Pre-Operative Medical Assessment : in Healthy Patients

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Pre-Operative Medical Assessment in Healthy
Patients

• Mazen Badawi
• Medical Resident
• 1/2010

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Introduction

• Goal decrease risk of surgery
• Identify unrecognized co-morbid disease and risk
  factors for medical complications of surgery
• Optimize preoperative medical condition
• Understand, recognize, and treat potential
  complications
• Work as a team with surgeon and anesthesiologist

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Questions to answer in each case

• Why was the consult requested?
• What is the benefit to the patient of the
  proposed procedure?
• May one substitute a lower risk procedure?
• What are the known risks?
• What is the balance of risk-benefit?
• What are the patient's goals?

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Things to remember

• Keep no. of recommendations to a minimum
• Clarify the specific reason for the consult
  request
• Adherence to recommendations is greater for
  consults requested early
• Follow patients through the postoperative period
• Dont say cleared , say Average risk

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Anesthesia factor

• Patient and surgical factors are more important
  risk predictors than anesthetic considerations
  (JAMA 19882602859)
• ASA (Dripps) Classification is a powerful
  predictor of overall perioperative mortality. It
  also predicts cardiac and pulmonary morbidity

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ASA classification
Mortality Sys. Disturb. Class
lt0.03 Healthy patient with no disease outside of the surgical process 1
0.2 Mild-to-mod. systemic disease caused by the surgical condition or by other pathologic processes 2
1.2 Severe disease process which limits activity but is not incapacitating 3
8 Severe incapacitating disease process that is a constant threat to life 4
34 Dying patient not expected to survive 24 hours with or without an operation 5
Increased Suffix to indicate an emergency surgery for any class E
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Anesthesia risk

• Drugs Stress response, interaction, SE
• Mechanical and operational errors
• Cardiac
• Inhalational agents are mycardial depressant ?
  Accentuated hypotensive response

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Anesthesia risk

• Pulm.
• Vital capacity decreased by 50
• Decreased Fun.Resd.C below closing volumes ?
  atelectasis and V/Q mismatch
• Decreased mucociliary clearance
• Depression of response to hypoxia and hypercarbia
• Diaphragmatic dysfunction

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Anesthesia risk

• Spinal vs. epidural
• No difference in cardiac mortality.
• Probable decrease in the risk of pulm.
  complications

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Assessment of healthy indiv.

• High false ve , ?
• Questionnaire
• If all answered NO no need for complete Hx, Ex

Wilson, ME, Williams, MB, Baskett, PJ, et al.
Assessment of fitness for surgical procedures and
the variability of anaesthetists' judgments. Br
Med J 1980 1509
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Questionnaire for healthy people

• 13 questions
• General past serious illnesses
• Resp, CVS exertional SOB, anginal chest pain,
  cough, wheeze, ankle swelling
• Rx pills in the last 3 months (incl. excess
  alcohol)
• Allergies
• Anesthetic in last 2 months, problem with
  anesthesia (pt. or relative)

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Q. To determine need for anesth. App.

• 17 Q
• Resp, CVS SOB, chest pain when climbing 2
  flight of stairs, hx of heart attack, angina, HF,
  asthma, bronchitis
• Renal disease
• Neuro stroke, epilepsy
• Anesthesia previous problems in family
• Thyroid disease
• Liver disease
• Joint pain, stiffness esp. neck and jaw
• DM and insulin use

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Clinical assessment

• 1- Exercise capacity
• poor if symptomatic with walking 4 blocks
  or climbing 2 flights of stairs ? doubles the
  risk for post op. complications, CVS
  complications but not pulm.

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Clinical assessment

• 2- Medication use
• Including OTC, complementary, alternative

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Clinical assessment

• 3- Obesity surprisingly, it is not a risk
  factor for most major adverse postoperative
  outcomes
• there was no difference in postop. complication
  rates between patients whose BMI was gt or lt 30
  incl. pulm.
• But it still a major risk for postop. DVT PE

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Clinical Assessment

• 3- Age lt60 yr ? 1.3 mortality
• 80-89 yr ? 11.3
• Age 70 as turning point

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Labs

• Routine lab inv. Arent usually recommended in
  healthy indiv.
• In a study of 2000 patients undergoing elective
  surgery, 60 of routinely ordered tests would not
  have been performed if testing had only been done
  for recognizable indications only 0.22 of
  these revealed abnormalities that might influence
  perioperative management

