Instant dowload and all chapters Test Bank Pilbeam's Mechanical Ventilation Physiological and Clinical Applications 6th Edition Cairo https://testbanklab.com/download/test-bank-pilbeams-mechanical-ventilation-physiologicalclinical-applications-6th-edition-cairo/ Chapter 05: Selecting the Ventilator and the Mode Cairo: Pilbeam s Mechanical Ventilation: Physiological and Clinical Applications, 6th Edition MULTIPLE CHOICE 1. A 68-year-old female admitted for congestive heart failure is in respiratory distress and is being seen by the hospital s medical emergency team in her regular room. The patient is in obvious respiratory distress and is immediately placed on a nonrebreather mask. Physical assessment reveals: pulse 138 and thready; respiratory rate 30, shallow and labored; temperature 37 C; blood pressure 110/68. Breath sounds are bilaterally decreased with coarse crackles on inspiration. EKG shows normal sinus rhythm with widened cardiac output (QT) interval and an occasional irregular beat. No coughing is noted. The arterial blood gas on the nonrebreather mask is: ph 7.34; PCO 2 46 mm Hg; partial pressure of oxygen in the arteries (P a O 2 ) is 52 mm Hg; oxygen saturation is 86%; bicarbonate (HCO 3 ) is 24 meq/l. The patient is diaphoretic. The most appropriate ventilator mode to manage this patient initially is which of the following? a. Noninvasive positive pressure ventilation (NIV) b. Airway pressure release ventilation (APRV) c. Volume-controlled intermittent mandatory ventilation (VC-IMV) d. Pressure-controlled intermittent mandatory ventilation (PC-IMV) ANS: A This patient is in impending respiratory failure due to a congestive heart failure (CHF) exacerbation. The arterial blood gas (ABG) also reveals mild hypercapnia and severe hypoxemia. With the proper treatment this exacerbation could be reversed fairly quickly. Noninvasive positive pressure ventilation (NIV), in the form of bilevel positive airway pressure, is appropriate because of this. All the other choices require intubation. If the NIV doesn t work to decrease the patient s respiratory failure then intubation would be the next step. REF: pg. 59 2. A patient has recently been diagnosed with obstructive sleep apnea. The most appropriate treatment includes which of the following? a. Pressure support ventilation (PSV) b. Noninvasive positive pressure ventilation (NIV) c. Continuous positive airway pressure (CPAP) d. Pressure-controlled continuous mandatory ventilation (PC-CMV)
Continuous positive airway pressure (CPAP) is an accepted method used to treat obstructive sleep apnea. Noninvasive positive pressure ventilation (NIV) would be appropriate if the patient had central sleep apnea, since there would be no respiratory efforts during the apnea periods. Pressure support ventilation (PSV) and pressure- controlled continuous mandatory ventilation (PC-CMV) would require the patient to be intubated. REF: pg. 59 3. Which of the following is the minimum ventilator rate that is considered full ventilatory support? a. 4 breaths/min b. 6 breaths/min c. 8 breaths/min d. 10 breaths/min Full ventilatory support is provided when the ventilator-initiated rates are 8 breaths/min or more. REF: pg. 60 4. Partial ventilatory support can be provided by which of the following ventilator modes? 1. Pressure-controlled continuous mandatory ventilation (PC-CMV) set rate 8 breaths/min 2. Volume-controlled intermittent mandatory ventilation (VC-IMV) set rate 4 breaths/min 3. Pressure-controlled intermittent mandatory ventilation (PC-IMV) set rate 10 breaths/min 4. VC-MMV set V e 8 L/min a. 1 and 2 only b. 2 and 3 only c. 2 and 4 only d. 3 and 4 only Continuous mandatory ventilation (CMV) is a full ventilatory support mode. Therefore, a pressure-controlled continuous mandatory ventilation (PC-CMV) rate of 8 breaths/min is not partial ventilatory support. A ventilator rate setting of 8 breaths/min or more is also considered full support. Therefore, even though pressure-controlled intermittent mandatory ventilation (PC-IMV) could be partial ventilatory support, it is full support because of the set rate of 10 breaths/min. Volume-controlled intermittent mandatory ventilation (VC-IMV) with a set rate of 4 breaths/min is partial ventilatory support and MMV can be partial ventilatory support when the patient is participating in the work of breathing (WOB) to maintain effective alveolar ventilation. REF: pg. 60 5. Of the following breath descriptions, which one is considered spontaneous? a. Flow triggered, pressure limited, flow cycled b. Time triggered, volume limited, volume cycled c. Pressure triggered, pressure limited, time cycled d. Patient triggered, patient cycled, baseline pressure +5 cm H 2 O ANS: D
