Advanced True Learn #2

Question 1

Hoow do gabapentoids create relief on a molecular level?

Answer 1

The gabapentinoids (gabapentin and pregabalin) result in a

1. Decreased release of glutamate*, *norepinephrine*, and *substance P (all chemicals that are considered pronociceptive) via their binding to voltage-gated calcium channels within the central nervous system.

Question 2

The most common cause of death from subarachnoid hemorrhage (SAH) within the first 24 hours?

Answer 2

Rebleeding (Peaks at 24 hours)

Question 3

When does vasospasm events occur most commonly after SAH?

Answer 3

Vasospasm typically develops by the third day and peaks within 5-10 days, resolve over 10-14 days

2/3 of SAH patients vasospasm

Question 4

What blood product should be used to minimize dilutional coagulopathy?

Answer 4

Fresh frozen plasma should be used to reduce the risk of dilutional coagulopathy during massive transfusion.

Question 5

With obstructive disease, who responds the most to bronchodilator therapy?

Answer 5

Moderate disease

Healthy, severe, and mild disease = Mild Response to bronchodilators

Question 6

The most common cause of sudden stridor 24 to 96 hours post thyroidectomy is what?

Answer 6

The most common cause of sudden stridor 24 to 96 hours post thyroidectomy is hypocalcemia.

Question 7

Post Op Thyroidectomy

Stridor and difficulty with phonation.

Diagnosis?

Answer 7

Damage to the recurrent laryngeal nerve is more likely to cause early stridor and difficulty with phonation.

Question 8

Post Op Thyroidectomy

Change in Pitch of Voice noted on extubation

Diagnosis?

Answer 8

Damage to the superior laryngeal nerve would cause a change in the pitch of the patient’s voice as the superior laryngeal nerve innervates the cricothyroid muscle.

Question 9

Why does phosphorous and glucose levels drop with TPN?

Answer 9

Total parenteral nutrition carries a significant glucose load that increases the pancreatic secretion of insulin.

Insulin causes several metabolic effects, including the cellular uptake of glucose and phosphate

Question 10

What are 3 scenarios that low phosphate levels are encountered?

Answer 10

1. Refeeding syndrome
2. Diabetic ketoacidosis
3. Large decreases in PCO2 (e.g., hyperventilation during hypercarbic respiratory failure)

Question 11

What is Refeeeding Syndrome?

Answer 11

Refeeding syndrome is a term that refers to various metabolic abnormalities that may complicate carbohydrate administration in subnourished patient populations.

Refeeding syndrome (a constellation of fluid and electrolyte disorders, most notably severe hypophosphatemia) after starting TPN occurs frequently in patients who have had poor or no nutritional intake for >72-96 hours. Patients at high risk for refeeding syndrome also have reduced levels of prealbumin (< 10 mg/dL).

Hypophosphatemia is the most well known, and perhaps most significant, element of the refeeding syndrome, and may result in sudden death, rhabdomyolysis, red cell dysfunction, and respiratory insufficiency.

Question 12

Hypokalemic periodic paralysis:

Inheritance pattern?

What channel is affected?

Answer 12

Hypokalemic periodic paralysis is a rare autosomal dominant disorder resulting in an abnormal dihydropyridine sensitive calcium channel

Question 13

Gastroschis vs. Omphalocele

Which is more common?

Answer 13

The incidence of gastroschisis is 0.4-3 per 10,000 births, compared to the more common omphalocele, occurring in 1.5-3 per 10,000 births

Question 14

What is the Pentalogy of Cantrell?

Answer 14

1) Omphalocele
2) Ectopia cordis (heart partially or completely outside thorax)
3) Ventricular septal defect or ventricular diverticula
4) Sternal cleft
5) Anterior diaphragmatic hernia

Question 15

What is the best test for carcinoid syndrome diagnosis?

Answer 15

urine 5-hydroxyindoleacetic acid. (Urine 5-HIAA)

Question 16

What is the formula for determining how much sodium bicarbonate to give?

Answer 16

Initial sodium bicarbonate (mEq) =

[0.3 * patient weight (kg) * (24 – patient HCO3 mEq/L)]/2

OR

The amount of sodium bicarbonate that will normalize the pH in most patients can be approximated using the formula:

Sodium bicarbonate (mEq) = 0.2 * (kg) * base deficit

Question 17

Butorphanol mechanism?

Answer 17

Butorphanol is a mixed opioid agonist-antagonist with partial agonism of the mu and kappa opioid receptors.

If it is used with opioid full agonists, the partial agonist properties of butorphanol will behave as an antagonist. The effect of butorphanol leads to pain relief but does not lower the seizure threshold.

Question 18

What are the absolute contraindications to ECT?

Answer 18

pheochromocytoma

Recent stroke

Recent intracranial surgery

Intracranial mass lesion

Recent MI

Unstable cervical spine

Question 19

What physiological changes are seen in ECT?

Answer 19

The first 5-10 second tonic phase of the seizure is characterized by parasympathetic activity with bradycardia and hypotension.

The second clonic phase of the seizure lasts up to 10 minutes and is characterized by sympathetic activation with hypertension and tachycardia.

Question 20

How soon do you have to wait after an MI to have ECT?

