I. Pathophysiology—impairment of respiratory function
affecting O2 uptake and CO2 elimination, requiring mechanical
assist to support or replace spontaneous breathing
a. Inability to maintain adequate oxygenation (hypoxemia)
b. Inability to maintain adequate ventilation due to apnea or
alveolar hypoventilation causing a rise in PaCO2 and a fall
in serum pH (respiratory acidosis)
c. Inability to continue the work of breathing (respiratory muscle
weakness or failure)
II. Mechanical Ventilators
a. Classified by method of cycling from the inspiratory phase to
the expiratory phase with signal to terminate the inspiratory
activity of the machine:
i. Preset volume (volume-cycled ventilator)
ii. Preset pressure limit (pressure-cycled ventilator)
iii. Preset time factor (time-cycled ventilator)
b. Mode of ventilation
i. Assist control: provides a breath with either a preset volume
for ventilator-initiated breaths or peak pressure
every time client takes a breath
ii. Pressure support ventilation: delivers preset level of positive
airway pressure, rather than volume, to decrease
work of breathing between ventilator-initiated breaths
iii. Continuous positive airway pressure (CPAP): continuous
level of elevated pressure during client-initiated breaths
to maintain adequate oxygenation and decrease the work
of breathing and the work of the heart
iv. Positive end-expiratory pressure (PEEP): adjunct to
mechanical ventilation using elevated pressure during the
expiratory phase of the ventilatory cycle to increase functional
residual capacity and surface area for gas exchange
c. Complications
i. Associated with endotracheal (ET) tube: tissue damage
to lips, tongue, throat; mucous plugs impairing ventilation
and obstruction caused by client biting tube; auto
PEEP; sinusitis or otitis; cuff herniation (rare)
ii. Associated with the ventilator: infection, hemodynamic
instability from positive-pressure ventilation, barotrauma,
gastrointestinal (GI) bleeding due to stress ulcer
III. Etiology
a. Acute respiratory hypoxemia: pulmonary edema, severe
pneumonia, sepsis, shock, acute respiratory distress syndrome
(ARDS), embolism, drug reaction of overdose, lung
trauma, high altitude
b. Acute respiratory acidosis: acute exacerbation of chronic
emphysema or asthma
c. Respiratory muscle weakness or failure: paralysis of the
diaphragm due to Guillain-Barré syndrome, myasthenia
gravis, spinal cord injury, or the affects of anesthetic and
muscle relaxant drugs; central nervous system (CNS) conditions,
such as stroke, brain tumor, infections, sleep apnea;
chest trauma, including fractures, pneumothorax
IV. Statistics
a. Morbidity: Acute respiratory failure requiring mechanical
ventilation accounts for approximately 30% of admissions
to intensive care units (ICUs) (Esteban et al, 2002).
b. Mortality: Hospital rate is 36%; 6-month mortality rate is
approximately 67% for ages 65 and older (Seneff et al, 2000).
c. Cost: Mean ICU cost in United States is $31,574 to $42,570
per year (Dasta et al, 2005); average total hospital stay,
$78,474; daily costs, $2,655; estimated cost for long-term
acute-care facility admissions, $56,825 (Seneff, 2000).
Care Setting
The focus of this plan of care is the client with invasive
mechanical ventilation who remains on a ventilator, whether in
an acute or postacute care setting. The expectation is that the
majority of clients will be weaned before discharge. However,
some clients are either unsuccessful at weaning or are not candidates
for weaning. For these clients, portions of this plan of
care would need to be modified for the discharge care setting,
whether it be an extended care facility or home.
Client Assessment
Database
Gathered data depend on the underlying pathophysiology
and reason for ventilatory support. Refer to the appropriate
plan of care.
Discharge Plan
Considerations
If ventilator-dependent, the plan may require changes in
physical layout of home, acquisition of equipment and
supplies, provision of a back-up power source, instruction
of significant other (SO) and caregivers, provision
for continuation of plan of care, assistance with transportation,
and coordination of resources and support
systems.
NURSING DIAGNOSIS: ineffective Breathing Pattern/impaired Spontaneous
Ventilation
May be related to
Respiratory center depression
Respiratory muscle weakness or paralysis
Noncompliant lung tissue (decreased lung expansion)
Alteration of client’s usual O2/CO2 ratio
Possibly evidenced by
Changes in rate and depth of respirations
Dyspnea and increased work of breathing, use of accessory muscles
Reduced VC and total lung volume
Tachypnea and bradypnea or cessation of respirations when off the ventilator
Cyanosis
Decreased PO2 and SaO2, increased PCO2
Increased restlessness, apprehension, and metabolic rate
Desired Outcomes/Evaluation Criteria—Client Will
Respiratory Status: Ventilation
Reestablish and maintain effective respiratory pattern via ventilator with absence of retractions and use of accessory muscles,
cyanosis, or other signs of hypoxia; ABGs and oxygen saturation within acceptable range.