Flow triggered and pressure triggered mean that the patient has initiated the breath. Pressure limited and volume limited mean that either one of these variables is not allowed to be exceeded during a breath. This occurs with either ventilator or assisted breaths. Patient triggered could either be pressure or flow and could be part of a spontaneous breath as long as the pressure during inspiration does not rise above the baseline setting. During spontaneous breathing the patient will control both the beginning and the ending of the breath. REF: pg. 60 6. What type of breath occurs when the ventilator controls the timing, tidal volume, or inspiratory pressure? a. Assisted b. Mandatory c. Spontaneous d. Controlled Mandatory breaths occur when the ventilator is time triggered, volume or pressure targeted. Spontaneous breaths are patient triggered, and the volume or pressure is based on the patient s demand and lung characteristics. Assisted breaths have characteristics of both mandatory and spontaneous, the patient triggers the breath, the ventilator delivers a set pressure or volume, and the airway pressure rises above baseline during inspiration. The term control is not used to describe the type of breath delivery. This term is used to describe the variable that is being manipulated as the target for the breaths (e.g., pressure control or volume control). REF: pg. 61 7. A home care patient diagnosed with central sleep apnea would benefit from which of the following modes of ventilation? a. Pressure support ventilation (PSV) b. Noninvasive positive pressure ventilation (NIV) c. Continuous positive airway pressure (CPAP) d. Pressure controlled intermittent mandatory ventilation (PC-IMV) Noninvasive positive pressure ventilation (NIV) is appropriate for this patient because during the periods of apnea there are no respiratory efforts. Continuous positive airway pressure (CPAP) is an accepted method used to treat obstructive sleep apnea. Pressure support ventilation (PSV) and pressure-controlled intermittent mandatory ventilation (PC-CMV) would require the patient to be intubated. REF: pg. 59 pg. 60 8. During volume control ventilation a patient s airway resistance increases. This change will cause which of the following to occur? a. Increase in delivered volume b. Increase in peak airway pressure c. Decrease in plateau pressure d. Decrease in peak airway pressure
During volume control ventilation, changes in lung characteristics cause changes in pressure. Increasing airway resistance causes an increase in the amount of pressure required to deliver the volume, thereby increasing peak airway pressure. REF: pg. 61 pg. 62 (Box 5-4) 9. A 28-year-old male has arrived in the emergency department following a motor vehicle accident. He has a Glasgow Coma Score of 14. Chest X-ray reveals five ribs broken anteriorly in two areas each. Physical assessment reveals paradoxical movement of the chest. Breath sounds are diminished and the trachea is midline. Arterial blood gas on nonrebreather mask is: ph 7.53, partial pressure of carbon dioxide (P a CO 2 ) is 25 mm Hg, partial pressure of oxygen (P a O 2 ) is 59 mm Hg, arterial oxygen saturation (S a O 2 ) 93%, bicarbonate (HCO 3 ) 23 meq/l. The respiratory therapist should recommend which of the following for this patient? a. Noninvasive positive pressure ventilation (NIV) with supplemental oxygen b. Intubation with volume-controlled continuous mandatory ventilation (VC-CMV) with positive end-expiratory pressure (PEEP) c. Mask continuous positive airway pressure (CPAP) with supplemental oxygen d. Intubation with CPAP and pressure support The arterial blood gas shows that the patient is ventilating, as evidenced by the partial pressure of carbon dioxide (P a CO 2 ) of 25 mm Hg. Therefore, this patient does not need to be intubated and ventilated at this time. This also means that the patient does not require noninvasive positive pressure ventilation (NIV). The patient does have an oxygenation problem, as evidenced by the partial pressure of oxygen (P a O 2 ) of 59 mm Hg while on a