ARDS Guidelines. Dr. George John, Critical Care, Christian Medical College, Vellore. Causative Factors in ARDS. PRIMARY INJURY. HOST RESPONSE. CONSEQUENCES OF THERAPY. SPECTRUM OF LUNG “INJURY”. ALI. ARDS. Cardiogenic pulmonary oedema. P/F RATIO < 200.
Dr. George John,
Christian Medical College,
P/F RATIO < 200
Altered Starling’s Forces
P/F RATIO 200 - 300
Early Exudative Phase < 1 week
Late Fibro Proliferative Phase > 1 week
- to keep PaO2 55 – 80mm Hg
Increase Alveolar Recruitment = degree of penetration of gas into poorly / nonaerated lung regions
- recruitment manoeuver
- inverse ratio ventilation
Prone positioning ( “proning” )
NO (Nitric Oxide)
Volume Control mode; I:E ratio 1:1 – 1:3
- Tidal Volume 6ml / kg
- Plateau Pressure < 30cm H2O
- High rate if CO2 high – up to 35 / minute
Measures to decrease CO2 production (sedation, decrease temperature)
If pH < 7.30 – use HCO3 infusion
?Tracheal gas insufflation (TGI) / Expiratory washout (EWO)
(use humidified gas only)
? Pressure Control Mode with pressure = 30
- many with less pressure needed for ventilation in the study
- study done with VC mode
maintain a low target filling pressure (CVP of less than 4mm Hg or PAOP
of less than 8 mm Hg)
Liberal strategy: maintain higher filling pressure CVP 10 – 14mm Hg or
PAOP 14-18mm Hg. This was achieved by a combination of bolus fluid
administration, use of frusemide or dobutamine, depending on the
perfusion, urine output , measured filling pressures and cardiac output (if
There was no significant difference in mortality (25.5% in the conservative group vs. 28.4% in the liberal group). However, the conservative strategy improved the oxygenation index, lung injury score, increased the number of ventilator free days and days not spent in ICU. The conservative strategy did not increase the incidence or prevalence of shock during the study. In addition, the conservative strategy did not increase the use of dialysis during the first 60 days.
Use inotropes as needed
Evidence that use of steroids after the first week of ARDS improves prognosis significantly.
No benefit in the use of methylprednisolone after the first week of ARDS. Use of sterods after 14 days of ARDS was associated with increased mortality at 60 days. This was in spite of the steroid therapy and improving ventilator free shock free days during the first 28 days. Methyprednisolone did not increase infectious complications but was associated with a higher rate of neuromuscular weakness.
The beta agonist lung injury trial (BALTI) has shown that treatment with
intravenous albutamol (15ug / kg / hr) reduces extravascular lung water (EVLW)
in patients with ALI / ARDS with a reduction in plateau pressures at Day 7.
The effect on EVLW started at 48 hours. Patients receiving intravenous
salbutamol had a higher incidence ofsupraventricular arrhythmias these were not
sustained as the dose of salbutamol was modified in these patients. There was
no improvement in mortality with the use of salbutamol – however the study was
not Powered to detect a difference in mortality.