Participate in efforts to wean (as appropriate) within individual ability.
Caregiver Will
Demonstrate behaviors necessary to maintain client’s respiratory function.
ACTIONS/INTERVENTIONS
Mechanical Ventilation Management: Invasive
Independent
Investigate etiology of respiratory failure.
Observe overall breathing pattern. Note respiratory rate,
distinguishing between spontaneous respirations and
ventilator breaths.
Auscultate chest periodically, noting presence or absence and
equality of breath sounds, adventitious breath sounds, and
symmetry of chest movement.
Count client’s respirations for 1 full minute and compare with
desired respirations and ventilator set rate.
Verify that client’s respirations are in phase with the ventilator.
Position client by elevating head of bed or chair if possible;
place in prone position, as indicated.
Inflate tracheal or ET tube cuff properly, using minimal leak
and occlusive technique. Check cuff inflation every 4 to 8
hours and whenever cuff is deflated and reinflated.
Check tubing for obstruction, such as kinking or accumulation
of water. Drain tubing as indicated, avoiding draining
toward client or back into the reservoir.
Check ventilator alarms for proper functioning. Do not turn off
alarms, even for suctioning. Remove from ventilator and
ventilate manually if source of ventilator alarm cannot be
quickly identified and rectified. Ascertain that alarms can be
heard in the nurses’ station.
Keep resuscitation bag at bedside and ventilate manually
whenever indicated.
Assist client in “taking control” of breathing if weaning is
attempted or ventilatory support is interrupted during procedure
or activity.
Collaborative
Assess ventilator settings routinely and readjust, as indicated:
Note operating mode of ventilation, that is, AC, pressure
support (PS), and so on.
Observe oxygen concentration percentage (FiO2); verify that
oxygen line is in proper outlet or tank; and monitor in-line
oxygen analyzer or perform periodic oxygen analysis.
Observe end-tidal CO2 (ETCO2) values.
Assess set respiratory frequency (f).
Assess VT. Verify proper function of spirometer, bellows, or
computer readout of delivered volume; note alterations
from desired volume delivery.
Flow rate
Pressure limit
Monitor I:E ratio
Set sigh rate, when used
Note inspired humidity and temperature; use heat moisture
exchanger (HME), as indicated.
Monitor serial ABGs and pulse oximetry
RATIONALE
Understanding the underlying cause of client’s particular
ventilatory problem is essential to the care of client, for
example, decisions about future capabilities and ventilation
needs and most appropriate type of ventilatory support.
Client on a ventilator can experience hyperventilation,
hypoventilation, or dyspnea and “air hunger” and attempt
to correct deficiency by overbreathing.
Provides information regarding airflow through the tracheobronchial
tree and the presence or absence of fluid,
mucous obstruction. Note: Frequent crackles or rhonchi
that do not clear with coughing or suctioning may indicate
developing complications, such as atelectasis, pneumonia,
acute bronchospasm, and pulmonary edema. Changes in
chest symmetry may indicate improper placement of the ET
tube or development of barotrauma.
Respirations vary depending on problem requiring ventilatory
assistance; for example, client may be totally ventilator dependent
or be able to take breath(s) on own between ventilatordelivered
breaths. Rapid client respirations can produce respiratory
alkalosis and prevent desired volume from being delivered
by ventilator. Slow client respirations and hypoventilation
increases PaCO2 levels and may cause acidosis.
Adjustments may be required in flow, tidal volume, respiratory
rate, and dead space of the ventilator, or client may need
sedation to synchronize respirations and reduce work of
breathing and energy expenditure.
Elevating the client’s head and helping client get out of bed while
still on the ventilator is both physically—helps decrease risk of
aspiration—and psychologically beneficial. Note: Use of prone
position is thought to improve oxygenation in client with
severe hypoxic respiratory failure. However, it is not widely
used due to the difficulties associated with placing and providing
care to the intubated client in prone position as well as
lack of studies showing its benefit in reducing mortality or
duration of ventilation (Sud et al, 2008).
The cuff must be properly inflated to ensure adequate ventilation
and delivery of desired tidal volume and to decrease
risk of aspiration. Note: In long-term clients, the cuff may
be deflated most of the time or a noncuffed tracheostomy
tube used if the client’s airway is protected.
