This document discusses ventilator management in different disease entities, with a focus on mechanical ventilation for acute respiratory failure and ARDS. It provides details on: - Indications for mechanical ventilation and initial setup decisions - The ARDSnet approach of using low tidal volumes (6 ml/kg predicted body weight) and monitoring plateau pressures - Evidence from the landmark NIH ARDS Network trial that showed reduced mortality using a lower tidal volume strategy - Exclusion criteria and respiratory values observed in the NIH ARDS Network study patients over the first 7 days

1. Ventilator Management
in Different Disease Entities

2. Mechanical Ventilation
 Use of sophisticated life support
technology aimed at maintaining tissue
oxygenation and removal of carbon
dioxide
 Support or replace the normal ventilatory
pump in moving air into and out of the
lungs – inadequate or absent
spontaneous breathing

3. Mechanical Ventilation
 Not without risk – complications and
hazards an be life threatening
 Decision to initiate mechanical
ventilation
 Serious one
 Sound clinical judgment
 Clear understanding of the indications
and associated goals

4. Indications for Mechanical
Ventilatory Support
 Respiratory failure
 An inability of the heart and lungs to provide
adequate tissue oxygenation or removal of
carbon dioxide
 Acute respiratory failure
 PaO2 < 60 mm Hg
 SpO2 < 90%
 With or without PaCO2 > 45 mm Hg

5. Acute Respiratory Failure
 Hypoxemic respiratory failure – lung
failure
 Hypercapnic respiratory failure – pump
failure
 Acute ventilatory failure
A sudden increase in PaCO2 with a corresponding
decrease in pH
 Chronic ventilatory failure
 Elevated PaCO2 with a normal or near normal pH

6. Initial Ventilator Setup
Key Decisions
 Indications for ventilatory support present
 Negative pressure versus positive pressure ventilation
 Non-invasive versus invasive positive pressure
ventilation
 Type and method of establishment of an airway
 Pressure versus volume ventilation
 Partial or full ventilatory support
 Choice of ventilator
 Mode of ventilation
 Assist-control ventilation versus SIMV (with or without pressure
support)
 Pressure support
 Pressure control
 Mixed or dual control modes
 Other newer modes of adjuncts

7. Indications for Mechanical
Ventilation in ARDS
 Hypoxemia
 Application of PEEP
 Delivery of high FiO2
 Increased work of breathing
 Use of ventilator to reduce work of breathing
 Impending or acute ventilatory failure
 Maintenance of normal pH and/or PaCO2

8. Ventilator Settings for ALI or ARDS
ARDSnet Approach
 Maintaining a low tidal volume
 Monitoring plateau pressure
 Setting
PEEP based on the FiO2
requirement

9. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 Calculate predicted body weight
 Male :
 PBW (kg) = 50 ± 2.3 [(height in inches)-60]
= 50 ± 0.91[(height in cm) –152.4]
 Female :
 PBW (kg) = 45.5 ± 2.3 [(height in inches)-60]
= 45.5 ± 0.91[(height in cm) –152.4]
 Ventilator mode : Volume assist/control
until weaning

10. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 Tidal Volume(Vt)
 Initial Vt : adjust Vt in steps of 1 ml/kg PBW
every 1-2 hours until Vt = 6 ml/kg
 Measure inspiratory plateau pressure (Pplat;
0.5 second inspiratory pause) every 4 hours
and after each change in PEEP or Vt
 If Pplat > 30 cm H2O, decrease Vt to 5 or 4
ml/kg
 If Pplat < 25 cm H2O, and Vt,6ml/kg, increase
Vt by 1 ml/kg PBW

11. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 Respiratory Rate (RR)
 With initial change in Vt, adjust RR to
maintain minute ventilation
 Make subsequent adjustments to RR to
maintain pH 7.30-7.45, but do not
exceed RR = 35/min and do not increase
set rate if PaCO2 <25 mm Hg
 I:E ratio : Acceptable range = 1:1 –
1:3 (no inverse ratio)

12. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 FiO2, PEEP and arterial oxygenation: Maintain
PaO2 55-80 mm Hg or SpO2 88%-95%
 Use only the following PEEP/FiO2 combinations:
 FiO2 PEEP (cm H2O)
 0.3-0.4 5
 0.4 8
 0.5 8-10
 0.6 10
 0.7 10-14
 0.8 14
 0.9 16-18
 1 18-25

13. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 Acidosis management
 If pH<7.30, increase RR until pH>1≧ 7.30 or
RR=35/min
 If pH remains <7.30 with RR = 35, consider
bicarbonate infusion
 If pH <7.15, Vt may be increased (Pplat may
exceed 30 cm H2O)
 Alkalosis management
 If pH > 7.45 and patient not triggering
ventilator, decrease set RR but not below
6/min

14. Lower Tidal Volume Ventilation Strategy
NIH ARDS Network
 Weaning
 Initiate weaning by pressure support when all
of the following criteria are present:
 FiO2 <0.4 and PEEP<8cm H2O
 Not receiving neuromuscular blocking agents
 Inspiratory efforts are apparent (ventilator rate may
be decreased to 50%of baseline level for up to 5
minutes to detect inspiratory effort)
 Systolic arterial pressure > 90 mm Hg without
vasopressor support

15. Traditional Tidal Volume
NIH ARDS Network
 Volume assist control
 Tidal Volume(Vt) : 12 ml/kg predicted
body weight
 Plateau pressure : < 50 cm H2O
 Ventilator rate setting needed to
achieve a pH goal of 7.3-7.45 : 6-35
breath/min
 I;E ratio : 1:1 – 1:3

16. Patients Excluded in
NIH ARDS Network Study
 36 hours had elapsed since they met the first
three criteria
 Younger than 18 years of age
 Participated in other trials within 30 days before
the three criteria were met
 Pregnant
 Neuromuscular disease that impair spontaneous
breathing
 Sickle cell disease
 Severe chronic respiratory disease

17. Patients Excluded in
NIH ARDS Network Study
 Weighed more than 1 kg per centimeter of
height
 Burns over more than 30 percent of their BSA
 Other conditions with an estimated 6-month
mortality rate > 50%
 Undergone bone marrow or lung transplantation
 Chronic liver disease (as defined by Child-Pugh
class C)
 Their attending physician refused or unwilling to
dull life support

18. Respiratory Values during the First 7
days in NIH ARDS Network Study
Variable Day 1 Day 3 Day 7
LVT TVT LVT TVT LVT TVT
Tidal volume 6.2±0.9 11.8±0.8 6.2±1.1 11.8±0.8 6.5±1.4 11.4±1.4
Plateau pressure 25±7 33±9 26±7 34±9 26±7 37±9
Peak insp pressure 32±8 39±10 33±9 40±10 33±9 44±10
Mean aw pressure 17±13 17±12 17±14 19±17 17±14 20±10
RR 29±7 16±6 30±7 17±7 30±7 20±7
Minute ventilation 12.9±3.6 12.6±4.5 13.4±3.5 13.4±4.8 13.7±3.8 14.9±5.3
PEEP 9.4±3.6 8.6±3.6 9.2±3.6 8.6±4.2 8.1±3.4 9.1±4.2

19. Main Outcome Variables in
NIH ARDS Network
Lower VT Traditional VT P Value
Death before discharge home 31.0 39.8 0.007
and breathing without
assistance (%)
Weaning by day 28 (%) 65.7 55.0 <0.001
No. of ventilator-free days, 12 ± 11 10 ± 11 0.007
days 1 to 28
Barotrauma, days 1 to 28 (%) 10 11 0.43
No. of days without failure 15 ± 11 12 ± 11 0.006
of non-pulmonary organs
or systems, days 1 to 28

20. Clinical Trials of Traditional Versus Lower Tidal Volume Ventilation
Strategies in Acute Lung Injury and Acute Respiratory Distress Syndrome
Number of Tidal Volumes Tidal Volumes Mortality
Patients as Reported per kg PBW (%)
Randomized T L T L T L
Stewart et al 120 10.8+ 7.2+ 12.2 8.1 47 50
Brochard et al 116 10.3 7.1 11.3 7.8 38 47
Brower et al 52 10.2 7.3 10.2 7.3 46 50
ARDS Network 861 11.8 6.2 11.8 6.2 40 31

21. Evidence-Based Medicine
In Mechanical Ventilation in ARDS
The ARDS network trial
provided strong evidence that
a lower tidal volume strategy
can improve clinical outcomes
in patients with ALI or ARDS