Answer 20

American College of Cardiology-American Heart Associate guidelines suggest a 4-6 week delay in elective surgery, such as ECT, after an uncomplicated myocardial infarction

Question 21

What is the osmolarity difference of LR and Plasmalyte?

Answer 21

The osmolarity of Plasmalyte is 294 mOsm/L, which is iso-osmolar compared to the lactated Ringer solution, which is hypoosmolar (273 mOsm/L).

Question 22

How do you identify the Lateral Femoral Cutaneous nerve by landmark technique?

Answer 22

The LFCN may be anesthetized by injecting local anesthetic:

2-2.5 cm medial and 2-2.5 cm inferior to the ASIS and above and below the fascia lata.

Question 23

What position do you put the patient should you suspect you have an air lock on TEE for Venous Air Embolism?

Answer 23

Left Lateral Decubitus Position

Place surgical site below heart (if able)

Lower the head position & compress the jugular veins (if surgical site above the neck)

Reposition the patient into left lateral decubitus, trendelenberg, or left lateral decubitus head down position (controversial - poor evidence & often impractical to do in the OR)

Question 24

What are the benefits to adding Epinephrine in Locals Anesthetics?

Answer 24

1. Increases the block duration and intensity
2. Decreases systemic absorption due to its vasoconstrictive properties
3. Direct analgesia via its α2-adrenergic agonist properties

Question 25

What is the max dose of Mepivacaine with and without epinephrine?

Answer 25

5 mg/kg without epi

7 mg/kg with epi

Question 26

What is the max dose of Ropivacaine with and without epinephrine?

Answer 26

3 mg/kg without epinephrinie

3.5 mg/kg with epinephrine

Question 27

Tracheoesophageal fistulas (TEFs) are the result of a midline defect during the development of the fetus.

Other defects occur as part of the VACTERL association: Vertebral, Anal, Cardiac, Tracheal, Esophageal, Renal, and Limb.

Of these associatons, which is most common?

Answer 27

The most common defect associated with TEF is a cardiac defect.

20-35% of the time

Question 28

What physiological derangements can be found to negative affect SSEP?

Answer 28

Evoked potentials are sensitive to physiologic changes including:

hypotension

Temperatue - hypothermia + hyperthermia

hypoxia

anemia

**Bad SSEP –> Fix one of these if you can**

Acid-base balance has not been shown to negatively impact SERs.

Question 29

When do neurological findings of evoked potential monitoring become clinically signficant (Flow / mass)?

What critical value can anesthesia drop this to?

SSEP above what value may not be clinically affected?

Answer 29

Clinical neurologic findings become abnormal below a cortical blood flow of 25 ml/min/100g of brain tissue.

Anesthesia may lower this critical value to as low as 15 ml/min/100g of brain tissue.

Somatosensory evoked potential recordings are not affected until cortical blood flow falls below 20 ml/min/100g of brain tissue.

Question 30

What is a positive apnea test utilized in the ICU?

Answer 30

To determine whether or not there is spontaneous ventilation, an apnea test is performed. This is done by removing the patient from the ventilator while providing oxygen insufflation at the level of the carina. If the patient does not take a spontaneous breath by the time their PaCO2 reaches 60mmHg (or 20 mmHg above baseline), the apnea test is declared positive.

Question 31

What is the pathology associated with malignant hyperthermia?

Answer 31

Malignant hyperthermia-susceptible patients have RYR1 defects that, in the presence of a triggering agent (succinylcholine or any volatile anesthetic), cause prolonged opening of the channel which leads to sustained muscle contraction.

Question 32

What anti-arrythmics are contraindicated in the setting of Malignant Hyperthermia?

Answer 32

Antiarrhythmics may be necessary, but CCBs are contraindicated when a patient has been treated with dantrolene.

Although the exact mechanism for interaction is unknown, dantrolene can decrease the release of calcium from the SR resulting in an additive or synergistic effects with calcium channel blockers.

Arrhythmias, myocardial depression, worsening hyperkalemia, and severe cardiovascular collapse have all been reported in animal models and humans.

Question 33

Each 20 mg vial of dantrolene contains how many grams mannitol?

Answer 33

each 20 mg vial of dantrolene contains 3 g of mannitol.

Question 34

What is the dose of Dantrolene to treat malignant hyperthermia?

Answer 34

Assign several people to prepare 2.5 mg/kg IV Dantrolene or

Initial: 2.5 mg/kg

Monitor patient continuously

Give repeat doses of 1 mg/kg until symptoms subside or a cumulative dose of 10 mg/kg is reached

Question 35

Symptomatic patients with serum Na+ = 120 mEq/L should have the serum osmolality corrected with what therapies?

Answer 35

1. 3% hypertonic saline (not normal saline)
2. Loop diuretics (Furosemide, are utilized to eliminate excess free water and treat the sodium deficit.)

Question 36

What is the dose of hypertonic saline?

Answer 36

Asymptomatic: IV: Hypertonic saline: 3% NaCl: 50 mL bolus over at least 5 minutes

Symptomatic: IV: Hypertonic saline: 3% NaCl: 100 mL over 10 minutes; if symptoms persist, may repeat up to a total of 3 doses over a period of 30 minutes (Sterns 2019; Verbalis 2013).

