PDF Format - American Nurse Today

The Five P’s spell
positive outcomes for
ARDS patients
Use these evidence-based interventions to avoid the
dangers of ARDS, its complications, and its therapy.
By Janice Powers, MSN, RN, CCRN, CCNS, CNRN, CWCN
CE
1.8 contact
hours
L E A R N I N G O B J E C T I V E S
1. Identify the incidence of ARDS
in the patient population.
2. Discuss the causes and pathophysiology
of ARDS.
3. Describe strategies and nursing
interventions for improving the
outcomes of ARDS patients.
IN THE UNITED STATES, patients
with acute respiratory distress syndrome
(ARDS) occupy 1 in 10 critical
care beds. Each year, ARDS kills
150,000 Americans. Most of the
deaths are triggered by an event,
such as sepsis or pneumonia.
What is ARDS?
Usually, ARDS starts with acute
lung injury (ALI), which kills about
75,000 Americans
a year and whose
risk increases with age.
ARDS itself develops from an injury
to the alveoli, the site of gas exchange.
ALI and ARDS have these
characteristics in common:
• Acute onset
• Bilateral infiltrates on chest X-ray
• Pulmonary artery wedge pressure
(PAWP) of less than 18 mm Hg.
What distinguishes
ALI from ARDS is the
P/F ratio, the comparison
of arterial partial pressure of
oxygen (PaO 2 ) with inspired fractional
concentration of oxygen
(FiO 2 ). Simply put, the P/F ratio is
a comparison of the amount of
oxygen given to a patient with the
amount of oxygen actually entering
the patient’s bloodstream.
34 American Nurse Today March 2007

The higher the P/F ratio, the better
the gas exchange. The normal
measurement is around 500 mm Hg.
A P/F ratio below 300 mm Hg regardless
of the positive end-expiratory
pressure (PEEP) measurement
indicates ALI. A P/F ratio below 200
mm Hg regardless of the PEEP
measurement indicates ARDS.
If a patient’s oxygen requirements
continue increasing while oxygen
saturation levels (based on fingerprobe
readings and arterial blood
gas [ABG] measurements) remain
low, ALI is progressing to ARDS.
This condition is called refractory
hypoxemia.
A patient with ARDS has decreased
functional residual lung capacity,
which may lead to organ failure
and death. Typically, ARDS
requires admission to an intensive
care unit (ICU) and mechanical ventilation.
(See What causes ARDS?)
What’s the damage?
ARDS is marked by inflammation,
increased permeability of alveoli
membranes, and cytokine activation.
Damage to the endothelium, or lining
of the capillary, interferes with
alveolar gas exchange. The damage
causes macrophages to release cytokines,
inflicting more damage on
the alveolar endothelium. Protein
levels build, pulling fluid into the
alveolar spaces and causing noncardiac
pulmonary edema and a reduced
surfactant level.
Normally, surfactant decreases
surface tension and allows the alveoli
to open easily. In ARDS, the edema
and reduced surfactant level
compromise gas exchange, causing
decreased oxygen and increased carbon
dioxide in the blood. The result
is hypoxemia, pulmonary hypertension,
and decreased pulmonary
compliance. In later stages of ARDS,
progressive alveolitis and fibrosis—
stiff lungs—further decrease pulmonary
function.
Signs and symptoms
In the first 24 to 48 hours, signs and
What causes ARDS?
Acute respiratory distress syndrome (ARDS) starts with a lung injury, either direct
or indirect.
Direct injuries
With direct injuries, damage results from such events as:
• near-drowning
• aspiration
• chemical inhalation
• aspiration pneumonia.
Indirect injuries
With indirect injuries, damage results from an inflammatory response to an acute
condition, such as:
• sepsis
• disseminated intravascular coagulation
• shock
• pancreatitis
• multiple trauma.
Cigarette smoking and alcohol abuse can also cause indirect injuries.
symptoms include dyspnea, tachypnea,
dry cough, fatigue, and tachycardia.
Even with supplemental oxygen,
a patient’s skin may look
cyanotic and mottled. Auscultation
reveals adventitious breath sounds
(crackles, rhonchi, and wheezes) or
increasingly diminished breath
sounds. As oxygenation and perfusion
diminish, the patient may become
agitated, anxious, confused,
and restless.
