Risk stratification & Risk ScoringF I N A L F R C A T E A C H I N G 0 2 / 1 2 / 2 0 2 0

D R V I N E S H M I S T R Y

Outline

• Cardiac risk scoring

• Cardiac Surgery risk scoring

• Respiratory risk scoring

• General risk scoring

• Vascular risk scoring

• Intensive care

Cardiac Risk scoring

• Goldman Cardiac Risk index

• Lee’s (revised) risk Index (RCRI)

Goldman cardiac risk index

• Lee Goldman published this score in 1977;• It was later revised by Lee in 1999;• The Cardiac Risk Index results range from 0 to

53, where the higher the score, the greater the risk for complications:

0-5 Points: Class I 1% Complications6-12 Points: Class II 7% Complications13-25 Points: Class III 14% Complications26-53 Points: Class IV 78% Complications

History:Age > 70 years (+5)Myocardial infarction within 6 months (+10)

Cardiac ExamSigns of CHF: ventricular gallop or JVP (+11)Significant aortic stenosis (+3)

ECGArrhythmia other than sinus or premature atrial contractions (+7)5 or more PVC's per minute (+7)

General Medical ConditionsPO2 <60; PCO2 >50; K <3; HCO3 <20; BUN >50; Creatinine >3; elevated SGOT; chronic liver disease; bedridden (+3)

OperationEmergency (+4)Intraperitoneal, intrathoracic or aortic (+3)

Lee’s RCRI

• High risk surgery; 1

• History of IHD; 1

• History of CCF; 1

• History of cerebrovascular disease; 1

• Diabetes treated with Insulin therapy; 1

• Pre-op serum creatinine > 177 μmols/L; 1

Example 1 – Risk of cardiac event?

• 68 year old male radical nephrectomy for RCC.

• PMH: COPD smoker. Systolic murmur. On haemodialysis. BMI 31. Angina, Pacemaker inserted

Investigations:

• Normochromic normocytic anaemia Hb 90 g/L

• Low platelets

• Raised urea and creatinine urea 17.9, creatinine 586 (potassium normal).

• X-Ray: Cardiomegaly and dual chamber pacemaker, vascath

• ECG: Paced rhythm (atria and ventricles)

• PFTs: Moderate to severe obstruction, Low TLCO(FEV1 55%)

• Echo shows mild MR and LVH

Lee’s Revised score: 4(11% - 1 in 10 chance of serious cardiac complication

Example 2 – Risk of cardiac event?

• 78 male admitted with acute ischaemic lower limb. Radiological management attempted and failed. Listed

for fempop bypass. Also had an episode of chest pain lasting 20 mins, relieved by GTN

• PMH: CABG 20 years ago, PVD, L3-5 spinal decompression but chronic back pain, takes GTN regularly for

chest pain

• Medications: ACE inhibitor, beta-blocker, oral nitrates, diuretic, MST (high dose), aspirin, statin

• BP 135/70, HR60, chest clear, ECG LAD, ?RBBB, no CXR given, weight 75kg, ht 1.75m

Investigations:

• ECG – L axis deviation, LBBB, inferior q waves., slow AF?

• ECHO – moderate LV dysfunction, mild TR, EF 50%, no LVH

• Angio (from 2 years ago) – patent grafted vessels, complete occlusion of original vessels.

• Bloods - Hb 117 (normochromic, normocytic anaemia) U+Es normal, creat was 96 eGFR 64. Clotting normal.

Lee’s Revised score: 2(7% - 1 in 14 chance of serious cardiac complication

Cardiac Surgery Risk scoring

• Parsonnet Score

• Euroscore

Parsonnet Score

• Published in 1989 and still used at

present in some centres.

Parsonnetscore

RiskPredicted

Mortality (%)

0 - 4 Good 1

5 - 9 Fair 5

10 - 14 Poor 9

15 - 19 High 17

20+ Extremely high 30

Euroscore

Euroscore II

Euroscore

• Euroscore I published in 1999; is an additive score; the higher the score the greater

the risk of mortality;

• Euroscore II published in 2003 uses slightly more specific parameters and a linear

regression model. It gives you the mortality risk as a percentage.

