Exam 1 - Preop Assessment Flashcards
What are the components of a complete medical history?
- Past medical history
- Reason for surgery
- Review of systems
- Previous anesthetic complications
- Medications
- Allergies
- Drug use
- Functional capacity
What is the (metric) formula for BMI?
BMI = weight (kg) / height (m)²
What is the (imperial) formula for BMI?
703 · BW (lbs) ÷ height (inches)²
What is a normal BMI?
What is an obese BMI?
Why is BMI not very accurate?
Normal: 18.5-24.9
Obese: > 30.0
BMI does not account for muscle mass
Why is it important to complete a baseline neuro exam?
To determine patients pre-surgical baseline to be able to catch any new defecits post-op
What mnemonic guides an emergent physical examination?
AMPLE
- Allergies
- Medications
- Past medical history
- Last meal (assume full stomach)
- Events leading up to need for surgery
What are the components of a pre-op airway examination?
- Mallampati
- Inter-incisors gap
- Thyromental distance
- Forward movement mandible
- Range of cervical spine (flexion and extension)
- Loose/chipped teeth (ensure patient is aware of danger of loss of teeth during intubation)
- Tracheal deviation (mass?)
What complications account for almost half of perioperative mortalities?
Cardiovascular complications
What is the most significant adverse respiratory event that can occur during anesthesia?
Hypoxemia
What court case helped establish the practice of informed consent in modern medicine?
Salgo v. Leland Stanford Jr. University Board of Trustees(1957)
What is frailty?
A state of increased vulnerability to physiologic stressors
What group of surgeries has the highest risk?
Vascular (Aortic, major, & peripheral vascular) > 5%
What is the Revised Cardiac Risk Index (RCRI)?
What are the components?
Estimates risk of cardiac complications after surgery
What is functional capacity?
Assesses cardiopulmonary fitness and estimates risk for major post-op morbidity and mortality
How is funcitonal capacity measured?
What is its units?
What level is desired before surgery?
- METs (metabolic equivalent of task)
- 1 MET = 3.5 mL O2/kg/min
- > 4 METs is desired (need to climb one flight of stairs without getting short of breath or chest pain)
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 patient.
Who described the 6 degree ASA Physical Status grading?
Meyer Saklad
Describe an ASA I patient?
A normal healthy patient
Describe an ASA II patient?
A patient with mild systemic disease without functional limitations (smoker, social drinker, pregnancy)
Describe an ASA III patient?
A patient with severe systemic disease with substantive functional limitations (poorly controlled DM or HTN, COPD, CVA, morbid obesity)
Describe an ASA IV patient?
A patient with severe systemic disease that is a constant threat to life (recent <3 months MI, CVA, or stents, sepsis, ARDS, severe valve dysfunction)
Describe an ASA V patient?
A moribound patient that is not expected to survive without surgery (ruptured AAA, massive trauma, ischemic bowel with MODS)
Describe and ASA VI patient?
A declared brain-dead patient whose organs are being removed for donation
When should pre-op testing be ordered?
If it can identify abnormalities, change the diagnosis or management plan, or change the patients outcome.
When should CBC or H/H be ordered pre-op?
- Surgery with potential blood loss
- ASA III or IV
- All patient undergoing major operations
- Known coagulopathies
When should renal testing be ordered pre-op?
- DM, HTN, cardiac dx, N/V, ESRD
- ASA III and IV undergoing intermediate risk procedures
- ASA II, III, IV undergoing major operations
What lab test is for wafarin?
What pathway does in test?
PT, extrinsic pathway
Warfarin
Extrinsic
PT
Fill in the labs in the image below:
What condition makes one more prone to latex allergy?
- Spina Bifida
What is important to notify women of if they recieve sugammedex?
They need to use alternative forms of birth control because sugammadex can inactivate birth control
What are the most common anaphylactic drug allergy?
What other two drugs have really common allergies?
- NMBs with rocuronium being the most common
- Antibiotics & chlorhexidine
What antibiotic classes are the most common causes of anaphylaxis?
Penicillins and cephalosporins
What may a patient be experiencing when they say they have a vancomycin allergy?
Red man syndrome - side effect caused by histamine release, not an allergy
What are people reacting to when given an ester local anesthetic?
The preservative in the solution - para-aminobenzoic acid (PABA)
What cross-reactivity allergies are possible for someone who has a known neuromuscular blocking agent allergy?
- Neostigmine & Morphine
What medications should be continued prior to surgery?
- Antihypertensives - not ACEi or ARBs
- Antidepressants and other psych meds
- Thyroid medications
- Opiods
- Anticonvulsants
- Asthma meds
- Corticosteroids
- Statins
4 A’s To Obtain Cornelius’ Standards
How should you adjust your anesthestia plan for someone taking an MAOI?
Avoid meperidine and in-direct acting vasopressers (ephedrine)
What medications need to be discontinued for surgery?
- Aspirin & P2Y12 Inhibitors (clopidogrel & ticlopidine)
- Topical Medications
- Diuretics
- Sildenafil
- NSAIDs
- Warfarin (continue for cataract sx)
- Post Menopausal Hormone Replacement Therapy
- Non-insulin DM meds (SGLT2 inhibitors)
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 drug and dose of steroids is standard for a patient having surgery taking gluccocorticoids?
Why is it important to bolus them steroids perioperatively?
- Hydrocortisone 100 mg q6-8h
- Exogenous gluccocorticoids supress cortisol secretion
- Stress dose steroid regimens replace physiologic cortisol levels. (thus prevent adrenal crisis)
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
- Melatonin
Which herbs/supplements carry a cardiovascular risk (especially intraoperatively)? Why?
- Ephedra (ma huang)
- Basically ephedrine = ↑ HR & BP
How long before a procedure should a patient be NPO after a full fatty meal?
8 hours
If a patient just ate toast mith coffee and milk, how long should they be NPO prior to surgery?
6 hours
How long does an infant need to be NPO after having breast milk?
4 hours
How long after drinking water or tea can a patient have surgery?
2 hours
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 (ex. sodium citrate;↑pH)
- H2 Antagonists (ex. famotidine; ↑pH, ↓ secretion)
- PPI’s (ex. omeprazole; ↑pH, ↓ secretion)
- D2 Antagonist (ex. metaclopramide; reduces gastric volume) - give sedation before this drug d/t dyskinesia
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?
Treatments?
- Severe risk
- Avoid volatiles, use propofol. No opioids if possible, use 3 different classes of 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 initiated within 2 hours before incision.
What is the most commonly administerd surgical antibiotic?
What does it treat?
Dose?
- Cefazolin
- Broad-spectrum beta-lactam antimicrobial agent that treats most aerobic gram-positive bacteria
- 2g; if >120 kg then 3g
What does clindamycin treat?
Dose?
- gram-positve and gram negative aerobic bacteria
- recommended in many intrabdominal procedures
- 900 mg
What does vancomycin treat?
Dose?
- Gram-positive bacteria
- Recommended for distal ilium, colon, and appendix surgeries
- 15mg/kg
