Pre-Op Assessment (1) Flashcards
What is the goal of pre-operative eval?
Ensure patient can safely tolerate anesthesia
Mitigate perioperative risks
Clinical examination
What are the possible outcomes after preoperative evaluation?
Proceed to surgery as planned
Delay surgery
Defer surgery
If surgery is delayed, what are some things that can be done to try to proceed with surgery at a later time?
Optimize comorbid diseases
Consult specialist
Specialized testing
Initiate interventions to decrease perioperative risk
Identify previously unrecognized comorbid conditions
How does the patient benefit from pre-op evaluation?
Reduce anxiety
Provides education and options
Questions answered
Discuss medications
Reduces post-op morbidity
Why is the pre-op eval important for anesthesia providers?
Learn of medical conditions
Devise an anesthetic plan (intra and post op)
Allows time to consult others if needed
Address DNR
What is the main part of the pre-op assessment that reduces morbidity and mortality during surgery?
Talking to the patient–the more we talk the better the interview and the more knowledge we have going into the procedure
How does the surgeon benefit from pre-op assessment?
Decreases cost of peri-operative care
Improve efficiency
Decreases cancellations/delays
Correct diagnosis can be made in ___% of cases on the basis of history alone.
56
What are the big “red flags” when discussing previous anesthesia/health history with a patient?
Malignant Hyperthermia
Acetylcholinesterase Deficiency
Hx of difficult airway
What are 2 medications that are important to know when the patient last took?
Lisinopril
Anticoagulants
What would be a concern if the patient is drunk?
worried about vomiting
What would be an issue if the patient is a chronic alcoholic?
Timing of last drink, worried about withdrawals/DTs
Things to consider if a patient uses methamphedamine?
If BP drops may not have expected response to pressor because they have been using ephedrine
What is the formula to calculate BMI?
Weight (kg) / [Height (m)]^2
OR
703 x weight (lbs) / [Height (in)]^2
Where did BMI originate from?
What is BMI used for in pre-op assessment?
Insurance companies
Used for risk factor assessment–doesnt account for muscle mass
What is the range for underweight, normal, overweight, and obese BMI?
What are some components of baseline neuro exam?
Arousal level
Sensation/movement in limbs
Ask about seizures–AEDs greatly decrease action of volatile anesthetics
What are 2 common CV related reasons to cancel/delay surgery?
Unstable angina
Decompensated heart failure
What is a big cause for post op renal issues?
Hypotension in OR
What can we do if pre-op assessment we find out pt has COPD/asthma?
mitigate risk with NEBs/steroids
What components are part of the emergent physical exam?
“AMPLE”
A: allergies
M: Meds
P: Past medical hx
L: Last meal eaten
E: Events leading up to surgery
If emergent surgery is required what do you want to pay special attention to during the physical exam?
Vitals (CNS, heart, lung)
Airway
If using regional block assess the site of the block pre-op
If surgery is emergent, what can be assumed in regards to GI?
Anticipate full stomach–digestion shuts off 8-10 hrs during fight/flight
How many classes are there for mallampati airway classifaction?
4
What is the inter-incisor gap measuring?
Gap between top and bottom of the teeth in the front of the mouth
What is the thyromental distance measuring?
Airway examination–measuring distance between thyroid and chin
What are other considerations for the airway pre-op exam?
Forward mandible movement (c-collar may impair)
Range of cervical spine motion
Document loose or chipped teeth, tracheal deviation (may need imaging)
What is responsible for 50% of deaths that occur in the OR?
CV event
What are the 3 big CV disorders we are worried about?
Aortic Stenosis
—hard to correct low BP
Heart failure
Ischemia
—If ischemic in one area probably ischemic in other areas
Why is AICD in a young person a red flag?
Probably cardiomyopathy–new push for echos in athletes preop (undiagnosed cardiomyopathy)
What is the most significant adverse event that can occur during anesthesia?
Hypoxemia
What can be used as predictors of outcome following anesthesia and surgery?
Integrative measures of respiratory function
What is the number on reason for lung surgery?
Masses/cancer
True of False: To diagnose OSA its important to look at body habitus.
