Transcript Risk - uOSSC

Preoperative
Assessment
Dr. Greg Bryson
Head, Pre-Admission Units
Department of Anesthesiology
2009.01.06
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Goals n objectives
Understand the role of patient history in
preoperative evaluation
 Identify risk factors adverse outcomes
 Recognize limited role of testing in healthy
patients
 Highlight planning issues for common
preoperative problems
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2009.01.06
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Resectable vs Operable

Resectability is surgical decision making
 Does
this operation suit the patient’s problem?
 You folks will be the experts on this subject
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Operability is a shared responsibility
 Will
this patient tolerate the given procedure?
 Will this patient leave the hospital? Return to function?
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2009.01.06
Anesthesia
Critical Care
Internal medicine
Rehabilitation
Family medicine
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Anesthesia is bad for you

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Unable to protect airway
Altered control of ventilation
 Diminished

Altered respiratory mechanics
 FRC,
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response to  Raw, CO2, and O2
restrictive chest wall defect
Decreased contractility
Decreased conduction
Vasodilatation
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The Killing Fields
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Getting patients out of the OR is easy
Getting patients home is another matter
Postoperative course complicated by:
 Increased
O2 demand
 Myocardial ischemia/infarction
 Respiratory depression / VQ mismatching
 Hemorrhage
 Fluid and electrolyte shifts
 Hypercoagulable
 Protein catabolism
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Functional capacity and outcome
The ability to do predicts risk
 Patients who can’t hack the activities of
daily living must be carefully
evaluated/optimized before surgery
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Put your clinic on the 3rd floor
Girish M. Chest 2001;120:1147-51
2009.01.06
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ACC-AHA 2007 Guidelines
Fleisher LA. Circulation 2007; 116:e418-99
2009.01.06
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Pulmonary resection
Slinger PD. J Cardiothorac Vasc Anesth 2000;14:202-11
2009.01.06
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ASA Physical Status Classification
Class
I
II
III
IV
V
E
2009.01.06
Description
Healthy
Systemic disease
Systemic disease
Systemic disease
no functional limitation
with functional limitation
with functional limitation
constant threat to life
Moribund
unlikely to survive 24 hrs
with or without surgery
Emergency procedure
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ASA class and mortality
ASA
Class
I
2009.01.06
Vercanti Cohen Forrest Lagasse
1970
1986
1990
2005
0.07
0.07
0.00
0.01
II
0.24
0.20
0.04
0.03
III
1.43
1.15
0.59
0.13
IV
7.46
7.66
7.95
0.84
V
9.38
-
-
22.02
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Causes of 3-day postop death
System implicated
Cardiovascular
% of cases
59
Respiratory
Renal
Sepsis
25
22
21
Hematological
GI
Metabolic
Surgical condition
12
11
10
9
CNS
Hepatic
8
6
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NCEPOD 2002
www.ncepod.org. uk
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Cardiac risks
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Revised Cardiac Risk Index
High risk surgery
Coronary artery disease
Congestive heart failure
Prevalence
n (%)
490 (34)
478 (34)
255 (18)
Adjusted OR
(95% CI)
2.6 (1.3 – 5.3)
3.8 (1.7 – 8.2)
4.3 (2.1 – 8.8)
Cerebrovascular disease
Insulin therapy
Creatinine > 177 umol/l
140 (10)
59 (4)
55 (4)
3.0 (1.3 – 6.8)
1.0 (0.3 – 3.8)
0.9 (0.2 – 3.3)
Risk Factor
Validation cohort n = 1422
Major cardiac events = 36 (2.5%)
2009.01.06
Lee TH. Circulation 1999;100:1043-1049
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Revised Cardiac Risk Index
Risk Factor
High risk surgery
Events
Risk Factors
(%)
0
0.4
95% CI
0.05 – 1.5
 History of CAD
1
0.9
0.3 – 2.1
History of CHF
2
6.6
3.9 – 10.3
History of stroke
3
11.0
5.8 – 18.4
 Diabetes mellitus
Cr > 177
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Preoperative ECG in the elderly
Liu LL. JAGS 2002;
50:1186-91
2009.01.06
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Pulmonary risks
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CXR - systematic review
Tests
Routine (8)
Routine +
Indicated
(28)
%Abnormal
7.4
2151
(2.5–37)
18913
20
(1.4–60)
%Change
0.5
(0–2.1)
%Events
1.2
(0–6.8)
2.4
(0–5.9)
1.2
(0–8.8)
Results reported as median (range)
Munro J. Health Technol Assess 1997;1:1-62
2009.01.06
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What is the risk of
postop pneumonia?
Score
0-15
16-25
26-40
41-55
56 or more
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Risk (%)
0.2
1.2
4.6
10.8
15.9
Arozullah AM. Ann Intern Med 2001;135:847-57.
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Spirometry and pulmonary events?
Variable
Age > 65
Cough Test
Odds Ratio P Value
5.9
<0.001
3.8
0.01
NG Tube
GA > 2.5 hrs
7.7
3.3
<0.001
0.008
Abnormal CXR
FEV1<1000
1.80 (0.41-7.85)
6.51 (1.36-30.6)
McAlister FA. Am J Resp Crit Care Med 2005;171:514-7
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Renal risks
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Risk factors for renal failure
2009.01.06
Kheterpal S. Anesthesiology 2007;107:869-70
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Risk factors for renal failure
2009.01.06
Kheterpal S. Anesthesiology 2007;107:869-70
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What tests would you order?
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Preop bloodwork in the elderly?
Risk Factor
ASA Class > II
Surgical Risk
OR (95% CI)
2.55 (1.6 – 4.2)
3.48 (2.3 – 5.2)
Dzankic S. Anesth Analg 2001; 93(2):301-8
2009.01.06
