Oral Boards Flashcards
(131 cards)
What are the signs of venous air embolism? What is the treatmfent algorithm?
Symptoms: decreased ETCO2, decreased O2 saturation, hypotension, “sporadic roaring sounds” on precordial doppler, and a “millwheel murmur”
Treatment algorithm:
1) Call for help and code cart
2) Turn FiO2 to 100%
3) Stop source of air entry by flooding wound with irrigation, compressing proximal vein if possible, and using bone wax
4) Attempt to aspirate air through CVP catheter
5) Provide cardiovascular support with fluid, vasoconstrictors, and inotropes
6) Treat bronchospasm with beta-2-agonists
- Reflex bronchospasm may occur with entry of air into PA
7) Consider positioning patient with left side down (left lateral decubitus) to prevent air from entering the PA
What are the signs of anaphylaxis? What are the common causative agents? What is the treatment algorithm?
Symptoms: hypotension, bronchospasm, high peak-airway pressures, decreased breath sounds, tachycardia, urticaria
Common causes: NMBs, antibiotics, latex products, IV contrast
Treatment algorithm:
1) Call for help and code cart
2) Ventilate with 100% O2
3) Turn off any infusions and inhalational agents
4) Open IV fluids/give fluid bolus
5) Give IV epinephrine (10 - 100 mcg)
- Alpha agonist activity causes vasoconstriction and reverses hypotension
- Beta agonst activity relaxes bronchial smooth muscle and decreases the release of inflammatory mediators
6) Give corticosteroids, anti-histamines, H2-blocker
7) Support hemodynamics
8) Consider:
- Repeating Epi dose until satisfactory BP is reached
- Vasopressin (1-2 units IV) if pt remains hypotensive after repeated doses of epi
- Check tryptase levels: 1st hr, 4 hrs, 24 hr post-reaction
What are the signs of unstable bradycardia? What is the treatment algorithm?
Symptoms: HR less than 50 bpm with hypotension, AMS, shock, chest discomfort, or acute heart failure
Treatment algorithm:
1) Call for help and code cart
2) Turn FIO2 to 100% and verify that oxygenation/ventilation are adequate
3) Give atropine (0.5 mg IV, repeated up to 3 mg total)
4) Stop any form of surgical stimulation
5) If atropine ineffective:
- Start epi (2-10 mcg/min) or dopamine (2-10 mcg/min) infusion
- Start transcutaneous pacing
6) Consider:
- Turning off volatiles if pt remains unstable
- Assess for drug induced causes (B blockers, Ca channel blockers, digoxin)
- Call for expert cardiology consult
What rhythms during cardiac arrest are considered non-shockable? What is the treatment algorithm?
Non-shockable rhythms: asystole and PEA
Treatment algorithm:
1) Call for help and code cart
2) Place pt supine on backboard
3) Turn FIO2 to 100% and turn off volatiles
4) Start CPR and assessment cycle:
- Perform CPR (“hard and fast” 100 compressions/min)
- Give epi (1 mg IV) every 3-5 minutes
- Assess rhythm every 2 minutes and change compression provider
5) Consider:
- ROSC if ETCO2 > 40 mm Hg
- H’s and T’s as causes
What are the “H’s and T’s” of cardiac arrest?
Hydrogen ions (acidosis) Hyper- or Hypo-kalemia Hypothermia Hypovolemia Hypoxia Hypoglycemia Tamponade Tension pneumothorax Thrombosis Toxins
What is the treatment algorithm for severe hyperkalemia?
1) Calcium gluconate or calcium chloride
2) Insulin (10 units regular IV) with 1-2 amps D50W
3) Sodium bicarbonate if pH under 7.2 (1-2 mEq/kg slowly)
What rhythms during cardiac arrest are considered shockable? What is the treatment algorithm?
Shockable rhythms: pulseless Vtach and Vfib
Treatment algorithm:
1) Call for help and code cart
2) Place pt supine on backboard
3) Turn FIO2 to 100% and turn off volatiles
4) Start CPR and assessment cycle:
- Perform CPR (“hard and fast” 100 compressions/min)
- Defibrillate (biphasic 120-200 Joules)
- Give epi (1 mg IV) every 3-5 minutes
- Consider giving amiodarone for refractory VF/VT (300 mg first then 150 mg)
- Assess rhythm every 2 minutes and change compression provider
5) Consider:
- ROSC if ETCO2 > 40 mm Hg
- H’s and T’s as causes
What defines a failed airway? What is the difficult airway algorithm? What is the incidence of “cannot ventilate, cannot intubate”? What is the incidence of difficult DL?