Respiratory Risk scoring

• Obstructive Sleep Apnoea:

• STOP-BANG

• Thoracic Surgery:

• Thoracoscore

STOP-BANG

• STOP-BANG questionnaire is a screening tool for obstructive sleep apnoea;

• Does not correlate for any other cardio-respiratory conditions or post-operative

complications;

• Sensitivity of 93% for moderate-severe OSA and 100% for severe OSA;

STOP-BANG Cut-off Sensitivity Specificity PPV NPV

STOP-Bang ≥ 3

87.3 30.7 43.8 79.7

STOP ≥ 2 + Bang ≥ 1

71.6 46.1 45.0 72.4

STOP ≥ 2 + BMI > 35 kg/m2

20.8 85.0 46.1 63.5

STOP ≥ 2 + Neck > 40 cm

33.5 79.0 49.6 65.8

STOP ≥ 2 + male gender

40.1 76.8 51.6 67.5

STOP ≥ 2 + age > 50 y

59.4 56.1 45.5 69.1

• Different combination is used to

increase specificity.

• Overall specificity is only 43% which

results in numerous false positives.

• 33y male, globe rupture after falling on a radiator. He has poorly controlled epilepsy (1-2 seizures per

day) since childhood but says his fall was not as a result of a fit.

• DH- carbamazepine, levetiracetam.

• On examination height 167cm, weight 125kg, BMI 44.9

• Capped upper incisors, MP 3, full beard

Investigations:

• CXR showing: obese, Vagal nerve stimulator

• ABG showing: pH normal range, pO2 8.9, pCO2 6.8, high bicarbonate (>32mmols), HB 170

• Sleep studies showing: AHI 77, 170 desaturations period hour, average says 85%

• PFTs showing normal fev1/fvc, PEFR 55% predicted (although footnote at the bottom mentioned

technique was poor), reduced vital capacity and residual volume

Example 3 - OSA

STOP-BANG score: 5

Thoracoscore

• Thoracoscore was

developed in 2006 and is

currently recommended

by the BTS for patients

undergoing

pneumonectomy.

• However, multiple studies

have shown inconsistent

results, therefore it has not

been widely adopted,

especially in the U.K.

General Risk scoring

• Elective

• SORT - NCEPOD

• ACS – NSQIP

• Emergency

• P-Possum/ NELA-Possum

SORT - NCEPOD

• Surgical Outcome Risk Tool published in 2014.

• Specific for the UK using the information from NCEPOD data for mortality within

30 days of surgery.

• Used 16, 788 patients from NCEPOD

• Validated for use in the U.K.

• Uses 6 variables.

• Obstetrics, neurosurgery, cardiac and transplant surgery not included.

SORT - NCEPOD

ACS NSQIP

• American College of Surgeons – National Surgical Quality Improvement

Programme.

• Based on American data therefore not totally representative of UK population

but reasonably close.

• ACS Risk Calculator - Home Page (facs.org)

ACS NSQIP

ACS NSQIP

P-POSSUM

• Original POSSUM paper published in

1991.

• Physiological and Operative Severity

Score for the enUmeration of Mortality

and morbidity.

• A modification to POSSUM called the

P-POSSUM was published in 1998.

• A systematic review published in 2013

rated P-POSSUM as the most accurate.

[Moonesinghe, 2013]

Vascular Risk scoring

• Elective

• Emergency

• Glasgow Aneurysm Score (GAS)

• Hardman Index

• Vascular Possum score (V-Possum)

Vasc - POSSUM

• Vascular possum uses the same physiological data as P-POSSUM but a different logistic

regression equation is used.

• It is a better fit for predicting mortality in vascular patients than POSSUM or P-POSSUM.

• Extra items considered to be important by the VSSGBI were added to P-POSSUM

however this not add to accuracy of V-POSSUM in predicting mortality.

Example 4 – Mortality risk?

• 78 male admitted with acute ischaemic lower limb. Radiological management attempted and failed. Listed

for fempop bypass. Also had an episode of chest pain lasting 20 mins, relieved by GTN

• PMH: CABG 20 years ago, PVD, L3-5 spinal decompression but chronic back pain, takes GTN regularly for

chest pain

• Medications: ACE inhibitor, beta-blocker, oral nitrates, diuretic, MST (high dose), aspirin, statin

• BP 135/70, HR60, chest clear, ECG LAD, ?RBBB, no CXR given, weight 75kg, ht 1.75m

Investigations:

• ECG – L axis deviation, LBBB, inferior q waves., slow AF?