Alternatively, some experts recommend 150 mL over 20 minutes up to a total of 2 doses while measuring serum sodium between infusions (ESE/ESICM/ERAEDTA [Spasovski 2014]).

Question 37

What is anesthesia dolorosa?

Answer 37

Anesthesia dolorosa is pain in an area that lacks sensation, often involving the face.

Question 38

When is anesthesia dolorosa most seen?

Answer 38

Anesthesia dolorosa is a feared complication of neurolytic blocks for the treatment of trigeminal neuralgia (eg, radiofrequency rhizotomy).

It can also be in the distribution of one of the divisions of the trigeminal nerve or the occipital nerve. Anesthesia dolorosa is difficult to treat and is generally considered to be nonreversible.

Anticonvulsants, antidepressants, opiates, and psychological support are the mainstays of management. Motor cortex stimulation has been shown to, have some promise in preliminary studies. Anesthesia dolorosa after the neurolytic treatment of trigeminal neuralgia is often accompanied by eye pain.

Question 39

The majority of patients with myelomeningocele also have what pathology?

Answer 39

Chiari II

Hydrocephalus

The majority of patients with myelomeningocele also have Chiari II malformation, which involves herniation of the brainstem through the foramen magnum and frequently hydrocephalus secondary to blockage of the fourth ventricle.

Question 40

What are the three phases to Liver Transplantation?

Answer 40

The preanhepatic stage begins with incision and ends with cross-clamping of the major vessels of the liver (portal vein, hepatic artery, inferior vena cava, or hepatic vein).

The anhepatic stage starts with cross clamping and continues until anastomosis are made and perfusion restarts – in other words from occlusion of vascular inflow to start of graft reperfusion.

The neohepatic phase begins with unclamping of the portal vein when reperfusion of the donor liver starts and continues during hepatic artery, biliary duct anastomosis, and abdominal closure.

Question 41

What is the blood flow & Oxygen contents of portal vein and hepatic artery for liver?

Answer 41

• *Oxygen:**
• 50% Portal Vein & 50% Hepatic Artery*

Blood flow:

1. 75% Portal Vein

2. 25% Hepatic Artery

Question 42

What enzyme is defective in Gilbert’s Disease?

Answer 42

Gilbert syndrome is the most common cause of jaundice in the adult population of the United States and is characterized by a decrease in the activity of the hepatic enzyme

bilirubin glucuronyltransferase

Patients with Gilbert syndrome are said to only have about 1/3 of the normal enzyme activity.

Question 43

What is the gold standard medication and dose for ECT?

Answer 43

The gold standard induction agent is methohexital (1-1.5 mg/kg) because it has less anticonvulsant activity compared with other anesthetic agents.

Question 44

What does Etomidate do to seizure duration for ECT?

Answer 44

Etomidate increases the seizure duration for ECT

Question 45

What does Methohexital effects have on hemodynamics?

Answer 45

Methohexital does have:

1. Cardiovascular depressant effects
2. Lower SVR
   - but the cardiovascular effects occur in a dose-dependent manner

Question 46

How does Methohexital affect seizure duration?

Answer 46

Methohexital does not prolong the seizure duration

Question 47

A blood gas taken from a patient in DHCA shows pH 7.25 and PaCO2 60 mm Hg when run at 37 °C.

If the patient’s temperature is 18 °C, which of the following would be the expected temperature-corrected values?

Answer 47

1. pH is increased by 0.015 for each degree below 37 °C
2. PaCO2 is decreased by 2 mm Hg for each degree below 37 °C

pH = 7.535

PaCO2 = 22

Question 48

Why are PaO2 leves normal in Severe Anemia, CO poisoning and Methemoglobinemia?

Answer 48

PaO2 is not a function of hemoglobin content or of its characteristics, but only of the alveolar PO2 and the lung architecture (alveolar-capillary interface).

This explains why patients with severe anemia, carbon monoxide poisoning, or methemoglobinemia can (and often do) have a normal PaO2.

Question 49

How do volatile anesthetics affect cerebral parameters?

CMRO2, CBF, ICP

Answer 49

Decrease CMRO2

increase CBF

Increase ICP

Question 50

Past 1 MAC how do volatile anesthetics behave on cerebral parameters?

Answer 50

In general, volatile agents produce increases in CBF and ICP with reduction in CMRO2 when given at > 1.0 MAC.

Question 51

For an epidurarl, which has least amount of placental transfer?

Answer 51

2-chloroprocaine has the least amount of placental transfer of all local anesthetics because it is rapidly metabolized in the plasma by plasma cholinesterase.

Question 52

What type of local anesthetic is 2-chloroprocaine?

Answer 52

Ester (One “i”)

Question 53

How do you dose single-shot caudal epidural blocks?

Answer 53

For most standard concentrations of local anesthetics (e.g. 0.125-0.25% bupivacaine or 0.2-0.3% ropivacaine)

Dosing of single-shot caudal epidural blocks in infants and young children is done on a ml/kg basis.

(Dosing for a single-shot block in infants and young children is done on a ml/kg basis since it is volume of local anesthetic that affects the height of the block, not the mg of drug)

Using 0.5 mL/kg of local anesthetic will cover the sacral dermatomes

1 mL/kg will cover up to the low thoracic dermatomes

1.25 mL/kg will cover up to the mid thoracic dermatomes

Question 54

In newborns, the dural sac typically ends at “A” and the conus medullaris at “B”. ?

