Diagnostic Criteria: Severe Community-Acquired

Pneumonia

Antonio Anzueto

The University of Texas Health Science Center at San Antonio, Texas

Our Secret weapon !!!

Diagnostic criteria SCAP

Are we aware of existing criteria and if so, do we use them ?

Validity of CriteriaWhere we need to go

Diagnostic criteria SCAP

Are we aware of existing criteria and if so, do we use them ?

Validity of CriteriaWhere we need to go

Aims

Hypothesis

To understand the perception of physician attitudes to define which patients with CAP should be admitted to the intensive care unit (ICU)

Significant variation among physicians occur regarding who

should be admitted to the ICU

DemographicsPractice variables No (%)

Profession

Physician 370 (98.7)

Other 5 (1.3)

Specialty

Pulmonary disease 290 (75.5)

Critical care 262 (68.2)

Type

Academic 161 (41.9)

Other

Location

Urban 220 (57.3)

Other 164 (42.7)

n=383

Aware and Use it!!

50

28 27

0

20

40

60

80

100

ATS 2001 APACHE PSI class V

Per

cen

tag

e

Aware and DO NOT Use it!!

7468 67

0

20

40

60

80

100

SAPS ATS 1993 APACHE

Per

cen

tag

e

NOT Aware and DO NOT Use it!!

77 74

45

0

20

40

60

80

100

CURB CURB-65 BTS

Per

cen

tag

e

Practice setting

63

51

69

56

87

71

0

10

20

30

40

50

60

70

80

90

BTS PSI class IV SAPS

Per

cen

tag

e

Academic (n=182) vs. Non-academic (n=203)

p=0.04 p=0.02 p<0.01

Conclusions

Criteria to define the need for ICU admission were infrequently reported by survey responders

Important differences were found in academic vs. non-academic practitioners regarding the criteria used to admit patients to the ICU with CAP

Implications

There is a need for more unified and appropriate criteria to define which patients with CAP require admission to the ICU

Diagnostic criteria SCAP

Are we aware of existing criteria and if so, do we use them ?

Validity of CriteriaWhere we need to go

Mortality and Care

0

5

10

15

20

25

30

Low Intermediate High

Risk of dying due to CAP

Home

Ward

ICU

Stratification CAP-PORT

Fine MJ, et al. N Engl J Med. 1997;336:243-250

Step-1Risk class I (lowest

severity level)Age < 50 yearsNo comorbid

conditions (neoplastic diseases, liver disease, congestive heart failure, cerebrovascular disease, or renal disease)

Normal or only mildly deranged vital signs and normal mental status

Step-2Not Risk class IClasses II-V

3 -Demographics5 -Comorbid

conditions5 -Physical exam

findings7 -Laboratory or

radiographic findings

Risk-class mortality rates

Risk Class

No. of points

Mortality%

Recommended site of care

I -- 0.1 Outpatient

II <70 0.6 Outpatient

III 71-90 2.8 Outpatient or brief inpatient

IV 91-130 8.2 Inpatient

V >130 29.2 Inpatient

Fine MJ, et al. N Engl J Med. 1997;336:243-250

Step-1 (Pre-morbid conditions) + Step-2 (PSI score) + Step-3 (Clinical judgment)

Mortality – CURB-65 score

0

5

10

15

20

25

0-1 2 > 3

Confusion; U rea (>19.1 mg/dL); Respirations (> 30 rpm); Blood pressure (DBP < 60); 65 years of age

CURB-65 ScoreLim et al. Thorax 2003 58:377

n=1,068

n=324

n=184

n=210

Severe Pneumonia Criteria

MAJORMechanical ventilationMultilobar or increase

infiltrates >50% in 48h

Septic Shock or need for vasopressors >4h

Acute renal failure

MINORSBP < 90 mm Hg• DBP < 60 mm Hg• RR >30/min

PaO2/FiO2 < 250

Bilateral or multilobar infiltrates

1 of 2 major criteria 2 of 3 minor criteria

ATS guidelines. AJRCCM. 2001;163:1730-1754

Methods

Study Design A retrospective observational cohort study

of patients hospitalized at a two teaching hospitals in San Antonio, Texas

VA medical center and county-run referral hospital

Admission between Jan 1, 1999 and Dec 31, 2001

Study was approved by the institutional board review

DemographicsVariables Alive

n= 714 (%)

Deadn=72 (%)

p value

Age in years, mean + SD 60 + 16 63 + 16 0.09

Sex, n (%) male 561 (79) 60 (83) NS

Nursing home resident 41 (6) 13 (18) < 0.001

Admission thru ED 598 (84) 58 (81) NS

ICU admission within 24 h 118 (17) 36 (50) < 0.001

n=787

NS=p>0.05

Predictors FrequencyPredictors 30-day

Mortality, n (%)

ICU admission

, n (%)

CURB-65 Group 1 (scores 0-1) 20/461 (4) 63/461 (14)

CURB-65 Group 2 (scores 2) 29/187 (15) 47/187 (25)

