Red Book - High Risk Surgical Patients

Question 1

Define

Answer 1

Many definitions and scoring systems.

A high risk patient - has an expected mortality of >5%. Or twice the average risk of population having that procedure.

High risk procedure - a procedure with a mortality of >5%

Question 2

Factors associated with peri-op risk

Answer 2

Patient, institutional, surgical

Pt - Age> 65, Male (1.7x) Frail, porr nutrition, comorbid (CCF, cirrhosis)

Institute - poor pre-op assessment, no ICU access, delated surgery, no seniors

Surgical - Emergency cavity surgery, complex (aoritc etc) intra-op events

Question 3

Scoring systems

Answer 3

ASA, Lee’s Revised Cardiac Risk Index, Possum, Dukes, CPET

ASA - widely used, inter-observer variability. No discriminatory power
1 - 5 plus 6 for BSD

1 - normal
2 - mild systemic
3 - majro systemic
4 - systemic disease that is a constant threat to life
5 - moribund and will not survive without op

Lee’s
6 factors, 1point. Cardiac complication risk increases with poijnts

High Risk Surgery
IHD
CCF
Creatninine>176
Inuslin for DM
Stroke

Dukes - quantifiy things in terms of METs 1=3.5ml/kg/min VO2
<4 is bad

Question 4

Describe CPET

Answer 4

Test of dynamic cardiac function to give objective assessment of functional capacity

Anaearobic threshold - the level of O2 consumption above which aerobic energy production is supplemented by anaerobic.

<11ml/kg/min —> increased mort

Peak oxygen consumption <15mls/kg/min (4 met)

Ventilatroy efficiency (VE/VCO2)

Question 5

Other tests to requests

Answer 5

ECG
Echo
Dobutamine stress testing —> inducible myocardial ischaemia
Myocardial perufsion scanning, exercise tests
CPET
BNP