In adults, the dural sac typically ends at “C” and the conus medullaris at “D”?

Answer 54

In newborns, the dural sac typically ends at S3 and the conus medullaris at L3

In adults, the dural sac typically ends at S1-S2 and the conus medullaris at L1-L2

Question 55

What is the treatment for active bleeding for a Hemophilia A patient?

Answer 55

In the event of active bleeding, cryoprecipitate is typically the product of choice as it contains high concentrations of:

1. factor VIII (Cryo, FFP or Recombinant)

2. fibrinogen

Question 56

HIT Type 1:

Timing?

Clinical picture?

Mechanism?

Answer 56

2-5 days of heparin.

Mild thrombocytopenia & no thrombosis. It is generally not considered clinically significant.

The mechanism behind Type I thrombocytopenia is heparin binding to platelets at GPIb receptors causing the release of ADP, which results in platelet aggregation.

Question 57

HIT Type 2

Timing?

Clinical picture?

Mechanism?

Answer 57

5-9 days after heparin

Severe thrombocytopenia, with platelet counts < 100k or a fall of >30-50% from baseline values over several days.

The mechanism is via IgG-, IgA-, and IgM-mediated antibodies towards heparin and platelet factor 4 (PF4) complexes, which results in platelet activation and clot formation.

About 20% of patients with Type II thrombocytopenia will develop thrombosis due to massive thrombin generation (HIT with thrombosis or HITT)

Question 58

How do you diagnose HIT Type 2?

Answer 58

1) Heparin-induced serotonin release assay (SRA). This is considered the GOLD STANDARD for diagnosis.
2) Enzyme-linked immunosorbent assay (ELISA) specific for heparin and PF4 complexes. Although these patients may have a positive test they do not always go on to develop thrombosis.
3) Heparin-induced platelet activation assay. The table below may serve as a primer for serologically diagnosing HIT type II:

Question 59

What is the half life of Bivalirudin?

Dosing for CPB?

Answer 59

24 minutes

Typical CPB dosing is a 1 mg/kg bolus followed by a 2.5 mg/kg/hr infusion.

Question 60

What does the CAM-ICU questions ask?

Answer 60

The CAM-ICU asks the following:

Is there an acute change in mental status or fluctuating course? (yes/no)

Is the patient inattentive or easily distracted? (yes/no)

Is there an altered level of consciousness or RASS other than zero? (yes/no)

Does the patient experience disorganized thinking? (yes/no)

Question 61

List the confirmatory tests for Brain Death when you cannot perform apnea test or contraindications to apnea test.

Answer 61

1. Crebral angiography
2. Transcranial Doppler
3. Magnetic resonance angiography
4. Computed tomographic angiography
5. Radionuclide brain imaging
6. Electrophysiology such as electroencephalography

Question 62

Phentolamine

Mechanism? (Receptors, Selectivity)

Answer 62

Phentolamine is a short-acting non-selective alpha-1 and alpha-2 antagonist

Question 63

Phentolamine

Duration of action?

Answer 63

10-15 minutes

Question 64

Phenoxybenzamine

Mechanism? (Receptors and Selectivity)?

Half Life?

Answer 64

Phenoxybenzamine is a long-acting non-selective alpha-1 and alpha-2 antagonist

Elimination half-life of 24 hours

It is commonly used in the preoperative treatment of pheochromocytoma. It should be noted that the alpha-2 effects can potentially worsen tachycardia and hypertension (opposite effects of dexmedetomidine).

Question 65

Mirtazapine

Mechanism?

Indication?

Answer 65

Mirtazapine is a selective alpha-2 blocker that is used in the treatment of depression.

Question 66

Prazosin

Mechanism? (Selective? Receptors?)

Answer 66

Prazosin and other drugs in the same class (e.g. terazosin, doxazosin) are selective alpha-1 antagonists with varying lengths of action

Question 67

How do you determine atlantoaxial instability/injury radiographically?

Answer 67

AADI: anterior atlantodental interval

The anterior atlantodental interval is the distance between the atlas and the dens in the midsagittal view.

Greater than 2-3 mm is considered abnormal and is suggestive of atlantoaxial instability or injury.

If instability at the atlantoaxial joint is present, widening will be seen with flexion, as seen in these images.

Question 68

What is ankyloglossia?

Answer 68

Ankyloglossia, or “tongue-tie” is a congenital defect that limits tongue movement.

(See photo)

Question 69

What is the treatment for Pneumocephalus?

Answer 69

Pneumocephalus after craniotomy is a common occurrence with resolution generally occurring at about 2-3 weeks.

Treatment:

1. Supportive/Conservative
2. Bed rest in an upright position
3. High concentration oxygen
4. Avoidance of maneuvers that might increase intrasinus pressure (such as nose-blowing or valsalva maneuver)
5. Antibiotics if there is evidence of meningism.
6. Aspiration of air loculi by neurosurgery (Defintive and if there is tension)

Question 70

What is the risk factors for Acute MR following MI?

