Dr. Stuart McCorkell BSc FRCA FFICM Anaesthetic Department, Guy s & St. Thomas s NHS Foundation Trust 2017 POPS

Transcription

1 Dr. Stuart McCorkell BSc FRCA FFICM Anaesthetic Department, Guy s & St. Thomas s NHS Foundation Trust

2 Why assess (estimate) risk? Patient information and informed consent (patient, surgeon) Stratify resource allocation higher levels of care (Anaesthesia, critical care) Plan for and circumvent likely complications (patient, geriatrician, surgeon) Predict LOS and model activity? (Hospital, NHS)

3 Good decisions come from experience Experience comes from making bad decisions

4 Patient risk Operative risk Institutional/pathway risk e.g. high/low volume centre, day surgery, HDU/ITU Not all scoring systems account for all these factors, some address only one

5 For morbidity and mortality the major factors are: Patient: Cardio-respiratory impairment Comorbidities Frailty Surgery: major intracavity surgery

6 POPS Patient only: ASA (not a risk score) Revised Cardiac Risk Index Surgery 2017 specific: EUROSCORE Generic: POSSUM NSQIP SORT

7 Introduced 1941 as basis for statistical comparisons, expanded to 5 classes in 1963 ASA Physical Status 1 - A normal healthy patient ASA Physical Status 2 - A patient with mild systemic disease - no functional limitation ASA Physical Status 3 - A patient with severe systemic disease - definite functional limitation ASA Physical Status 4 - A patient with severe systemic disease that is a constant threat to life ASA Physical Status 5 - A moribund patient who is not expected to survive without the operation

8 ASA 1 Puritan ASA 2 - current smoker, social alcohol drinker, pregnancy, obesity (BMI 30-40) well-controlled DM/HTN, mild lung disease ASA 3 - poorly controlled DM or HTN, COPD, BMI 40, active hepatitis, alcohol dependence or abuse, moderate reduction of ejection fraction, undergoing dialysis, history (>3 months) of MI, CVA, TIA, or CAD/stents.

9 ASA 4 recent MI, CVA, TIA, or CAD/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, Acute renal failure (ASA 5 lies outside the scope of a planned pre-assessment service)

10 In-hospital mortality: ASA 1 0.1% ASA 2 0.7% ASA3 3.5% ASA4 18.3% ASA5 93.3% % 80.00% 60.00% 40.00% 20.00% 0.00% ASA 1 ASA 2 ASA3 ASA4 ASA5

11 Questionnaire of 10 hypothetical patients 255 anaesthetists scored ASA for each patient Number of patients rated identically by authors and responders: mean 5.9, mode 6 Owens et al 1978 PMID

12 Correlates with outcome in large studies NOT a predictor of outcome in individual patients +ve predictive value 57%, -ve predictive value 80% Poor inter-observer agreement Does not consider operative/pathway factors and is a somewhat coarse scale May be useful to guide more detailed assessment

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14 Simple predictors of cardiac risk High-risk type surgery Ischaemic heart disease History of congestive heart failure History of cerebrovascular disease Insulin therapy for diabetes Preop creatinine > 177 mmol/l - Specific but not sensitive Number of risk factors 0 0.4% 1 0.9% 2 6.6% More than 2 11% Lee et al Circulation 1999 PMID Risk of major cardiac complication

15 Logistic EUROSCORE II takes 18 variables and combines to provide an estimate of in-hospital/30-day mortality Derived from 19,000 consecutive patients retrospective logistic regression analysis of 97 data points Reasonable accuracy validated in dozens of studies and systematic reviews ROC area under curve Only useful for specific procedures PMID

16 Physiological and Operative Severity Score for enumeration of Mortality and Morbidity Surgical audit tool across range of specialties Derived from data on 1440 consecutive patinets in Broadgreen, Liverpool in 1988/9 Logistic regression analysis Uses 12 physiological, 6 operative factors PMID

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18 NOT a preop tool need operative data Several studies demonstrate POSSUM overestimates mortality esp. at low-risk Logistic regression analysis model lowest mortality 1.08% Mortality improves with time 1980 s cohort PMID

19 Updated 1998 at Portsmouth P-POSSUM Shown to be more accurate at predicting local mortality than POSSUM But P-POSSUM lacks morbidity prediction Stratifies by age (<61, 61-70, 70+) but not frailty PMID

20 Several specialty specific variations validated on large patient groups Cr-POSSUM colorectal V-POSSUM vascular O-POSSUM - oesophagogastric

21 Systematic review of 10 studies of POSSUM scores in gastro-oesophageal surgery showed P-POSSUM predicted mortality more accurately than both POSSUM and O- POSSUM Both POSSUM and O-POSSUM overestimated mortality PMID

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23 (image removed for copyright reasons) No Possums were harmed in the redaction of this image. PMID

24 POSSUM limited as a pre-op risk score because: It requires operative data There is variability in different settings with under- and over-estimation of mortality P-POSSUM doesn t address morbidity

25 Predicts in-hospital mortality 4300 patient prospective audit Three surgeons, 3100 procedures, 134 deaths Composite of CEPOD category, BUPA category and ASA-PS classification

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27 Systematic review in 2013 analysed 27 studies of 8 risk stratification tools P-POSSUM and SRS performed best Limitations of both highlighted P-POSSUM not solely preop data, SRS relies on ASA with it s interobserver variability PMID

28 A new pre-op assessment based on NCEPOD data, 7 days in March 2010 derivation cohort 11,219 patients Essentially adds age and (slightly) more surgery detail to SRS Online calculator makes it very accessible PMID

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30 American College of Surgeons National Surgical Quality Improvement Program Originated in 1990s in VA hospitals of USA 30 day surgical outcomes, risk adjusted Surgery specific, model adjusted annually for each hospital No such project in UK

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32 Potentially valuable quantify cardiorespiratory function, or lack of it Expensive ca. 165 per test Systematic review supports it as a tool to predict outcome in some intra-abdominal surgery, no universal cut-point for test values Not clear how it compares to other risk tools PMID

33 Probably of most value as part of multimodal assessment in major surgery typically at tertiary centres e.g. vascular, pancreatic surgery - these patients already receive increased postoperative resources May be bigger gains from other workstreams e.g. prehabilitation

34 Reddy S et al J Am Coll Surg 28 Jan patients undergoing elective abdominal surgery Preop timed stair climb, 338 (93%) completed 90 day postop complications Accordion Severity grading system PMID

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36 84 (25%) patients had grade 2 or higher complications, overall mortality 8 (2.4%) Slower stair climb time = increased complication rate p> Multivariate analysis stair climb single strongest predictor of complications No other single comorbidity reached significance

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40 Comorbidity, Disability and Frailty need to be clearly recognised as independent markers of risk in the elderly

41 Bewildering (to me) range of definitions, indices, scales Clear there is a relationship with mortality, LoS, need for step-down care

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43 ASA is ubiquitous and can guide investigations but is not a risk score Cardiac risk indices only predict cardiac risk If you want a POSSUM, pick P-POSSUM SORT is simple to access Measure functional capacity somehow, anyhow shuttle walk, TUAG etc CPET is nice if you have it

44 Mortality alone is not a useful risk for the majority of our patients, morbidity and return to independence matter Frailty is essentially missing from existing scores and needs incorporating Estimating risk achieves little unless it alters our approach to the patient via multidisciplinary collaboration

45 online SORT score calculator

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