Presentation on theme: "ICU Scoring Systems Iman Hassan, MD Pulmonary Medicine Department E-mail: email@example.com."— Presentation transcript:
1 ICU Scoring SystemsIman Hassan, MD Pulmonary Medicine Department
2 IntroductionSeverity of illness scoring systems are developed to evaluate delivery of care & provide prediction of outcome of groups of critically ill patients who are admitted to ICUs.Scoring systems consists of two parts: a severity score, which is a number (generally the higher this is, the more severe the condition) & a calculated probability of mortality.
3 Classification of Scoring Systems Anatomical scores: depend on the anatomical area involved. Mainly used for trauma patients [e.g. abbreviated injury score (AIS) & injury severity score (ISS)].Therapeutic weighted scores: based on the assumption that very ill patients require more complex interventions & procedures than patients who are less ill e.g., the therapeutic intervention scoring system (TISS).Organ-specific score: similar to therapeutic scoring; the sicker a patient the more organ systems will be involved, ranging from organ dysfunction to failure [e.g. sequential organ failure assessment (SOFA)].
4 Classification of Scoring Systems Physiological assessment: based on the degree of derangement of routinely measured physiological variables [e.g. acute physiology and chronic health evaluation (APACHE) & simplified acute physiology score (SAPS)].Simple scales: based on clinical judgment (e.g. survive or die).Disease specific: [e.g. Ranson’s criteria for acute pancreatitis, subarachnoid haemorrhage assessment using the World Federation of Neurosurgeons score & liver failure assessment using Child-Pugh or model for endstage liver disease (MELD) scoring].
5 Types of Scoring Systems First day scoring systems:APACHE scoring systemsSAPS (simplified acute physiology score)MPM (mortality prediction model)Repetitive scoring systems:OSF (organ system failure)SOFA (sequential organ failure assessment)ODIN (organ dysfunction & infection system)MODS (multiple organs dysfunction score)LOD (logistic organ dysfunction)
6 The Ideal Scoring System On the basis of easily/routinely recordable variablesWell calibratedA high level of discriminationApplicable to all patient populationsCan be used in different countriesThe ability to predict functional status or quality of life after ICU discharge.No scoring system currently incorporates all these featuresCalibration: assesses the degree of correspondence between the estimated probability of mortality and that actually observed. Calibration is considered to be good if the predicted mortality is close to the observed mortalityDiscrimination: means the ability of the scoring model to discriminate between patients who die from those who survive, based on the predicted mortalities especially using a ROC curve, an AUC is required to be > 0.70Area under ROC:0.5 –chance performance1 perfect prediction0.8 accepted cut-off
7 Severity scores in Medical & Surgical ICU APACHESAPSAPACHE IISAPS IIMPMAPACHE IIIMODSMPM IIODINSOFACIS2000-currentSAPS IIIAPACHE IV
8 Acute Physiology & Chronic Health Evaluation (APACHE) Common Scoring SystemsAcute Physiology & Chronic Health Evaluation (APACHE)
9 Acute Physiology & Chronic Health Evaluation (APACHE) The APACHE score is the best-known & most widely used score with good calibration & discrimination.The original APACHE score was developed in 1981 to classify groups of patients according to severity of illness & was divided into 2 sections: physiology score to assess the degree of acute illness & preadmission evaluation to determine the chronic health status of the patient.