False–cant assume obstruction based off body habitus
What is associated with upper respiratory tract infections in kids?
Ear infections
How does hyperglycemia affect anesthesia?
Delayed wound healing
Is it better to have higher BG or lower BG in pre-op before putting someone under anesthesia?
Better to be a little high–can give IV insulin in OR and check POC glucose
Unable to recognize hypoglycemia in someone under anesthesia–may need POC
What is the ideal blood sugar patients should have before going under GA?
Depends on patient–if uncontrolled DM runs in the 400s we want to definitely bring down but maybe 180s or so is ok
What pre-op lab value should be checked in a diabetic patient to see how brittle they are?
HA1C
Why is it important to know if someone has pheochromocytoma pre-op?
Can anticipate HTN with induction
What could be a complication of patient who says they have thyroid/parathyroid issues in pre-op assessment?
Electrolytes out of wack
What is the number one predictor of post of renal dysfunction?
Pre-op renal dysfunction
What happens to renal blood flow under surgical stress and anesthetic agents?
GFR decreases
What is emphasized in the pre-op evaluation of patients with renal insufficiency?
CV system
Cerebrovascular system
Fluid volume
Electrolyte status
What is the number one source of malignancy in the US?
Alcohol
Why is it important to know if your patient has advanced liver disease?
Sedative/opioids might have exaggerated effects
What things should be considered for a sickle cell patient who is scheduled for surgery?
Dehydration from NPO–may need fluid
Hematology consult
May need transfusion of special blood products (takes time to get)
When addressing is a patient is on blood thinners, what are important questions to ask?
List of medication
Genetics
supplements (gensing increases bleeding)
If a patient tells you in pre-op they have parkinsons, what is a concern for you?
If they are taking levodopa–causes issues with anesthesia
Get a good baseline neuro exam
Why is it important to know if a patient is taking steroids prior to surgery?
If someone is taking steroids every day they may not respond to stress the same way
What is ankylosing spondylitis?
Causes connective tissue to become hard and brittle–common to have in neck and makes it difficult to move (possible issue when intubating)
If a patient has RA, how does that affect your anesthesia care plan?
Knowing they are high risk for atlantooccipital dislocation–maybe modify intubation plan
Why should we ask about autoimmune diseases during patient pre-op assessment?
potential for big sympathetic overload associated with autoimmune diseases
Your patient tells you they have Raynauds during pre-op assessment–how could this discovery alter your anesthetic plan?
Patient is vasoconstricted baseline–caution with vasoconstricting medication
May need to adjust where SpO2 is monitored (poor blood flow in fingers)
How would a morbidly obese patient change your plan?
would need to consider difficult airway, positioning, etc.
What do you need to consider for patient’s that have had a previously transplanted organ?
- They may be on steroids (won’t respond to stress the same) -
- Transplanted hearts don’t respond to vagal stimulation
talk to patient’s transplant center before surgery
What are some of the miscellaneous conditions to consider in an anesthetic care plan?
- morbidly obese
- pt with transplanted organs
- pt with allergies
- pt with substance abuse
How would an anesthetic plan change for the pediatric population?
- you have to deal with parents; make sure to include them
- may have devices that the parents know more about
- may need to gas down before placing an IV
How would an anesthetic pan change for the pregnant population?
- you’re taking care of 2 patients, mom and baby
- would have to resuscitate both mom and baby
What consideration would you take when caring for a breast feeding mother?
Will the drugs I give affect the milk? If so, make sure to inform them so they can pump and dump
What is important to remember when caring for elderly patients?
They have more comorbidities
What court case in 1957 helped establish what the practice of informed consent was supposed to look like in the practice of modern medicine?
Salgo v. Leland Stanford Jr. University Board of Trustees
Why is informed consent important?
- Respect for pt autonomy
- Duty to inform pts about the risk and alternatives to treatment, procedures, and consequences
What are the 3 goals of shared decision making?
- Communicating with the pts about the risks and benefits of interventions
- Eliciting pts goals, values, and concerns
- Assisting pts in how to conceptualize the risks and benefits/how to approach the decision
What are the 3 types of code status orders in the peri-operative period?
