Pre-Operative Evaluation (Exam I) Flashcards
What is the (metric) formula for BMI?
BMI = weight (kg) / [height (m)]²
What is the (imperial) formula for BMI?
BMI= 703 · weight (lbs) / [height (inches)]²
What mnemonic guides an emergent physical examination?
AMPLE
- Allergies
- Medications
- Past medical history
- Last meal eaten
- Events leading up to the need for surgery/procedure
What factors are worth one point on the Revised Cardiac Risk Index (RCRI)?
- High risk surgery
- Ischemic heart disease
- Hx of CHF
- Hx of CVA
- DM w/ insulin dependence
- Creatinine > 2 mg/dL (176 umol/L)
What group of surgeries has the highest risk?
High (>5% mortality risk)
Vascular (Aortic, major, & peripheral)
What sort of risk would be seen on the Revised Cardiac Risk Index with a score of 0?
What about with a score of 3 or greater?
- RCRI score of 0 = 0.4% risk of major cardiac events
- RCRI score of 3 = 5.4% risk of major cardiac events
What are METs?
- Metabolic Equivalent of Tasks (measurement of rate of energy consumption).
What is one MET equal to?
- 1 MET = 3.5 mLO₂ /kg/min
How would one assess functional capacity?
- Through METs
What is the range of this assessment?
- MET of 1 = eating, working at computer,
- MET of 3 = walking 1 or 2 blocks on level ground
- MET of 8 = rapidly climbing stairs or jogging slowly
- MET of 12 = running rapidly for long distances
What are the three levels of urgency of surgery?
- Emergent - Life or limb threatened, sx needed within 6 hours, no cardiac pre-op necessary.
- Urgent - Life or limb threatened, sx needed in 6-24 hours.
- Time-sensitive - delays exceeding 1-6 weeks would adversely affect patients.
What is ASA Physical status (APA-PS)?
A commonly used method by anesthesiologists to assess the overall perioperative risk.
What ASA level would an otherwise healthy 22 year old who got in a car wreck with massive trauma necessitating emergent surgery have?
- ASA V (won’t live without sx)
What ASA level would a healthy non-smoking 27 year old with diabetes have coming in for an EGD?
- ASA II (healthy but has well-controlled DM)
What ASA level would a 56 year old male who had an MI 2 months ago have for his follow up TEE today?
- ASA IV (MI less than 3 months ago)
What ASA level would a 12 year old girl with no hx have coming in for a routine tonscillectomy?
- ASA I (no hx, healthy, routine sx)
What ASA level would a 42 year old male with COPD and poorly controlled DM have?
- ASA III (COPD, poorly controlled DM)
Define ASA I
A normal healthy patient
Examples of ASA I
healthy, non-smoking, no or minimal alcohol use
Define ASA II
A patient with mild systemic disease w/o substantive functional limitations
Examples of ASA II
Current smokers, social alcohol drinkers, pregnancy, obesity (BMI range of 30-40), mild lung disease, controlled DM/HTN
Define ASA III
A patient with severe systemic disease with substantive functional imitations. (one or more moderate to severe diseases)
Example of ASA III
poor controlled DM, HTN, COPD, BMI = or > 40, pacemaker, ESRD w/ dialysis
Define ASA IV
A patient with severe systemic disease that is a constant threat to life
Define ASA V
A moribund patient who is not expected to survive without an operation.
Define ASA VI
A declared brain-dead patient whose organs are being removed for donor purposes.
What is the most common anaphylactic drug allergy?
- NMBs
What other two drugs have really common allergies?
- Antibiotics & chlorhexidine
What condition makes one more prone to latex allergy?
- Spina Bifida
What three things discussed in the lecture would prompt you to order coagulation studies?
- Known or suspected coagulopathy
- Known bleeding disorder, hepatic disease, or anticoagulant use.
- ASA 3-4; undergoing moderate - major surgery
Is Lidocaine and amide or an ester?
How can you tell?
