Surgical Risk Dr Chris Snowden MD FRCA Consultant Anaesthetist Freeman Hospital Newcastle upon Tyne

Population Studies: Safety in Numbers Metanalyses Multiple RCTs Trial Omissions Large Cohort e.g. NSQUIP clinically meaningful data standardized outcome definition validated risk-adjustment Decreased unadjusted 30-day mortality (3.2% to 2.3%) 30-day morbidity (17.4% to 9.9%)

Procedural Risk Netherlands Population study 3.5 M Operations 1991-2005 Evaluated trends Elective, open, non-laparoscopic Results All cause 30 d mortality – 1.85% Hugely Variable High/Low stratification unacceptable Anesthesiology 2010; 112:1105

Mortality N= 110,000 pts Ghaferi et al. Annals of Surgery 2009: 250;6,

Across Procedures Ghaferi et al NEJM 2009: 361:1638

Population 105,952 pts Khuri SF et al; Ann Surg 2005

Complications and Outcome Khuri et al. Ann Surg 2005

Defining Surgical Risk Abdominal Ortho Vascular Transplant Surgical Intervention “FTR” Outcome Survival Mortality Complications

Complication Types Prospective data 3970 pts Age >50 yrs Non-cardiac surgery Adjusted Data Complications Length of Stay (Days) None 4 (3-4) Non-cardiac 11 (10-12) Cardiac and non-cardiac 15 (12-18) Fleischmann KE et al; Am J Med: 2003

Patterns of Complications No GI comps GI comps Median: 10 vs 17 days P=0.0001

Cardiorespiratory Complications Median: 8 vs 12 vs 23 days P<0.0001 CVS/RS Non-CVS/RS No Comps

Defining Surgical Risk Death Abdominal Ortho Vascular Transplant FTR Survival Complications No Extended Recovery CVS RS Complications Delayed Recovery GI Inf Ren Appropriate Recovery

Surgical Risk

Defining Surgical Risk Death Abdominal Ortho Vascular Transplant FTR Complications No Extended Recovery CVS RS Patient Delayed Recovery GI Inf Ren Appropriate Recovery

Ischaemia or Heart Failure Elderly (> 65 yrs) 159,327 procedures 18% HF; 34% CAD Mortality/Readmissions Hazard Ratios HF 1.63 CAD 1.08 Hammill et al. Anesthesiology 2008; 108. 599

Heart Failure Prevalence

“Asymptomatic” Heart failure Retrospective study Three groups; EF > 40 (n=385) EF < 40 (n=192) Controls (n=10,000) “Optimised” heart failure Results: No Difference in mortality (short term) Difference ; Longer hospital stays - 2 days Hospital readmissions - 18% (EF >40% more likely than EF >40) Long term outcome Xu-Cai et al. Mayo clinic Proc 2008; 83. 203

501 (50%) LV dysfunction (EF<50%) 52% diastolic dysfunction 1000 patients 501 (50%) LV dysfunction (EF<50%) 52% diastolic dysfunction Anesthesiology 2010; 112:1316 –24

Defining Surgical Risk Death Exercise Ability Abdominal Ortho Vascular Transplant FTR Complications No Extended Recovery CVS RS Patient Cardiorespiratory Dysfunction Delayed Recovery GI Inf Ren Appropriate Recovery

CPET: Risk Tool ? CPeT Structured approach Comorbidity summary measure Quantitative and Qualitative endpoints Multiple, simultaneous CVS/RS components Structured approach Concept Proof Incremental value Clinical Utility Predictive validity Intervention

Evidence n Patients Outcome Trial Concept Incremental Clinical Utility Older 1993 187 Elderly Mortality Prospective Cohort (?Blinded) >11 ; 4% <11 ; 42% 1999 548 Prospective Cohort (No blinding) CP deaths confined to <11 or ischaemia Forshaw 2008 78 Oesophagus Morbidity 13.2 vs 14.4 CP complications Readmissions NA Carlisle 2007 130 Vascular Mid term mortality Retrospective Cohort CPeT related to survival AT VE/VCO2 RCRI Hazard Ratio Hightower 2010 32 Major Abdominal Prospective, Pilot (Blinded) PC related to outcome ASA vs AT,HR Wilson 2010 847 Major Surgery (No Blinding) <11 Relative risk 7x death Greater than Clinical factors Snowden 116 Prospective CPeT variables related to outcome Improvement on subjective and established factors Risk increase

847 Pts Mortality 2.1% Hospital mortality by AT group - effect of cardiac risk factors: AT < 11 AT >11 RR (95% CI) Patients with 1 or more cardiac risk factors (n=271) 3.8% 1.1% 3.3 (0.5-20.6) Patients with no cardiac risk factors (n=576) 3.2% 0.3% 10.0 (1.7-61.0) BJA . 2010 105; 297

Optimum AT 10.1 ml/min/kg AUC 0.85 ; Sens 88%; Spec 79% Snowden et al 2010 Ann Surg

Types of Complications

Modelling Outcome

Exercise Ability and Cardiorespiratory Complications * ***

Proportion Remaining in Hospital “High Risk” CCU Groups Proportion Remaining in Hospital ITU 3 ITU 7 n Day 3 Poms Day 7 Poms LOS No 45 2 9 Yes 3 1 12 20 5 4 19 31 28

CCU and Exercise Prediction 12.0 11.4 (2.6) 11.0 ROC Analysis: Opt AT 10.6 (62%,80%) AUC 0.873 (0.80-0.95) P=0.0001 10.0 9.0 9.6 (2.3) 8.0 Low Risk High Risk High risk ITU 29

The CPeT “Package of Care” CPX Clinic No clinic 30 day mortality 3/194 (2%) 8/139 (6%) Critical Care 22% 10% CPX Clinic _________ No CPX Clinic _________ Swart et al. Personal communication

High Risk Surgery: Liver Transplantation Highest Surgical Risk (O.R. 15.8) Early Mortality - 18% Ensure appropriate organ allocation Limited resource Marginal Organs High Comorbidity

Recipient Scores Survivors Non Survivors Signif N= 49 6 AGE (Mean;SD) 53.1 (10.6) 49.2 (12.4) NS BMI (Mean;SD) 26.3 (5.3) 26.7 (6.9) Waiting List (Mean;SD) 94 (82) 129 (112) UKELD (Mean;SD) 53 (5.2) 53 (6.7) MELD (Mean;SD) 17 (9) 18 (9) Snowden et al (In Prep) 32

Transplantation and Exercise ROC analysis: Optimum AT 9.6 ml/min/kg AUC 0.97 ; (p=0.001) p<0.00001 Snowden et al (In Prep) 33

CCU Stay and Liver Tx Median CCU LOS 9 days vs 27 days P=0.001 Proportion remaining in CCU AT< 9.6 AT>= 9.6 Days in CCU 34

Donor – Recipient Matching Snowden et al (In Prep)

Selective Training Effect

Summary Surgical risk - evolving concept Insights from large population studies New concepts for: Operative risk variability Mortality and “Failure to rescue” Importance of complications (esp CVS) Cardiac “Dysfunction”

Summary Exercise Ability (and assessment): Future Defines important end point for comorbidity Relates to mortality and morbidity Varying surgical specialities Pedigree in cardiorespiratory dysfunction Future Prospective comparative trials Interventional strategy tool