• ECHO – moderate LV dysfunction, mild TR, EF 50%, no LVH

• Angio (from 2 years ago) – patent grafted vessels, complete occlusion of original vessels.

• Bloods - Hb 117 (normochromic, normocytic anaemia) U+Es normal, creat was 96 eGFR 64. Clotting normal.

Vasc-POSSUM

• V-POSSUM with VSSGBI items; 9.4% Mortality

• V-POSSUM (PS) uses the physiology data only from P-POSSUM

Ruptured AAA

• Hardman index was published in

1996

• 1 point for each

• Score ≥ 2 consistent with a

mortality > 80%

Ruptured AAA

• GAS can be used for both elective

and emergency AAA patients;

Emergency:

• Score = 84 associated with Mortality

of >65%.

• <84 Mortality of 28%.

Elective:

• Mortality of 8.7% score >78.8

• Mortality of 1.4% score <78.8

Myocardial Disease: Angina or prev MICerebrovascular Disease: Prev stroke or TIARenal Disease: Urea >20 or Creatinine > 150

ITU Risk scoring

• APACHE II (Acute Physiology And Chronic Health Evaluation II)

•

• SAPS II (Simplified Acute Physiology Score II)

• SOFAscore

APACHE II

• Acute Physiology And Chronic Health Evaluation II (APACHE) II.

• The APACHE II mortality predictor was originally published in 1985.

• Not used as a predictor in the medical management of patients.

• It use is to compare actual mortality of a critical care units patients population

with the predicted mortality of its population for audit data calculated in the first

24 hours.

• This risk predictor was used in the UK until 2007 and was superseded by

ICNARC’s own risk predictor.

APACHE II

APACHE II

• Most recent variant is APACHE IV

APACHE II Score

Nonoperative Postoperative

0-4 4% 1%

5-9 8% 3%

10-14 15% 7%

15-19 25% 12%

20-24 40% 30%

25-29 55% 35%

30-34 73% 73%

>34 85% 88%

ICNARC

SOFA score for Sepsis

• Initially published in 1996

for the Working Group on

Sepsis-Related Problems of

the European Society of

Intensive Care Medicine.

• Sequential Organ Failure

Assessment (SOFA) score

• Validated across Europe in

1998

• Clinical impact in the U.K.

published in 2009

SOFA score for Sepsis

Mean SOFA Score Mortality

0-1.0 1.2%

1.1-2.0 5.4%

2.1-3.0 20.0%

3.1-4.0 36.1%

4.1-5.0 73.1%

>5.1 84.4%

SOFA ScoreMortality if initial score

Mortality if highest score

0-1 0.0% 0.0%

2-3 6.4% 1.5%

4-5 20.2% 6.7%

6-7 21.5% 18.2%

8-9 33.3% 26.3%

10-11 50.0% 45.8%

12-14 95.2% 80.0%

>14 95.2% 89.7%

SAPSVariable Points

Age, years

<40 0

40-59 7

60-69 12

70-74 15

75-79 16

≥80 18

Heart rate

Worst value in 24 hours; if patient has had both cardiac arrest (11 points) and extreme tachycardia (7 points), assign 11 points

<40 11

40-69 2

70-119 0

120-159 4

≥160 7

Systolic BP, mm Hg

Worst value in 24 hours

<70 13

70-99 5

100-199 0

≥200 2

Temperature ≥39ºC (102.2ºF)

Highest temperature in 24 hours

No 0

Yes 3

GCS

Lowest value in 24 hours; if patient is sedated, use estimated GCS before sedation

14-15 0

11-13 5

9-10 7

6-8 13

<6 26

PaO₂/FiO₂, if on mechanical ventilation or CPAP

Lowest value in 24 hours; if patient was extubated <24 hours ago, use lowest value while on mechanical ventilation

<100 mm Hg/% (13.3 kPa/%)

11

100-199 mm Hg/% (13.3-26.5 kPa/%)

9

≥200 mm Hg/% (26.6 kPa/%)