- Full attempt at resuscitation
- Limited attempt at resuscitation defined with regared to specific procedures
- Limited attempt at resuscitation defined with regard to the pts goals and values
What does a DNR order “limited attempt at resuscitation defined with regard to specific procedures” mean?
- Pt may refuse certain/specific resuscitation procedures
- Anesthesia should inform pt about which procedures are essential and not essential for the success of the anesthetic and proposed surgery
What does a DNR order “limited attempt at resuscitation defined with regard to the pts goals and values” mean?
Allows the anesthesia and surgical team to use clinical judgement in determining appropriate resuscitation procedures
What are some modifiable risks factors in the elderly that you want to identify to optimize surgical outcomes?
Malnutrition, poor physical function, anxiety, social isolation
Function declines is associated with ____, _____, and _____ after surgery
morbidity, mortality, and loss of function
**assess ADLs and history of falls
What can be caused by cognitive impairment in the elderly?
Delirium, complications, functional decline, and death post-op
How does poor nutritional status in the elderly affect surgery?
Can cause infectious complications, wound complications, and increased length of stay
- Ex. surgical site infections, pneumonias, UTIs, dehiscence, anastomotic leaks
What is frailty and what is it associated with?
- An increased state of increased vulnerability to physiologic stressors
- associated with adverse health outcomes post medical and surgical interventions and decreased life expectancy
What is underdiagnosed in the eldery population?
Anxiety, depression, substance abuse, social isolation
What is the percent chance of mortality in a high risk procedure?
Greater than 5%
What are some examples of high risk procedures?
- Aortic and major vascular surgery
- peripheral vascular surgery
What is the percent chance of mortality in an intermediate risk procedure?
1-5%
What are some examples of intermediate risk procedures?
- intraabdominal surgery
- intrathoracic surgery
- carotid endarterectomy
- head/neck surgery
What is the percent chance of mortality in a low risk procedure?
<1%
What are examples of some low risk procedures?
-Ambulatory surgery
-Breast surgery
-Endo procedures
-Cataracts
-Skin surgery
-Urology surgery
-Ortho surgery
What is the prediction tool recommended by ACC/AHA that estimates risk of cardaic complications after surgery?
Revised Cardiac Risk Index
What are the components of the Cardiac Risk Index assessment?
High risk surgery
Ischemic heart disease
Hx of CHF
Hx Cerebrovascular disease
DM on insulin
Creatinine >2.0
What is used to assess cardiopulmonary fitness in patients and what does it help to predict?
Functional capacity
Estimates pt risk for major post-op morbidity/mortality
What “units” is functional capacity measured in?
METs (metabolic equivalent of task)
How many METs is considered good functional capacity?
> 4 METs (proceed with surgery)
What exercise level do we want the patient to be able to achieve?
-Walk up stairs or walk at least 2 blocks without chest pain or sob
1 MET = ________ mL/kg/min
3.5 mL/kg/min
What are the 3 levels of timeliness for surgery?
Emergency
- directly to OR no pre-op cardiac assessment
-30min-6hr (usually want in OR within 1 hour)
Urgent
-Life/limb threatened if surgery did not happen within 6-24 hours
Time-sensitive
-Delay >1-6 weeks would adversely affect patient outcomes
What is considered an elevated risk based on Revised Cardiac Risk Index?
Score >2
What are other operative risk factors to consider in addition to the ASA-PS overall risk assessment??
-The planned surgical procedure
-The ability/skill or surgeon
-Attention to postop care
-Past experience of anesthetist
____________ is a widely used method of classifying the severity of coexisiting disease among surgical patients.
ASA Physical Status (American Society of Anesthesiologists)
What are limitations to ASA-PS?
Variation is rankings determined by individual anesthesia providers
What ASA-PS classification is a normal healthy patient?
ASA 1
What ASA classification is a patient with mild systemic disease?
ASA 2
Current smoker, social drinker, pregnant, BMI >30 <40, well controlled DM, mild lung disease are examples of which ASA classification (no substantive functional limitations)?
ASA 2
What ASA-PS classification is a patient with severe systemic disease?
ASA 3
What are examples of severe systemic disease in ASA III?