Answer 70

1. Advanced age
2. Prior myocardial infarction
3. Infarct extension
4. Inferior or posterior MI (Severe MR is ten times more likely to occur after posterior or inferior wall compared with anterior wall myocardial infarction)
5. Multiple vessel CAD
6. Recurrent ischemia

Question 71

The spread of neuraxial opioids is predicated on what?

Answer 71

The spread of opioids is related to the hydrophilicity and lipophilicity of the opioid.

Fentanyl is very lipid soluble and remains near the spinal level it is injected at, whereas morphine has a wide spread in the CSF.

Question 72

What is pKA influence on onset?

Answer 72

When considering pKa, it is often associated with the speed of onset of the drug, especially local anesthetics.

This is why sodium bicarbonate may be added to some local anesthetic mixtures.

Question 73

What determines duration of action of local anesthetics?

Answer 73

Protein binding is related to the duration of action of LA

Question 74

What determines potency of action of local anesthetics?

Answer 74

Lipid Solubility

Question 75

How does 2,3 DPG affect oxy-hemoglobin curve shifts?

Answer 75

Decreased = Left Shift

Increased = Right shift

Question 76

For pyloric stenosis, what should be your bolus rate for a 4 week old 3 kg neonate?

Answer 76

10 to 20 mL/kg/hr of normal saline with 20 mEq/L of potassium.

For a 3-kg infant, this includes an infusion rate in the range of 30 to 60 mL/hr.

Question 77

How quickly does the temperature change in Malignant Hyperthermia?

Answer 77

The temperature rise in malignant hyperthermia can be as high as 1°C every 5 minutes accompanied by an increase in end-tidal CO2

Question 78

How long will a Bier Block last?

Answer 78

It can provide complete motor and sensory anesthesia for up to approximately 90 minutes with a success rate of 94-98%.

Question 79

After injection for Bier Block, what is the minimum time you must wait?

Answer 79

Following the procedure (or after 20-30 minutes after the local anesthetic was injected if the procedure is short), the tourniquet is then released

Question 80

What medications and doses you use for Bier Block?

Answer 80

Lidocaine is most commonly used; 15-20mL of 2% lidocaine is a fairly standard dose

• Also can use 30-40 mL of 0.5% (More volume but lower concentration)
• Ropivacaine has been described (1.2 and 1.8 mg/kg)

Question 81

Mechanism of how a Bier Block works

Answer 81

1. Blockade of distal nerves is achieved via diffusion of local anesthetic across the vascular bed from veins into capillaries surrounding peripheral nerves and then into vasa nervorum which then produce nerve conduction block
2. Diffusion of local anesthetic into local tissues
3. Tissue acidosis
4. Hypothermia
5. Distal Ischemia - contributes to a degree of anesthesia and analgesia by impairing nerve conduction and motor end plate function. Even without any local anesthetic injection, after 20 minutes of tourniquet time, there is analgesia to pinprick sensation. Local anesthetic, therefore, significantly improves the speed of onset and density of anesthesia but is not the sole cause.

Question 82

Retrobulbar vs. Peribulbar Blocks:

Which is higher incidence of retrobulbar hematoma?

Answer 82

Retrobulbar is higher incidence than peribulbar

Question 83

Retrobulbar vs. Peribulbar Blocks:

Which is higher incidence of globe rupture?

Answer 83

Retrobulbar has higher incidence of globe rupture

Question 84

What is the downside of peribulbar blocks compared to retrobulbar blocks?

Answer 84

Peribulbar blocks have a higher incidence of chemosis but a lower incidence of retrobulbar hematoma when compared with the retrobulbar block.

Chemosis is swelling of the tissue that lines the eyelids and surface of the eye (conjunctiva). Chemosis is swelling of the eye surface membranes because of accumulation of fluid. This symptom is often related to an allergic response.

Question 85

What is the ideal leak pressure of an uncuffed ETT tube in a pediatric patient?

Answer 85

The ideal leak pressure of an uncuffed ETT in pediatric patients is 20-30 cm H2O.

Question 86

If a leak pressure of what level H2O is measured during pediatric case, the ETT should be replaced with a smaller size.

Answer 86

If a leak pressure >40 cm H2O is measured, the ETT should be replaced with a smaller size.

Question 87

A leak pressure of what value H2O may indicate an inadequate seal and may result in an increased risk of aspiration, difficulty providing positive pressure ventilation, and/or inaccurate EtCO2 monitoring>

Answer 87

A leak pressure < 10-20 cm H2O may indicate an inadequate seal and may result in an increased risk of aspiration, difficulty providing positive pressure ventilation, and/or inaccurate EtCO2 monitoring.

Question 88

How do NSAIDS like ketorolac work?

Answer 88

Administration of NSAIDs results in the reversible inhibition of prostaglandin synthesis, which is vital for maintaining renal perfusion.

Normal = Prostaglandins vasodilate the afferent arterioles maintaining renal perfusion.

With the inhibition, the afferent arterioles vasoconstrict, decreasing renal perfusion.

Question 89

What is the gold standard for pulmonary fibrosis diagnosis?

Answer 89

Pulmonary fibrosis requires a biopsy for definitive diagnosis.

A lung biopsy remains the gold standard for diagnosis of IPF. In order to obtain adequate samples, surgical biopsies via thoracotomy or VATs are needed because larger pieces of tissue from multiple sites are required.