nonrebreather mask. This is an indication for continuous positive airway pressure (CPAP). REF: pg. 59 10. An assisted breath in the pressure controlled continuous mandatory ventilation (PC-CMV) mode can be described by which of the following? a. Time triggered, pressure limited, time cycled b. Patient triggered, pressure limited, time cycled c. Time triggered, pressure limited, pressure cycled d. Patient triggered, volume limited, volume cycled An assisted breath is always patient triggered. In the pressure control or targeted mode the pressure set is the pressure limit and the inspiratory time setting ends inspiration (cycle). Therefore, the correct answer is patient triggered, pressure limited, time cycled. The time triggered, pressure limited, and time cycled breath is a mandatory breath in the pressurecontrolled continuous mandatory ventilation (PC-CMV) mode. The time triggered, pressure limited, and pressure cycled breath describes an intermittent positive pressure breathing (IPPB)-type mandatory breath. The patient triggered, volume limited, and volume cycled is a mandatory breath in the volume-controlled continuous mandatory ventilation (VC-CMV) mode. REF: pg. 60 pg. 61 11. The ventilator mode that allows the patient to breathe spontaneously between operatorselected time-triggered volume and pressure-targeted breaths is which of the following?
a. Pressure support ventilation (PSV) b. Continuous mandatory ventilation (CMV) c. Intermittent mandatory ventilation (IMV) d. Airway pressure release ventilation (APRV) The intermittent mandatory ventilation (IMV) mode allows the patient to breathe spontaneously between operator mandatory ventilator breaths. During these spontaneous breaths the baseline pressure may be set at ambient pressure or above ambient pressure. In addition, pressure support may be used during the spontaneous breathing period. Pressure support ventilation (PSV) has no time-triggered breaths, nor does it have volume-targeted breaths. Continuous mandatory ventilation (CMV) does not allow for spontaneous breathing; it only allows the patient to trigger the mandatory ventilator breath. Airway pressure release ventilation (APRV) does not have volume-targeted breaths. It is designed to be two levels of continuous positive airway pressure (CPAP) where the patients breathe spontaneously at both levels. REF: pg. 60 pg. 61 12. A hemodynamically unstable patient being ventilated in the volume-controlled continuous mandatory ventilation (VC-CMV) mode is triggering inspiration at a rate of 25 breaths/min and has the following arterial blood gas results: ph 7.50, partial pressure of carbon dioxide (P a CO 2 ) 30 mm Hg, partial pressure of oxygen (P a O 2 ) 98 mm Hg, arterial oxygen saturation (S a O 2 ) 100%, bicarbonate (HCO 3 ) 24 meq/l. The respiratory therapist should perform which of the following? a. Extubate and administer noninvasive positive pressure ventilation (NIV). b. Change the mode to pressure-controlled continuous mandatory ventilation (PC- CMV). c. Change the mode to volume-controlled intermittent mandatory ventilation (VC- IMV). d. Sedate and paralyze the patient. This patient has ventilator-induced hyperventilation as evidenced by the partial pressure of carbon dioxide (P a CO 2 ) of 30 mm Hg with a trigger rate of 25 breaths/min. Switching to the volume-controlled intermittent mandatory ventilation (VC-IMV) mode will decrease the number of ventilator breaths the patient triggers by allowing the patient to breathe spontaneously between the mandatory ventilator breaths. This will reduce the patient s minute ventilation and normalize the P a CO 2 and ph. Another potential advantage is to put less of a strain on an already hemodynamically unstable patient. There is nothing in this patient s scenario that suggests extubation and use of noninvasive positive pressure ventilation (NIV). Switching to the pressure-controlled continuous mandatory ventilation (PC-CMV) mode will most likely not correct the patient s problem because the patient will still be able to trigger ventilator set breaths and could continue to hyperventilate. Although sedating and medically paralyzing the patient could normalize the patient s acid-base balance, it is not the treatment of choice because of the hemodynamic instability of the patient. REF: pg. 60 pg. 61 13. The pressure-time scalar shown in the figure represents which of the following?
