Page 66 - Critical Care Nursing Demystified

Chapter 2 CARE OF THE PATIENT WITH CRITICAL RESPIRATORY NEEDS 51

TABLE 2–7 Ventilator Setting and Modes of Ventilation
Description
Settings
Tidal volume (V ) Amount of oxygen pumped into the lungs with one breath
T
Respiratory rate The number of breaths the machine gives the patient in a
minute
Fraction of The concentration of oxygen delivered. Can be ordered as
inspired oxygen a percentage (%) or fraction. For example, 50% FiO = 0.5
2
(FiO )
2
Modes
Assist controlled All breaths that are given to the patient have the same
(AC) tidal volume even if they are spontaneously generated by
the patient.
Synchronized The patient can breathe spontaneously between ventilator
intermittent breaths but at his or her own tidal volume. Tidal volume
mandatory will vary depending upon how much and how often the
ventilation (SIMV) patient breathes.
Positive end- Keeps a small positive pressure in the airway at the end of
expiratory inspiration. Increases oxygenation and keeps alveoli open.
pressure (PEEP) Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
Continuous Used when patient is ready to be weaned off the ventila-
positive airway tor. Physiologically like PEEP but with the patient breath-
pressure (CPAP) ing without ventilator breaths. In other words, breathing
on his or her own but still hooked up to the ventilator.
Pressure support Boost given to the patient while inhaling. Like a fan, helps
aid in patient comfort and decreases the work of breathing.

Ventilator Alarms

Ventilator alarms are designed to tell the nurse when something is wrong with
the system or the patient and can be scary for the nurse and the patient. The
nurse is not expected to solve every problem with a ventilator alarm. However,
the nurse is expected to support the patient while troubleshooting in an orga-
nized fashion from the patient to the machine. There are basically two types of
alarms: high pressure and low pressure (see Table 2–8).
Low-pressure alarms sound most commonly when the ventilator disconnects
from the patient. The nurse should check all circuits and reattach the tubing
that was disconnected. Another reason could be an underinflated airway bal-
loon on the ETT or tracheostomy. Measure the lateral wall pressure and
instill more air using the minimal leak technique described under Advanced
Airway Techniques. If the airway balloon will not hold air, prepare to remove