A chest X-ray shows diffuse infiltrates,
and ABG results indicate respiratory
alkalosis with very low
PaO 2 levels. In the later stages, hypercapnia
may develop. Further
metabolic imbalances can lead to
mixed acidosis, signaling a low ventilation-to-perfusion
(V . /Q . ) ratio and
a deteriorating P/F ratio. To rule out
a cardiogenic cause of pulmonary
edema, a physician may order PAWP
measurements.
5 P’s of ARDS therapy
Managing patients with ARDS requires
maintaining the airway, providing
adequate oxygenation, and
supporting hemodynamic function.
The five P’s of supportive therapy
include perfusion, positioning, protective
lung ventilation, protocol weaning,
and preventing complications.
Perfusion
The goal of care for ARDS patients
is to maximize perfusion in the pulmonary
capillary system by increasing
oxygen transport between the
alveoli and pulmonary capillaries.
To achieve the goal, you need to
increase fluid volume without overloading
the patient. Give either
crystalloids or colloids to replace
the fluids that have leaked from the
capillaries into the alveolar spaces.
Blood transfusions can improve
oxygen delivery, but remember
they can also cause an increased
inflammatory response and increase
the risk of infection and death.
Evaluate the patient’s volume
status by measuring blood pressure,
respiratory variations of pulmonary
and systemic arterial pulse pressure,
central venous pressure, and urine
output. Confirm intravascular status
with pulmonary artery catheter data,
cardiac output, cardiac index,
pulmonary vascular resistance, and
venous oxygen saturation (SvO 2 ).
Certain drugs can also help increase
perfusion. Inotropics such as
dobutamine (Dobutrex) can increase
cardiac output to boost oxygenation.
Milrinone lactate (Primacor), another
inotropic, improves perfusion by causing
vasodilation in the pulmonary bed.
March 2007 American Nurse Today 35

Turning your ARDS patient to the prone position
Vasopressors, such as norepinephrine
and dopamine, promote
systemic vasoconstriction, thus increasing
blood pressure and perfusion.
When administering these
drugs, monitor vital signs, skin color
and temperature, and the patient’s
tolerance to therapy.
Positioning
Patient positioning also affects perfusion.
If a patient is standing, blood
flow moves to the base of the lung
and away from the apex. If a patient
is supine, the posterior area of the
lung will be more perfused than the
anterior area. Because the better aerated
surfaces of the lungs are the
nondependent areas, the result is a
ventilation/perfusion mismatch.
The same thing happens with
PEEP, which primarily aerates the
anterior, nondependent areas of the
lungs instead of the dependent areas
that would benefit most.
Immobility, a major cause of pulmonary
complications, greatly influences
perfusion distribution. Three
positioning therapies can decrease
these complications and improve
perfusion in ARDS patients:
• Kinetic Therapy (bilateral turning
of a patient 40 degrees or more
per side)
• continuous lateral rotational therapy
(bilateral turning of a patient
no more than 40 degrees per side)
• prone positioning.
These therapies improve oxygenation
by mobilizing secretions,
resolving atelectasis, improving V . /Q .
ratio, recruiting functional but collapsed
or consolidated alveolar
units, and decreasing interstitial fluid
accumulation. Rotational therapy reduces
nosocomial pneumonia, skin
breakdown, ICU length of stay, and
the number of ventilator days.
There’s a correlation between the
degree of rotation and the therapeutic
benefit. With rotational therapy,
the patient must be turned consistently
to 40 degrees; otherwise, the
therapy doesn’t significantly affect
the clearance of secretions, risk of
A
pneumonia, or the length of ICU
stay. Kinetic Therapy is effective in
immobilized patients at angles up to
62 degrees.
Kinetic Therapy effectively prevents
and treats severe respiratory
complications of prolonged immobilization.
When started early, it
prevents and treats pneumonia and
ARDS, saving hospital resources
and lives.
Using the prone position
Prone positioning improves the V . /Q .
ratio. Aeration improves because the
heart no longer compresses the posterior
areas of the left lung as it does
in the supine position. With the patient
in the prone position, most
lung tissue, which is in the posterior
areas, moves toward the anterior,
clearing the airways of debris, decreasing
atelectasis, reducing lung
inflammation, and producing more
efficient oxygenation and perfusion.