22. Summary of Alternative Ventilator
Strategies for ALI/ARDS
Ventilatory No. of
Strategy Year How Studies Patients Comments Study
Low tidal 1999 Phase III 861 Mortality was reduced by ARDS
volume 22% with a 6 ml/kg Network
predicted body weight
tidal volume. This is the
first large randomized
multicenter controlled
trial to show a mortality
benefit from a specific
therapy in ALI/ARDS
Low tidal 2002 Phase III 549 There was no mortality ARDS
volume with benefit to increase levels Network
high PEEP of PEEP compared with
the standard ARDS Network

23. Higher versus Lower
Positive End-Expiratory
Pressures in Patients with
the Acute Respiratory
Distress Syndrome
ARDS Network
NEJM 2002

24. Methods
 October 1999-February 2002
 23 hospitals of the National Heart, Lung,
and Blood Institute (NHLBI) ARDS Clinical
Trials Network

25. Patient
 Intubation with MV due to
 a sudden decrease in the ratio of the
PaO2/FiO2≦ 300
 a recent appearance of bilateral pulmonary
infiltrates consistent with the presence of
edema
 no clinical evidence of left atrial hypertension
(defined by PAWP≦18 mmHg)

26. Criteria of exclusion
 <13 y/o
 participated in other trials involving ALI within the
preceding 30 days;
 Pregnant;
 IICP
 severe neuromuscular disease,
 sickle cell disease,
 severe chronic respiratory disease,

27. Criteria of exclusion
 BW> 1 kg/cm,
 Burns> 40 % BSA,
 Severe chronic liver disease,
 Vasculitis with diffuse alveolar hemorrhage,
 A coexisting condition associated with an
estimated 6-month mortality rate >50 %;
 Post- BMT or lung transplant;
 Their attending physician refused to allow
enrollment.

31. Figure 1. Probabilities of Survival and of Discharge Home While
Breathing without Assistance, from the Day of Randomization (Day 0) to
Day 60 among Patients with Acute Lung Injury and ARDS, According to
Whether Patients Received Lower or Higher Levels of PEEP.

34. Evidence-Based Medicine
In Mechanical Ventilation in ARDS
with Higher PEEP
The ARDS Network higher versus
lower PEEP trial provided strong
evidence that there was no
mortality benefit to increase levels
of PEEP compared with the
standard ARDS Network low tidal
volume strategy

35. Algorithm for ventilator management of ARDS using the ARDSnet protocol
START Calculate predicted body weight
CMV (A/C). VCV. Set initial volume to 8 mL/kg, then 7 mL/kg after 1 hr, then 6 mL/kg after next hr.
increase respiratory rate to maintain minute ventilation. I:E ratio 1:2. PEEP and FiO2 per FiO2/PEEP table
no no ↓VT to
Pplat <
↑VT by 1 mL/kg VT 4 mL/kg 4 mL/kg
30 cm H2O
yes yes
yes Pplat < yes
VT < 6 mL/kg
25 cm H2O
no no
yes
↑VT to 7-8 mL/kg Severe dyspnea
no
PaO2 55-80 no Adjust FiO2 or PEEP
SpO2 88-95 per FiO2/PEEP table
yes
↑rate yes pH< FiO2≦0.4 no
Consider HCO3 pH ↓rate
7.15 <7.30 PEEP=8
↑VT >7.45
no yes
↑rate 7.30-7.45 Evaluate for weaning
ARDS Network N Engl J Med 2000; 342:1301

36. Indications for Mechanical Ventilation in
Patients with Chronic Pulmonary Disease
 Acute on chronic ventilatory failure and
hypoxemia
 Elevated PaCO2 and resulting hypoxemia
 Unloading work-of-breathing
 Increased work-of-breathing due to increased resistance
 Resting ventilatory muscles
 Exhausted muscles
 Improving bronchial hygiene
 Increased airway secretions

37. Ventilator Strategy in Chronic
Pulmonary Obstructive Disease
 Primary
concern : patient-ventilator
synchrony
 To avoid unnecessary work of breathing
 To reduce anxiety
 To decrease ventilatory drive
 To minimize auto-PEEP

