ARDS Flashcards
what is ARDS
hypoxic respiratory failure caused by intense pulmonary inflammation
primary insult in ARDS
pneumonia, aspiration, near drowning, smoke inhalation
secondary insult in ARDS
sepsis/SIRS, trauma, cardiac arrest, burns
pulmonary artery wedge pressure of ARDS
less than 18
most common causes of ARDS
shock, sepsis and drowning
What happens with increased inflammation in lungs
increased permeability of pulmonary capillaries and alveoli, pulmonary edema, and ultimately pulmonary fibrosis
how can increased pulmonary inflammation lead to pulmonary hypertension
refractory hypoxia causing loss of pulmonary vasomotor tone
3 phases of ARDS
inflammation or exudative 0-7 days
proliferative 7-21 days
fibrotic phase 7-1 days
what happens in first phase of ARDS
inflammation phase, causing pulmonary hypertension
what happens in second phase ARDS
fibroblast proliferation
Ventilatory goals for ARDS
maximize PEEP while minimizing ventilator induced lung injury
medications that may be helpful in ARDS
nitric oxide
corticosteroids
surfactant
indications to intubate
worsening lung disease
hypoxemia despite non invasive delivery of O2
increased WOB, increased dead space, decreased lung compliance
to what level of permissive hypercapnia is allowed to avoid Ventilator induced lung injury
pH 7.2
When is High frequency oscillatory ventilation used
when there needs to be low tidal volume and avoid barotrauma
maintains lung volume at sustained pressure
Mean airway pressure for oscillatory ventilation
4-8 cm H2O
What is airway pressure release ventilation
facilitates oxygenation at a baseline, works with spontaneous breathing at high P and a brief deflation to low pressure
once hemodynamically stable after fluid resuscitation in ARDS what is next step
aggressive diuresis
what is a positional change for patients with ARDS
prone positioning because improves VQ mismatch
redistributes tidal volume to atelectatic areas
improved diaphragmatic excursion by reducing effects of abdominal pressure
improved postural drainage
why is nitric oxide useful in ARDS
it is a selective pulmonary vasodilator with short half life and no systemic effects
improves VQ mismatch by improving blood flow to well ventilated areas
initial improvement in oxygenation
why are corticosteroids useful in ARDS
no evidence based in children
methylprednisolone showed trend toward reduced mortality and morbidity in steroid treated patients
why is surfactant useful in ARDS
acute improvement
early in course if oxygenation not achieved
Rescue therapy for ARDS
ECMO
more effective earlier in treatment
