The document discusses methods for diagnosing ventilator-associated pneumonia (VAP) in intensive care unit patients on mechanical ventilation. Clinical criteria are commonly used but can lead to overdiagnosis and underdiagnosis of VAP. Several studies evaluated the sensitivity and specificity of various clinical criteria and scoring systems and found limitations. Early diagnosis of VAP remains challenging and new diagnostic biomarkers and treatment approaches are being investigated to improve patient outcomes.

1. Did my patient have VAP?.
Dr. Andrés Esteban
Servicio de Cuidados Intensivos y Grandes Quemados

4. 84 patients with more than 72 h. of MV
suspected of having nosocomial pneumonia.
Definitive bacterial pneumonia
● Positive pleural fluid culture (n=4)
● Rapid cavitation of lung infiltrates (n=4)
● Histopathologic demonstration (n=9)
27 patients with ultimately pneumonia
J. Y. Fagon, J. Chastre, et al
Chest 1993;103:547

5. Patients
without
Pneumonia
Patients
with
Pneumonia
9±7
9±6
Temperature
38.3 ± 0.8
38.4 ± 1.1
Change in temperature
+ 0.1 ± 1.0
+0.5 ± 1.0
Blood Leukocytes (103)
15.2 ± 5.8
14.5 ± 5.4
Change in Leukocytes
+2.0 ± 7.0
+2.0 ± 5.6
Radiologic score
6±2
6±2
Change in Radiologic score
+2 ± 1
+2 ± 2
Duration prior ventilation
J. Y. Fagon, J. Chastre, et al
Chest 1993;103:547

7. The reliability coefficient (Kappa)
among the four pathologists
was ……………… 0.916
The 6 months later resulted in
reclassification of 3 patients
S. H. Kirtland,D.E.Corley et al.
Chest 1997;112:458

8. 39 patients died after a mean 14 d. M.V.
Mechanical ventilation
14 d. (mean)
Airspace disease (Chest radiograph) 36 / 39
Antimicrobial treatment
38 / 39
With Pneumonia (Hist)
9 / 39
Without Pneumonia (Hist)
30 / 39
S.H. Kirtland, D. Corley, et al
Chest 1997;112:445

9. Correlation (Kappa) with Clinical Findings
(during the 48 h. prior to death)
Histologic
diagnosis of
Pneumonia
Temperature >38.5 ºC
0.15
WBC count ≥ 15,000
-0.03
Bacterial or fungal on
sputun cultive
-0.06
Chest Radiograph
0.04
Decrease PaO2/FiO2
0.11
S.H. Kirtland, D. Corley, et al
Chest 1997;112:445

10. 25 patients with MV >72 h.
16 biopsy speciement per patient
N. Fabregas, S. Ewing et al.
Thorax 1999;54:867

11. Sensitivity
Specificity
PPV
NPV
Chest
radiography
0.92
0.33
0.60
0.80
Leukocytosis
0.77
0.58
0.67
0.70
Fever
0.46
0.42
0.46
0.42
Purulent
secretions
0.69
0.42
0.56
0.56
Johanson 2/3
0.69
0.75
0.75
0.69
Johanson 3/3
0.23
0.92
0.75
0.52
Pugin
score >6
0.77
0.42
0.67
0.42
N. Fabregas, S. Ewing et al.
Thorax 1999;54:867

12. 9906
Patients admitted to ICU
1633 (16.5 %)
Died
497 (35 %)
Obtained consent and
Performed a clinical autopsy
253
Patients included
(VM >48 h.)
120
Organ donor
101
Patients with legally
mandated autopsies
30
Lost information
A.Esteban,F.Frutos,et al. (submitted)

13. 253 patients with autopsy
> 48 hours of MV
Following during the preceding
14 days of death

14. Clinical suspicion of pneumonia according
to the LOOSE DEFINITION
Infiltrate on the chest radiograph and
at least two of the folloving
● Leucocytosis >12 x 109/ml
● Fever >38.5 ºC
● Presence of purulent tracheobronquial
secretions

15. Clinical suspicion of pneumonia according
to the RIGOROUS DEFINITION
Infiltrate on the chest radiograph and
all three of the folloving
● Leucocytosis >12 x 109/ml
● Fever >38.5 ºC
● Presence of purulent tracheobronquial
secretions

16. Clinical Pulmonary Infection Score (CPIS)
Clinical suspicion of pneumonia in the presence
of a positive score at different cut offs (1-12 points)
which include the following variables.
● Body temperature
● Blood leucocyte count and number of band forms
● Tracheobronchial secretions (purulen or not and
quanty)
● Microscopic examination of bronchial secretions
(Gram and semiquantitative culture)
● PaO2/FiO2
● Chest radiograph

