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Can Scoring Systems Be Used to Determine Prognosis and Site of Care for CAP?

Michael S. Niederman, MD

Chairman, Department of Medicine

Winthrop-University Hospital

Mineola, New York

Professor of Medicine

Vice-Chairman, Department of Medicine

State University of New York at Stony Brook

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CAN EXPECTANT ICU CARE IMPROVE OUTCOMES IN SEVERE CAP?

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LEROY 2 MOINE RELLO FELDMAN

%MORTALITY

% MV

• When ICU care is late, and most (93%) ICU admitted patients are ventilated, mortality is high (> 75%) in pneumococcal bacteremic pneumonia. Hook et al: JAMA 1983;249:1055.

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When is the ICU Used in CAP?

• National database in UK of 172 ICU’s with 17,869 CAP cases (5.9% of all ICU admits)

• 59% admitted within first 2 days, 21.5% days 2-7, 19.5% > 7 days.

• 54.6% mechanically ventilated on admission to ICU

• Mortality rate in ICU 34.9%, 49.4% in hospital– 46.3% mortality if admit in first

2 days– 50.4% if admit day 2-7, 57.6%

if after day 7 ( p<0.001)• Woodhead et al. Critical Care

2006; 10: S10

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Why The PSI and CURB-65 Alone Cannot Help with Site of Care Decisions

• PSI is not very accurate for deciding who should be admitted to the hospital or ICU– PSI is good for mortality prediction.

BUT : Risk of death does not equate with need for hospitalization or need for ICU Care• PSI is not a direct measure of disease severity• PSI is too complex for routine clinical use• PSI does not account for “social” factors and

disease factors that influence site of care decision

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Why The PSI and CURB-65 Alone Cannot Help with Site of Care Decisions

• PSI is not very accurate for deciding who should be admitted to the hospital or ICU– PSI is good for mortality prediction.

BUT : Risk of death does not equate with need for hospitalization or need for ICU Care• PSI is not a direct measure of disease severity• PSI is too complex for routine clinical use• PSI does not account for “social” factors and

disease factors that influence site of care decision

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PSI System

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Predicting Low-Risk Patients

1575/2287 PORT patients in classes I-III, with only 7 deaths. 15,500/38,039 Medis Group patients in classes I-III. Suggest outpatient for I, II; brief admit for III; inpatient care for IV and V. PORT PATIENTS:

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

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Predictive Rules for Severe CAP

• Modified ATS– One major: Mechanical vent, septic shock OR– 2 of 3 minor: SBP < 90 mm Hg, multilobar, P/F< 250

• BTS 1: 2 of 3 of R > 30/min, DBP < 60 mm Hg, BUN > 19.6 mg/dL

• BTS 2: Use confusion instead of BUN

• Modified BTS: 2 of 4 present (CURB)

• PSI calculated on Admit

• Ewig et al: Thorax 2004; 59: 421-427

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Predictive Rules for Severe CAP

• 696 CAP admits, 116 to ICU– Evaluate ICU need by

modified ATS rule, two BTS rules and the PSI • 37% of ICU admits PSI I-III• 15% with positive modified

ATS rule in PSI I-III.– Once again, PSI good for

mortality prediction, but NOT for identifying need for ICU care.

• Ewig et al: Thorax 2004; 59: 421-427

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Predicting Need for ICU Admit

• 1339 inpatients in PORT study, 170 admitted to ICU

• 6% of Class I, 5.6% of Class II, 8.7% of Class III, 15.9% of Class IV, 23.8% of Class V to ICU. Overall 27% of all ICU patients Class I-III

• Most rules sensitive, not specific. Many who meet criteria NOT admitted to ICU

• Revised ATS rule best for ICU admit need , BUT sens=70.7%, specif= 72.4%. High PSI less specific, original ATS criteria more sensitive– Angus et al: Am J Respir Crit

Care Med 2002; 166:7170

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Overall mortality= 18.2%. NEED for ICU Not correlate with Mortality

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Why Are So Few PSI V Patients Admitted to ICU?

• 457 admitted CAP patients with PSI V, 1996-2003.– 92 admitted to ICU

• ICU used more if: young (OR=12.9 if < 80, p<0.001), less comorbidity (8% vs. 34%, p<0.001), more acute illness parameters (lower diastolic BP, lower P/F ratio, more with pH < 7.35).