10 Original APACHE score: 34 physiologic measures (0-4)Sum of all acute physiology scores (APS)Worst of the initial 24 hour after ICU admissionChronic healthA (excellent health)BCD (severe chronic organ system insufficiency)Crit Care Med 1981; 9:591
11 Original APACHE score: Crit Care Med 1981; 9:591
12 APACHE II score:The APACHE II scoring system was released in 1985 and included a reduction in the number of variables to 12.The APACHE II scoring system is measured during the first 24 h of ICU admission with a maximum score of 71. A score of 25 represents a predicted mortality of 50% and a score of over 35 represents a predicted mortality of 80%.APACHE II score is sum of:Acute physiology scoreAgeChronic health score
13 APACHE II score: The APACHE II score (0 – 71) Total APACHE II = A+B+C A → APS pointsB → Age pointsC → Chronic Health points
17 The Glasgow Coma Scale (GCS) Lancet 1974;304:81-84
18 APACHE III score: 17 physiological variables & Total score (0 – 299) APACHE III, released in 1991, was developed with the objectives of improved statistical power, ability to predict individual patient outcome, and identify the factors in ICU that influence outcome variations but it is far more complex than the 2 previous scoring systems.17 physiological variables & Total score (0 – 299)Acid-base disturbancesGCS score – based on the worstAge score7 co-morbidities (cardiac, respiratory & renal failures excluded)Chest 1991, 100:
23 The APACHE III ScoreShaded areas without score = unlikely or unusual combinations
24 The APACHE III Scoring for Chronic Health Condition Chronic health condition (Co-morbid condition)AIDS → 23Hepatic failure → 16Lymphoma → 13Metastatic cancer → 11Leukemia/multiple myeloma → 10Immunosuppression → 10Cirrhosis → 4
25 Prediction at 50%probability APACHE scoreROCPrediction at 50%probabilityCalibrationAPACHE II0.8585.5APACHE III version (H)0.9088.248.7APACHE III version (I)Unpublished24.2APACHE III (H) in cohort
26 APACHE IV score: Limitations: The APACHE IV scoring system was published in 2006.Limitations:Complexity – has 142 variables.But web-based calculations can be done.Developed and validated in ICUs of USA only.Crit Care Med 2006; 34:1297–1310
28 Simplified Acute Physiology Score (SAPS) The SAPS score was first released in 1984 as an alternative to APACHE scoring.The original SAPS score is obtained in the first 24 h of ICU admission by assessment of 14 physiological variables, but no input of pre-existing disease was included.It has been superseded by the SAPS II & SAPS III, both of which assess the 12 physiological variables in the first 24 h of ICU admission & include weightings for pre-admission health status & age.
29 Simplified Acute Physiology Score (SAPS) Predicted mortality = ,0844 * SAPS II * log (SAPS II+1)Area under ROC for SAPS is 0.8 where as SAPS II has a better value of 0.86JAMA 1993;270:
31 SAPS IIIScores based on data collected within 1st hour of entry to ICU.Allows predicting outcome before ICU intervention occurs.Better evaluation of individual patient rather than an ICU.Limitations:Time for collecting dataCan have greater missing informationIntensive Care Med 2005; 31:1345–1355
32 Sequential Organ Failure Assessment (SOFA) Common Scoring SystemsSequential Organ Failure Assessment (SOFA)
33 Sequential Organ Failure Assessment (SOFA) Previously known as Sepsis-related Organ Failure Assessment because it was initially developed in 1994 to describe the degree of organ dysfunction associated with sepsis in a mixed, medical-surgical ICU patients.Nowadays, it has since been validated to describe the degree of organ dysfunction in various ICU patient groups with organ dysfunctions not due to sepsis.The SOFA score involves six organ systems (respiratory, cardiovascular, renal, hepatic, central nervous, coagulation), and the function of each is scored from 0 (normal function) to 4 (most abnormal), giving a possible score of 0 to 24.
34 Sequential Organ Failure Assessment (SOFA) Mortality rate increases as number of organs with dysfunction increases.Unlike other scores, the worst value on each day is recorded.A key difference is in the cardiovascular component; instead of the composite variable, the SOFA score uses a treatment-related variable (dose of vasopressor agents).
