirations decrease to 4 breaths/min. Which acid-base disturbance will likely occur?

• Metabolic acidosis
• Metabolic alkalosis
• Respiratory acidosis
• Respiratory alkalosis

ANS: C

The morphine caused respiratory depression. As a result, the frequency and depth of respiration is compromised, which can lead to respiratory acidosis.A patient is being mechanically ventilated in the synchronized intermittent mandatory ventilation mode at a rate of 4 breaths/min. His spontaneous respirations are 12 breaths/min. He receives a dose of morphine sulfate, and his respirations decrease to 4 breaths/min. What adjustments may need to be made to the patient's ventilator settings?

• Add positive end-expiratory pressure (PEEP).
• Add pressure support.
• Change to assist/control ventilation at a rate of 4

breaths/min.

• Increase the synchronized intermittent mandatory

ventilation respiratory rate.

ANS: D

The morphine caused respiratory depression. As a result, the frequency and depth of respiration is compromised, which can lead to respiratory acidosis. The respiratory rate on the mechanical ventilator needs to be increased. PEEP is added to improve oxygenation; it does not increase the rate or depth of respirations. Pressure support will not be effective in increasing the rate of spontaneous respiration. Changing to assist/control ventilation is an option; however, the rate needs to be set higher than 4 breaths/min.Current guidelines recommend the oral route for endotracheal intubation. The rationale for this recommendation is that nasotracheal intubation is associated with a greater risk for

• basilar skull fracture.
• cervical hyperextension.
• impaired ability to "mouth" words.
• sinusitis and infection.

ANS: D

Nasotracheal intubation is associated with an increased risk for sinusitis, which may contribute to ventilator-associated infection. Nasal intubation is contraindicated in patients with basilar skull fracture. The procedure is sometimes performed in patients with cervical spine injury; the procedure can be done without hyperextending the neck. Patients with nasotracheal tubes are generally more comfortable and have a greater ability to "mouth words." Oxygen saturation (SaO2) represents

• alveolar oxygen tension.
• oxygen that is chemically combined with hemoglobin.
• oxygen that is physically dissolved in plasma.
• total oxygen consumption.

ANS: B

Oxygen saturation value reflects the saturation of the hemoglobin. It does not represent alveolar oxygen tension, oxygen that is dissolved in plasma, or total oxygen consumption.