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Sickle Cell Screen AST/ALP/ BILI Blood glucose Urea Creat. Lytes INR/ PT Type/ Screen CBC CBC ECG Chest X-Ray
Sickle Cell Screen AST/ALP/ BILI Blood glucose Urea Creat. Lytes INR/ PT Type/ Screen F M ECG Chest X-Ray
Surgical Procedure on Type Screen List No of Units
Age lt45
45-70
gt70
Cvs, HTN
Pulmonary disease
Malignancy
Hepatic disease/ETOH
Renal disease
Blood disorders
Diabetes
Smoking gt20 pack years
Use of Digoxin, Diuretics, ACE inhib.
Use of Steroids
Use of Anticoagulants
CNS disease
Sickle Risk
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CBC

• Anemia is present in 1 of asymptomatic ppl
• In a study of 2000 pt, 30 days mortality
• Pre op. Hb gt 12 ? 1.3 mort.
• Pre op. Hb lt 6 ? 33.3 mort.

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CBC

• Conclusion
• CBC is recommended in
• All pt. gt65 yr before major surgery
• All pt. lt65 yr before major surgery with expected
  significant blood loss
• All pt with symptoms of anemia before minor
  surgery

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Electrolytes

• Frequency of unexpected electrolyte abnormalities
  is low, 0.6
• No solid relation of abnormalities with periop.
  complications
• Hints easily collectable from hx
• ? routine electrolyte determinations are NOT
  recommended

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Renal funct.

• Mild to moderate renal impairment is usually
  asymptomatic
• High Cr among asymptomatic patients with no
  history of renal disease is only 0.2 ,rises in gt
  46 yrs to reach 9.8

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Renal funct.

• Ass. Of Cr gt177 with cardiac, pulm., and post op
  mortality
• Cr level is recommended esp. in
• gt50 yr
• Hypotension expected
• Nephrotoxic Rx

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B.S

• 25 of gt60 yr have abnormal b.s level.
• incidence of asymptomatic hyperglycemia is
  unknown.
• No relationship between op. risk and DM except in
  vascular CABG (but not asymp. hyperglycemia)
• ? routine measurement of b.s is not recommended
  in healthy ppl before surgery

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LFT

• Only 0.3 of healthy ppl. Have abnormal LFTs
• ? routine LFT pre op. in healthy ppl isnt
  recommended

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Hemostasis

• routine preoperative tests of hemostasis are NOT
  recommended.
• should be restricted to patients with a known
  bleeding diathesis or an illness associated with
  bleeding tendency

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Urinalysis

• Done to
• identify unsuspected renal disease
• UTI
• It is not necessary for the detection of
  asymptomatic renal disease if a serum creatinine
  measurement is Normal
• relationship between asymptomatic UTI and
  surgical infection is unclear
• ? not recommended as routine

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ECG

• Guidelines
• Men gt 45 years
• Women gt 55 years
• Known cardiac disease
• Clinical evaluation suggesting the possibility of
  cardiac disease
• Patients at risk for electrolyte abnormalities,
  such as diuretic use
• Systemic disease associated with possible
  unrecognized heart disease, such as DM, HTN
• Patients undergoing major surgical procedures

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CXR

• Recommended in
• gt50 yr undergoing major surg.
• Suspected cardiac or pulm. disease

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PFT

• not indicated for healthy patients prior to
  surgery
• reserved for patients who have SOB that remains
  unexplained after careful clinical evaluation
• Clinical findings are more predictive of the risk
  of postop. Pulm. complication than are
  spirometric results
• decreased breath sounds,
• prolonged expiratory phase,
• added sounds.

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Summary for healthy pt.

• screening questionnaire for all patients
• Hx of exercise tolerance for all patients
• Blood pressure and pulse for all patients
• Hx Ex if one of the above is abnormal, in
  patients over 60 years, or in those undergoing
  major surgery
• Pregnancy test for women who may be pregnant
• HCT for all patients undergoing surgery with
  expected major blood loss and for patients 65
  years or older undergoing major surgery
  irrespective of potential for perioperative blood
  loss

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Summary

• Serum Cr if major surgery, hypotension is
  expected, nephrotoxic drugs will be used, or the
  patient is above age 50
• ECG recommendations as above, unless obtained
  within the previous month
• Chest x-ray for patients over 50 years undergoing
  major surgery, or those with suspected cardiac or
  pulmonary disease, unless one has been performed
  within the past six months
• All other tests only if the clinical evaluation
  suggests a likelihood of disease

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• Thank you..