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2009.01.06 1
Preoperative Assessment
Dr. Greg BrysonHead, Pre-Admission UnitsDepartment of Anesthesiology
22009.01.06
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
32009.01.06
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
Operability is a shared responsibility Will this patient tolerate the given procedure? Will this patient leave the hospital? Return to function?
Anesthesia Critical Care Internal medicine Rehabilitation Family medicine
42009.01.06
Anesthesia is bad for you Unable to protect airway Altered control of ventilation
Diminished response to Raw, CO2, and O2
Altered respiratory mechanics FRC, restrictive chest wall defect
Decreased contractility Decreased conduction Vasodilatation
52009.01.06
The Killing Fields 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
62009.01.06
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
72009.01.06
Put your clinic on the 3rd floor
Girish M. Chest 2001;120:1147-51
82009.01.06
ACC-AHA 2007 Guidelines
Fleisher LA. Circulation 2007; 116:e418-99
92009.01.06
Pulmonary resection
Slinger PD. J Cardiothorac Vasc Anesth 2000;14:202-11
102009.01.06
ASA Physical Status Classification
Class Description I Healthy II Systemic disease no functional limitation III Systemic disease with functional limitation IV Systemic disease with functional limitation
constant threat to life V Moribund unlikely to survive 24 hrs
with or without surgery E Emergency procedure
112009.01.06
ASA class and mortalityASA
Class Vercanti
1970 Cohen 1986
Forrest 1990
Lagasse 2005
I 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
122009.01.06
Causes of 3-day postop deathSystem implicated % of cases
Cardiovascular 59
Respiratory 25
Renal 22
Sepsis 21
Hematological 12
GI 11
Metabolic 10
Surgical condition 9
CNS 8
Hepatic 6NCEPOD 2002 www.ncepod.org. uk
132009.01.06
Cardiac risks
142009.01.06
Revised Cardiac Risk Index
Risk FactorPrevalence
n (%)Adjusted OR
(95% CI)
High risk surgery 490 (34)
2.6 (1.3 – 5.3)
Coronary artery disease 478 (34) 3.8 (1.7 – 8.2)
Congestive heart failure 255 (18) 4.3 (2.1 – 8.8)
Cerebrovascular disease 140 (10) 3.0 (1.3 – 6.8)
Insulin therapy 59 (4) 1.0 (0.3 – 3.8)
Creatinine > 177 umol/l 55 (4) 0.9 (0.2 – 3.3)
Lee TH. Circulation 1999;100:1043-1049
Validation cohort n = 1422Major cardiac events = 36 (2.5%)
152009.01.06
Revised Cardiac Risk Index
Risk Factor
High risk surgery
History of CAD
History of CHF
History of stroke
Diabetes mellitus
Cr > 177
Risk FactorsEvents
(%)95% CI
0 0.4 0.05 – 1.5
1 0.9 0.3 – 2.1
2 6.6 3.9 – 10.3
3 11.0 5.8 – 18.4
162009.01.06
Preoperative ECG in the elderly
Liu LL. JAGS 2002;
50:1186-91
172009.01.06
Pulmonary risks
182009.01.06
CXR - systematic review
Tests %Abnormal %Change %Events
Routine (8) 21517.4
(2.5–37)
0.5
(0–2.1)
1.2
(0–6.8)
Routine + Indicated
(28)18913
20
(1.4–60)
2.4
(0–5.9)
1.2
(0–8.8)
Results reported as median (range)
Munro J. Health Technol Assess 1997;1:1-62
192009.01.06
What is the risk of postop pneumonia?
Score Risk (%)
0-15 0.2
16-25 1.2
26-40 4.6
41-55 10.8
56 or more 15.9
Arozullah AM. Ann Intern Med 2001;135:847-57.
202009.01.06
Spirometry and pulmonary events?
McAlister FA. Am J Resp Crit Care Med 2005;171:514-7
Variable Odds Ratio P Value
Age > 65 5.9 <0.001
Cough Test 3.8 0.01
NG Tube 7.7 <0.001
GA > 2.5 hrs 3.3 0.008
Abnormal CXR 1.80 (0.41-7.85)FEV1<1000 6.51 (1.36-30.6)
212009.01.06
Renal risks
222009.01.06
Risk factors for renal failure
Kheterpal S. Anesthesiology 2007;107:869-70
232009.01.06
Risk factors for renal failure
Kheterpal S. Anesthesiology 2007;107:869-70
242009.01.06
What tests would you order?
252009.01.06
Preop bloodwork in the elderly?
Risk Factor OR (95% CI)
ASA Class > II 2.55 (1.6 – 4.2)
Surgical Risk 3.48 (2.3 – 5.2)
Dzankic S. Anesth Analg 2001; 93(2):301-8
262009.01.06
NHS - Routine preoperative tests
“…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
272009.01.06
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
282009.01.06
Some Caveats… Trials reflect elective surgery
Acute illness should influence choice of tests Trials don’t reflect your staff guy
Some tests ordered as part of a larger workup Some habits are hard to break
Be reasonable Get an INR on someone taking coumadin Get an ECG in a guy with a pacemaker
Refer to testing directive if in doubt Appendix M in the Periop Navigator
292009.01.06
Trouble spots Some patients cause more trouble in the
OR than others.Anesthesiologist looks pissed offSurgeon upset case cancelled$#!t runs down hill
These issues can be worked around if communicated in advance
302009.01.06
A is for Airway Misadventures in airway management are
leading cause of anesthesia-related morbidity/mortality Past history of airway problems Head and neck trauma Head and neck masses Morbid obesity Short chin (think Joe Clark)
Easily dealt with, but requires planning
312009.01.06
Fasting is about the airway Regurgitation and aspiration of gastric
contents under anesthesia can make a bad airway day worse.
Increased morbidity/mortality with solid, acidic gastric contents
Ottawa Hospital Fasting Guidelines 8 hour fast for solids 3 hour fast for water
Ranitidine 90 min preop to increase pH in those with reflux
322009.01.06
B is for Breathing Chronic, stable pulmonary disease is
something to be worked around Acute decompensation should be fixed
preopWheezing asthmatic Increased SOB in COPDProductive cough with fever
332009.01.06
C is for Circulation/Clopidogrel
Artang R. Am J Cardiol 2007;99:1039–43
342009.01.06
D is for Device/Defibrillator Pacemakers
Electrocautery may inhibit pacing If pacemaker dependent, reprogram to VOO Use bipolar cautery, if possible Short bursts if monopolar required
AICDs Electrocautery may cause defibrillation Must be turned off in monitored environment Sign of badness
352009.01.06
E is for Electrolytes Euvolemia is expected Beware the patient with
GI pathology Diuretics Malignancy
These numbers will usually get you cancelled K+ less than 2.7 or greater than 5.5 Na+ less than 120 or greater than 150 Ca + + less than 1.0 or greater than 3.0
362009.01.06
F is for Family History Malignant hyperthermia
Autosomal dominant, variable, 1:50000 Disordered calcium handling by skeletal muscle TO, acidosis, rhambdomyolysis,hyperkalemia…
Atypical plasma cholinesterase Autosomal recessive, 1:3000 Unable to metabolize succinylcholine 10 minute drug now lasts hours.
Friend of a friend
372009.01.06
G is for G$d D#mn Anticoagulants 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
Don’t drown folks with FFP Octaplex 40 units for average adult Vitamin K 1-2 mg (plus time) often enough
382009.01.06
H is for Held Medications 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
392009.01.06
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
402009.01.06
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