Approach to Pneumonia in Patients with ARDS

Richard G. Wunderink MDNorthwestern University

Chicago IL USA

Pneumonia and ARDSCommunity-acquired pneumonia is the

most common infectious cause of ARDSViral pneumonia very significant mortalityAspiration pneumonitis is often confusedVAP as a cause of ARDS is uncommon

ARDS secondary to pneumonia has the highest associated mortality

BAL Neutrophilia

85.4 80.482.2

37.8

82.3 77.1

0

20

40

60

80

100

High

ly Pos

*

Ster O

ff AB

ICO >

2%

ICO >

7%

Pos G

S

Therap

y Chan

ge

PM

N %

(95

% C

I)

* BAL > 106, PSB > 105 cfu/ml

BAL Amylase

Visual inspection of data – clear separation >80 IU/L

14 patients with 20 BALs >80 IU/L 5/14 BALs diagnostic colony

counts as well (2 oral flora only)

3/14 known esophogeal disease

6/14 severe neurologic disease

9/14 suspected aspiration 10/14 subsequently diagnosed

swallowing dysfunction No significant pancreas-

specific amylase (N=78)

13862

42.7

2

13.8

434

24.5

1

10

100

1000

10000

100000

Raw value Log transf

Mea

n an

d 95

% C

I

N= 136 consecutive BALs

13

ARDS and VAPVAP occurs frequently in ARDS

ARDS and VAP: Incidence

60

28

43

55

3228

3731

23

0

10

20

30

40

50

60

%

Delclaux Meduri Chastre Markowicz

VAP Recurrent VAP Non-ARDS

ARDS and VAP: Mortality

78

92

6352

72

57 59

47

0

50

100

Mor

tali

ty (

%)

Delclaux Meduri Chastre Markowicz

VAP No VAP VAP, no ARDS

ARDS and VAP: Diagnosis

VAP occurs frequently in ARDSVAP hard to diagnose in ARDS

Frequent empirical antibiotic useMultiple other potential causes of signsPre-existing CXR abnormalities

ARDS and VAP: Diagnosis

VAP occurs frequently in ARDSVAP hard to diagnose in ARDS

Frequent empirical antibiotic use Multiple other potential causes of signs Pre-existing CXR abnormalities

Quantitative culture techniques (bronchoscopic or nonbronchoscopic) are more likely to define true VAP in

ARDS

Invasive versus Clinical Diagnosis of VAP

25.8

16.2

5.8 4.97.5

11.5

2

14

0

5

10

15

20

25

30

Mortality*(%)

Organ FailureDay 7

Antibiotic-Free days

No antibiotics(%)

ClinicalInvasive

* 14 Day: 28-Day severity-adjusted mortality significantly

higher also ( RR 1.25, 95% CI 1.05-1.47)

ARDS and VAP: Response to Treatment

VAP occurs frequently in ARDSVAP hard to diagnose in ARDS

Ineffective antibiotic therapy for VAP is difficult to detect in ARDSHigh frequency of MDR pathogens like

Pseudomonas and MRSACompromises ability to use “therapeutic response”

to assess presence of pneumonia

Treatment Failure in VAP

53

62

43.6

60

0

10

20

30

40

50

60

70

Fai

lure

(%

)

Luna Ionas Chastre Luyt

Resolution of VAP

5

3

6

3

8

6

10

7

6 6

0

1

2

3

4

5

6

7

8

9

10

Dur

atio

n to

Res

olut

ion

(Day

s)

Fever PaO2/FiO2 WBC ETA QC All

Mean

Median

Dennesen, AJRCCM, 2001

Clinical Pulmonary Infection Score (CPIS)

OriginalTemperatureLeukocytosisSecretionsPaO2/Fio2 ratioCXR pattern (0

points for ARDS)

ModificationsLeukocytosis definitionSecretion definitionCXR definitions

Resolution of VAP

Survivors

All patients

Nonsurvivors

Luna, Crit Care Med, 2003

Resolution of VAP

Procalcitonin Response to VAPProcalcitonin Response in VAP

-50

0

50

100

150

200

250

300

350

400

450

Responders

Nonresponders

104 cfu/ml

Qu

anti

tati

ve C

ult

ure

(cf

u/m

l)

MRSA VAP: Microbiologic Response to Vancomycin

16.7

84.6

67

46

0102030405060708090

%

<1000 cfu/ml 28 day Mortality

MRSA

Control VAP

p < 0.05

Baughman, J Intensive Care Med, 2003

Repeat PSB after 72 hours

Follow-up Bronchoscopy in Nonfermenter VAP

0

25

19.2

38.9

23.1

38.9

0

5

10

15

20

25

30

35

40

14 Day 28 Day MechanicalVentilation

Follow-upNo Follow-up

P = 0.008

Mortality

Pneumonia and ARDS

Pneumonia common cause of ARDSVAP common complication of ARDSVAP difficult to diagnosis

May need more aggressive approach to both initial diagnosis and subsequent evaluation