Basic anesthesiology Flashcards
What is the Dibucaine number?
A high number tells you that a person has a normal pseudocholinesterase. Dibucaine inhibits normal pseudocholinesterase. The amount that it inhibits is the amount that you have of the normal receptor. Dibucaine 80 is normal. Numbers < 30 mean you have an abnormal enzyme leading to prolonged succinylcholine
What drugs are broken down by pseudocholinesterase?
Succinylcholine, cocaine, procaine, and mivecurium
What inhaled agents are most affected by a R to L shunt?
The least soluble. This is because the Pa to Pi ratio takes longer to equilibrate due to the shunt and the fact that less blood is taken up into the alveoli
Who is at risk for ulnar neuropathy? What are the signs/symptoms? How do you diagnose it?
- Males, thin/obese people
- Decreased sensation to the 4th/5th digits, atrophied intrinsic hand muscles, inability to oppose the 5th digit
- Diagnosis with EMG: tells exact location of nerve injury, it takes about 4 weeks to obtain abnormal nerve firing (sign of denervation) or nerve conduction (does both motor and sensory)
What food group is associated with an increased risk for latex allergy?
tropical fruits
What is the treatment for organophosphate poisoning?
- Atropine
- Diazepam
- Pralidoxime (binds out the organophosphate)
What is the minimum amount of time you have to wait to do an elective surgery in each of these situations?
- Recent MI with NO intervention
- Recent MI with angioplasty
- Recent MI with bare metal stent
- Recent MI with drug eluding stent
- 60 days
- 14 days
- 30 days
- 6 months
What can you given in children who are at risk for emergence delirium? What age group is at risk?
- Dexmedetomidine, fentanyl, ketamine, propofol
2. Age 2-5
What are the two locations of non shivering thermogenesis in adults? When does non-shivering thermogenesis not apply?
- brown fat
- skeletal muscle
- Non-shivering thermogenesis does not occur under GA
Which nerve is at risk for damage during brachial artery line placement? What are other associated complications?
Median nerve injury
thrombosis
infection
What is the gold standard marker for liver function?
PT/INR
What are the NPO guidelines?
2 hours: clears
4 hours: breast milk
6 hours: non-milk formula, non-human milk, light snacks
8 hours: full meals
What is the gold standard test for detection of malignant hyperthermia?
halothane-caffeine contracture test
What are the two most common things that delay outpatient surgical discharge?
- PONV
2. Uncontrolled pain
What is a hydroxyethyl starch? What effects does it have on the body? Explain general dosing differences between hetastarches and tetra starches.
- hydroxyethyl starches are synthetic colloids that have groups added on to them to increase availablity and half life in the intravascular space. They are relatively CI in renal failure
- These can interfere with plt function, decrease VIIi and vWF
- Hetastarches have more subsitutions than tetra starches, so the dosing for hetastarches is lower
Who is at risk for negative pressure pulmonary edema? What is the timeline of occurrence?
- younger people, as they have stronger muscles and can generate a greater negative inspiratory force against obstruction
- Occurs immediately following relief of the obstruction
What hormone increases hepatic artery blood flow? How does it do this?
Glucagon decreases hepatic artery resistance
What effects does vasopressin have on hepatic blood flow?
- Decreases portal venous resistance
- Increases hepatic artery resistance
* * this is good for people with increased portal venous pressures and systemic hypotension
Describe hepatic blood flow
- The liver gets 25% of our cardiac output
2. The hepatic artery provides 25% of the liver’s blood supply, while the portal vein provides the other 75%
What is the max dose of epinephrine with and without lidocaine?
- Without lidocaine: 5mg/kg
2. With lidocaine: 7 mg/kg, because the epi makes it more acidic, which means slower onset
What is the max dose of lidocaine in tumescence? Epinephrine?
- 55 mg/kg
2. .055 mg/kg
How can you cause median nerve injury during positioning? What is at risk due to constant BP cuff cycling?
- Forced flexion of the elbow following muscle relaxant
2. constant blood pressure cycling can cause problems with the radial nerve as it is in the musculospiral groove
What is the triad of symptoms seen with intra-operative vision loss? What are the two types of ION?