Failed airway = 2 unsuccessful attempts
Treatment algorithm:
1) Call for extra help
2) Get difficult airway cart and video laryngoscope
3) Bag-mask ventilate with 100% O2
4) Figure out if ventilation is adequate
If ventilation is NOT adequate
- optimize ventilation by repositioning pt, using oral/nasal airway, two-handed masking
- check that equipment is proper and working
- attempt to place LMA
- attempt intubation via video laryngoscopy
- surgical airway
If ventilation IS adequate
- take time to consider other options or even waking pt up
“Cannot ventilate, cannot intubate” occur 1 in 5,000 cases
Difficult DL occurs in up to 10% of cases
What is the treatment algorithm for intra-op hemorrhage?
1) Call for help and code cart
2) Open IV fluids and assess for adequate IV access
3) Turn FIO2 to 100% and turn off volatiles
4) Call blood bank and activate massive transfusion protocol (4 FFP: 4 PRBC: 1 Cryo: 1 Plt) - can give uncrossmatched type O blood if crossmatched not available
5) Request rapid infuser or pressure bags
6) Discuss plan with surgical team and consider packing/closure
7) Keep pt warm
9) Send labs to assess for coagulopathy and electrolyte disturbances (hypocalcemia and hyperkalemia)
10) special populations:
- Obstetric (empirical administration of 1 pool of cryo)
- Trauma (give TXA 10 mg/kg q3h)
- Non-surgical bleeding (consider recombinant Factor VIIa 40 mcg/kg)
What is your differential diagnosis for intraop hypotension?
1) Pulmonary: hypoxia, hypercarbia, tension pneumo
2) Hypovolemia: fluid deficit, acute blood loss
3) Cardiac: arrhythmia, HF, MI, tamponade
4) Shock: hypovolemia, cardiogenic, septic
5) Surgical compression
6) Embolus: pulmonary, air, fat, amniotic
7) Electrolyte/hormonal: hypoglycemia, hypocalcemia, hypermagnesemia, adrenal insufficiency
8) Anaphylaxis
9) Deep anesthesia
10) Hypothermia
11) Sympathetic blockade or neuraxial block
12) Venodilation
13) Laparoscopy: hypercarbia, increased vagal tone, compression, venous gas embolism
What are the side effects of lithium treatment? How would a pt being on lithium effect your anesthetic management?
Side effects: polyuria, DI, skeletal muscle weakness, wide QRS, AV block, hypotension, cognitive changes, ataxia, seizures
Anesthetic management:
- Check lithium level pre-op
- Avoid drugs that lead to toxicity (thiazide diuretics, NSAIDs, ACE inhibitors)
- Monitor anesthetic depth and neuromuscular blockade (lithium can decrease MAC requirements and potentiate NMB)
How should you evaluate a pt for possible airway obstruction? How would you interpret flow-volume loops?
Evaluation:
- Determine history and severity of symptoms
- Exam pt in multiple positions (supine vs prone vs upright)
- Review imaging to assess degree of airway compression
Flow-volume loops:
- Fixed obstruction - decreases both inspiratory and expiratory components
- Extrathoracic obstruction - decreases inspiratory component
- Intrathoracic obstruction - decreases expiratory component
What are the risks of non-obstetric surgery in a pregnant pt? When is the safest time to perform surgery?
Risks to the mother:
- Failed intubation
- Pulmonary aspiration
- Hemorrhage
- Infection
- Thromboembolism
Risks to the fetus:
- Preterm labor/delivery
- Teratogenesis
- Fetal hypoxia
- IUGR
- Miscarriage
Ideal time for surgery is 2nd trimester
- Avoids miscarriage and teratogenesis of 1st trimester and risk of preterm labor in 3rd trimester
What is the utility of prophylactic glucocorticoids in pregnant patients undergoing non-obstetric surgery? When should they be given?
Prophylactic glucocorticoids have been shown to significantly decrease the incidence of:
- Respiratory distress syndrome
- Intraventricular hemmorhage
- Neonatal death
Current recommendation is to give a single course of glucocorticoids between weeks 24 and 34, when there is a significant risk of preterm labor
What are the signs/symptoms of DKA? What is the physiologic basis? How is it diagnosed? What is the treatment?
