Week 4 - Labs, Chest X-Ray Interpretation and Radiation Safety Flashcards
Who must do the pre-operative assessment on the patient?
A qualified anesthesia practitioner
What has been found to be most predictive of surgical complications?
A thoughtfully executed preoperative history and physical.
What are some conditions that would benefit from early preoperative evaluations?
Poorly controlled HTN, asthma/COPD requiring medicine, morbid obesity, cervical or thoracic spine injuries
What would be suspected if a patient had vague reports of fever and convulsions last time they were under anesthesia?
Malignant hyperthermia, further investigation needs to be done to rule this out before surgery.
How can we prevent adverse drug reactions prior to surgery?
Advise patients to not take unnecessary medications preoperatively.
Most common cause of drug hypersensitivities during anesthesia?
Antibiotics and NMBA
A patient states that they are allergic to oxycodone because it makes them dizzy. What should you next step be?
Further investigate a true allergic reaction opposed to adverse reactions. A true allergic reaction is a absolute contraindication to give a drug, whereas an adverse reaction isn’t.
How long before surgery should patients be advised to not smoke?
12-18 hours
Smoking effects on the body
Hyper coagulability, increased blood viscosity, left shift on oxy-hem curve, COPD, recurrent chest infections…
Perioperative complications in children exposed to smoke
Laryngospasm, coughing on induction/emergence, breath holding, postop O2 desaturations, and hyper secretion
Anesthetic requirements are _________ in alcoholics or illicit drug users
Increased
Important to know prior to surgery (if patient will tell you)
Alcoholics have increased postoperative morbidity and mortality due to
Poor wound healing, infection, bleeding, pneumonia, and further hepatic deterioration
Most common recreational drugs
Marijuana and cocaine
Signs that indicate illicit drug use during physical exam
Evidence of drug injections, ophthalmologic changes, malnourishment, poor dental care/bruxism, and nasal perforation
How do you preform a Mallampati exam?
Ask patient to open mouth as wide as possible and maximally extrude their tongue. DO NOT phonate because this may elevate the soft palate
What does a Class IV Mallampati classification indicate?
Soft palate not visualized, tracheal intubation will be difficult
How far should patient be able to open mouth?
4 cm (2 finger widths). Less than 4 indicates difficult intubation
How would you assess a patient for mandibular mobility?
Have patient protrude the mandible in front of the central incisors. If they can do this, this indicates relative ease with maneuvering the laryngoscope.
Most common reason for anesthesia related legal claims?
Dental injuries
What should you do if you are worried about a patients risk for dental injury?
Talk to them about the risks, if they wish to proceed have them sign informed consent.
What is the ideal body weight for a 5 foot 5 inch man? woman?
Starting at 5 feet
Man = 105 + 6 lbs per per inch –> 135 lbs
Woman = 100 + 5 lbs per inch –> 125 lbs
BMI formula
Weight in kg/(height in meters)^2
What does a BMI of 32.4 indicate?
Moderate obesity
What patients are at risk for adrenal insufficiency?
Those who are/have taken 20 mg of hydrocortisone for longer than 2 weeks DURING the previous year
How does your anesthetic plan change for a patient who has taken 20 mg of hydrocortisone for a month, 6 months ago?
May be at risk for adrenal insufficiency, should be evaluated for the need of steroid coverage preoperatively.
Patients with a GCS score of less than _______ usually require tracheal intubation
8
What should be done with patients currently taking dexamethasone or methylprednisolone?
Check blood glucose levels
Hypertension is defined as blood pressure greater than
140/90 in patients aged 30-59, 150/90 in patients 60 and older
What does a MET score of 5 indicate?
Good functional capacity
What does a MET score signify?
The patients functional capacity. Set of questions to show cardiac risk
Routine testing with a 12-lead ECG _________ recommended for low risk surgeries
Isn’t
What is associated with the highest risk for a perioperative MI?
Unstable angina
Why were drug eluding stents developed?
Reduce stent thrombosis
What percentage and lower is considered reduced ejection fraction?
49%
A left ventricular ejection fraction of less than ________ is associated with a greater incidence of postoperative heart failure and death
35%
What is associated with routine beta blocker therapy on low risk patients?
Increased mortality and morbidity from hypotension, bradycardia, and stroke
Elective surgeries should be delayed for how many days in patients with bare metal stents or drug eluting stents?
Bare metal = 30 days
Drug eluting = 6 months
A patient taking an anticoagulant, without a reversal agent, should stop taking this drug ________ elimination half-lives prior to surgery
3-5, these agents should be resumed 24-48 hours postoperatively if bleeding is controlled.