Transbronchial biopsies obtained via bronchoscopy are not large enough and can only rule out other causes of similar presentations (e.g. infection, cancer, sarcoidosis).

Question 90

What is the difference in increased Airway resistance vs. Increased Pulmonary Compliance?

Answer 90

Both peak inspiratory and plateau pressure increase when elastic resistance (compliance) increases.

Only peak inspiratory pressure increases when airway resistance increases.

Question 91

What is the differential for elevated peak airway pressures but unchanged plateau pressures?

Answer 91

(Think of obstruction prior to the main bronchioles)

Airway compression
Bronchospasm (Not the tube but the circuit)
Foreign body
Kinked endotracheal tube
Mucus plug
Secretions

Question 92

What is the differential for elevated peak airway pressures and elevated plateau pressures?

Answer 92

Abdominal insufflation
Ascites
Intrinsic lung disease
Obesity
Pulmonary edema
Tension pneumothorax
Trendelenburg position?

Question 93

What two metals are considered MRI safe?

Answer 93

Aluminum and brass are the two metals considered MRI safe.

Question 94

What is the mechanism of Phenoxybenzamine?

Answer 94

Phenoxybenzamine is a non-specific irreversible alpha blocker, thus blockade of alpha-2 receptors can cause increased heart rate and blood pressure.

Question 95

What constellation make up Tetralogy of Fallot?

Answer 95

Tetralogy of Fallot is the most common and prototypical cyanotic congenital heart disease. Associated defects include:

1. VSD

2. Overriding aorta (Aorta sits on top of VSD)

3. Infundibular pulmonic stenosis

3. RVH as a result of RVOT obstruction

Question 96

What is the half life of Phenoxybenzamine?

Answer 96

irreversible alpha blocker with a half-life of approximately 24 hours

Question 97

What is the anesthetic goals of a Tetralogy of Fallot patient?

Answer 97

The goals of anesthetic management include:

1. Maintaining SVR

2. Reducing heart rate

3. Reduce contractility

3. Ensuring adequate oxygenation

4. Normocarbia

Question 98

A steeple sign can be found on frontal neck radiographs of patients with what pathology?

What does the image indicate?

Answer 98

A steeple sign can be found on frontal neck radiographs of patients with laryngotracheobronchitis (croup) and is indicative of tracheal mucosal edema causing tracheal narrowing.

Question 99

Retropharyngeal soft tissue widening is a common (80-90%) radiographic finding in patients with a what pathology?

Answer 99

Retropharyngeal soft tissue widening is a common (80-90%) radiographic finding in patients with a retropharyngeal abscess. It is also a sign of cervical spine trauma.

Question 100

A lateral neck radiograph will demonstrate a thumbprint sign in what pathology?

Answer 100

A lateral neck radiograph will demonstrate a thumbprint sign due to the swelling of the epiglottis (Epiglottitis)

Question 101

What blood dyscrasia can occur with nitric oxide?

Answer 101

Inhaled nitric oxide (NO) can result in methemoglobinemia resulting in a left shift in the oxyhemoglobin curve and a decrease in the P50.

Question 102

What is the formula for predicted body weight?

Answer 102

• *Males**: 50 + 2.3 * (height in inches - 60)
• *Females**: 45.5 + 2.3 * (height in inches - 60)

Question 103

What is the expert opinion on where you should keep the Hematocrit level in a sickle cell patient?

Answer 103

30-40%

Question 104

What is the recommended precurarization dosage for a nondepolarizing agent?

Answer 104

The recommended precurarization dosage for a nondepolarizing agent is 10% of the ED95, given about 3-5 minutes prior to succinylcholine.

Question 105

What is the precurariation dose of rocuronium when giving succinylcholine?

Answer 105

Rocuronium

0.3 mg/kg (ED95)

.03 mg/kg (Pre-curarization dose)

Question 106

What is the reasoning if giving precurarization dose of Rocuronium with Succinylcholine?

Answer 106

Normally the difference between intragastric pressure (typical mean value of 10 cmH2O) and lower esophageal sphincter pressure (normal value 36 cmH2O) prevents reflux of gastric contents into the esophagus.

When succinylcholine is given, the increase in intragastric pressure due to fasciculations can reach levels as high as 40 cmH2O, which may lead to aspiration of gastric contents into the esophagus and potentially the pulmonary tree.

Precurarization with a small dose of nondepolarizing neuromuscular blocking agent has been proposed to help decrease muscle fasciculation and the subsequent rise in intraabdominal pressure.

Question 107

What are the downsides of precurarization?

Answer 107

1. Reduces potency of succinylcholine
2. Delays the onset of action.
3. Dose for succinylcholine has to be increased to 1.5 mg/kg to antagonize the nondepolarizing agent.

Question 108

What does the ED95 for NDNB drugs mean?

How does the intubating dose differe from ED95?

Answer 108

The ED95 for nondepolarizing neuromuscular blocking drugs is the dose that causes 95% twitch suppression in 50% of the population.

Intubating dose is double the ED95 dose (Typically)

Question 109

The mainstay of treatment for botulism for <1 year old is?