Prone positioning can be
achieved with or without a device,
such as the Stryker frame,
Triadyne Proning Accessory Kit,
Vollman Proner, and RotoProne.
If you’re not using a device, turn
the patient from the supine position
toward the ventilator, using the chest
and pelvic area to allow for better
diaphragm motion and lung mechanics.
Depending on the size of
B
Turn the patient from the supine (A) to the prone (B) position with pillows or cushions
supporting the chest and pelvis. When the patient is in the prone position, arrange the
arms in the swimmer’s pose (C) and place the headrest appropriately (D). Be sure to align
all tubes and drains at the head or foot of the bed to prevent dislodgement.
C
D
the patient, the turn may take four
to eight nurses. Place the patient in
the prone position with pillows or
cushions supporting the chest and
pelvis to allow the abdomen to hang
free. When the patient is in the
prone position, arrange the arms in
the swimmer’s pose—one at the side
of the body and the other extended
above the head. (See Turning your
ARDS patient to the prone position.)
Align all tubes and drains at the
head or foot of the bed to prevent
dislodgement. Rotate the patient’s
head from side to side to relieve
pressure and prevent skin breakdown.
And reposition the patient
every couple of hours and assess
the pressure points.
Using positioning devices
The Stryker frame uses two boards
that sandwich the patient to maintain
the prone position. However,
this device doesn’t offer any pressure
relief or safety features.
Both the Triadyne Proning Accessory
Kit and the Vollman Proner
make positioning the patient easier
and more effective. The Triadyne
Proning Accessory Kit consists of a
sheet to aid in positioning the patient
and position packs to support
the patient in the prone position.
The Vollman Proner positioning
device is a frame with padding over
36 American Nurse Today March 2007

the forehead, chin, chest, and pelvic
areas and straps to aid in positioning
the patient. The device goes on top
of the patient, and you can use the
straps to pull and roll the patient into
the prone position. The patient
then rests on the padded areas.
The RotoProne bed is an automated
system that combines Kinetic
Therapy with prone positioning for
up to 62 degrees. This device allows
one nurse to make position changes
and to provide several intervals of
prone positioning throughout the
day. In a 24-hour period, an ARDS
patient should be in the prone position
for at least 18 hours.
Disadvantages of prone
positioning
Prone positioning does have its
share of disadvantages, including
possible tube dislodgement, patient
desaturation, skin breakdown, and
facial edema. With diligent nursing
care and awareness, however, you
can prevent or treat most of these
complications.
Typically, patients with refractory
hypoxemia are placed in the prone
position when ventilator settings are
already maximized, with FiO 2 at
100% and high levels of PEEP. We
are learning that outcomes are better
when positioning starts early in the
course of ARDS.
Protective Lung Ventilation
During the early stages of ARDS, use
mechanical ventilation to open collapsed
alveoli.
The primary goal of ventilation is
to support organ function by providing
adequate ventilation and oxygenation
while decreasing the patient’s
work of breathing. But
mechanical ventilation itself can
damage the alveoli, making protective
lung ventilation necessary.
In the past, ventilatory management
of ARDS meant using high tidal
volumes (VT) of 10 to 15 ml/kg to
prevent atelectasis and normalize partial
pressure of carbon dioxide with
increased levels of PEEP to reduce
Mechanical ventilation itself can
damage the alveoli, making protective
lung ventilation necessary.
FiO 2 . But high VTs overstretch the
alveoli, causing shearing forces on
them and thus increasing the inflammatory
response. The less affected
lung regions must then accommodate
most of the VT, which can lead to
ventilator-induced lung injury (VILI)—
a condition that exacerbates the physiologic
responses to ARDS. VILI is a
complex process caused by repetitive
application of excessive stress or
strain to the lung’s fibroskeleton, microvasculature,
terminal airways, and
delicate alveolar tissue.
PEEP opens collapsed alveoli and
prevents end-tidal alveolar collapse.
This pressure also keeps the alveoli
clear of fluid. For ARDS patients,
ARDSNet guidelines recommend
titration of PEEP up to a high level
of 22 to 24 cm. Because PEEP can
increase intrathoracic pressure that
lowers cardiac output, you should
use hemodynamic monitoring to determine
the best PEEP setting for
each ARDS patient.
