Page 414 - ACCCN's Critical Care Nursing

Ventilation and Oxygenation Management 391

by either CPAP or NIPPV resulted in symptomatic
improvements, but failed to demonstrate a mortality TABLE 15.4 Monitoring priorities for non-invasive
102
benefit. Practice surveys indicate CPAP may be the pre- ventilation 104
ferred method of NIV for patients with CHF in Australia
and internationally. 103,104 Priority Assessment
NIV in Weaning Patient comfort Restlessness
Mask tolerance
NIV may be used as an adjunct to weaning to reduce the Anxiety level
duration of invasive ventilation and associated complica- Dyspnoea score
105
tions. Patients are extubated directly to NIV and then Pain score
weaned to standard oxygen therapy. This use of NIV Conscious level Glasgow coma score
differs from its role in preventing reintubation in patients Work of breathing Chest wall motion
that develop, or who are at high risk of, postextubation Accessory muscle activation
106
respiratory failure. A recent systematic review and meta- Respiratory rate
analysis of 12 trials of NIV as a weaning adjunct found Gas exchange parameters
reductions in mortality, ICU and hospital lengths of stay, Continuous SpO 2
Arterial blood gas analysis
107
duration of ventilation and rates of VAP. Conversely the (Baseline and 1–2 hourly
largest study of NIV use in postextubation respiratory subsequently)
failure reported worsened survival rates hypothesised as Patient colour
108
a result of delayed reintubation. A subsequent meta- Haemodynamic status Continuous heart rate
analysis suggested NIV may have a role in preventing the Intermittent blood pressure
development of respiratory failure postextubation for Ventilator parameters Air leak around mask
those at risk, but should be used with caution once respi- Adequacy of pressure support
ratory failure has developed and should not delay the (V T , pH, PaCO 2 )
decision to reintubate. 106 Adequacy peak end expiratory
pressure (SpO 2, PaO 2 )
Other Indications SpO 2 : saturation of peripheral oxygen; V T : tidal volume; PaCO 2 : partial
Other indications for NIV include: pressure of carbon dioxide in arterial blood; PaO 2 : partial pressure of
oxygen in arterial blood.
● asthma 109
● neuromuscular disorders (e.g. muscular dystrophy,
amyotrophic lateral sclerosis) features, commencing with low pressure levels, holding
● severe obstructive sleep apnoea the mask gently in position prior to securing with the
● palliation. straps/headgear, and ensuring straps prevent major leaks
INTERFACES AND SETTINGS but are not so tight they increase discomfort. Once
NIV is commenced, the patient should be monitored
NIV requires an interface that connects the patient to for respiratory and haemodynamic stability, response
either a ventilator, portable compressor or flow generator to NIV treatment, ongoing tolerance, and presence of
with a CPAP valve. The selection of an appropriate inter- air leaks (Table 15.4). Arterial blood gas analysis should
face can influence NIV success or failure. Oronasal masks be performed at baseline and within the first one to
cover both the mouth and nose and are the preferred two hours of commencement. During the initiation
97
mask type for the management of acute respiratory and stabilisation period, patients should be monitored
110
failure. Nasal masks enable speech, eating and drink- using a nurse-to-patient ratio of 1 : 1 with ongoing
ing, and therefore are used more frequently for long-term coaching to promote NIV tolerance throughout the early
NIV use. An oronasal mask enables delivery of higher stabilisation period.
ventilation pressures with less leak and greater comfort
111
for the patient. Other interfaces include full-face
111
masks that seal around the perimeter of the face and
cover the eyes as well as the nose and mouth, nasal Practice tip
pillows, mouthpieces that are placed between the patient’s
lips, and helmets that cover the whole head and consist NIV tolerance may be promoted with a simple explanation of
of a transparent plastic hood attached to a soft neck the therapy, reassurance and constant monitoring for your
collar. 112,113 These alternative interfaces may increase patient. During initiation, allow them to take short breaks
patient tolerance by reducing pressure ulceration, air from the mask if they are in discomfort or experiencing
leaks and patient discomfort. 114 claustrophobia.

INITIATION AND MONITORING PRIORITIES
Successful initiation of NIV is dependent on patient
acceptance and tolerance. Patient acceptance of NIV may POTENTIAL COMPLICATIONS
be aided by a brief explanation of the procedure and Masks need to be tight-fitting to reduce air leaks; however,
its benefits. Strategies to enhance patient tolerance this contributes to pressure ulceration on the bridge of
include: use of an interface that fits the patient’s facial the nose or above the ears (due to mask straps/headgear).