Substantive functional limitations–one or more moderate to severe disease(s)
poorly controlled DM, HTN, COPD, BMI >40, active hepatitis, alcohol abuse/dependence, pacemaker, moderate decrease EF, ESRD on HD, Hx >3 months MI, CVA, TIA, CAD/stents
ASA-PS classification for a patient with severe systemic disease that is a constant threat to life:
ASA 4
Examples of severe systemic disease that is constant threat to life (ASA IV)
<3months MI, CVA, TIA or CAD/stents, on going cardiac ischemia, severe valve dysfunction, severe reduction in EF, sepsis, ARDS, ESRD not going to HD
ASA-PS class for a moribund (brink of death) patient not expected to survive without operation:
ASA Class 5
only class that talks about surgery
What are example of ASA class V?
Ruptured AAA/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in face of significant cardiac pathology, MODS
What ASA class is a declared brain-dead patient whose organs are being removed for donation?
ASA 6
What type of surgical case is ASA VI?
Emergent case
When is additional pre-op testing indicated?
If it can identify abnormalities, change the diagnosis and management plan, or change the pt outcome
When would you want to order CBC?
ASA-PS 3 or 4 undergoing intermediate risk procedures
All Pts undergoing major procedures
Which patient would you want to check renal function on?
DM, HTN, cardiac disease, dehydrated, renal disease
ASA-PS 3 or 4 undergoing intermediated procedures
ASA-PS 2,3, or 4 undergoing major procedures
When should pre-op coags be tested on patients?
Check on any patient who is:
-anticoagulated
-bleeding disorder
-anyone undergoing a major case
What is the best assessment of diabetic therapy?
HbA1c: measurement of long term control over 3 months
Your patient has unexplained fever/chills, what laboratory test would you order?
Urinalysis
What is important to consider if giving sugammadex to a female patient?
Sugammadex could inactivate birth control for a few weeks–need to educate
What are the 4 types of anesthesia?
- General
- IV/Monitored Sedation
- Regional
- Local
What defines general anesthesia and when would you use it?
Total loss of consciousness and airway control
- ET or LMA used
- would be used for major surgeries (open heart, bowel, total joints)
What is IV/Monitored sedation and when would you use it?
Level of sedation ranges - could be minimal (drowsy, able to talk) to deep (sleeping, may not remember)
- NC or face mask used
- would be used for minor surgeries/procedures or shorter (biopsy, colonoscopy)
What is regional anesthesia and when would you use it?
Pain management method that numbs a large part of the body using a local anesthetic
- Epidural or spinal
- used for child birth or joint replacement in elderly patients
What is local anesthesia and when would you use it?
Pain management method, usually a one time injection of local anesthetic that numbs a small area of the body
- used for skin or breast biopsy, bone/joint repair, procedures done in the ER
What is the #1 group of drugs that cause anaphylaxis?
Neuromuscular blockers
What is the #1 drug that causes anaphylaxis?
Rocuronium
(hypotensive, tachycardia, increased airway pressures, can’t ventilate)
What are the 3 most common agents that cause anaphylaxis?
- NMB
- Antibiotics
- Chlorhexidine (iodine, skin prep)
Patients with spina bifida are at high risk for ___ allergies
Latex
What are risk factors for latex allergies?
- multiple surgeries
- occupational exposure to latex
- food allergies that cross react (mango, kiwi, avocado, passion fruit, banana, chestnuts)
What antibiotics are the most common causes of anaphylaxis?
Penicillin and cephalosporins
- small risk of cross-reactivity, usually rashes
- avoid in IgE -mediated allergy
What are the two classes of local anesthetics?
Amides and esters
What are people usually allergic to in esters?
The preservative Para-aminobenzoic acid (PABA)
____ in local anesthetic causes adverse side effects, not an allergy
Epinephrine
Most neuromuscular blocking agents are ____.
Quaternary ammonium compounds
Cross-reactivity possible with allergy to neostigmine and ____.
Morphine
Why are opioids often listed as an “allergy”?
Commonly cause nausea, vomiting, itching, sleepiness - usually a side-effect, not an allergy
What antihypertensive meds would you want to discontinue in pre-op?