6

Not on mechanical ventilation or CPAP within the last 24 hours

0

UN, mg/dL (serum urea, mmol/L)

Highest value in 24 hours

BUN <28 or urea <10

0

BUN 28-83 or urea 10-29.6

6

BUN ≥84 or urea ≥30

10

Urine output, mL/day

If patient in ICU <24 hours, calculate for 24 hours (e.g. if 1 L in 8 hours, then mark 3 L in 24 hours)

<500 11

500-999 4

≥1,000 0

Sodium, mEq/L or mmol/L

Worst value in 24 hours

<125 5

125-144 0

≥145 1

Potassium, mEq/L

Worst value in 24 hours

<3.0 3

3.0-4.9 0

≥5.0 3

Bicarbonate, mEq/L

Lowest value in 24 hours

<15 6

15-19 3

≥20 0

SAPS

BilirubinHighest value in 24 hours

<4.0 mg/dL (<68.4 µmol/L)

0

4.0-5.9 mg/dL (68.4-102.5 µmol/L)

4

≥6.0 mg/dL (≥102.6 µmol/L)

9

WBC, x 10³/mm³

Worst value in 24 hours

<1.0 12

1.0-19.9 0

≥20.0 3

Chronic disease

None 0

Metastatic cancer

9

Hematologic malignancy

10

AIDS 17

Type of admission

Scheduled surgical = surgery scheduled ≥24 hours in advanceMedical = no surgery within one week of admissionUnscheduled surgical = surgery scheduled ≤24 hours in advance

Scheduled surgical

0

Medical 6

Unscheduled surgical

8

Interpretation:In-hospital mortality, % = ex / 1+ex

where x = −7.7631 + 0.0737 x (SAPS II Score) + 0.9971 x [ ln(SAPS II Score + 1) ]

QUESTIONS?

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Slater E. E.. Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med. 1977;297(16):845 – 850. DOI: 10.1056/NEJM197710202971601.

PMID: 904659

• Martinez G., Faber P. Obstructive sleep apnoea. CEACCP. 2011. 1 (11): 5 – 11.

• Sankar A., Beattie W. S., Tait G., Wijeysundera D. N. Evaluation of validity of the STOP-BANG questionnaire in major elective noncardiac surgery. BJA (2019). 122 (2): 255 –262. DOI: https://doi.org/10.1016/j.bja.2018.10.059

• Chung F., Abdullah H. R.,Liao P. STOP-Bang Questionnaire: A Practical Approach to Screen for Obstructive Sleep Apnea. Chest. (2016) Volume 149; (3): 631- 638. https://doi.org/10.1378/chest.15-0903.

• Copeland G. P., Jones D., Walters M. POSSUM: A scoring system for surgical audit. Brit Jour Surg. 1991. 78 (3): 355 – 360.

• Prytherch D. R., Whiteley M. S., Higgins B., Weaver P. C., Prout W. G., Powell S. J. POSSUM and Portsmouth POSSUM for predicting mortality. British Journal of Surgery 1998, 85, 1217 – 1220.

• Prytherch et al. A Model for national Outcome audit in Vascular surgery. Eur J Vasc Endovasc Surg. (2001) 21. 477 – 483

• Tang T. Y., Walsh S. R., Prytherch D. R., Wijewardena C., Gaunt M. E., Varty K., Boyle J. R. POSSUM Models in Open Abdominal Aortic Aneurysm Surgery. Eur J VascEndovasc Surg (2007) 34, 499 - 504.

• Knaus W. A., Draper E. A., Wagner D. P., Zimmerman J. E. APACHE II: A severity of disease classification system. Crit Care Med. 1985: 13 (10): 818 – 829.

• Vincent J. L., Moreno R., Takala J., Willatts S., De Mendonça A., Bruining H., Reinhart C. K., Suter P. M., Thijs L. G. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. On behalf of the Working Group on Sepsis-Related Problems of the European Society of Intensive Care Medicine. Intensive Care Med. 1996; 22 (7): 707 – 710 . DOI: 10.1007/BF01709751.

• Le Gall J. R., Lemeshow S., Saulnier F. A New Simplified Acute Physiology Score (SAPS II) Based on a European/North American Multicenter Study. JAMA. 1993;270(24):2957-2963. doi:10.1001/jama.1993.03510240069035