Smoking patients can quit smoking _____ weeks prior to surgery, and have the complication rates of those associated with non-smokers
8
Normal phosphorus blood level
2.2 - 4.2
A safe goal of perioperative insulin therapy is to maintain glucose levels less than __________, while avoiding hypoglycemia
180 mg/dL
Blood glucose levels in patients with diabetes or medications that raise blood sugars are taken at ______ - _______ intervals in the intra-operative and postoperative period.
1 - 4 hour
What is the most common approach regarding blood sugar therapy in type 1 diabetes for brief procedures?
Give 50% of normal dose SQ of intermediate/long acting insulin, and institute 5% glucose infusion.
In what circumstances should a pregnancy test be obtained?
Whenever pregnancy is suspected. If refused, an informed consent needs to be signed regarding the risks to the fetus.
HcG serum test is standard
A modest amount of clear liquids _____ - ______ prior to surgery have been considered acceptable
2-3 hours
Purpose of the ASA classification?
Describe the physical status of the patient in a consistent manner. DOES NOT represent an estimate of anesthesia risk
How would you describe an patient given an ASA of III?
A patient with severe systemic disease
Where is the costophrenic angle
What is wrong with this?
Airway deviation to the right
What is wrong with this?
Subcutaneous emphysema
What is wrong with this?
Pleural effusion
What is wrong with this?
Pericardial effusion
What is wrong with this?
Lizzo sat on his face
How would you describe cardiomegaly?
Heart is 50% or more of cardiothoracic width
Where is the left ventricle?
Where is the ascending aorta?
Where is the aortopulmonary window?
When should blood glucose levels be assessed?
DM, current corticosteroid use, history of hypoglycemia, adrenal disease, cystic fibrosis
What is a normal fasting blood sugar?
80-100
Indications for a serum chemistry panel?
Renal disease, adrenal or thyroid disease, chemo, pituitary/hypothalamic disease, body fluid loss or shifts (dehydration or bowel prep)
Indications for potassium level?
Digoxin, diuretics, ace-inhibitors, ARBS, renal disease, dialysis patients
Indications for creatinine and BUN levels
HTN, cardiovascular disease, renal disease, adrenal disease, DM, diuretics, digoxin, body fluid loss, procedure requiring constant radio contrast.
Indications for liver function tests?
Hepatic disease, exposure to hepatitis, therapy with hepatotoxic agents.
Indications for Coagulation studies?
Leukemia, hepatic disease, bleeding disorders, anticoagulation therapy, severe malnutrition or malabsorption, postop anticoagulation
Normal platelet count
150-450 (thousand)
Normal INR, PT, and PTT
INR = 1
PT = 10 - 12.5 seconds
PTT = 25 - 35 seconds
What are some drug levels that should be monitored a patient may be taking?
Theophylline, phenytoin, digoxin
When should a preoperative EKG be ordered?
Any cardiac history or new history, diabetic older than 40, 40+ pack year smoking history, morbid obesity, sleep apnea, Pierre Robin snydrome - RHF, patients 65 and older
A 67 year old patient is scheduled for a hernia repair with no significant health history, should you order an EKG?
Yes, any patient older than 65
Can use previous EKG if within 6 months
Indications for a CXR
Signs or symptoms of a heart or lung condition, age older than 70, or a surgery on the heart, lungs, or another part of the chest.
Can use previous CXR if within 6 months
What is the systematic approach for assessing a CXR?
ABCDEF = Airways, Bones, Cardiac silhouette, Diaphragm, Effusions, Fields (lines, tubes, devices, surgeries)
Airway assessment of a CXR
Trachea and bronchi, hilar structures, lung zones, pleura, lung lobes and fissures, costophrenic angles
Cardiac silhouette of a CXR
Whats wrong with this CXR?
Cardiomegaly
What lung zone is this?
Upper lung zone
What lung zone is this?
Apical lung zone
What lung zone is this?
Mid lung zone
What lung zone is this?
Lower lung zone
How should the ET tube be positioned in the trachea?
5 cm above the carina
What is radioactive decay?
A spontaneous process by which an unstable nucleus goes from a level of higher energy to lower energy.
What are Primordial radioactive materials?
Radionuclides that have been around since the earliest times of our solar system. Their long half lives enable us to detect them today.
What are Cosmogenic radioactive materials?
Radionuclides formed by radiation from space, cosmic rays, interacting with matter. Ex - C14 vs C12 –> carbon dating
What are Anthropogenic radioactive materials?
Radionuclides occurring in the environment as a result of human activities including nuclear medicine, electricity generation by nuclear power stations, and nuclear weapons testing.