- Lidocaine = Amide
- Two “i’s” would indicate and amide (ex. bupivicaine)
What cross-reactivity allergies are possible for someone who has a known neuromuscular blocking agent allergy?
- Neostigmine & Morphine
What medications need to be discontinued for surgery?
- Aspirin & P2Y12 Inhibitors
- Topical Medications
- Diuretics
- Sildenafil (unless for CHF, then continue)
- NSAIDs
- Warfarin
- Hormone Replacement Therapy
- Non-insulin DM meds
What insulin should a type 1 diabetic take (or not take) the day of their surgery?
- DC short-acting
- Continue basal rate if using a pump
- Take 1/3 of normal long-acting if no pump.
What insulin should a type 2 diabetic take (or not take) the day of their surgery?
- DC short-acting
- Continue basal rate if using a pump
- 0 - 50% of normal long-acting dose
What is a normal dosing regimen of stress-dose steroid for a major surgery?
Why is this necessary?
- 100mg Hydrocortisone Q8 for 24hrs
- Stress dose steroid regimen’s replace physiologic cortisol levels. (thus prevent adrenal crisis)
What is the HPA Axis?
- Hypothalamus, Pituitary, & Adrenal glands.
What herbs/supplements carry an increased risk of bleeding?
- Saw Palmetto
- Garlic
- Ginger
- Ginkgo
- Ginseng
- Green Tea
(essentially; saw palmetto & anything starting with a “g”)
Which herbs/supplements carry an increased risk of excessive sedation/anxiolysis?
- Kava
- St. John’s Wort
- Valerian
Which herbs/supplements carry an increased risk of hypoglycemia?
- Ginseng
Which herbs/supplements carry a cardiovascular risk (especially intraoperatively)? Why?
- Ephedra (ma huang)
- Basically ephedrine = ↑ HR & BP
Which herbs/supplements boost immune system response?
- Echinacea
If a patient just ate a full, fatty meal, how long until they can have surgery?
- 8 hours
If an infant needs an anesthetic procedure in the morning at 8AM when can their last feeding prior to this occur?
- 4AM
If a patient has toast with coffee and milk in the morning, how long will it be until they can have surgery?
- 6 hours
If a patient had a gatorade at 6AM when are they clear for their anesthetic procedure?
- 8AM
What is Mendelson syndrome?
What two factors increase your risk for this?
- Aspiration Pneumonitis
- Increased risk of aspiration due to > 25mL of gastric contents and a gastric pH < 2.5.
What can be done to prevent aspiration pneumonitis?
- ↓gastric volume and ↑gastric pH
What drugs are given to help prevent aspiration pneumonitis?
- Antacids (↑pH)
- H2 Antagonists (ex. famotidine; ↑pH)
- PPI’s (ex. omeprazole; ↑pH)
- D2 Antagonist (ex. metaclopramide; reduces gastric volume)
What scoring tool is used to determine PONV risk?
- Simplified Apfel Score
What are the four risk factors of a Simplified Apfel Score?
- Female
- Hx of PONV/motion sickness
- Non-smoker
- Post-op opioids
What sort of risk is conferred by an Apfel score of 1-2?
What would be done with this score?
- Moderate-severe risk
- Prevention with 2-3 antiemetics & limiting opioids.
What sort of risk is conferred by an Apfel score of 3-4?
- Severe risk
- Avoid volatiles, use propofol. No opioids if possible, use 2-3 antiemetics.
What drugs are useful in prevention/treatment of PONV?
- Scopolamine (necessary well in advance)
- GABA analogs (lower opioid usage)
- Ondansetron (5HT3 antagonist)
- Promethazine (H1 Antagonist)
- Dexamethasone (may cause perineal burning)
What should be known about presurgical antibiotics?
- Prophylactic abx should be given within 1 hour before incision
- Vanc & fluoroquinolone should be given within 2 hours of incision.
What chance of cross-reactivity exists with cephalosporins and penicillin?
- 10%
