Page 15 - Critical Care Notes

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breaths and controls flow rate and tidal volume. Decreases work of breath-
ing and promotes weaning.
■ Pressure-Controlled ventilation (PCV): Controls plateau pressures
in patients with ARDS and persistent oxygenation problems despite high
levels of PEEP and FIO 2 .
■ Pressure-Regulated Volume Control (PRVC): Preset rate, FIO 2 , and pressure
limit. Improves patient-ventilator synchrony and reduces barotrauma. May
require sedation.
■ Volume-Assured Pressure Support (VAPS) or Volume Guaranteed Pressure
Options (VGPO): Combination of pressure with guaranteed volume control.
■ High-Frequency Ventilation (HFV): Delivers very high breaths/min with low
tidal volumes. These include high-frequency oscillatory ventilation (HFOV
or HFO), high-frequency jet ventilation (HFJV), and high-frequency positive
pressure ventilation (HFPPV).
■ Inverse Ratio Ventilation (IRV): All breaths are pressure limited and time
cycled. Inspiratory time usually set shorter than expiratory time. I:E ratio is
usually 1:1.3–1.5
Noninvasive Mechanical Ventilation (NIV)
■ Continuous Positive Airway Pressure (CPAP): A form of noninvasive
mechanical ventilation (NIMC). Maintains positive pressure throughout the
respiratory cycle of a spontaneously breathing patient. Increases the
amount of air remaining in the lungs at the end of expiration. Fewer com-
plications than PEEP. Ordered as 5–10 cm H 2 O.
■ Bilevel Positive Airway Pressure (BiPAP): Same as CPAP but settings can be
adjusted for both inspiration and expiration.
SIMV, CPAP, BiPAP, and PSV can all be used in the weaning process.
General Nursing Care for Mechanically Ventilated
Patients
■ General routine head-to-toe assessment to monitor for complications related
to mechanical ventilation.
■ Check ventilator settings for accuracy, especially rate, tidal volume, FIO 2 ,
PEEP level, and pressure gauge; monitor ABGs after ventilator setting
changes.
■ Assess for oxygen toxicity. Cellular damage causing capillary leak →
pulmonary edema and ARDS. May develop if patient on 100% FIO 2 for
>12 hr or >50% FIO 2 for >24 hr. Monitor for dyspnea, ↑ lung compliance,
↓ A-a gradient, paresthesia in the extremities, and retrosternal pain. Keep
O 2 at lowest possible concentration. Consider PEEP to ↑ FIO 2 . If patient is
anemic, transfuse RBCs.
■ Administer analgesics, sedation drugs, and neuromuscular blocking agents
as needed.

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