Two types of radiation with examples
Non-ionizing = Relatively harmless.
Ex –> Visible light, infrared radiation, microwaves, radio waves, some medical imaging like ultrasound/MRI
Ionizing = HARMFUL, can cause cellular injury. Removing orbital electrons from matter.
Ex –> x-rays, gamma rays, as wellas alpha and beta particles.
What is the systematic approach to assessing a CXR?
Airways
Bones
Cardiac silhouette
Diaphragm
Effusions
Fields (lines, tubes, devices, surgeries)
What things should be done during the pre-operative workup?
Review:
Medical history
Surgical and anesthetic history (including familial)
Medications (allergies, latex, herbals, OTC)
Social history (Smoking, substance use, alcohol intake, vaping, steroids)
Non-reassuring physical exam airway findings
Relativley long upper incisors, prominent overbite, Mallampati of III or IV, highly arched or very narrow palate, patient can’t touch tip of chin to chest.
When is a CXR recommended for an obese patient?
BMI greater than 40. Morbid obesity
What does the STOP-Bang questionnaire screen for?
Sleep apnea. Less than 3 –> low risk, 3 or greater –> High risk
Why should corticosteroid therapy be continued preoperatively for a CNS tumor?
Reduces CSF production and cerebral edema
What should be done for a patient with a MET score of less than 4?
This indicates they have poor functional capacity, further assessment needs to be done
May need referral to cardiologist and cancelectomy
When should a serum creatinine level be drawn regardless of history?
All patients over than 50
True or false:
An EKG should be drawn on a healthy patient with no risk factors undergoing an intermediate risk surgery?
False, must also have one risk factor.
Healthy patients undergoing a high risk surgery require an EKG.
When should a CBC be drawn?
Patients with hematologic disorders, vascular procedures, chemo, and sickle cell status
When should a Hemoglobin and Hematocrit be drawn?
Hematologic malignancy, recent radiation or chemo, renal disease, anticoagulant therapy, procedure with moderate to high risk blood loss, systemic disorders (cystic fibrosis, renal failure, liver failure)
When should a White blood cell count be drawn?
Leukemia and lymphomas, recent radiation or chemo, suspected infection, aplastic anemia, hypersplenism, autoimmune collagen vascular disease
Heat transfer involving electromagnetic waves
Radiation
Heat transfer that occurs by physical contact between objects
Conduction
Heat transfer due to the movement of matter from one location to another
Convection
Electromagnetic waves with an increased frequency and decreased wavelength are _______ energy waves
high
Electromagnetic waves with an decreased frequency and increased wavelength are _______ energy waves
low
A spontaneous process by which an unstable nucleus goes from a level of higher energy to a level of lower energy.
Radioactive decay
If you have a radioactive material with a high decay constant, this means this is _________ radioactive
more
Three things that can happen to cells hit by ionizing radiation
- Enzymes may be unable to repair the cell and it dies
- Enzymes correctly repair the cell
- Enzymes incorrectly repair the damaged DNA resulting in chromosomal aberrations
5 physical characteristics of ionizing radiation
Mass, energy, velocity, charge, and origin
What is the equivalent dose formula (Sv)
Absorbed dose (Gy) x radiation weighting factor (WR)
What is the recommended maximum radiation exposure for a pregnant anesthesia provider?
500 mRem or 5 mSv for the entire gestation period or less
What is the recommended maximum radiation exposure for an anesthesia provider?
5,000 mRem or 50 mSv per year or less
What type of radioactive decay are we most worried about as anesthesia providers?
Alpha and beta particle decay
What should you do if you feel like you need a pre-operative test ordered but its not necessarily indicated?
DO IT. You are the provider and need to do what you feel is best for the patient
How do you test a patients thyromental distance?
Measure the distance from the bottom of the patients chin to the thyroid notch.
A distance of 7 cm or 4 finger breadths is a reassuring sign for intubation
Why is knowing a patients BMI or IBW important in anesthesia?
This helps us gauge how much anesthetic a patient will need. KNOW FORMULAS
You see bright white lines outlining the pleura on CXR. You know this may indicate ___________ ___________
Pleural effusion
Your patient is scheduled for a total knee replacement, upon physical assessment you notice a blood pressure of 155/96. What is your next step?
Ask patient if they are usually hypertensive and what a normal blood pressure is for them. Many times patients will present with increased BP’s due to anxiety and stress
An abnormal lab value comes back for your next case that your feel uneasy about. The surgeon reassures you that they look fine, so you shouldn’t worry and to start setting up for the case. What should you do?
You have ultimate say. If you don’t feel surgery is safe, don’t do it