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NHS - Routine preoperative tests
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“…produce a wide range of abnormal results,
even in apparently healthy individuals.”
“..the clinical importance of these abnormal
results is uncertain.”
“…lead to changes in clinical management in
only a very small proportion of patients and for
some tests virtually never.”
Munro J Health Technol Assess 1997;1:1-62
2009.01.06
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Big picture…
Information from history provides most
predictive value
 Preoperative assessment is not about
ordering tests
 Preoperative assessment is about talking
to patients
 Consult if unsure or unusual condition
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Some Caveats…
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Trials reflect elective surgery
 Acute
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Trials don’t reflect your staff guy
 Some
 Some
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illness should influence choice of tests
tests ordered as part of a larger workup
habits are hard to break
Be reasonable
 Get
an INR on someone taking coumadin
 Get an ECG in a guy with a pacemaker
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Refer to testing directive if in doubt
 Appendix
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M in the Periop Navigator
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Trouble spots
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Some patients cause more trouble in the
OR than others.
 Anesthesiologist
looks pissed off
 Surgeon upset case cancelled
 $#!t runs down hill
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These issues can be worked around if
communicated in advance
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A is for Airway
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Misadventures in airway management are
leading cause of anesthesia-related
morbidity/mortality
 Past
history of airway problems
 Head and neck trauma
 Head and neck masses
 Morbid obesity
 Short chin (think Joe Clark)
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Easily dealt with, but requires planning
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Fasting is about the airway
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Regurgitation and aspiration of gastric
contents under anesthesia can make a bad
airway day worse.
Increased morbidity/mortality with solid, acidic
gastric contents
Ottawa Hospital Fasting Guidelines
8
hour fast for solids
 3 hour fast for water
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Ranitidine 90 min preop to increase pH in
those with reflux
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B is for Breathing
Chronic, stable pulmonary disease is
something to be worked around
 Acute decompensation should be fixed
preop
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 Wheezing
asthmatic
 Increased SOB in COPD
 Productive cough with fever
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C is for Circulation/Clopidogrel
Artang R. Am J Cardiol 2007;99:1039–43
2009.01.06
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D is for Device/Defibrillator
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Pacemakers
 Electrocautery
may inhibit pacing
 If pacemaker dependent, reprogram to VOO
 Use bipolar cautery, if possible
 Short bursts if monopolar required
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AICDs
 Electrocautery
may cause defibrillation
 Must be turned off in monitored environment
 Sign of badness
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E is for Electrolytes
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Euvolemia is expected
Beware the patient with
 GI
pathology
 Diuretics
 Malignancy
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These numbers will usually get you cancelled
 K+
less than 2.7 or greater than 5.5
 Na+ less than 120 or greater than 150
 Ca + + less than 1.0 or greater than 3.0
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F is for Family History
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Malignant hyperthermia
 Autosomal
dominant, variable, 1:50000
 Disordered calcium handling by skeletal muscle
 TO, acidosis, rhambdomyolysis,hyperkalemia…
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Atypical plasma cholinesterase
 Autosomal
recessive, 1:3000
 Unable to metabolize succinylcholine
 10 minute drug now lasts hours.
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Friend of a friend
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G is for G$d D#mn Anticoagulants
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Normal coagulation expected preoperatively
Neuraxial hematoma & surgical hemorrhage
 Coumadin
held for 5 days
 INR less than 1.4
 LMWH held for 24 hours
 UFH held for 6 hours
 Fancy antiplatelet drugs withdrawn (7 days)
 Beware drug eluting stents
 ASA is OK for most procedures
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Don’t drown folks with FFP
 Octaplex
40 units for average adult
 Vitamin K 1-2 mg (plus time) often enough
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H is for Held Medications
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NPO does not mean hold medications
In general, keep patients on the medications
they take every day, in particular…
 Antianginals
 Antihypertensive
 Antiarrythmics
 Puffers
 Steroids
 Narcotics
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Withholding preop medications
% of patients in whom
drug was withheld
Drug Class
All surgeries Non-emergency
Anti-anginal
27
22
Anti-arrhythmic
25
20
Anti-hypertensive
34
33
Bronchodilator
16
15
Steroids
19
17
NCEPOD 2002
www.ncepod.org. uk
2009.01.06
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Summary
Patients not expected to be perfect
 Patients expected to be at “their best”
 More talk…less test
 Poor functional capacity is trouble
 Shared care
 Trouble starts when they leave the OR
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