Answer 109

The mainstay of treatment for botulism includes human-derived immune globulin in patients < 1 year of age

Question 110

What is the treatment for botulism in >1 year old?

Answer 110

(Horse) Equine-derived antitoxin in patients > 1 year of age.

Question 111

What is the mechanism for Botulism toxin?

Answer 111

This neurotoxin causes the inhibition of exocytosis of acetylcholine at the peripheral cholinergic, motor, and autonomic nerve terminals.

Thus, acetylcholine is not released into the synapse (exocytosis). Decreased acetylcholine at the motor nerve terminals leads to a chemical paralysis that can be partial or complete, depending on the amount of neurotoxin.

Question 112

Radiation intensity (exposure) with respect to distance decreases according to What equation?

I.e. If you double the distance from a radiation source, by what factor do you decrease radiation exposure?

Answer 112

Radiation intensity (exposure) with respect to distance decreases according to the inverse square law:

I ∝ 1 / r^2.

Accordingly, doubling the distance from a radiation source decreases exposure by a factor of 4.

Question 113

What is the average stroke volume and stroke volume index?

Answer 113

Stroke Volume (SV) 60 - 100 mL/beat

Stroke Volume Index (SVI) 33 - 47 mL/m^2/beat

Question 114

Can roller pumps for CPB deliver pulsatile flow?

Answer 114

There are commercially available pumps that can also deliver pulsatile flow, for both rollers and centrifugal.

Question 115

What are the two most common complications of celiac plexus blocks?

Answer 115

1. Orthostatic hypotension = #1
2. Diarrhea

Question 116

What causes improvements in a patients pain diagnosed with spinal stenosis?

Answer 116

Pain is improved by walking uphill or squatting (Think about them going to the gym)

(Think about spinal flexion)

Question 117

What causes worsening in a patients pain diagnosed with spinal stenosis?

Answer 117

Spinal Extension

Question 118

Bare-metal cardiac stents require what length dual antiplatelet therapy (aspirin and adenosine diphosphate [ADP]-receptor antagonist) before stopping the ADP-receptor antagonist prior to a scheduled surgery?

Answer 118

Bare-metal cardiac stents require 1 month of dual antiplatelet therapy (aspirin and adenosine diphosphate [ADP]-receptor antagonist) before stopping the ADP-receptor antagonist prior to a scheduled surgery

Question 119

Dual antiplatelet therapy should continue for how long in the case of drug-eluting stent placement?

Answer 119

Dual antiplatelet therapy should continue for 6 months in the case of drug-eluting stent placement, with continuation of aspirin perioperatively.

Question 120

What is the mechanism of action of Aspirin?

Answer 120

Acetylsalicylic acid (ASA) blocks prostaglandin synthesis.

It is non-selective for COX-1 and COX-2 enzymes

Inhibition of COX-1 results in the inhibition of platelet aggregation for about 7-10 days (average platelet lifespan). The acetyl group of acetylsalicylic acid binds with a serine residue of the cyclooxygenase-1 (COX-1) enzyme, leading to irreversible inhibition. This prevents the production of pain-causing prostaglandins. This process also stops the conversion of arachidonic acid to thromboxane A2 (TXA2), which is a potent inducer of platelet aggregation.

Platelet aggregation can result in clots and harmful venous and arterial thromboembolism, leading to conditions such as pulmonary embolism and stroke.

Question 121

What are the side effects of PGE-1 given to ductal dependent lesions?

Answer 121

Apnea

Hypotension, fevers, and CNS irritability.

Question 122

How does hyperbaric oxygen therapy affect CO poisoning?

Answer 122

1. Increasing the O2 dissolved in plasma
2. Decreases the half-life of carbon monoxide bound to hemoglobin. Increased Partial pressure pushes CO off the Hgb molecule
3. Half-life of carboxyhemoglobin is normally 4 to 6 hr
   - FiO2 of 1.0 = Half Life decreases to 40 to 80 min.
   - Hyperbaric oxygen therapy, the half-life becomes 15 to 30 min.

Question 123

Should Torsades be cardioverted or defibrillated?

Answer 123

Defibrillated

Question 124

What situation is activated charcoal ineffective?

Answer 124

Even in the setting of recent ingestion (< 4 hrs), activated charcoal is ineffective for methanol poisoning since it does not absorb alcohols.

Question 125

What is the fire triangle or triad?

Answer 125

Operating room fires traditionally require three components, known as the “fire triad”:

• *1) An oxidizer
  2) An ignition source
  3) A fuel source**

Question 126

What is the glucose level in CSF?

Answer 126

Glucose is present in the CSF at 40-70 mg/dL and is not present in normal saline.

Question 127

What is important to know about the Nd:YAG laser?

What color eye glasses should be worn?

Answer 127

The Nd-YAG laser is a general-purpose laser that thermally coagulates several millimeters of tissue upon exposure. The light passes through the cornea but can permanently damage the retina within milliseconds of exposure.

Protective eyewear with green filters should be worn to prevent eye damag

Question 128

In multisystem trauma, what dose of Scopalamine is given IV?

Answer 128

In extreme hemodynamic instability, such as multi-system trauma with refractory shock, scopolamine 5 mcg/kg IV (0.2-0.4 mg for an adult) is an option to provide amnesia

Question 129

What is the half life of IV Scopalamine?