Research also shows that using
continuous positive airway pressure
at 35 to 40 cm H 2 O for 30 to 40 seconds
can also open collapsed alveoli
without severe hemodynamic compromise
or barotrauma.
Current recommendations for
protective lung ventilation include:
• limiting plateau pressures to less
than 30 cm H 2 O
• maintaining PEEP
• reducing FiO 2 to 50% to 60%, if doing
so doesn’t compromise PaO 2
• providing low VTs (6 ml/kg of
ideal body weight).
Be sure to monitor the patient for
changes in respiratory status—such
as increased respiratory rate, adventitious
breath sounds, decreased
oxygenation saturation, and dyspnea—at
least every 4 hours and after
every change in PEEP or VT.
Protocol weaning
Weaning protocols can reduce the
time and cost of care while improving
outcomes for ARDS patients. The
rule of thumb is: The patient either
needs full ventilatory support or
should be weaning. Evidence-based
guidelines suggest the following:
• using spontaneous breathing trials
instead of synchronous intermittent
mechanical ventilation
• designing and implementing protocols
for all appropriate healthcare
professionals, not just physicians
• tailoring protocols not as rigid
rules but as guidelines to patient
care
• using protocols to enhance clinical
judgment, not replace it
• using sedation goals to reduce
the duration of mechanical ventilation
and ICU length of stay.
Preventing complications
The most common complications
are VILI, deep vein thrombosis
(DVT), pressure ulcers, decreased
nutritional status, and ventilatorassociated
pneumonia (VAP).
Deep vein thrombosis
DVT is an acute condition characterized
by inflammation and thrombus
formation in the deep veins
that may lead to pulmonary embolism.
About 16% of patients receiving
mechanical ventilation develop
DVT, typically during the first
5 days in the ICU. To prevent DVT,
therapy—including range-of-motion
exercises, frequent position
changes, anticoagulant prophylaxis,
and use of sequential compression
devices and thromboembolic stockings—should
start on admission.
Treatment for DVT includes these
interventions:
• applying warm, moist compresses
• elevating the affected leg
• administering anticoagulants,
thrombolytics, and analgesics.
Pressure ulcers
Because of poor tissue perfusion
March 2007 American Nurse Today 37

Using evidence-based interventions for VAP
To decrease ventilator-associated pneumonia (VAP) in patients with acute respiratory
distress syndrome, use these interventions:
• Wear gloves and wash your hands frequently and effectively, particularly before
touching the ventilator circuit.
• Provide oral care every 2 hours.
• Elevate the head of the bed 30 to 45 degrees.
• Avoid instilling normal saline solution when suctioning the endotracheal tube.
• Provide deep vein thrombosis prophylatic therapy.
• Administer famotidine (Pepcid) to prevent ulcers.
• Provide a daily sedation vacation, if appropriate.
• Evaluate whether the patient is ready for weaning.
and limited movement, pressure ulcers
may develop. Nursing measures
that may prevent this complication
include relieving pressure with frequent
position changes, restoring
circulation with mobility, and promoting
adequate nutrition. By assessing
your patient’s skin frequently,
providing meticulous skin care,
monitoring nutrition status, and implementing
pressure-relieving devices
such as air mattresses, you can
reduce the risk of pressure ulcers.
Poor nutrition
ARDS patients have a severely compromised
nutritional status, so start
nutritional support as soon as possible—within
24 hours of admission,
if possible. The preferred support
method is enteral nutrition because
it causes fewer complications than
parenteral nutrition. When caring for
an ARDS patient, be sure to consult
with a nutrition expert.
VAP
As many as 40% of ARDS patients
develop VAP, which is nosocomial
pneumonia that develops after 48
hours or more of mechanical ventilation.
Most cases result from aspiration
of bacteria from the mouth and
GI tract. This condition complicates
the ARDS patient’s recovery and requires
a longer duration of mechanical
ventilation and longer length of
stay. (See Using evidence-based interventions
for VAP.)
Putting the 5 P’s into practice
ARDS, its complications, and its
therapy pose many dangers. By putting
the five evidence-based P’s into
practice, you can safely steer clear
of all the dangers, while improving
your patient’s outcome and decreasing
his length of stay in the ICU. ✯
Selected references
Bernard GR. Acute respiratory distress syndrome:
a historical perspective. Am J Respir
Crit Care Med. 2005;172(7):798-806.