• All PSI patients with similar bacteriology (incl. P. aeruginosa in 17% ICU and 11% non-ICU : reflection of comorbidity??)

• Mortality 37% vs. 20% , ICU vs. not, (p=.001)

• THUS PSI good for many things, but NOT site of care decision.

• Valencia M, et al. , In Press, Chest 2007

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Acute= physical exam, lab dataChronic= age, comorbidity, nurnsing home

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Which Prognostic Scoring System?

• Pneumonia Severity Index (PSI) is complex, heavily weights age and comorbidity, and divides patients into 5 risk groups for mortality.– Since age is so heavily weighted, it does not

really measure pneumonia severity

• British Thoracic Society (BTS) rule and its modifications are simple – Measure severity of illness more directly, often

without the need for laboratory data

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Defining Pneumonia Severity: CURB-65

• Three prospective inpatient CAP studies, 1068 patients– 80% as derivation cohort,

20% validation

• Mortality predictors (p <0.001): Confusion, BUN > 7 mmol/L, R > 30/min, SBP < 90 or DBP < 60 mm Hg), age > 65, fever < 37 C, albumin < 30 g/ dL

• 1 point for CURB and 65

• Lim et al: Thorax 2003; 58: 377-382

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A Comparision of PSI vs. CURB

• Prospective study of 3181 CAP patients seen in ED– PSI, CURB, CURB-65

• Low risk: PSI I-III, CURB<1, CURB-65 <2

• Low risk: – 68% by PSI (mortality 1.4%),– 51% by CURB (mort 1.7%), – 61% by CURB-65 (mort 1.7%)

• For higher risk: – 26% PSI IV(8.1% mortality), 6%

PSI V (24% mortality)– 24% CURB-65 2 (6.1% mortality),

CURB –65 3,4,5 (mortality): 12% (13%), 2%(17%), 0.2% (43%)

Aujesky D, et al: Am J Med 2005; 118: 384

ROC Curve For 30-day Mortality

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A European Comparison of PSI and CURB-65

• Apply both tools to 1100 outpatients and 676 inpatients

• 30 day mortality for CURB-65 of:1,2,3,4,5: 0%, 1.1%, 7.6%, 21%, 41.9%,60%– 29.2% of admitted patients with

score of 0,1 2 had comorbid illness• CURB-65 correlated with need for

mechanical ventilation, hospital admission, LOS

• CRB-65 equally effective (without measure of BUN).

• CURB-65, CRB-65, PSI all with similar ROC for Mortality

• Capelastegui A, et al. Eur Resp J 2006; 27: 151-157

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A European Comparison of PSI and CURB-65

• Comparision of PSI and CURB-65

• Capelastegui A, et al. Eur Resp J 2006; 27: 151-157

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Why The PSI and CURB-65 Alone Cannot Help with Site of Care Decisions

• PSI is not very accurate for deciding who should be admitted to the hospital or ICU– PSI is good for mortality prediction.

BUT : Risk of death does not equate with need for hospitalization or need for ICU Care• PSI is not a direct measure of disease severity• PSI is too complex for routine clinical use• PSI does not account for “social” factors and

disease factors that influence site of care decision

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PSI System

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Why The PSI and CURB-65 Alone Cannot Help with Site of Care Decisions

• PSI is not very accurate for deciding who should be admitted to the hospital or ICU– PSI is good for mortality prediction.

BUT : Risk of death does not equate with need for hospitalization or need for ICU Care• PSI is not a direct measure of disease severity• PSI is too complex for routine clinical use• PSI does not account for “social” factors and

disease factors that influence site of care decision

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Limits of The PSI In a Public Hospital

• Does the PSI help guide admission in a public hospital?– 253/425 admits in non-HIV population in Seattle were PSI

classes I-III.• 76 Class I, 89 Class II, 88 Class III• 1.6% died, BUT

– 115 (45%) with at least one acute process for admit: hypoxemia, hypotension, altered MS

– 138 (55%) potentially outpt., but 44% homeless, 33% R/O TB, 7% IVDA with R/O endocarditis, 20% drunk. Only 14% could be D/C.

– Low risk accounts for 45% of all CAP days and 35.4% of all CAP costs. Median LOS 4-5 days

• Do we need alternate sites of care for such patients?• Goss et al: Chest 2003; 124: 2148.