a. Airway pressure release ventilation (APRV) b. Volume-controlled intermittent ventilation (VC-IMV) with positive end-expiratory pressure (PEEP) c. Pressure-controlled intermittent mandatory ventilation (PC-IMV) with positive end-expiratory pressure (PEEP) d. Bilevel positive airway pressure The figure shows two levels of pressure-control ventilation. The higher level, around 22 cm H 2 O is the mandatory ventilator breaths. The lower level shows spontaneous breaths with a pressure support of approximately 15 cm H 2 O. Baseline (PEEP) is at 5 cm H 2 O. REF: pg. 60 pg. 61 14. Full ventilatory support is provided by which of the following modes? a. Pressure support ventilation (PSV) with continuous positive airway pressure (CPAP) b. Volume support ventilation (VSV) with continuous positive airway pressure (CPAP) c. Volume-controlled intermittent mandatory ventilation (VC-IMV) rate 6 with pressure support (PS) d. Pressure-controlled intermittent mandatory ventilation (PC-IMV) rate 12 with pressure support (PS) ANS: D Full ventilatory support is provided when the ventilator-initiated rates are set at 8 breaths/min or more in the continuous mandatory ventilation (CMV) or intermittent mandatory ventilation (IMV) modes with either pressure control or volume control. REF: pg. 60 pg. 61 15. The ventilator mode that would be most appropriate to iatrogenically induce hyperventilation to manage a closed head injury patient with severely elevated intracranial pressure (ICP) is which of the following? a. Volume support ventilation (VSV) b. Airway pressure release ventilation (APRV) c. Pressure-controlled continuous mandatory ventilation (PC-CMV) d. Volume-controlled intermittent mandatory ventilation (VC-IMV)
To deliberately hyperventilate a patient, each breath needs to be a machine breath (either volume or pressure). The only mode from the choices given that does that is the pressurecontrolled continuous mandatory ventilation (PC-CMV) mode. Volume support ventilation (VSV) is a patient triggered, volume targeted, flow cycled mode of ventilation that has no backup rate and therefore is a purely spontaneous mode. Airway pressure release ventilation (APRV) is designed to provide two levels of continuous positive airway pressure (CPAP) and to allow spontaneous breathing at both levels when spontaneous effort is present. If the patient is not breathing spontaneously, APRV resembles pressure-controlled inverse ratio ventilation (PCIRV) and could potentially elevate the patient s already elevated intracranial pressure (ICP). Volume-controlled intermittent mandatory ventilation (VC-IMV) actually could be made to hyperventilate the patient if the rate is set high enough. The IMV mode is actually used to reduce the effect of patient hyperventilation on acid-base balance. This happens because only the set rate is a ventilator breath; the rest are patient triggered with the patient s own tidal volume. REF: pg. 62 pg. 63 16. If flow or sensitivity is set incorrectly, which of the following is most likely to occur during the continuous mandatory ventilation (CMV) mode? a. Muscle atrophy b. Respiratory alkalosis c. Ventilator dyssynchrony d. Increase in mean airway pressure High or low flow rate settings can cause the patient to be out of synchrony with the ventilator. The higher the flow rate the shorter the inspiratory time. Incorrect sensitivity settings can lead to auto-triggering or locking out the patient. REF: pg. 65 pg. 66 17. In which of the following situations would NIV be tried? a. Patient in whom blood pressure is 65/35, heart rate is 150 beats/min, and respiratory frequency is 34 breaths/min b. Patient who nearly drowned who has copious amounts of white, frothy secretions c. Patient with chronic obstructive pulmonary disease (COPD) and right lower-lobe pneumonia with respiratory acidosis and increased work of breathing (WOB) d. A 5-year-old child who has aspirated a piece of chicken and is having trouble breathing In many cases, clinicians prefer using noninvasive positive pressure ventilator support in the form of bilevel positive airway pressure (bilevel PAP) rather than CPAP for patients with R aw - induced auto-peep. Bilevel PAP also is the method most often used to treat acute-on-chronic respiratory failure. REF: pg. 59 pg. 60 18. A breath that is triggered, limited, and cycled by the mechanical ventilator is which of the following? a. Assisted breath
