Patient's RR is 12 breaths/min, PaCO2 is 60 mm Hg. If a PaCO2 of 40 were desired, the RR be set at ...

(Answer to Q. 1)  ANS: B
This formula predicts what RR adjustment effects will be on PaCO2, with no change in VCO2 or VDphys:

(Answer to Q. 2)  ANS: B
Normally, when partial ventilatory support is indicated, IMV, PSV, volume support, PAV, and NAVA are the modes of choice.

(Answer to Q. 3)  ANS: B
Initial ventilator settings include choice of mode, tidal volume, rate, FiO2, and PEEP. The respir-atory therapist must set the trigger level, inspiratory flow or time, alarms and limits, backup ven-tilation, and humidification.

(Answer to Q. 4)  ANS: B
Primary goals of mechanical ventilation are: adequate alveolar ventilation (VA), maintaining tissue oxygenation, FiO2, PEEP, and MAP, restoring acid-base balance, reducing WOB and myocardial work, providing PEEP/CPAP to recruit lung, lung protective strategy: Small VT and appropriate PEEP levels and maintaining Pplat less than 30 cm H2O.

(Answer to Q. 5)  ANS: D
With assist-control mode, every breath is supported by the ventilator. Breaths are patient- or time-triggered to inspiration and may be volume or pressure limited. Inspiration may be volume, pressure, or time cycled to the expiratory phase. Assist-control ventilation typically is delivered as volume-controlled (VC) continuous mandatory ventilation. Suggested initial settings for as-sist-control volume ventilation in the care of adults are listed in Box 48-4. Advantages of as-sist-control volume ventilation include the assurance that a minimum, safe level of ventilation is achieved. Every breath is a volume breath, yet the patient can set his or her own breathing rate. In the event of sedation or apnea, a minimum, safe level of ventilation is guaranteed by the selection of an appropriate backup rate, usually approximately 2 to 4 breaths/min below the patient's assist rate, but not less than the rate necessary to provide a minimum safe level of ventilation (e.g., a backup rate of at least 8 to 10 breaths/min, depending on tidal volume set). Because assist-control ventilation usually provides full ventilatory support, it may result in a lower work of breathing than partial support modes.

(Answer to Q. 6)  ANS: A
Ventilation strategies for lung protection in ARDS include a low VT, rapid respiratory rates, and permissive hypercapnia if necessary to avoid overdistention or Pplat greater than 28 cm H2O.

(Answer to Q. 7)  ANS: B
Tidal volume of 6 to 8 ml/kg of ideal body weight.