Bernard GR, Artigas A, Brigham KL, Carlet J,
Falke K, Hudson L, et al. The American-European
Consensus Conference on ARDS.
Definitions, mechanisms, relevant outcomes,
and clinical trial coordination. Am J Respir
Crit Care Med. 1994;149(3):818-824. Available
at: http://ajrccm.atsjournals.org/cgi/content/
abstract/149/3/818. Accessed January 17, 2007.
Ely EW. Mechanical ventilator weaning protocols
driven by nonphysician health-care
professionals. Chest. 2001;120:454S-463S.
Grap MJ, Munro CL. Preventing ventilatorassociated
pneumonia: evidence-based care. Crit
Care Nurs Clin North Am. 2006;16(3):349-358.
Kollef M. Ventilator-associated pneumonia and
ventilator-induced lung injury: two peas in a
pod. Crit Care Med. 2002;30(10):2391-2392.
Markowicz P, Wolff M, Djedaini K, Cohen Y,
Chastre J, Delclaux C, et al. Multicenter
prospective study of ventilator-associated
pneumonia during acute respiratory distress
syndrome: incidence, prognosis, and risk
factors. ARDS Study Group. Am J Respir Crit
Care Med. 2000;161(6):1942-1948.
Marini JJ, Gattinoni L. Ventilatory management
of acute respiratory distress syndrome:
a consensus of two. Crit Care Med. 2004;
32(1):250-255.
Ware LB, Matthay MA. The acute respiratory
distress syndrome. N Engl J Med. 2000;342
(18):1334-1349.
www.ihi.org/IHI/Programs/Campaign/
Campaign.htm?TabId=2#PreventVentilator-
AssociatedPneumonia
For a complete list of selected references, visit
www.AmericanNurseToday.com.
Janice Powers, MSN, RN, CCRN, CCNS, CNRN, CWCN, is a
Clinical Nurse Specialist at Critical Care and Neuroscience
Methodist Hospital, Clarian Health Partners, in
Indianapolis, Indiana. Ms. Powers has disclosed that
she has received a speaker honorarium from KCI and
Eli Lilly and Company within the previous 12 months.
CE POST-TEST
The Five P’s spell positive outcomes for ARDS
Instructions
To take the post-test for this article and earn contact hour credit,
please go to www.AmericanNurseToday.com. Once you’ve successfully
passed the post-test and completed the evaluation
form, simply use your Visa or MasterCard to pay the processing
fee. (Online: ANA members $15; nonmembers $20.) You’ll then be
able to print out your certificate immediately.
If you are unable to take the post-test online, complete the print
form and mail it to the address at the bottom of the next page.
(Mail-in test fee: ANA members $20; nonmembers $25.)
Provider accreditation
The American Nurses Association (ANA) is accredited as a
provider of continuing nursing education by the American Nurses
Credentialing Center’s Commission on Accreditation.
ANA is approved by the California Board of Registered Nursing,
Provider # CEP6178.
Contact hours: 1.8. Expiration: 12/31/08.
Purpose/goal: To provide registered nurses with an overview of
ARDS, so they can deliver evidence-based care to ARDS patients.
38 American Nurse Today March 2007

POST-TEST • The Five P’s spell positive outcomes for ARDS
Earn contact hour credit online at www.AmericanNurseToday.com!
(ANT070301)
CE
1.8 contact
hours
1. How many Americans die from acute respiratory
distress syndrome (ARDS)?
a. 10% of the population a year
b. 20% of the population a year
c. 190,000 deaths a year
d. 150,000 deaths a year
2. Which of the following is a direct injury that
causes ARDS?
a. Disseminated intravascular coagulation
b. Alcohol abuse
c. Aspiration pneumonia
d. Cigarette smoking
3. Which of the following is an indirect injury
that causes ARDS?
a. Sepsis
b. Asthma
c. History of upper respiratory tract infection
d. Sinusitis
4. Which may contribute to the development of
acute lung injury (ALI), a precursor of ARDS?
a. Female sex
b. Advancing age
c. Asian heritage
d. Illicit drug use
5. Which drugs can improve perfusion by increasing
cardiac output in ARDS patients?
a. Inotropics
b. Diuretics
c. Anticoagulants
d. Calcium channel blockers
6. Which may be a side effect of giving blood
transfusions to an ARDS patient?