ACE inhibitors and ARBs
- may d/c 24 hours before surgery
- can cause profound hypotension that is difficult to manage
Meds to continue prior to surgery:
- Anti-hypertensives
- Cardiac medications
- Anti-depressants, anxiolytics, and other psychiatric medications
- Thyroid medications
- Oral contraceptives
- Eye drops
- GERD medications
- Opioids
- asthma medications
- Anticonvulsants
- Corticosteroids
- Statins
- COX 2 inhibitors
- MAOIs
Meds to discontinue prior to surgery:
- P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel, ticlopidine)
- Topical medications - d/c day of surgery
- Diuretics - d/c day of surgery
- Sildenafil - d/c 24 hours before surgery
Would you continue or discontinue aspirin prior to surgery?
Normally would d/c prior to surgery, but you would continue in patients with prior percutaneous coronary interventions, high-grade ischemic heart disease, or significant cardiovascular disease
- Typically d/c 10-14 days prior to surgery
How long before surgery would you d/c NSAIDs?
48 hours before
How long before surgery would you d/c Warfarin?
5 days before - continue in pt for cataract sx with topical or general anesthesia
- could substitute for lovenox or heparin
How long before surgery would you d/c post-menopausal HRT?
4 weeks prior to surgery
How long before surgery would you d/c non-insulin anti-diabetic medications?
Day of surgery - SGLT2 inhibitors d/c 24 hours before surgery
How would you manage insulin in pre-op?
D/C short acting (regular) on day of surgery
- Continue insulin pump at basal rate
Type 1: take a small amount (approx 1/3) of usual dose of morning long-acting insulin on day of surgery
Type 2: Take none or up to half of long acting or combination insulin dose on day of surgery
consult with endo
What medications would you want to avoid in patients taking MAOIs?
Meperidine and in-direct acting vasopressors (ephedrine)
____ suppresses cortisol secretion at HPA axis
Exogenous glucocorticoids
What percent of patients take multiple herbs?
50%
What percent of patients take prescription drugs?
25%
What are the effects and periop concerns for echinacea?
- Activation of cell mediated immunity
- allergic reactions, decreased effectiveness of immunosuppressants, potential for immunosuppressants with long term use
What are the effects and periop concerns for ephedra?
- Sympathomimetic effects
- Risk of myocardial ischemia and stroke from tachycardia and HTN, ventricular arrhythmias with halothane, long term use depletes endogenous catecholamines
- d/c 24 hours prior
What are the effects and periop concerns for garlic?
- inhibits platelet aggregation
- may increase risk of bleeding, especially when combined with other medications that inhibit platelet aggregation
- d/c 7 days prior
What are the effects and periop concerns for ginger?
- antiemetic, antiplatelet aggregation
- may increase risk of bleeding
What are the effects and periop concerns for ginkgo?
- inhibits platelet activating factor
- may increase risk of bleeding, especially when combined with other medications that inhibit platelet aggregation
What are the effects and periop concerns for ginseng?
- lowers blood glucose, inhibits platelet aggregation, increased PT/PTT in animals
- hypoglycemia, may increase risk of bleeding, may decrease anticoagulant effect of warfarin
- d/c 7 days prior
What are the effects and periop concerns for green tea?
- inhibits platelet aggregation, inhibits thromboxane A2 formation
- may increase risk of bleeding, may decrease anticoagulant effect of warfarin
- d/c 7 days prior
What are the effects and periop concerns for Kava?
- sedation, anxiolysis
- may increase sedative effect of anesethetics, increase in anesthetic requirements with long term use unstudied
- d/c 24 hours prior
What are the effects and periop concerns for saw palmetto?
- inhibits 5a reductase, inhibits cyclooygenase
- may increase risk of bleeding
What are the effects and periop concerns for St. John’s wort?
- inhibits neurotransmitter reuptake, MAO inhibition unlikely
- induction of cytochrome P450 enzymes, decreased serum digoxin levels, delayed emergence
- d/c 5 days prior
What are the effects and periop concerns for Valerian?
- sedation
- may increase sedative effect of anesthetics, benzodiazepine-like acute withdrawal, may increase anesthetic requirements with long term use
According to the fasting guidelines, what can be given up to 8 hours prior to surgery?