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Features of Low Risk Patients Who Are Amitted

• 11% COPD

• 12% Asthma

• 19% Malignancy

• 10% Seizure disorder

• Mean APACHE II 7.5

• Goss et al: Chest 2003; 124: 2148.

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COPD Is NOT a Comorbid Factor in The PSI

• 744 CAP patients, 215 with COPD

• COPD with higher PSI than non-COPD (105 vs. 87, p=0.05) ) and more ICU admit (25% vs. 18%,p=0.04)– BUT even after adjusting for

severity of illness, COPD patients had a higher 30 and 90 day mortality (HR= 1.32,1.34)

• Restropo MI, et al. Eur Resp J 2006, in press.

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What is the Best Approach for ICU Admission?

• Identify at risk patients early– Use clinical assessment– Use prognostic scoring systems

• BOTH PSI and CURB-65– Consider the role of serum markers

• CRP• PCT

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Combining Data from The PSI and CURB-65: Getting the Best of Both Worlds

• PSI was developed to define LOW RISK patients, and often UNDERESTIMATES need for hospital or ICU– Young, no comorbid illness, clinical variable below a

dichotomous variable cutoff– BUT may also OVERESTIMATE need for expensive

resources by emphasis on age and comorbitity and NOT severity features

• CURB-65 good for avoiding overlooking severe illness, BUT may be limited in elderly and those with comorbidity

• Suggest: Draw from BOTH. Either can define low risk (PSI of I-III, CURB-65 of 0-1). IF use PSI, add vital sign and severity evaluation; if use CURB-65, add assessment of comorbid illness and its stability. Add social factors to both.

• Niederman MS, et al. Eur Resp J 2006;27: 9-11.

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A New Rule for ICU Admission• A study using one derivation cohort

and two validation cohorts found that a rule identifying patients with:– one of two major criteria (arterial

pH < 7.30 or systolic blood pressure < 90 mm Hg )

– OR 2 of 6 minor criteria (confusion, BUN > 30 mg/dL, respiratory rate > 30/minute, multilobar infiltrates, PaO2/FiO2 < 250 mm Hg, and age of at least 80 )

– Up to 92% sensitive with a score of 10 or more for identifying those with severe CAP, and was more accurate than other rules such as the PSI, modified ATS criteria and CURB-65.

– Espana PP, et al. Am J Respir Crit Care Med 2006; 174: 1249-1256.

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Criteria for Severe CAP: New IDSA/ATS Guidelines

• Thrombocytopenia– Muliticenter study of 822 patients with

severe CAP – 3 categories according to platelet count:

>150x10(9)/L, 51-149x10(9)/L, and < 50x10(9)/L

– ICU mortality rates were 30.8% ,44.1% and 70.7% , respectively (p<0.0001). • Brogly et al: Infection 2007 e pub.

• Hyponatremia– On admit: 28% of 342 CAP patients with

hyponatremia ( < 136 mEq/L). 4.1% < 130 mEq/L.• Hyponatremia on admit with higher

HR, WBC, PSI class– Had increased mortality and

increased length of stay • 10.5% developed in hospital,

unrelated to severity of illness on admit.

• Nair, Niederman, et al: Am J 2007; 27:184-190.

Mandell LA et al. Clin Infect Dis 2007;44 Suppl 2:S27-72

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Relation of PCT to Severity of CAP

• Measure of serum PCT in 185 CAP patients within 24 hours of admit

• Relate levels to PORT score, bacteriology and complications

• No differences in PCT by etiology for groups overall. – In low PSI classes (I-II), PCT

tended to be higher with bacterial etiology; no difference in PCT by etiology in higher PSI groups.

• Masia M, et al. Chest 2005; 128:2223- 2229.

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Prognostic Value of PCT in ICU CAP

• 110 patients with severe CAP. Measure PCT within 48 hours admit (not serially).

• 20% <0.5 ng/ml, 30% 0.5-2.0 ng/ml, 50% > 2.0 ng/ml

• PCT 4.9 vs. 1.5 ng/ml for bacteriologically positive vs. negative patients (p<0.001); higher in those who died ( 5.6 vs. 1.5 ng/ml, p <0.0001)

• CRP did not predict outcomes

• Boussekey N, et al. Infection 2005; 33: 257-63.