a. Increased inflammatory response
b. Decreased oxygenation
c. Increased skin infection
d. Decreased peripheral vision
7. Which positioning therapy reduces nosocomial
infection and the number of ventilator days
in ARDS patients?
a. Kinetic Therapy
b. Prone positioning
c. Continuous lateral rotational therapy
d. Lung percussion therapy
8. Which of the following positioning therapies
does not improve perfusion in ARDS patients?
a. Lung percussion therapy
b. Continuous lateral rotational therapy
c. Supine position therapy
d. Continuous positive airway pressure therapy
9. Which is not a strategy for treating ARDS?
a. High tidal-volume ventilation
b. Positive end-expiratory pressure (PEEP)
c. Prone positioning therapy
d. Continuous positive airway pressure therapy
10. Which is used to open collapsed alveoli?
a. Increased tidal volume
b. Supine positioning
c. Increased carbon dioxide saturation
d. PEEP
11. Which is an effect of PEEP?
a. Reduction in V . /Q . ratio
b. Primary aeration of the anterior, nondependent
lung areas
c. Decreased number of functional alveoli
d. Increased cardiac output
12. Which of the following is an evidence-based
guideline for weaning?
a. Keep sedation at one level.
b. Adhere strictly to protocols.
c. Use spontaneous breathing trials.
d. Use synchronous intermittent mechanical
ventilation.
13. Deep vein thrombosis (DVT) occurs most
commonly:
a. in the first day in the ICU.
b. in the second week of hospitalization.
c. in the first 5 days in the ICU.
d. after discharge.
14. What percentage of ARDS patients develop
VAP?
a. 40%
b. 50%
c. 60%
d. 70%
15. Which is an evidence-based intervention
used to decrease VAP in ARDS patients?
a. Administering analgesics
b. Providing stringent wound care
c. Using effective hand washing
d. Using an air mattress overlay
CE post-test registration form
Are you a member of ANA/CMA? (circle) Yes No
■ If “No,” please send me membership information.
Test answers
Test code: ANT070301
a b c d a b c d a b c d
1. ● ● ● ● 6. ● ● ● ● 11. ● ● ● ●
2. ● ● ● ● 7. ● ● ● ● 12. ● ● ● ●
3. ● ● ● ● 8. ● ● ● ● 13. ● ● ● ●
4. ● ● ● ● 9. ● ● ● ● 14. ● ● ● ●
5. ● ● ● ● 10. ● ● ● ● 15. ● ● ● ●
Evaluation form
1. In each blank, rate the extent to which you achieved each objective of this
study module, from 1 (low/poor) to 5 (high/excellent).
(1.) Identify the incidence of ARDS in the patient population. ____
(2.) Discuss the causes and pathophysiology of ARDS. ____
(3.) Describe strategies and nursing interventions for improving the outcomes
of ARDS patients. ____
Also rate the following from 1 to 5.
2. To what extent were the purpose/goal, objectives, content, method, medium,
and resources congruent and effective? ____
3. To what extent was the article effective in achieving the overall purpose/goal? ____
4. To what extent did the article meet your personal expectations? ____
5. To what extent is the content applicable and usable in your nursing
practice, specialty, setting, and role? ____
6.. To what extent was the article free of evidence of bias from conflict of commercial
interest, commercial support, product endorsement, and unannounced
off-label product use? ____
7. State the total number of minutes it took you to read the article and complete
the post-test and evaluation. ____________________
Please add your comments here: ______________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
PLEASE PRINT CLEARLY
E-mail address ———————————————————————
Business phone ——————————————————————— State — — Zip ————— - ————
Name ——————————————————————————
Home phone ————————————————————————
Mailing address ———————————————————————
City ———————————————————————————
Method of payment
■ Check payable to American Nurses Association.
■ Visa ■ MasterCard
Amount authorized $____________________________________
PLEASE DO NOT SEND CASH
Mail completed evaluation, post-test, registration form, and payment
to: ANA, St. Louis, PO Box 504410, St. Louis, MO 63150-4410
For credit cards:
Account #
■■■■■■■■■■■■■■■■■
Security code (3 digit)
■■■
Expiration date________________________
Authorized signature ________________________________________
March 2007 American Nurse Today 39