- sluggish pupils
- visual field defects
- PAINLESS vision loss
- Anterior (cardiac) and posterior (spine)
What should you base your dosing on for NDMB and DMB?
- Non-depolarizers: use IBW
2. Succinylcholine: use TBW
What medication should you avoid in ECTs?
Lidocaine, because it shortens seizure duration
When should you avoid Midazolam in the pregnancy period?
Third trimester and during deliver: it can result in “floppy baby” syndrome
What three nerve injuries are associated with LMA placement?
- recurrent laryngeal nerve
- Lingual nerve
- hypoglossal nerve
How long should you wait to place an epidural or deep nerve catheter in a patient receiving 5,000 U of subq heparin BID or TID?
4-6 hours
What is true regarding fentanyl administration in the pre operative period as a pre-medication?
In patients without prior chronic pain, it can lead to increased sensitization to pain. Use solely in patients who have chronic pain issues
What value is NOT used in the Child-Pugh score?
Creatinine (because urine stinks)
What values are used in the MELD calculation?
INR, Creatinine, Bilirubin, Dialysis
What precaution do you have to take with local anesthetic administration following tumescence?
- Levels of injected LA may peak around 12-18 hours
2. Care must be taken when injecting further levels of LA
Describe the difference between moderate and deep sedation.
Moderate sedation: patient is breathing spontaneously and requires NO intervention
Deep sedation: patient requires some intervention and respirations may not be adequate
Describe the different ASA statuses
ASA 1. normal healthy patient
ASA 2. mild disease with no limitations
ASA 3. severe disease
ASA 4. severe systemic disease that is a constant threat to life
ASA 5. Patient will not survive unless they receive surgical intervention
ASA 6. Brain dead patient
How would you describe the inheritance pattern of MH?
Autosomal dominant with variable penetrance
What nerves are involved in laryngospasm?
- recurrent laryngeal nerve is stimulated, which causes reflex closure of the vocal cords by the RECURRENT LARYNGEAL NERVE
What lab test should be done on a patient who is taking long term dantrolene?
LFTs, chronic use of dantrolene can lead to liver failure
What are the spirometry changes seen with aging?
Increased FRC, RV, and CC due to loss of lung elasticity, increase in chest wall rigidity, and flattening of the diaphragm
What dose of propofol should be given to an unstable patient for induction? What is another agent that can be used instead?
- 0.4 mg/kg
2. Consider ketamine! Interestingly enough, in the unstable patient, increase in ICP is NOT a CI to using Ketamine
What is the most accurate method for diagnosing resuscitation status?
Pulse pressure variation
What cases are associated with the highest rates of intra-operative awareness?
- cardiac
- obstetric
- trauma
Which drug can interfere with pacemaker activity?
Succinylcholine. It can cause muscle fasciculations that can be interpreted as electrical activity that would then inhibit the pacemaker from working. It can also possible cause a shock if it has defibrillating capacity
What is the difference between schedule 1 and schedule II drugs?
Schedule 1: High abuse potential with no medical use found
Schedule 2: high abuse potential, severe physical or psychological dependence
What is the triad of symptoms for fat embolism syndrome?
- petechiae
- Hypoxia (respiratory insufficiency)
- CNS involvement (seizure or AMS)
What are the absolute CI to ECT therapy?
- Recent MI (4-6 weeks)
- Recent stroke ( < 3 months)
- Recent intracranial surgery ( < 3 months)
- intracranial mass or lesion
- unstable C spine
- Pheochromocytoma
What is the best predictor for difficult airway? Mallampati vs. lower bite test?
Lower bite test
Who is a good candidate for awake fiberoptic intubation?
A stable patient who you foresee having difficulties with mask ventilation and intubation
Where does A-flutter originate? Why will adenosine not work in termination of A flutter?
A flutter starts around the tricuspid valve. Adenosine blocks the AV node, which is located in the RA, not by the valve. It will slow A flutter, but not terminate it.
What are the respiratory changes seen in obese patients?
Increased chest wall rigidity, decreased ERV, decreased FRC, increased 02 consumption, increased RR
What are the respiratory changes seen in the elderly?
Increased closing capacity above the FRC, which leads to atelectasis. Unchanged TLC, Increased RV, decreased VC