CURB-65 Group 3 (scores 3-5) 20/116 (17) 36/116 (31)

CURB-65 Group 3 (scores 4-5) 5/23 (22) 9/23 (39)

rATS – Severe CAP criteria 21/74 (28) 70/74 (95)

PSI low risk class (I-III) 16/409 (10) 44/409 (11)

PSI moderate risk class (IV) 26/266 (10) 62/266 (23)

PSI high risk class (V) 30/112 (27) 48/112 (43)

n=787

ICU admission*

ICU admission Sn

(%)

Sp

(%)

PPV

(%)

NPV

(%)

ROC

(95% CI) Criteria rev. ATS 53 94 67 89 0.73

(0.68-0.78) Criteria CURB-65 6 98 39 81 0.59

(0.54-0.64) PSI high class V 31 90 43 84 0.67

(0.63-0.72)

* Sn, sensitivity; Sp, specificity; PPV, positive predictive value; NPV, negative predictive value; ROC, receiver operating curves

30-day Mortality *

ICU admission Sn

(%)

Sp

(%)

PPV

(%)

NPV

(%)

ROC

(95% CI) Criteria rev. ATS 39 87 23 93 0.63

(0.55-0.70) Criteria CURB-65 7 97 22 91 0.66

(0.59-0.73) PSI high class V 42 88 27 94 0.71

(0.65-0.78)

* Sn, sensitivity; Sp, specificity; PPV, positive predictive value; NPV, negative predictive value; ROC, receiver operating curves

ICU admission

ICU admission Sn

(%)

Sp

(%)

PPV

(%)

NPV

(%)

ROC

(95% CI) Criteria rev. ATS 53 94 67 89 0.73 (0.68-0.78)

Criteria rev. ATS 71 72 26 95 0.68 (0.64-0.73)

CURB-65 (4-5 criteria) 6 98 39 81 0.59 (0.54-0.64)

CURB (3-4 criteria) 40 78 20 90 0.58 (0.53-0.63)

PSI high (class V) 73 53 18 93 0.60 (0.56-0.65)

PSI high (class V) 73 53 18 93 0.60 (0.56-0.65)

Restrepo CURENT vs. Angus et al. AJRCCM 2002

Best severity predictors

Events Best Criteria ROC (95% CI)

ICU admission

Criteria rev. ATS 0.73 (0.68-0.78)

ICU admission

Criteria rev. ATS 0.68 (0.64-0.73)

30-day Mortality

PSI high (IV or V) 0.71 (0.65-0.78)

Death PSI high (IV or V) 0.75 (0.71-0.78)

Restrepo CURRENT vs. Angus et al. AJRCCM 2002

Diagnostic criteria SCAP

Are we aware of existing criteria and if so, do we use them ?

Validity of CriteriaWhere we need to go

CURXO - 80

C – ConfusionU – Urea > 30 mg/dlR – Resp rate > 30/minX – X Ray – multilobar, bilateralO – PaO2/FiO2 < 25080 – Age > 80 Years

Espana et al. AJRCCM 2006;174:1249

Charles et al CID 2008; 47:375

Need for Intensive respiratory -Vasopressors support(IRVS)

Need for Intensive respiratory -Vasopressors support, IRVS

Charles et al CID 2008; 47:375

Predicting 30 day Mortality

Charles et al CID 2008; 47:375

AUC analysis severity assessment

Charles et al CID 2008; 47:375

Procalcitonin (PCT)

Stimulated by bacterial endotoxinViral and localized infection have lower PCT

levels than systemic infectionsAutoimmune and neoplastic disease do not

induceShort half life

PCT and Diagnosis

Nyamande Int J TB Lung Dz 2006; 10: 510

0

5

10

15

20

25

PCT (ng/ml)

PCP

TB

Bacterial Pneumonia

P=0.0004

PCT and Antibiotics

RCT to examine whether PCT guidance associated with less antibiotic use

PCT strata <0.1- Antibiotics strongly discouraged0.1-0.25- Antibiotics discouraged0.25-0.5- Antibiotics advised>0.5- Antibiotics strongly recommended

Christ-Crain AJRCCM 2006 174: 84

PCT and Antibiotic Discontinuation

PCT/CRP and Treatment Failure

Prospective cohort of 453 CAP patients18% treatment failures

CRP & PCT higher in failuresDay 1

» CRP: 13.6 vs. 23.2» PCT: 0.5 vs. 1.5

Day 3» CRP: 4.5 vs. 12.1» PCT 0.3 vs. 0.5

Menendez Thorax 2008; 63:447

Conclusions

Revisited ATS rule has the best power to predict the need for ICU admission

PSI score is the best predictor for mortality due to CAP

The CURB-65 rule may be used as an alternative tool to the PSI for the detection of low risk patients, but is not a good rule to define ICU admission

Conclusions

Described rules are imperfect and have significant limitations due to the the difficult of application to individual patients

Further studies are needed to develop clinical prediction tools for high-risk patients requiring ICU admission

Obrigado