38. Algorithm for the ventilator management of the patient with COPD
START
Candidate yes yes yes yes
Patient Clinically Continue
For NPPV tolerates improved NPPV
NPPV
intubate intubate
intubate (A/C), PCV or VCV, VT 8-10 mL/kg, Pplat < 30 cm H2O, rate
10/min, Ti 0.6-1.2 s, PEEP 5 cm H2O, FiO2 for SpO2 90-95%
<55 PaO2 >75
↑ FiO2 mmHg ↓ FiO2
55-75 mmHg
no Pplat > Pplat < no
30 cm H2O pH 25 cm H2O
>7.45 <7.30
yes yes
↓rate ↓VT 7.30-7.45 ↑VT ↑rate
no Auto-PEEP
yes
no Clear secretions
Auto-PEEP
Administer bronchodilators
yes Fumeaux T et al Intensive Care Med 2001;27:1868
Gladwin MT et al Intensive Care Med 1998;24:898
↑PEEP if missed trigger efforts
Nava S et al Ann Intern Med 1998; 128:721
↓VT or rate

39. Indications for Mechanical Ventilation in
Patients with Chest Trauma
 Flail chest with paradoxical chest movement,
tachypnea, hypoxemia, hypercarbia
 Pulmonary contusion with tachypnea and severe
hypoxemia (PaO2< 60 mmHg) breathing 100% O2
 Rib fracture with chest pain requiring large dose of
narcotics for pain control
 Post-operative thoracotomy
 Hemodynamic instability, particularly with marginal
respiratory reserve (hypoxemia and tachypnea)
 Severe associated injuries ( head injury)

40. Ventilator Strategy in Patients
with Chest Trauma
 Full ventilatory support initially
 Sedation, or paralysis may be necessary
initially
 Barotrauma is common
 Tidal volume
 8-10 ml/kg with satisfactory lung compliance
 4-8 ml/kg with pulmonary contusion and
ARDS

41. Algorithm for Mechanical Ventilation of the Patient with Chest Trauma
START
CMV (A/C), VT 6 to 10 mL/kg, FiO2 1.0.
rate 15/min, Ti 1 s, VCV or PCV, PEEP 5 cm H2O
Titrate FiO2 to
SpO2 92-95%
Good lung down
yes
FiO2 no Broncho- no no
Pleural
ICP Unilateral
<0.6 fistula >20 disease ↑PEEP
no
yes
yes yes
↑FiO2
yes Pplat>
↓VT and
↑rate 30 cm H2O
no
>7.45 <7.30 >25
↓rate pH Pplat ↑rate
7.30-7,45 ≦25
Maintain ↑VT or
Current ↑rate Calhoon JH et al Chest Surg Clin N Am 1997;7:199
settings Ferguson M et al 1996 2:449
Gentilello LM et al Am J Respir Crit Care Med 2001 163:604

42. Indications for Mechanical Ventilation in
Patients with Acute Head Injury
 Depression due to primary neurologic
injury
 Associated injuries to the spine, chest
and abdomen
 Neurogenic pulmonary edema
 Treatment with respiratory suppressant
medications (barbiturate, sedatives,
paralysis)

43. Algorithm for Mechanical Ventilation of the Patient with Head Injury
START
CMV (A/C), PCV or VCV, CMV (A/C), PCV or VCV,
VT 4 t0 8 mL/kg.FiO2 1.0, yes Unilateral lung no VT 8 t0 12 mL/kg.FiO2 1.0,
rate 20/min, Ti 1 s, disease rate 20/min, Ti 1 s,
PEEP 5 cm H2O PEEP 5 cm H2O
Titrate FiO2 for
SpO2 ≧92%
no
↑rate PaCO2 Pplat ＞ 30 ↓rate
>45 <35
yes
35 - 45 ↓VT
no FiO2 <70 >100
>0.6
PaO2 ↓FiO2
yes 70 - 100
no ICP< yes FiO2 More aggressive
↑FiO2 Medical therapy
20 >0.6
yes no >20
↑PEEP <20 >20
ICP ↑rate ICP
<20
Maintain
Slowly ↓rate to initial
ventilator
setting
settings
Berrouschot J et al Crit Care Med 2000 28:2956

44. Management of Intracranial Pressure
 Hyperventilation : PaCO2 of 25- 30 mmHg
 Mean airway pressure : kept as low as possible
 Positioning : 30° elevation of the head
 Dehydration and osmotherapy : manitol and lasix
 Sedation and paralysis : agitation, cough
 Barbiturate therapy
 Temperature control
 Ventriculostomy