Full meal - fatty foods, enteral tube feeds
According to the fasting guidelines, what can be given up to 6 hours prior to surgery?
Light meal - toast and liquids, infant formula, nonhuman milk, coffee with milk
According to the fasting guidelines, what can be given up to 4 hours prior to surgery?
Breast milk
According to the fasting guidelines, what can be given up to 2 hours prior to surgery?
Clear liquids - water, sports drinks, carbonated beverages, coffee, tea, juice without pulp
What is Mendelson syndrome?
Increased risk of aspiration due to:
>25 mL gastric residual volume and pH <2.5
What can you do to prevent aspiration?
Decrease gastric volume and acidity
Raise pH
What medications can you give to prevent aspiration?
- Non-particulate antacids (sodium citrate) to increase gastric pH
- H2 receptor antagonists (famotidine, ranitidine) to increase gastric pH, decrease gastric acid secretion
- PPIs to increase gastric pH and decrease gastric acid secretion
- Dopamine 2 antagonist (metoclopramide) to reduce gastric volume
What are some risk factors for pulmonary aspiration?
- Hx of incompetence of lower esophageal sphincter with reflux
- active nausea/vomiting
- Symptomatic hiatal hernia
- Pregnancy
- Esophageal and gastric motility disorders
- Diabetes mellitus
- Significant opioid use
- Neuromuscular disorders
- Altered mental status
- Obesity
- Intra-abdominal masses
- Acute abdomen
- Bowel obstruction
- Emergency surgery
- Acute trauma
- Hx of gastric surgery
What are the 4 components of the Apfel score (PONV)?
Female gender
Hx of PONV
Nonsmoking status
Post op opioids
What are the 5 components of the Koivuranta scoring system (PONV)?
Female gender
Hx of PONV/motion sickness
Nonsmoking status
Age (less than 50)
Duration of surgery
What would be classified as low, moderate, and severe risk in the apfel score?
Low = 0 risk factors
1-2 risk factors = moderate to severe risk
3-4 risk factors = severe risk
What would you do if the patient is a moderate to severe risk on the apfel score?
Prevention with 2-3 drugs from different classes
What would you do if a patient is a severe risk on the apfel score?
- Consider avoiding GA or use a propofol-based anesthetic
- Minimize opioids
- Prevention with 3 drugs from different classes
PONV Risk factors in adults and children
Scopolamine class and side effects:
Class: acetylcholine muscarinic antagonist - crosses BBB
S/E: sedation, dry mouth, blurry vision, confusion, mydriasis (can worsen with narrow-angle glaucoma)
Pregabalin class and side effects:
Class: GABA analogue
- effects on PONV unclear; administered pre-induction
S/E: visual disturbances
Ondansetron class and side effects:
Class: Serotonin antagonist
- administer before conclusion of surgery
S/E: blurred vision, headache, prolong QTc
Promethazine class and side effects:
Class: histamine H1 antagonist
- administer small doses
S/E: sedation, dry mouth, blurred vision, prolong QTc
Dexamethasone class and side effects:
Class: steroid
- administer after induction
S/E: perineal irritation/burning, increased blood sugars
What medications can you use as adjunct analgesics?
NSAIDs, gabapentin, pregabalin, clonidine, acetaminophen
When should patients receive prophylactic antibiotics?
Within 1 hour before surgical incision
- Pts who received vancomycin or a fluoroquinolone for prophylactic antibiotics should have the antibiotics initiated within 2 hours before surgical incision
Which antibiotic is the most commonly adminstered for surgery?
Cefazolin - broad spectrum B-lactam antimicrobial agent
- some cross reactivity to PCN
Which antibiotic is used as an alternative for a B-lactam allergy or a MRSA infection?
Clindamycin - effective against gram-positive aerobic bacteria
What bacteria is vancomycin used for?
Gram-positive bacteria - alternative for B-lactam allergy or MRSA infection
Antibiotic dosing:
What are the 5 goals of a preop evaluation?
Decreased cost
Efficient services
Clinical productivity
Timely access to clinic
Patient and surgeon satisfaction
