This document discusses various strategies for managing acute respiratory distress syndrome (ARDS). It begins by describing the pathophysiology of ARDS including pulmonary capillary leak, surfactant inactivation, and diffuse lung injury. It then discusses various ventilator strategies and adjunctive therapies for ARDS management such as recruitment maneuvers, prone positioning, high frequency oscillatory ventilation, liquid ventilation, and application of surfactant. The document emphasizes an open lung approach with low tidal volumes and higher positive end expiratory pressures to minimize ventilator-induced lung injury while maintaining adequate oxygenation and ventilation.
4. Early pathologic features of ARDS
• Diffuse alveolar damage (DAD)
• There is minimal alveolar septal thickening,
hyperplasia of pneumocytes
• Eosinophilic hyaline membranes present
16. CT scan showed Severe surgical emphysema and pneumomediasteum
17.
18.
19.
20. Diseased Lungs Do
Not Fully Collapse,
Despite Tension Pneumothorax
…and
They cannot always
be fully “opened”
Dimensions of a fully
Collapsed Normal Lung
22. Spectrum of Regional Opening Pressures
(Supine Position)
Superimposed
Pressure Inflated 0
Alveolar Collapse
(Reabsorption) 20-60 cmH2O
Small Airway
Collapse
10-20 cmH2O
Consolidation
Lung Units at Risk for Tidal
Opening & Closure
=
Opening
Pressure
23. How Much Collapse Depends on the Plateau
R = 100%
20
60
100
Pressure [cmH2O]
20 40 60
TotalLungCapacity[%]
R = 22%
R = 81%
R = 93%
0
0
R = 0%
R = 59%
Some potentially
recruitable units
open only at high
pressure
More Extensive
Collapse But
Lower PPLAT
Less Extensive
Collapse But
Greater PPLAT
26. Recruitment Maneuvers (RMs)
Proposed for improving
Arterial oxygenation
Enhancing alveolar recruitment
All consisting of short-lasting increases in
intrathoracic pressures
27. Recruitment Maneuvers (RMs)
–Vital capacity maneuver
(inflation of the lungs up to 40 cm H2O,
maintained for 15 - 26 seconds)
–Intermittent sighs
–Extended sighs
28. Recruitment Maneuvers (RMs)
–Intermittent increase of PEEP
–Continuous positive airway pressure
(CPAP)
–Increasing the ventilatory pressures to a
plateau pressure of 50 cm H2O for 1-2
minutes
29. Other manoeuvres
• Prone positioning ventilation
• Prolonged inspiration
• Inverse ratio ventilation
30. Limit of open lung strategy
• To minimise VILI
to the less damaged alveoli
Max insp pressure
(plateau pressure 30-32cm H20)
31. Limit of open lung strategy
Max pressure remains unchanged
TV will decrease
Alveolar ventilation will decrease
Alv V: dead space vent ratio
will decrease
32. Increasing PaCO2
• Management options
Increase resp rate
Minute
volume
Delivered TV TV ml/kg Resp rate
6.4 L 640 ml 8 10
6.4 L 480 ml 6 14
6.4 L 320 ml 4 20
6.4 L 160 ml 2 40
Anatomical dead space 150ml
36. • Inert
• No odor
• No color
• Low surface tension
• Carry large amount of O2 & CO2
Perfluorocarbon
(PFC)
37. Medication:
Morphine sulfate
(0.1mg/kg/dose), pavulon
(0.1 mg/kg/dose)
Rimar (30 ml/kg)
Ventilation settings:
Ti 5 sec, hold 10 sec, Te 5
sec (3-6 cycles/min)
CO2 eleminated by
increase tidal volume
O2 managed by change O2
content and FRC
38.
39. ON START OF GAS
VENTILATION
ONE HOUR AFTER
PLV
48 HOUR AFTER PLV 3 WEEKS AFTER PLV
Partial liquid ventilation with perflubron in premature infants with severe
respiratory distress syndrome
55. GOOD LUCK
SAMIR EL ANSARY
ICU PROFESSOR
AIN SHAMS
CAIRO
elansarysamir@yahoo.com
Global Critical Care
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Wellcome in our new group ..... Dr.SAMIR EL ANSARY