ARDS Flashcards
***T or F: ARDS is a cause of acute respiratory failure.
True
***Among all of the causes of ARDS, what is the common denominator?
Intense Inflammation => mediators like IL-1, IL-6, TNF-alpha and other causes lung inflammation
• Inflammation results in destruction of alveoli and the leaking of HIGH protein (exudate) fluid into interstitial space
***Name 4 common precipitating causes of Acute Respiratory Distress Syndrome.
PAST • Pneumonia • Aspiration • Sepsis • Trauma
***T or F: edema in ARDS is associated with Left Ventricular Heart Failure.
FALSE, ARDS is severe NON-CARDIOGENIC pulmonary edema
***Why do people with ARDS suffer from hypoxemia?
ARDS = PULMONARY SHUNT
• they can’t ventilate the lung (V/Q ~ 0)
***What effect does ARDS have on lung compliance?
ARDS causes an acute decrease in lung compliance
***How do we correct the ventilation defect in ARDS? Why does this work?
PEEP - positive end expiratory pressure
- RECRUITS ATELECTATIC ALVEOLI
- INCREASES FUNCTIONAL RESIDUAL CAPACITY (FRC)
**What is the death rate of ARDS? **What causes death?
30-40% of people with ARDS die from it
people die from MULTI-ORGAN FAILURE
- **Why is there a risk of dying form pneumothorax in ARDS patients?
- **WHEN is this most likely to happen?
WHY?
• PEEP distends alveoli and may cause lungs to develop holes that cause pneumothorax
WHEN?
• Most likely to happen after the 2nd week of illness
***Do you want to use a high or low tidal volume when using Mechanical Ventilation on people with ARDS?
• LOW tidal volume is best because it reduces risk of rupture
• REDUCES MORTALITY
**Additionally, research by Dr. Waters has shown that increased lung distention can induce fibrosis thus increasing the long term complications of ARDS
- **How do you want to manage the DIET of someone with ARDS?
- **WHY would you do this?
- Reduce fluids
- No salt
***Reducing fluids reduces the number of days patients have to spend on Mechanical Ventilation (MV)
***T or F: Prone Ventilation reduces mortality in patients with ARDS.
TRUE
***If you survive an ARDS, what are the long term consequences?
• how will these problems progress with time after ARDS?
Long Term Consequences:
• mild to moderate RESTRICTIVE ventilatory defect
• mild reduction in DLCO (DIFFUSION defect too)
***Lungs will gradually improve over the year after treatment
***T or F: NO improves mortality in ARDS patients
FALSE, it improves oxygenation but DOES NOT reduce mortality
Why is edema in ARDS exudative instead of transudative?
ARDS edema is due to destruction of tissue that leads to leakage of protein rich content
Cardiogenic etiologies causes transudative leakage because the filter is still in tact but pulmonary vascular pressure increases
Will ARDS patients respond well to supplemental O2?
No because this is a shunting issue
What 4 key things are you looking for in a patient that you suspect has ARDS?
- ACUTE onset of RESPIRATORY FAILURE
- BILATERAL infiltrates on CXR
- NO evidence of VOLUME OVERLOAD
- PaO2/FiO2
Besides making it difficult to breath was does the protein rich exudate in ARDS do?
Exudate cause dysfunction of Surfactant in ARDS patients
Causes of ARDS via direct injury: • Pneumonia • Pulmonary Contusion, Penetrating Injury • Fat Emboli • Near Drowning • Inhalation Injury
Cause of ARDS via INdirect injury: • SEPSIS • Severe trauma with shock/hypoperfusion • Drug over dose • Cardiopulmonary Bypass • Acute Pancreatitis • Transfusion of Blood products • TRALI - Transfusion Related, Acute Lung Injury
How do you differentiate between Cardiogenic Pulmonary Edema and ARDS on CXR?
Cardiogenic - NOT dependent - aka it will be evenly distributed on CXR even when the patient is supine
Pulmonary Edema - DEPENDENT - it will be shifted to the front or back depending if the patient is prone or supine
What are the 4 phases of ARDS?
Exudative (acute) phase
Proliferative Phase
Fibrotic Phase
Recovery
***What are the 4 predictors of outcome in a patient with ARDS?
- Chronic Liver DIsease
- Non-pulmonary Organ Dysfunction
- Sepsis
- Advanced age
Is PEEP normal in healthy people?
YES, our vocal cords shut when we expire to maintain PEEP
We must apply some PEEP to anyone with a tube down their throat to keep a near physiologic value of PEEP at least
Why is laying people with ARDS in the prone position ideal?
Takes the pressure of the heart off of the lungs
How is ARDS cured?
TREAT THE UNDERLYING CAUSE