45. Indications for Mechanical Ventilation
in Post-operative Patients
 Apnea – unreversed anesthetic agents
 Iatrogenic hypothermia
 Need to reduce cardiopulmonary stress
 Presence of altered pulmonary mechanics
 Transplant recipients
 Minimize post-operative cardiopulmonary
stress
 Pre-existing lung disease compromising
cardiopulmonary reserve

46. Algorithm for Mechanical Ventilation of the Post-operative Patient
Prior lung yes Ventilate consistent
START disease with underlying
disease
no
Single lung yes Ventilate consistent
transplant with negative lung
pathology
no
CMV (A/C), VCV or PCV, VT 10 – 12
mL/kg, rate 12/min, I;E:1:3
PEEP 5 cm H2O, FiO2:1.0
Titrate FiO2
For SpO2> 92%
FiO2 ↑PEEP
≧0.6
<0.6
Adjust rate and tidal volume for
normal acid-base Consider extubation
yes
Spontaneous
Breathing efforts. Spontaneous
no yes breathing Tolerated no
Hemodunamically
Stable, FiO2≦0.5 trial
PEEP≦5

47. Initial Ventilator Settings for Postoperative
Patients with no Prior Disease
Setting Recommendation
Mode A/C (CMV)
Rate 10 - 16/min
Volume/pressure control Pressure or volume
Tidal volume 10-12 mL/kg IBW and plateau pressure
<30 cm H2O
Inspiratory time 1s
PEEP ≤ 5 cm H2O
FiO2 Sufficient to maintain PaO2 > 80 mm Hg
Flow waveform Descending ramp

48. Initial Ventilator Settings for Postoperative
Patients with Prior Obstructive Lung Disease
Setting Recommendation
Mode A/C (CMV)
Rate 8 – 12 /min
Volume/pressure control Pressure or volume
Tidal volume 8-10 mL/kg IBW and plateau pressure
<30 cm H2O
Inspiratory time 0.6 – 1.2 s
PEEP 5 cm H2O; counterbalance auto-PEEP
FiO2 Sufficient to maintain PaO2 > 60 mm Hg
Flow waveform Descending ramp

49. Initial Ventilator Settings for Postoperative
Patients with Prior Restrictive Lung Disease
Setting Recommendation
Mode A/C (CMV)
Rate 15 –25 /min
Volume/pressure control Pressure or volume
Tidal volume < 8 mL/kg IBW and plateau pressure
<30 cm H2O
Inspiratory time 1 s
PEEP 5 cm H2O
FiO2 Sufficient to maintain PaO2 > 60 mm Hg
Flow waveform Descending ramp

50. Respiratory Failure in Neuromuscular
Diseases and Chest Wall Deformities
 Rapid onset
 Myasthenia gravis
 Guillain-Barre syndrome
 High spinal cord injury
 Prolonged paralysis following use of neuromuscular
blocking agents in ICU
 Gradual onset
 Muscular dystrophy
 Amyotrophic lateral sclerosis
 Thoracic deformities (severe scoliosis, kyphosis,
kyphoscoliosis)
 Post-polio syndrome

51. Indications for Mechanical Ventilation in
Patients with Neuromuscular Disease
 Progressive ventilatory failure
 Acute ventilatory failure
 Oxygenation is not usually an issue – except
in patients with acquired critical illness
neuromusculopathy following prolonged
mechanical ventilation

52. Algorithm for Mechanical Ventilation of the Patient with Neuromuscular Disease without Lung Disease
START
CMV (A/C), VCV, VT 15 mL/kg, FiO2 0.40
Rate 10/min, Ti 1 s, PEEP 0 cm H2O
no
yes no Secretions <92% >95%
SpO2 SpO2
↑FiO2 <95% ↑PEEP or ↓FiO2
atelectasis
yes
92-95%
In-Exsufflattor
yes yes
↑VT dyspnea ↑rate dyspnea
no
no
↓rate or ↓VT
≦25 <7.35 >7.45 Consider
↑VT Pplat pH
mechanical
>25 dead space
7.35-7.45
↑rate no
secretions
yes
In-Exsufflattor
Maintain therapy

