ARDSnet



INCLUSION CRITERIA: Acute onset of
1. PaO2/FiO2 ≤ 300 (corrected for altitude)
2. Bilateral (patchy, diffuse, or homogeneous) infiltrates consistent with pulmonary edema.
3. No clinical evidence of left atrial hypertension
 

PART I:
1. Calculate predicted body weight (PBW)
  Males = 50 + 2.3 [height (inches) - 60]
  Females = 45.5 + 2.3 [height (inches) -60]
2. Select any ventilator mode (A/C).
3. Set ventilator settings to achieve initial VT = 8 ml/kg PBW
4. Reduce VT by 1 ml/kg at intervals ≤ 2 hours until VT = 6ml/kg PBW.
5. Set initial rate to approximate baseline minute ventilation (not > 35 bpm).
6. Adjust VT and RR to achieve pH and plateau pressure goals below..

 
OXYGENATION GOAL:
  PaO2 55-80 mmHg or SpO2 88-95%
Use a minimum PEEP of 5 cm H2O. Consider use of incremental FiO2/PEEP combinations such as shown below (not required) to achieve goal.
 
Low PEEP/High FiO2 High PEEP/Low FiO2
FiO2 PEEP FiO2 PEEP
0.3 5 0.3 5
0.4 5 0.3 8
0.4 8 0.3 10
0.5 8 0.3 12
0.5 10 0.3 14
0.6 10 0.4 14
0.7 10 0.4 16
0.7 12 0.5 16
0.7 14 0.5 18
0.8 14 0.5-0.8 20
0.9 14 0.8 22
0.9 16 0.9 22
0.9 18 1.0 22
1.0 18-24 1.0 24

PLATEAU PRESSURE GOAL: ≤ 30 cm H2O
Check Pplat (0.5 second inspiratory pa use), at least q 4h and after each  change in PEEP or VT.
If Pplat > 30 cm H2O:
 
Decrease VT by 1ml/kg steps (minimum = 4 ml/kg).

If Pplat < 25 cm H2O and VT< 6 ml/kg
  Increase VT by 1 ml/kg until Pplat > 25 cm H2O or VT = 6 ml/kg.

If Pplat < 30 and breath stacking or dys-synchrony occurs:
  May increase VT in 1ml/kg increments to 7 or 8 ml/kg if Pplat remains < 30 cm H2O.

 
pH GOAL: 7.30-7.45
Acidosis Management: (pH < 7.30)
  If pH 7.15-7.30:

  - Increase RR until pH > 7.30 or PaCO2 < 25  (Maximum set RR = 35).

  If pH < 7.15:
  -
Increase RR to 35.
  - If pH remains < 7.15, VT may be increased in 1 ml/kg steps until pH > 7.15 (Pplat target of 30 may be exceeded).
  - May give NaHCO3 2-5 mEq/kg IV x1

Alkalosis Management: (pH > 7.45)
  - Decrease vent rate if possible
 
I:E RATIO GOAL:
Recommend that duration of inspiration be < duration of expiration.
 


PART II: WEANING

A. Conduct a SPONTANEOUS BREATHING TRIAL daily when:
1. FiO2 ≤ 0.40 and PEEP ≤ 8.
2. PEEP and FiO2 ≤ values of previous day.
3. Patient has acceptable spontaneous breathing efforts. (May decrease vent rate by 50% for 5 minutes to detect effort.)
4. Systolic BP ≥ 90 mmHg without vasopressor support.
5. No neuromuscular blocking agents or blockade.
6. Able to tolerate 5/5 on PSV.

 
B. SPONTANEOUS BREATHING TRIAL (SBT):
If all above criteria are met and subject has been in the study for at least 12 hours, Initiate a trial of UP TO 120 minutes (2hr) of spontaneous breathing with PSV = FiO2 < 0.5, PEEP < 5:

1. Place on T-piece, trach collar, or CPAP ≤ 5 cm H2O with PS < 5
2. Assess for tolerance as below for up to 2 hours.
  a. SpO2 ≥ 90 and/or PaO2 ≥ 60 mmHg
  b. Spontaneous VT ≥ 4 ml/kg PBW
  c. RR ≤ 35/min
  d. pH ≥ 7.3
  e. No Respiratory Distress (distress = 2 or more)
     - HR > 120% of baseline
     - Marked accessory muscle use
     - Abdominal paradox
     - Diaphoresis
     - Marked dyspnea
3. If tolerated for at least 30 minutes, consider extubation.
4. If not tolerated resume pre-weaning settings.

 
Definition of UNASSISTED BREATHING
(Different from the spontaneous breathing criteria as PS is not allowed)
1. Extubated with face mask, nasal prong oxygen, or room air, OR
2. T-tube breathing, OR
3. Tracheostomy mask breathing, OR
4. CPAP less than or equal to 5 cm H20 without pressure support or IMV assistance.
 

Source: ARDS.org