b. Mandatory breath c. Spontaneous breath d. Breath Breaths that are triggered by the mechanical ventilator are considered mandatory breaths because the ventilator is controlling the timing of the breath and delivering either a set volume or set pressure. REF: pg. 60 19. A breath that is patient triggered, pressure targeted, and time cycled is which of the following? a. Assisted breath b. Mandatory breath c. Spontaneous breath d. Breath ANS: A Assisted breaths have characteristics of both mandatory and spontaneous breaths. In an assisted breath, all or part of the breath is generated by the ventilator, which does part of the work of breathing (WOB) for the patient. If the airway pressure rises above baseline during inspiration, which it does in this case, the breath is assisted. REF: pg. 61 20. Which mode of ventilation is shown in the pressure-time scalar in the figure? a. Pressure-controlled continuous mandatory ventilation (PC-CMV) b. Volume-controlled continuous mandatory ventilation (VC-CMV) c. Pressure-controlled intermittent mandatory ventilation (PC-IMV) d. Volume-controlled intermittent mandatory ventilation (VC-IMV) The pressure-time scalar shows all mandatory breaths, two time triggered and one pressure triggered. This means there is a combination of mandatory and assisted breaths. The scalar shows a peak inspiratory pressure that is not held. This means that the mode being shown is volume-controlled continuous mandatory ventilation (VC-CMV). REF: pg. 61 21. Which mode of ventilation is shown in the pressure-time scalar in the figure?
a. Pressure-controlled intermittent mandatory ventilation (PC-IMV) with pressure support (PS) b. Volume-controlled intermittent mandatory ventilation (VC-IMV) with pressure support (PS) c. Pressure-controlled continuous mandatory ventilation (PC-CMV) d. Airway pressure release ventilation (APRV) This graph shows two assisted mandatory breaths that have peak pressures. These are volume control breaths that are with the patient. The flat top waves are pressure targeted breaths that are indicative of pressure support. Therefore, there are mandatory breaths with spontaneous pressure supported breaths. This makes the mode volume-controlled intermittent mandatory ventilation (VC-IMV) with pressure support. REF: pg. 61 22. A patient triggered, pressure limited, flow cycled breath describes which of the following? a. Spontaneous breath b. Pressure-support breath c. Volume-control breath d. Pressure-control breath The term pressure limited points to either a pressure support breath or a pressure control breath. These breaths both are limited by the operator-selected pressure. A spontaneous breath is always flow cycled. This eliminates the pressure control breath because those breaths are always time cycled. Therefore, a patient triggered, pressure limited, flow cycled breath is a pressure support breath. REF: pg. 61 23. When a patient is to be switched from continuous mandatory ventilation (CMV) to intermittent mandatory ventilation (IMV) to facilitate weaning from mechanical ventilation, which of the following could be used in addition to IMV to assist this process? a. Continuous positive airway pressure (CPAP) b. Positive end-expiratory pressure (PEEP) c. Pressure support (PS) d. Pressure control (PC)
Spontaneous breaths during intermittent mandatory ventilation (IMV) can be supported with pressure support if the clinician wants to reduce the work of breathing (WOB) for the spontaneous breath. REF: pg. 67 (Figs 5-5, C and 5-5, D) 24. Every breath from the ventilator is time or patient triggered, pressure limited, and time cycled. This describes which of the following ventilator modes? a. Pressure support ventilation (PSV) b. Continuous positive airway pressure (CPAP) c. Pressure-controlled continuous mandatory ventilation (PC-CMV) d. Volume-controlled intermittent mandatory ventilation (VC-IMV) A mode in which the patient can receive a time triggered breath or a patient triggered breath is continuous mandatory ventilation (CMV or A/C). Pressure limited breaths that are either time or patient triggered occur in pressure-controlled continuous mandatory ventilation (PC-CMV), where the breath is also time cycled. Pressure support ventilation (PSV) breaths are always flow cycled. Continuous positive airway pressure (CPAP) breaths are always spontaneous, and volume-controlled intermittent mandatory ventilation (VC-IMV) breaths are volume limited and volume cycled. REF: pg. 66 25. If lung compliance decreases while a patient is receiving mechanical ventilation with pressure-controlled continuous mandatory ventilation (PC-CMV), which of the following would occur? a. Peak pressure increases. b. Peak pressure decreases. c. Tidal volume increases. d. Tidal volume decreases. ANS: D Reduced compliance results in lower volumes during pressure-controlled continuous mandatory ventilation (PC-CMV). REF: pg. 62 (Box 5-5) 26. A patient arrives in the emergency department following a motor vehicle accident in which the patient sustained a deceleration chest injury. The patient was intubated in the field for airway protection. Physical assessment reveals that the patient is spontaneously breathing at a rate of 16 breaths/min, and breath sounds reveal bibasilar fine crackles at end inspiration. A second arterial blood gas was drawn while the patient was receiving 100% oxygen from an air entrainment large volume nebulizer. Parameter 9:35 PM 10:10 PM ph 7.53 7.50 P a CO 2 (mm Hg) 27 30 P a O 2 (mm Hg) 48 56 S a O 2 (%) 90 91 HCO 3 (meq/l) 24 24
Supplemental oxygen Room air 100% Bland aerosol The most appropriate recommendation for this patient is which of the following? a. Continuous positive airway pressure (CPAP) with supplemental oxygen b. Pressure-controlled inverse ratio ventilation (PCIRV) with positive end-expiratory pressure (PEEP) and sedation c. Volume-controlled continuous mandatory ventilation (VC-CMV) d. Airway pressure release ventilation (APRV) ANS: A Both the assessment and blood gas results reveal that the patient is spontaneously breathing. However, it appears that the patient is suffering from air hunger. The blood gases reveal that the patient has refractory hypoxemia. With this information, the most appropriate recommendation would be to place the patient on continuous positive airway pressure (CPAP) with supplemental oxygen to improve the refractory hypoxemia by opening up atelectatic areas and maintaining them open. Since the patient is breathing spontaneously, mechanical ventilator breaths are not necessary. REF: pg. 59 27. A patient with acute respiratory distress syndrome (ARDS) has developed a pneumothorax from elevating peak and plateau pressures. The patient is currently being ventilated in the volume-controlled continuous mandatory ventilation (VC-CMV) mode with a set rate of 12 breaths/min. However, the patient is triggering the ventilator at a rate of 25 breaths/min. The arterial blood gas reveals ventilator-induced hyperventilation with corrected hypoxemia. The most appropriate recommendation to manage this patient on the ventilator is which of the following? a. Sedate the patient. b. Decrease the set ventilator rate. c. Switch the mode to pressure-controlled intermittent mandatory ventilation (PC- IMV). d. Switch the mode to pressure-controlled continuous mandatory ventilation (PC- CMV). Switching to pressure-controlled ventilation will reduce the continued risk of alveolar overdistention, which has already caused a pneumothorax, by limiting the amount of positive pressure applied to the lung. Using the intermittent mandatory ventilation (IMV) mode will decrease the ability of the patient to cause ventilator-induced hyperventilation by triggering mandatory breaths. IMV, with a low ventilator rate setting, can very well reduce this patient s respiratory alkalosis. Using pressure support with the pressure- controlled intermittent mandatory ventilation (PC-IMV) mode will decrease the WOB for the patient during spontaneous breaths. REF: pg. 61 pg. 62 28. A patient, who is nasally intubated, due to facial surgery, has been successful on her spontaneous breathing trial. She currently has moderate hypoxemia, despite a fractional inspired oxygen (F I O 2 ) of 40% and positive end-expiratory pressure (PEEP) of 5 cm H 2 O while on volume-controlled continuous mandatory ventilation (VC-CMV). The most appropriate ventilator mode for this patient is which of the following?