53. Methods to Treat Atelectasis
 In-exsufflator
 Maximal insufflation capacity
 Hyperinflation
 Assisted cough
 Peak cough flow > 160 L/min

55. Mechanical Insufflation-Exsufflation
 Artificial cough machine
 Stimulating cough by inflating the lung with
pressure, followed by a negative pressure
to produce a high expiratory flow
 Inspiratory pressure :25-35 cm H2O for
1-2 seconds
 Expiratory pressure:-40 cm H2O for 1-2
seconds
 Treatment periods: 5-6 breaths

56. Indications for Mechanical Ventilation in
Patients with Cardiovascular Failure
 Increased work of the myocardium
 Decrease myocardial work with MV
 Increased work of breathing
 Reduce the work of breathing with MV
 Hypoxemia
 Reverse hypoxemia with MV

57. Algorithm for Mechanical ventilation of the Patient with Cardiac Failure
Awake and yes no Mask CPAP,
START Acute MI 5-10 cm H2O, FiO2 1.0
cooperative
no intubate yes
CMV (A/C), VCV or PCV, VT 8-10 no Patient
intubate tolerates
mL/kg, Pplat < 30 cm H2O, I;E:1:2
PEEP 5 cm H2O, FiO2 1.0 yes
PaCO2> no
yes SpO2<92%; 45 mm Hg
↑PEEP Pulmonary edema
yes
no NPPV
Titrate FiO2
For SpO2>92%
yes PaCO2. no
≧30 45 mm Hg
↓VT Pplat
<30
>7.45 <7.35
↓ rate pH ↑ rate
7.35-7.45
Hemodynamic Continue therapy,
Manipulate no yes
stability Definitive medical therapy
PEEP and FiO2
Bersten AD et al New Engl J Med 1991 325:1825
Poppas A et al Am J Respir Crit Care Med 2002 165:4

58. Indications for Mechanical Ventilation in
Patients with Asthma
 Acute ventilatory failure
 Impending acute ventilatory
failure
 Severe hypoxemia

59. Ventilator Strategy
in Patients with Acute Asthma
 Major concern: auto-PEEP
 To minimize auto-PEEP
 Permissive hypercapnia
 Use of inhaled bronchodilators and
systemic steroids to reduce the airway
inflammation, edema, swelling and
bronchospasm
 Risk of barotrauma and hypotension

60. Algorithm for Mechanical Ventilation of Patient with Asthma
START
CMV (A/C), PCV or VCV, VT 4-8 mL/kg, Pplat≦ 30 cm H2O
rate 8-20/min, Ti 1 s, PEEP 5 cm H2O, FiO2 1.0
>95% <92%
↓FiO2 SpO2 ↑FiO2
92-95%
no Pplat> >7.45 <7.30 Pplat< no
30 cm H2O pH 25 cm H2O
yes yes
↓rate 7.30-7.45
↓VT ↑VT ↑rate
no
Auto-PEEP
yes
no
Auto-PEEP Administer bronchodilators
Afzal M et al Clin Rev Allergy Immunol 2001 20:385
yes
Mansel JK et al Am J Med 1990 89:42
Decrease minute ventilation Koh Y Int Aneshesiol Clin 2001 39:63

61. Indications for Mechanical
Ventilation in Patients with Burn
and Smoke Inhalation
 Smoke inhalation or pulmonary burn with
respiratory failure (ARDS)
 Severe burn with chest wall restriction
 Respiratory depression due to inhalation of
systemic toxin (carbon monoxide)
 Respiratory failure due to secondary infection –
pneumonia, sepsis
 Postoperative skin graft or escharotomy

62. Algorithm for Mechanical Ventilation of Patient with Burn and
Inhalation Injury
START
CMV (A/C), PCV or VCV, yes Continue
CO poisoning
VT 6 to 12 mL/kg, FiO2 1.0, 100% O2
rate 15/min, Ti 1 s
no
Titrate FiO2 for
SpO2≧92%
ABG
results
Treat with:
<7.30 Bronchodilators,
no >7.45 diuretics
↓ rate Pplat>30 pH
yes
↓ VT 7.30-7.45 Pplat>30 no
↑ VT
Cm H2O
yes FiO2< <70 >100
↑ FiO2 PaO2 yes
0.6
no 70-100 ↓Chest wall yes Consider
compliance VT ↑
Consider: no FiO2< ↓ FiO2
Bronchodilators 0.6 no
Diuretics
Secretion clearance
↑ rate
yes
PEEP
Recruitment maneuver Maintain
Prone ventilator
Inhaled nitric oxide settings

