Risk stratification & Risk Scoring

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Risk stratification & Risk Scoring

F 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

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Outline

• Cardiac risk scoring

• Cardiac Surgery risk scoring

• Respiratory risk scoring

• General risk scoring

• Vascular risk scoring

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Cardiac Risk scoring

• Goldman Cardiac Risk index

(4)

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% Complications 6-12 Points: Class II 7% Complications 13-25 Points: Class III 14% Complications 26-53 Points: Class IV 78% Complications

History:

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

Cardiac Exam

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

ECG

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

General Medical Conditions

PO2 <60; PCO2 >50; K <3; HCO3 <20; BUN >50; Creatinine >3; elevated SGOT; chronic liver disease; bedridden (+3)

Operation

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

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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

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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

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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

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Cardiac Surgery Risk scoring

• Parsonnet Score

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Parsonnet Score

• Published in 1989 and still used at

present in some centres.

Parsonnet

score Risk Mortality (%)Predicted

0 - 4 Good 1 5 - 9 Fair 5 10 - 14 Poor 9 15 - 19 High 17 20+ Extremely high 30

(10)

(11)

(12)

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

(13)

Respiratory Risk scoring

• Obstructive Sleep Apnoea:

• STOP-BANG

• Thoracic Surgery:

(14)

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;

(15)

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.

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• 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

(17)

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,

(18)

General Risk scoring

• Elective

• SORT - NCEPOD

• ACS – NSQIP

• Emergency

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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.

(20)

(21)

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.

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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]

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Vascular Risk scoring

• Elective

• Emergency

• Glasgow Aneurysm Score (GAS)

• Hardman Index

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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.

(27)

Example 4

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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.

(28)

Vasc-POSSUM

• V-POSSUM with VSSGBI items; 9.4% Mortality

(29)

Ruptured AAA

• Hardman index was published in

1996

• 1 point for each

• Score ≥ 2 consistent with a

(30)

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 MI

Cerebrovascular Disease: Prev stroke or TIA Renal Disease: Urea >20 or Creatinine > 150

(31)

ITU Risk scoring

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

•

• SAPS II (Simplified Acute Physiology Score II)

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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

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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%

(35)

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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

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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 Score Mortality 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%

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SAPS

Variable Points Age, years <40 0 40-59 7 60-69 12 70-74 15 75-79 16 ≥80 18 Heart rate Worstvalue 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

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SAPS

Bilirubin Highest 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 advance Medical = no surgery within one week of admission Unschedule d surgical = surgery scheduled ≤24 hours in advance Scheduled surgical 0 Medical 6 Unschedule d surgical 8

Interpretation:

In-hospital mortality, % = ex_{/ 1+}_ex

where x = −7.7631 + 0.0737 x (SAPS II Score) + 0.9971 x

(40)

(41)

References

• Goldman L., Caldera D. L., Nussbaum S. R., Southwick F. S., Krogstad D., Murray B., Burke D. S, O'Malley T. A., Goroll A. H., Caplan C. H., Nolan J., Carabello B., 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 Vasc Endovasc 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