a. Airway pressure release ventilation (APRV) b. Continuous positive airway pressure (CPAP) c. Pressure support ventilation (PSV) with positive end-expiratory pressure (PEEP) d. Intermittent mandatory ventilation (IMV) with pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP) ANS: D The patient is ready to wean and can be placed on intermittent mandatory ventilation (IMV) to allow some ventilator breaths but also allow the patient to breathe spontaneously. The pressure support will help to overcome the increased airway resistance of the small endotracheal tube, due to the nasal intubation. The positive end-expiratory pressure (PEEP) will maintain oxygenation and keep the alveoli open. REF: pgs. 67-69 29. A dual control mode provides pressure-limited ventilation with volume delivery targeted for every breath. If the desired volume is not met the ventilator will volume cycle. This describes which of the following ventilator modes? a. Airway pressure release ventilation (APRV) b. Pressure augmentation (Paug) c. MMV d. Pressure-regulated volume control (PRVC) The pressure augmentation mode is a dual control mode that provides pressure-limited ventilation with volume delivery targeted for every breath. Each breath is flow cycled when the target volume is reached. If the guaranteed volume is not achieved before flow drops to the set level, the ventilator maintains the flow at the set value until the volume is delivered, and at that point the ventilator volume cycles. Pressure-regulated volume control (PRVC) is similar in that it also targets pressure and guarantees volume; however, when the set volume is not achieved the ventilator will incrementally increase pressure to achieve the volume. REF: pg. 72 30. The ventilator mode that delivers pressure breaths that are patient or time triggered, volume targeted, time cycled, and where the pressure is automatically adjusted to maintain delivery of the targeted volume is which of the following? a. Volume support ventilation (VSV) b. Pressure augmentation (Paug) c. MMV d. Pressure-regulated volume control (PRVC) ANS: D
Pressure-regulated volume control (PRVC) is a volume targeted, pressure control mode that delivers breaths that are patient or time triggered, volume targeted, and time cycled. During each breath delivery the ventilator measures the tidal volume delivered and compares it to the targeted tidal volume, set by the operator. If the volume delivered is less than the set tidal volume, the ventilator will increase pressure delivery progressively over several breaths until the targeted tidal volume and the delivered tidal volume are about equal. Pressure augmentation (Paug) is similar, but the method for reaching the targeted volume is different. If the tidal volume is not reached the flow will continue until the ventilator volume cycles. Volume support ventilation (VSV) is also similar to PRVC. However, there is no time trigger in this mode and every breath is flow cycled. MMV requires the operator to set minute ventilation that serves as the threshold for ventilatory support. The ventilator increases or decreases the amount of support by increasing the rate of pressure, based on whether the patient is able to maintain the set minute ventilation. REF: pg. 72 31. The ventilator mode where every breath is patient triggered, pressure targeted, and flow cycled with a volume target is which of the following? a. Volume support ventilation (VSV) b. Pressure-regulated volume control (PRVC) c. Airway pressure release ventilation (APRV) d. Pressure augmentation (Paug) ANS: A The mode being described is basically pressure support with a volume target. This describes volume support ventilation (VSV). Pressure-regulated volume control (PRVC) is similar; however, the breaths can be either patient or time triggered. Pressure augmentation (Paug) is similar to VSV; however, not every breath is flow cycled. If the volume is not met during inspiration, the ventilator will change to volume cycle. Airway pressure release ventilation (APRV) is a dual mode of ventilation that allows spontaneous breathing at two levels of continuous positive airway pressure (CPAP), where pressure support can be added. REF: pg. 73 32. A leak around a patient s ET tube cuff during pressure support ventilation (PSV) will cause which of the following to occur? a. Volume cycle b. Time cycle c. Pressure cycle d. Flow cycle A leak around a cuff could cause a pressure support breath to never flow cycle. For this reason, most ventilators time cycle at a maximum inspiratory time of 1.5-2 seconds. REF: pg. 71 (Box 5-6)