63. Indications for Mechanical
Ventilation in Patients with
Bronchopleural Fistula
 Bronchopleural fistula is not by
itself an indication for mechanical
ventilation, but may be necessary
in the following settings:
 Apnea
 Acuteventilatory failure
 Impending acute ventilatory failure
 Oxygen deficit

64. Algorithm for Mechanical Ventilation of Patient with Bronchopleural Fistula
Start
CMV (A/C), VCV or PCV, rate 6-20/min
VT 4 – 8 mL/kg, Ti≤ 1 s
PEEP 3 cm H2O, FiO2:1.0
Exhaled VT
yes
>75%
Inhaled VT
no
Systemicaly evaluate changes in:
Tidal volume
Respiratory Rate Titrate FiO2 for
PEEP SpO2 92-95%
Inspiratory time
Pressure control vs. volume control
<7.25 >7.45
rate pH rate
7.25-7.45

65. Indications for Mechanical Ventilation in
Patients with Drug Overdose
 Apnea
 Acute respiratory failure
 Impending acute respiratory
failure

66. Algorithm for Mechanical Ventilation of Patient with Drug Overdose
START
CMV (A/C), VCV or PCV,,rate 10/min
VT 8 to 12 mL/kg, Ti 1 s,
PEEP 5 cm H2O, FiO2 1.0
Titrate FiO2
for SpO2 > 92%
≧0.60
FiO2 ↑PEEP
<0.60
Adjust rate and tidal volume for
normal acid-base
Consider extubation
yes
Spontaneous
no breathing efforts yes Spontaneous
hemodynamically no
Breathing tolerated
stable, FiO2≦0.5 trial
PEEP≦5

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68. Ventilator Setting for ALI or ARDS
Open Lung Approach
 Maintaining a low plateau
pressure
 Monitoring tidal volume
 Using recruitment maneuvers and
high levels of PEEP to maximize
alveolar recruiment

69. Algorithm for ventilator management of ARDS using the open lung approach
CMV (A/C). PCV to achieve VT of 4-8 mL/kg,
START Ti to Avoid auto-PEEP. Rate 20/min. FiO2 1.0.
PEEP 10 cm H2O
Recruitment maneuver
PEEP 20 cm H2O
FiO2 to maintain SpO2 90-95%
Decrease PEEP to maintain SpO2 90-95%
<7.25 >7.45 ↓pressure control
↑ pressure control if pH
Pplat < 30 cm H2O ↓ rate
↑rate (avoid auto-PEEP)
Consider accepting lower pH 7.25-7.45
Recruitment maneuver <90% >95% ↓FiO2
↑ increase PEEP SpO2
↓ PEEP if FiO2 < 0.05
↑increase FiO2
90-95%
≧90%
SpO2 Maintain ventilator settings
<90%
Consider prone position
Consider accepting lower level of oxygenation
Consider inhaled nitric oxide Amato MBP et al. N Engl J Med 1998 338:347

70. The ARDSnet protocol for ventilation of
patients with ALI and ARDS
 Initial ventilator tidal volume and rate
adjustment
 Calculate predicted body weight
 Male = 50 + 2.3 [ht (in) – 60 ] kg
 Female = 45.5 + 2.3 [ht (in) – 60 ] kg
 Mode : volume Assist-Control
 Set initial tidal volume to 8 mL/kg PBW
 Reduce tidal volume to 7 mL/kg PBW after 1-2 hrs
and then to 6 mL/kg PBW after a further 1-2 hrs
 Set initial ventilator rate to maintain baseline
minute ventilation (not > 35 /min)
ARDS Network N Engl J Med 2000; 342:1301

71. The ARDSnet protocol for ventilation of
patients with ALI and ARDS
 Subsequent tidal volume adjustments
 Plateau pressure goal : ≤ 30 cm H2O
 Check inspiratory plateau pressure (Pplat) with 0.5 s
pause at least every 4 hrs and after each change in
PEEP and tidal volume
 If Pplat >30 cm H2O, decrease tidal volume by 1 mL/kg PBW,
if necessary to 4 mL/kg PBW
 If Pplat < 25 cm H2O and tidal volume < 6 mL/kg PBW,
increase tidal volume by 1 mL/kg PBW until Pplat >25 cm H2O
and tidal volume =6 mL/kg
 If breath stacking or severe dyspnea occurs, tidal volume may
be increased (not required) to 7 or 8 mL/kg PBW 1f Pplat < 25
cm remains ≤ 30 cm H2O
ARDS Network N Engl J Med 2000; 342:1301