Kinks in tubing prevent adequate volume delivery and increase
airway pressure. Condensation in tubing prevents proper
gas distribution and predisposes to bacterial growth.
Ventilators have a series of visual and audible alarms, such
as oxygen, low volume or apnea, high pressure, and inspiratory/
expiratory (I:E) ratio. Turning off or failure to reset
alarms places client at risk for unobserved ventilator failure
or respiratory distress or arrest.
Provides or restores adequate ventilation when client or
equipment problems require client to be temporarily
removed from the ventilator.
Coaching client to take slower, deeper breaths; practice
abdominal or pursed-lip breathing; assume position of
comfort; and use relaxation techniques can be helpful in
maximizing respiratory function.
Controls or settings are adjusted according to client’s primary
disease and results of diagnostic testing to maintain
parameters within appropriate limits.
Client’s respiratory requirements, presence or absence of an
underlying disease process, and the extent to which client
can participate in ventilatory effort determine parameters of
each setting. PS has advantages for client on long-term
ventilation because it allows client to strengthen pulmonary
musculature without compromising oxygenation and
ventilation during the weaning process.
FiO2 is adjusted (21% to 100%) to maintain an acceptable
oxygen percentage and saturation, for example, 90%, for
client’s condition.
Measures the amount of exhaled CO2 with each breath and is
displayed graphically to spot CO2 exchange problems early
before they show up on ABGs. In some cases, a slightly
higher level of CO2 can be beneficial, such as for the client
with long-standing emphysema. In this instance, elevated
PCO2 is accepted without correction, leading to the term
“permissive hypercapnia” (Byrd et al, 2006).
Respiratory rate of 10 to 15 per minute may be appropriate
except for client with COPD and CO2 retention. In these individuals,
rate and volume should be adjusted to achieve personal
baseline PaCO2, not necessarily a “normal” PaCO2.
Monitors amount of air inspired and expired. Changes may
indicate alteration in lung compliance or leakage through
machine or around tube cuff. Note: For the client without
preexisting lung disease, the VT and rate are traditionally
selected by using VT of 12 mL/kg delivered 12 times per
minute in the AC mode. For clients with COPD, the VT and
rate are slightly reduced to 10 mL/kg at 10 breaths per minute
to prevent overinflation and hyperventilation (Girard &
Bernard, 2007). Many clinicians now use a smaller VT (6 to
8 mL/kg), especially in clients with ARDS and sometimes in
obstructive and restrictive lung disease, in order to reduce
air-trapping and mechanical stress on the lung.
Speed with which the VT is delivered is usually about 50 L/min,
but is variable in order to maintain I:E ratio appropriate for
specific situation.
Regulates the amount of pressure the volume-cycled ventilator
can generate to deliver the preset VT with usual setting at
10 to 20 cm H2O above the client’s peak inspiratory pressure.
Airway pressure should remain relatively constant.
Increased pressure alarm reading reflects (1) increased
airway resistance as may occur with bronchospasm;
(2) retained secretions; and (3) decreased lung compliance
as may occur with obstruction of the ET tube, development
of atelectasis, ARDS, pulmonary edema, worsening COPD,
or pneumothorax. Low airway-pressure alarms may be
triggered by pathophysiological conditions causing
hypoventilation, such as disconnection from ventilator, low
ET cuff pressure, ET tube displaced above the vocal cords,
client “overbreathing,” or out of phase with the ventilator.
Expiratory phase is usually twice the length of the inspiratory
rate, but may be longer to compensate for air-trapping to
improve gas exchange in the client with COPD.
Clinicians once recommended that periodic machine breaths
that were 1.5 to 2 times the preset VT be given 6 to 8 times
per hour. At present, accounting for sighs is not recommended
if the client is receiving VT of 10 to 12 mL/kg or if
PEEP is required. When a low VT is used, sighs are preset at
1.5 to 2 times the VT and delivered 6 to 8 times per hour if
the peak and plateau pressures are within acceptable limits
(Byrd et al, 2006).
Usual warming and humidifying function of nasopharynx is
bypassed with intubation. Dehydration can dry up normal
pulmonary fluids, cause secretions to thicken, and increase
risk of infection. Temperature should be maintained at
about body temperature to reduce risk of damage to cilia
and hyperthermia reactions. The introduction of a heated
wire circuit to the traditional system significantly reduces
the problem of “rainout” or condensation in the tubing.
Adjustments to ventilator settings may be required, depending
on client’s response and trends in gas exchange
parameters.
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