Signs/symptoms: high blood glucose, abdominal pain, nausea/vomiting, AMS
Due to absolute or relative deficiency of insulin that results in ketone acids in the blood
- Hyperglycemia, glucosuria, dehydration, acidosis, and electrolyte imbalance
Diagnosis:
- Serum ketones over 7
- Serum bicarbonate under 10
- pH under 7.25 (check ABG and determine anion gap [(Na+) + (K+)] - [(Cl-) + (HCO3-)] , as usually an increased anion gap metabolic acidosis in DKA)
Treatment:
- Fluid resuscitation
- 10 to 20 units of insulin followed by infusion to reduce glucose by 50-75 mg/dL/hr (too fast and you will get cerebral edema)
- Add 5% dextrose to insulin infusion when blood glucose reaches 250 (to prevent hypoglycemia and provide energy source)
- Replace potassium, phosphate, and magnesium
- Sodium bicarbonate to correct severe acidosis
- Monitor for closing of the anion gap
What is the acronym for diagnosing obstructive sleep apnea?
STOP-BANG: Snoring (loud) Tiredness (daytime) Observed apnea (during sleep) Pressure (high BP) BMI over 35 Age over 50 Neck circumference over 40 cm Gender (Male)
Less than 3 = low risk
More than 3 = high risk
More than 5 = high risk of mod-severe OSA
What is the proper way to anesthetize the airway for an awake intubation?
Administer nebulized lidocaine to the oropharanx (numbs above epiglottis)
Superior laryngeal nerve block (numbs epiglottis to vocal cords)
Trans-tracheal recurrent laryngeal nerve block (numbs below vocal cords)
Care must be taken in situations in which pts do not have normal anatomy or underlying tumors
What are the signs/symptoms of intra-op bronchospasm? What should you do? How should it be treated?
Signs/symptoms: hypoxia and expiratory wheezing
Immediate steps:
- Turn FIO2 to 100%
- Auscultate chest
- Hand ventilate to check compliance
- Check airway pressures and check circuit/machine
- Take pt out of trendelenburg position
Treatment:
1) 100% FIO2
2) Increase volatile concentration to deepen anesthetic
3) Administer albuterol via ETT
4) Small dose of epi
What are some indications for intubation?
- Unstable vital signs
- Inability of pt to protect own airway
- Respiratory rate over 35
- Vital capacity under 15 mL/kg
- NIF less than 20-25 cm H2O
- PaO2 less than 60 on 50% FiO2
- A-a gradient over 350 on 100% FiO2
- PaCO2 over 55
What are some criteria for extubation?
- Stable vital signs
- Minimal end-expiratory concentration of volatile
- Adequately reversed NMB (sustained head lift over 5 seconds)
- Adequate gag and cough
- Awake and following commands
- PaO2 over 60 and PaCO2 under 55 on 40% FiO2
- A-a gradient under 350 on 100% FiO2
- FVC over 10-15 mL/kg
- FEV1 over 10 mL/kg
- Tidal volume over 4-6 mL/kg
- NIF greater than 20 cm H2O
How would you treat intra-op laryngospasm?
1) Turn off any inhaled agents and turn to 100% FiO2
2) Remove any stimulating factors
3) Apply jaw thrust
4) Apply CPAP via tight mask fit
5) Increase depth of anesthetic via IV agent
6) Call for help
7) Give rapid-acting muscle relaxant
8) Attempt to intubate from above if laryngospasm ongoing
9) Eventually, hypoxia results in less vigorous glottic closure and reversal of laryngospasm
What are the treatment options for post-op stridor?
1) Emergent intubation if pt unstable
2) Oxygen via facemask
3) Sit pt up
4) Nebulized racemic epinephrine
5) Heliox (70% helium, 30% oxygen)
What are the indications for a bronchial blocker? What are the limitations?
Indications:
- Critically ill pt in whom it may not be feasible to place a DLT
- Intubated pts
- Pts with known/suspected difficult airway
- Expected post-op ventilator
Limitations:
- Slow lung deflation/re-inflation times
- Difficulty suctioning of operative lung
During one-lung ventilation, what is treatment algorithm for hypoxia?
- Check position of DLT with fiber-optic scope
- Bronchodilators and suctioning
- CPAP to the non-dependent, non-ventilated lung (decreases shunt from atelectasis)
- PEEP to the dependent, ventilated lung
- Occluding the PA of the non-ventilated lung
- If severe and emergent, switch back to two-lung ventilation!