72. The ARDSnet protocol for ventilation of
patients with ALI and ARDS
 Arterial oxygenation
 Goal : PaO2 55-80 mm Hg or SpO2 88 –
95%
 Use these FiO2/PEEP combinations to
achieve oxygenation goal
FiO2 - 0.3 0.4 0.4 0.5 0.5 0.6 0.7 0.7 0.7 0.8 0.9 0.9 0.9 1.0
PEEP 5 5 8 8 10 10 10 12 14 14 16 16 18 20-24
ARDS Network N Engl J Med 2000; 342:1301

74. Figure 1. Probabilities of Survival and of Discharge Home While
Breathing without Assistance, from the Day of Randomization (Day 0) to
Day 60 among Patients with Acute Lung Injury and ARDS, According to
Whether Patients Received Lower or Higher Levels of PEEP.

75. The ARDSnet protocol for ventilation of
patients with ALI and ARDS
 Respiratory rate and arterial pH
 Arterial pH Goal : 7.30 – 7.45
 A. Acidosis management
 If pH 7.15 – 7.30
 Increase set rate until pH >7.30 or PaCO2 < 25 (max rate =
35/min)
 If set rate = 35 /min and pH < 7.30, NaHCO3 may be given (not
required)
 If pH < 7.15
 Increase set respiratory rate to 35 /min
 If set rate = 35 /min and pH < 7.15 and NaHCO3 has been
considered, tidal volume may be increased in 1 mL/kg PBW
steps until pH > 7.15 (Pplat target may be exceeded)
 Alkalosis management
 Decrease set rate until patient rate > set rate. Minimum set
rate = 6 /min
 I:E Ratio Goal : 1:1 – 1:3
 Adjust flow and inspiratory flow waveform to achieve goal
ARDS Network N Engl J Med 2000; 342:1301

76. Recruitment Maneuvers
 In the first 80 patients, higher-PEEP
group, => assessed the safety and
efficacy of recruitment maneuvers
 single sustained inflations of the lungs to
higher airway pressures and volumes than
are obtained during tidal ventilation
 An effort to improve arterial oxygenation.

77. Recruitment Maneuvers
 One or two such maneuvers were
conducted during the first four days, by
applying CPAP 35 to 40 cmH2O for 30
seconds.
 The subsequent mean increase in arterial
oxygenation was small and transient.
 Discontinued recruitment maneuvers for
the remainder of the trial.

78. General Guideline for Initial Ventilator
Settings for Adult Patients
 Tidal Volume
 8 to 12 mL/kg IBW
 Avoid over-distension
 Prefer volume on the steep part of the pressure-volume
curve
 Maintain Pplat at 30 cm H2O or less
 10-12 mL/kg IBW is a good starting point for most of the
patients
 12 – 15 mL/kg IBW –neuromuscular diseases or post-
operative patients with normal lungs
 8-10 mL/kg IBW in SIMV with adequate expiratory time
 In ARDS patients, start with 8 mL/kg, reduce gradually to 6
mL/kg to maintain Pplat at 30 cm H2O or less

79. Alarm and Backup Ventilation Settings
for Initial Ventilator Setup (Adult)
Low pressure 8 cm H2O 0r 5-10 cm H2O below PIP
Low PEEP/CPAP 3-5 cm H2O below PEEP
High pressure limit 50 cm H2O
adjust to 10-20 cmH2O above PIP
Low exhaled tidal volume 100 mL or 10-15% below set VT
Low exhaled minute ventilation 2-5 L/min or 10-15% below backup minute
ventilation
High minute ventilation 5 L/min or 10-15% above baseline
minute ventilation
Oxygen percentage 5% above and below set O2 %
Temperature 2°C above and below set temperature
High temperature not to exceed 37°C
Apnea delay 20 seconds
Apnea values Tidal volume and rate set to achieve full
ventilatory support with 100 % O2