Transcript Preoperative Evaluation

Preoperative Evaluation,
Preparation and
Premedication
Prepared by
Dr. Mahmoud Abdel-Khalek
Jan 2015
Preoperative Evaluation
Anesthetic drugs and techniques have profound effects
on human physiology. Hence, a focused review of all major
organ systems should be completed prior to surgery.
Goals of the preoperative evaluation is to ensure that the
patient is in the best (or optimal) condition.
Patients with unstable symptoms should be postponed
for optimization prior to elective surgery.
Steps of the preoperative visit :
I. Problem Identification
II. Risk Assessment
III. Preoperative Preparation
IV. Plan of Anesthetic Technique
I. Problem Identification
Through :
●History
(including a review of the patient's chart)
●Physical examination
●laboratory investigation
Problem Identification Cont’d
•
Cardiovascular :
•
Respiratory :
•
Neuromuscular :
•
Endocrlne :
•
GI - Hepatic :
hypertension ; ischemic , valvular or
congenital heart disease; CHF or cardiomyopathy, ,
arrhythmias
smoking; COPD; restrictive lung
disease; altered control of breathing (obstructive sleep
apnea, CNS disorders, etc.)
raised ICP ; TIA's or CVA's;
seizures; spinal cord Injury; disorders of NM junction e.g
myasthenia gravis, muscular dystrophies ,MH
steroid therapy
DM; thyroid disease; pheochromocytoma;
hepatic disease; gastresophageal reflux
Problem Identification Cont’d
•
Renal :
•
Hematologic :
•
Elderly , Children, Pregnancy
•
Medications and Allergies
•
Prior Anesthetics
•
Related to Surgery :
renal failure
anemias; coagulopathies
significant blood loss;
respiratory compromise; positioning
Physical Examination:
 General
& Local examination
 Should focus on evaluation of :
• Upper airway
• Respiratory system
• Cardiovascular system
• other systems’ problems identified from the history
Preoperative Laboratory Testing:
only if indicated from the preoperative history and physical examination.
"Routine or standing" pre operative tests should be discouraged
-CBC anticipated significant blood loss, suspected hematological
disorder (eg.anemia, thalassemia, SCD), or recent chemotherapy.
-Electrolytes
diuretics, chemotherapy, renal or adrenal disorders
-ECG age >50 yrs ,history of cardiac disease, hypertension, peripheral
vascular disease, DM, renal, thyroid or metabolic disease.
-Chest X-rays prior cardiothoracic procedures ,COPD, asthma, a
change in respiratory symptoms in the past six months.
-Urine analysis DM, renal disease or recent UTI.
-tests for different systems according to history and examination
II. Risk Assessment
Components for evaluating perioperative risk:
1. Preoperative patient's medical condition
2. Extent of the surgical procedure
3. Risk from the anesthetic
ASA Physical Status Classification System
medical status
mortality
ASA I
normal healthy patient without organic,
biochemical, or psychiatric disease
0.06-0.08%
ASA
II
mild systemic disease with no significant impact
on daily activity e.g. mild diabetes, controlled
hypertension, obesity .
Unlikely to have
an impact
0.27-0.4%
ASA
III
severe systemic disease that limits activity e.g.
angina, COPD, prior myocardial infarction
Probable impact
1.8-4.3%
ASA
IV
an incapacitating disease that is a constant threat
to life e.g. CHF, unstable angina, renal failure
,acute MI, respiratory failure requiring mechanical
ventilation
Major impact
7.8-23%
ASA V
moribund patient not expected to survive 24 hours
e.g. ruptured aneurysm
9.4-51%
ASA
VI
brain-dead patient whose organs are being
harvested
For emergent operations, you have to add the letter ‘E’ after
the classification.
Surgical Risk
Low Risk Procedures

Low surgical risk:
–
–
–
–
–
–
Endoscopy
Bronchoscopy
Cystoscopy
Dermatologic procedures
Breast biopsy
Opthalmologic procedures
Surgical Risk

Intermediate surgical risk:
–
–
–
–
Orthopedic surgery
Urologic surgery
Uncomplicated abdominal surgery
Uncomplicated head and neck
Surgical Risk

High surgical risk:
–
–
–
–
Emergency surgery
Cardiac procedures
Aortic or vascular surgery
Anticipated prolonged surgery
 Large fluid shifts or blood loss
 Ex: Whipple, spinal surgery
III. Preoperative Preparation
• Anesthetic indications:
-Anxiolysis, sedation and amnesia. e.g. benzodiazepine(diazepam ,lorazepam)
-Analgesia e.g narcotics
-Drying of airway secretions e.g atropine,glycopyrrolate,scopolamine
-Reduction of anesthetic requirements ,Facilitation of smooth induction
-Patients at risk for GE reflux :ranitidine ,metoclopramide , sodium citrate
• Surgical indications:
-Antibiotic prophylaxis for infective endocarditis.
-Prophylaxis against DVT for high risk patients : low-dose heparin or aspirin
intermittent calf compression, or warfarin.
• Co-existing Disease indications:
Some medications should be continued on the day of surgery e,g B blockers,
thyroxine. Others are stopped e.g oral hypoglycemics and antidepressants .
Steroids within the last six months may require supplemental steroids
Fasting Recommendations
Ingested material
Minimum fasting period (hr)
Clear liquids
2
Breast milk
4
Infant formula
6
Nonhuman milk
6
Light meal (toast and clear liquids)
6
IV. Plan of Anesthetic Technique
1. Is the patient's condition optimal?
2. Are there any problems which require consultation or special
tests? “Please assess and advise “
3. Is there an alternative procedure which may be more
appropriate?
4. What are the plans for postoperative management of the patient?
5. What premedication if any is appropriate?
Finally, we plan our anesthetic technique :
1. Local or Regional anesthesia
2. General anesthesia; with or without intubation.
Spontaneous or controlled ventilation is used.
3. Combined regional with general anesthesia.