17. n = 253 patients
Age, mean ± SD
66.2 ± 13.5
157 (62.1 %), 96 (37.9 %)
Sex (Male and female), n %
SAPS II, mean ± SD
49.5 ± 15.8
Length of ICU stay d. mean ± SD
16.7 ± 17.9
Cause of ICU admission, n (%)
● Medical
142 (56.1 %)
● Surgical
88 (34.8 %)
● Coronary
23 (9.1 %)
Temperature (ºC), mean ± SD
37.63 ± 1.13
Leucocytes (x 109/L) mean ± SD
16.16 ± 12.21
PaO2 / FiO2, mean ± SD
182.86 ± 85.94
Chest x-ray findings, n (%)
● No infiltrates
● Localizated
8 (3.2 %)
76 (30 %)

18. The Kappa statistict
agreement between the two
intensivist in the chest
radiographies was 0.382

22. Chest Radiography
76 / 253 (30 %)
169 / 253 (66.8 %)
Localized infiltrates
Diffuse infiltrates

23. Sensibility
Specificity
(%, CI 95%)
(%, CI 95%)
Loose
Definition
64.8
(56.6–72.2)
Rigurous
Definition
Definition
CPIS
LR (+)
LR (-)
36
(27.7-45.3)
1.01
(0.84-1.22)
0.98
(0.72-1.32)
15.5
(10.5-22.3)
91
(84.2-95)
1.72
(0.85-3.48)
0.93
(0.82-1.06)
45.8
(37.8-54)
60.4
(51.1-69)
1.15
(0.86-1.54)
0.90
(0.72-1.11)
A.Esteban,F.Frutos,et al. (submitted)

24. N. Fabregas
Thorax 1999
(n= 25)
Definition
A. Esteban
(n = 253)
Sensibility
Specificity
Sensibility
Specificity
Johanson 2/3
0.69
0.75
0.65
0.46
Johanson 3/3
0.23
0.92
0.15
0.91
CPIS
0.77
0.42
0.46
0.61

25. Sensitivity
Specificity
LR (+)
LR (-)
(%, CI 95 %)
(%, CI 95 %)
(CI 95 %)
(CI 95 %)
Loose
64.9
(56.5 – 72.2)
36
(27.7 – 45.3)
1.01
(0.84– 1.22)
0.98
(0.72 – 1.32)
Loose
+ localized
infitrates
11.3
(7.1 – 17.5)
91.9
(85.3 – 95.7)
1.39
(0.64 – 3.03)
0.97
(0.85 – 1.1)
Rigorous
15.5
(10.5 – 23.6)
91
(84.2 – 95)
1.72
(0.85 – 3.48)
0.93
(0.82 – 1.06)
2.1
(0.7 – 6)
100
(96.7 – 100)
-
0.98
(0.96 – 1.0)
45.8
(37.8 – 54)
60.4
(51.1 – 69)
1.15
(0.86– 1.54)
0.90
(0.72 – 1.11)
Definition
Rigorous
+ localized
infiltrates
CPIS
A.Esteban,F.Frutos,et al. (submitted)

26. OVERALL
GROUP
PPV
NPV
Sensitivity
Specificity
Likelihood
(+)
Likelihood
(-)
RISK
FACTOR
PULMON.
RISK
FACTOR
EXTRAPU
L. RISK
FACTOR
75 %
84 %
66 %
89 %
6.02
76 %
75 %
66 %
83 %
3.85
61 %
69 %
59 %
72 %
2.07
85 %
78 %
70 %
90 %
6.83
0.38
0.41
0.58
0.55
A.Esteban,P.Fdez-Segoviano,F.Frutos,et al.
Ann Intern Med 2004;141:440

27. Decisions based on clinical criteria
resulted in inappropriate treatment
of many patients without pneumonia
J. Y. Fagon, J. Chastre, et al
Chest 1993;103:547

28. Early diagnosis
Fast cultures
(microarray based(-4h)detection of
ten significant bacterial species)
Procalcitonin (High NPV)
s-TREM-1( in BAL or in plasma)
Early treatments
Lipopolysacharide
Late proinflam . Mediators
Complements cascade
Apoptosis
Inducible NO synthasa

29. ● Clinical criteria may lead to underdiagnosis, which
result an increase risk of death in patients with
ventilator-associated pneumonia not receiving
antibiotic treatment.
● Also the clinical criteria may lead to overdiagnosis
which result in overuse of antibiotics that favour
colonization with potentially resistant pathogenic
microorganisms and superinfection.

34. MANUEL
JULIO
DATE
376
1999
DIAGNOSIS
Craneal
Stab wound
Craneal
Stab wound
TREATMENT
Catholic Church
Bishop
University Hospital
ICU
OUTCOME
Saint Manuel
Altar of the Church
Neurosurgery bill
ICU bill
Chart number
124123
Psychiatric Nursery