Because of the nature of ARDS and its treatment modalities AND the fact that it kills 150,000 Americans each year(1), I thought it fitting to include as the first post in a series I'm beginning called "Breaking It Down c NurseMike". In the "Breaking It Down" series I'll be taking a rather daunting disease process and then breaking it down to a much easier to understand, retain, and teach to your peers (AND NOT TO MENTION IMPRESS THE LADIES WITH YOUR BIG BRAIN ;)).
Let's break this down homeys...
What is it?
ARDS aka Acute Respiratory Distress Syndrome is a disease process that develops from an injury to the alveoli, which is where all the gas exchange is happening. So just think of ARDS as a gas exchange problem.
How does it happen?
Just like when a younger version of yourself tries to put the moves on your daughter, injuries result from P.A.P.I. (Pneumonia, Aspiration, Pulmonary contusion, or Indirect injuries [EX.-sepsis, nonthoracic trauma, and cardiac bypass]).
*S/S of ARDS develop QUICK! 24-48 hours after the initial injury.
ARDS is characterized by inflammation, increased permeability of alveolar membrane (increased ease of fluid passing through the membrane) and cytokine activation (cytokines are a type of cell-signaling protein that causes increased damage to alveolar endothelium). All this causes protein build up, which causes fluid build up and lower surfactant levels so gas exchange is compromised and alveoli collapse. THIS causes decreased O2 in the blood and more CO2 in the blood.
Because of all this you have hypoxemia, pulmonary hypertension & decreased pulmonary compliance. (Later stages you've got Progressive alveolitis and fibrosis "stiff lung")
What's ARDS Look Like?
-DIFFUSE bilateral infiltrates on X-Ray when NO Left Atrial Hypertension is present (indicated by Pulm Cap Wedge Pressure < 18mm Hg)
-Poor Oxygenation (P/F ratio < 200) Normal is 500mm Hg**
-Progressively worsening dyspnea and tachypnea despite maximum supplemental O2
-As it progresses-diminished breath sounds, pulmonary crackles and wheezes may occur with signs of consolidation on X-Ray
-Skin may be mottled with cyanosis to nailbeds and mouth
-SpO2 and PaO2 indicate moderate to severe hypoxemia
**P/F ratio=P is partial pressure of arterial oxygen (PaO2)/F is the fraction of inspired oxygen the patient receives (FiO2).
Easy Way to Remember: P is the oxygen PROVIDED to the patient and the F is the amount of oxygen that FLOWS into the bloodstream.
5 P's of ARDS Therapy
3. Protective lung ventilation
4. Protocol weaning
5. Preventing complications
Goal is focused on maximizing transport of O2 between alveoli and pulmonary capillaries.
-Increase fluid volume w/out overloading patient (crystalloids or colloids to replace fluid that's leaked into alveolar space.)
-Meds-Inotropes/Vasopressors to increase BP and increase Perfusion
-Rotoprone Beds-Improves oxygenation by mobilizing secretions, resolving atelectasis, improving V/Q ratio (ventilation/perfusion), recruiting functional but collapsed alveolar units and decreasing interstitial fluid collection. (Also shown to reduce nosocomial PNA, skin breakdown, ICU length of stay, and # of vent days)
3.Protective Lung Ventilation-
During early ARDS use mechanical ventilation to open collapsed alveoli.
-High PEEP 22-24cm BUT watch out for barotrauma and decreased cardiac output (use hemodynamic monitoring to determine best PEEP setting).
-Current Recommendations for Protective Lung Ventilation
1.Limiting Plateau Pressures <30cm
3.Reducing FiO2 50%-60%
4.Providing Low Tidal Volumes (6ml/kg of ideal body weight)
1.Using spontaneous breathing trials
2.Instituting Protocols for RNs as well as MDs
3.Tailoring Protocols to enhance clinical judgement
4.Using sedation goals to decrease duration of vent and ICU stay
*Most common complications: VILI (ventilator induced lung injury), DVT, Pressure ulcers, decreased nutritional status, VAP (40% get VAP).
1. Frequent Position changes
2.Assess Skin Frequently
3.Administer anti-coagulants, thrombolytics
4.Start nutritional support ASAP
TO SUM UP:
1. ARDS is an inflammatory disease process where gas exchange is compromised at the alveolar level characterized by increased alveolar permeability, loss of aerated lung with hypoxemia, bilateral infiltrates and/or opacities on X-Ray and eventually decreased lung compliance.
2.Goal is to improve oxygenation (increase P/F ratio)
3.Familiarize yourself with and implement the 5Ps of ARDS therapy
ARDS is rough! People that go through this horrible disease process and live to tell the tell experience a severe reduction in quality of life, depression, anxiety, and even PTSD. Some even experience cognitive impairments d/t length of hypoxemia.
This is just a brief overview of a very complicated disease process. However, as a nurse, I've equipped you with EXACTLY what you'll need to know to identify and provide EXCELLENT nursing care to these extremely sick patients. If you're like me and really like to get to the "meat" of things I've listed a few sources down below that you can go to in Google Scholar and get your fix.
Thanks for taking the time to go through this. If you want to be an amazing health professional, work on yourself more than you work on your job. I hope this explanation of ARDS has been helpful and will increase your confidence and skill level as a Nurse Pro. Got a crazy story about an ARDS patient you've taken care of? Leave a comment below! Are you on Twitter? Follow me by clicking the "Follow" button above.
-Powers, J. (2007). The five P’s spell positive outcomes for ARDS patients. Am Nurse Today, 2(3), 34-39.
-Dickinson, S., Park, P. K., & Napolitano, L. M. (2011). Prone-positioning therapy in ARDS. Critical care clinics, 27(3), 511-523.
-Ware LB, Matthay MA. The acute respiratory distress syndrome. The New England journal of medicine. 342(18):1334-49. 2000.