35 Sequential Organ Failure Assessment (SOFA) Maximal (highest total) SOFA score: is the sum of highest scores per individual during the entire ICU stay. A score of >15 predicted mortality of 90%.Mean SOFA score (ΔSOFA): is the average of all total SOFA scores in the entire ICU stay. ΔSOFA for 1st 10 days is significantly higher in non-survivors.Delta SOFA score: maximum SOFA – admission SOFACrit Care Med 1998;26:
37 Multiple Organ Dysfunction Score (MODS) Common Scoring SystemsMultiple Organ Dysfunction Score (MODS)
38 Multiple Organ Dysfunction Score (MODS) The MODS scores six organ systems: respiratory (PO2/FIO2 in arterial blood); renal (serum creatinine); hepatic (serum bilirubin); cardiovascular (pressure-adjusted heart rate); haematological (platelet count) & CNS (Glasgow Coma Score) with weighted scores (0–4) awarded for increasing abnormality of each organ systems.Scoring is performed on a daily basis.Total score ranges from 0-24.Area under ROCΔMODS predicts mortality to a greater extent than Admission MODS score .Crit Care Med. 1995; 23:
41 Logistic Organ Dysfunction System (LODS) Common Scoring SystemsLogistic Organ Dysfunction System (LODS)
42 Logistic Organ Dysfunction System (LODS) Worst values in 1st 24 hrs of ICU stay.Worst value in each of 6 organ systems.Total score ranges from 0-22.Good calibration and discrimination (area under ROC 0.85)JAMA 1996;276:
45 Clinical Pulmonary Infection Score (CPIS) A score developed to establish a numerical value of clinical, radiographic, and laboratory markers of pneumonia.Serial measurements of the CPIS could be used to identify survivors versus non-survivors as early as day 3 of therapy.The CPIS correlated with mortality rate.CPIS scores > 6 suggest pneumonia.CPIS is an important variable to monitor during VAP therapy. Patients with VAP having CPIS ≤ 6 can safely discontinue antibiotics after 3 days.AJRCCM 2000;162:
46 Clinical Pulmonary Infection Score (CPIS) 12Temperature≥36.5 & ≤38.4≥38.5 & ≤38.9≥39 & ≤36.4TLC≥4 & ≤11<4 or >12Tracheal SecretionsNoneNon-purulentPurulentOxygenationPaO2/FIO2 mmHg>240 or ARDS≤240 & no ARDSChest RadiographNo opacityDiffuse (patchy) opacitiesLocalized opacityProgression of Radiograpgic OpacitiesNo progressionProgression (after HF & ARDS excluded)Culture of Tracheal AspiratePathogenic bacteria cultured in rare/few quantities or no growthPathogenic bacteria cultured in moderate or heavy quantityAJRCCM 2000;162:
47 Mortality Probability Model (MPM) Common Scoring SystemsMortality Probability Model (MPM)
48 Mortality Probability Model (MPM) Not applicable for patients <14yrs, patients with burns, cardiac/ cardiac surgery patients.MPM score:Admission MPM (MPM0) →11 variablesMPM at 24 Hrs (MPM24) → 14 variablesMPM at 48 Hrs (MPM48) → 11 variablesMPM over the time (MPMOT) → (MPM24-MPM0)(MPM48-MPM24)Probability is derived directly from these variables.MPMOT predicted better than MPM0 for long term patients.Crit care med 1988;16:
49 10 beat/min relative risk MPM0Variable1Level of consciousnessComa / deep stuporNo coma/deep stuporAdmissionEmergencyElectivePrior CPRYesNoCancerPresentAbsentCRFInfectionProbableNot probablePrevious ICU admission in 6 moSurgery before ICU admissionSBPHR10 beat/min relative riskAge10 years relative risk
50 Therapeutic Intervention Scoring System (TISS) Common Scoring SystemsTherapeutic Intervention Scoring System (TISS)
51 Therapeutic Intervention Scoring System (TISS) Measuring sickness severity based on type & amount of treatment received.Both clinical & administrative applications:assessing severity of illnessDetermining resource requirementsAssessing use of critical care facilities & functionNot standardisedDaily data collected from each patient on 76 possible clinical interventions
52 TISSFour classes of pt recognised: Class I < 10 points does not require ICUClass II points 1:2 nurse : pt ratioClass III points 1 ICU nurseClass IV > 40 points 1:1 nurse : pt ratio
55 Other Scores Scores for surgical patients: Thoracoscore (thoracic surgery)Lung Resection Score (thoracic surgery)EUROSCORE (cardiac surgery)ONTARIO (cardiac surgery)Parsonnet score (cardiac surgery)System 97 score (cardiac surgery)QMMI score (coronary surgery)Early mortality risk in redocoronary artery surgeryMPM for cancer patientsScores for Pediatric patients:PRISM (Pediatric RISk of Mortality)P-MODS (Pediatric MODS)DORA (Dynamic Objective Risk Assessment)PELOD (Pediatric Logistic Organ Dysfunction)PIM II (Paediatric Index of Mortality II)PIM (Paediatric Index of Mortality)Scores for trauma patients:Trauma ScoreRevised Trauma ScoreTrauma and injury Severity score (TRISS)A Severity Characterization of trauma (ASCOT)
56 Which score to use? APACHE, SAPS, MPM → only of historic significance APACHE II → most widely used in USASAPS II → commonly used in EuropeAPACHE III → not in public domainSAPS III, APACHE IV → better designMODS & LODS → uncommonly used