Answer 129

5-11 hours

Question 130

What are the risk factors for post operative apnea?

Answer 130

GA

IV sedation

Anemia

Question 131

What is the qSOFA criteria?

Answer 131

qSOFA criteria are scored from 0-3 with one point for each of the following:

1. Altered mental status (GCS < 15)

2. Respiratory rate ≥ 22

3. Systolic blood pressure ≤ 100 mm Hg.

Question 132

Poor pneumonectomy outcomes are associated with:

1. What PVR cutoff?
2. What VO2 cutoff?
3. A decrease in arterial oxygen saturation (SaO2)?

Answer 132

1) PVR >190 dynes/sec/cm^5

Normal = 100 – 200 dynes/sec/cm
2) Maximum VO2 < 15 mL/kg/min

average sedentary male will achieve a VO2 max of approximately 35 to 40 mL/kg/min.

3) A decrease in arterial oxygen saturation (SaO2) > 2-4 %

Question 133

Treatment of myotonia or myotonic crises includes what 3 medications?

Answer 133

Treatment of myotonia or myotonic crises includes phenytoin, quinine, and procainamide.

The drugs work by decreasing sodium influx into skeletal myocytes and delaying the return of membrane excitability following an action potential

Question 134

What are the 4 ways that positive pressure ventilation decreases UOP?

Answer 134

Positive pressure ventilation increases intrathoracic pressure which can decrease urine output through four main effects:

1) Impaired renal perfusion and renal venous drainage
2) Decreased preload and increased right ventricular afterload
3) Stimulation of the sympathetic nervous system
4) Release of inflammatory cytokines

Question 135

What evoked potentials are best to monitor brainstem ischemia?

Answer 135

BAERs

Brainstem auditory evoked potentials are the best monitor for brainstem ischemia with posterior fossa craniotomy due to proximity to the surgical site as well as the relative resistance to anesthetic used, therefore eliminating other confounding variables in ischemia evaluation.

Question 136

When unfractionated heparin or low–molecular-weight heparin is administered for >4 days, the American Society of Regional Anesthesia and Pain Medicine (ASRA) guidelines recommend checking what lab before neuraxial placement?

Answer 136

Platelet Counts

Question 137

When you start TPN, what are the expected electrolyte changes:

Phosphate?

Potassium?

Magnesium?

Answer 137

All Hypo

Question 138

What other nerve needs to be blocked during TURP under spinal?

Answer 138

Transurethral surgery of the bladder usually can be performed with spinal anesthesia without further consideration. If the tumor is along the lateral aspect of the bladder then the obturator nerve may be stimulated and the jerk reflex initiated even under spinal anesthesia.

An obturator nerve block should be performed to help prevent this.

Alternatively, general anesthesia with muscle relaxation can also be performed to prevent the reflex. If neuromuscular blocking agents are not used during general anesthesia, the obturator nerve block will still need to be performed.

Question 139

Tigecycline covers what organisms?

Answer 139

Tigecycline is a glycylcycline antibiotic that covers:

1. MRSA

2. Gram-negative organisms

Question 140

What does Daptomycin cover?

Answer 140

Daptomycin is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by:

1. Gram-positive organisms.

2. It is useful for MRSA, but does not cover Gram-negative organisms.

Question 141

What does Linezolid cover?

Answer 141

Linezolid is an oxazolidinone antibiotic. Linezolid is bacteriostatic by inhibition of bacterial protein synthesis. Linezolid inhibits the 50S subunit of the bacterial ribosome.

Linezolid is effective against a wide variety of Gram-positive organisms, including MRSA and vancomycin resistant enterococcus (VRE). However, linezolid is not effective against Gram-negative bacteria.

Question 142

What is necessary to diagnose Fat Embolism?

Answer 142

Diagnosis of FES using the Gurd criteria requires:

1. At least one major criterion

• respiratory insufficiency
• Petechial rash
• CNS involvement
• Hypoxemia)

2. At least four minor criteria

• tachycardia
• fever
• unexplained drop in hematocrit or platelets
• elevated erythrocyte sedimentation rate
• retinal fat emboli
• fat in urine
• fat in sputum)

3. Presence of fat macroglobulinemia.

Question 143

A classic triad of symptoms for fat embolism is?

Answer 143

A classic triad of symptoms has been described consisting of:

1. Petechiae (mostly around the head, neck, and axillae)
2. Hypoxemia

3. Neurologic abnormalities (e.g., altered level of consciousness or seizure).

Question 144

What is the treatment for cyanide toxicity who do not have IV access?

Answer 144

Amyl nitrite is an inhaled nitrite that is oftentimes used to treat cyanide toxicity in patients who do not have established IV access. I

t is an older drug that has many more side effects than hydroxocobalamin and thus has fallen out of favor as first-line therapy

Question 145

Other than hydrocobalamin which is gold standard for cyanide, what are the 3 options?

Answer 145

Amyl Nitrate

Sodium Nitrite

Sodium Thiosulfate

Question 146

What is the maximum epinephrine for tumescent lidocaine?

Answer 146

0.07 mg/kg (1:1,000,000)

Question 147

What is required to diagnose idiopathic intracranial hypertension?

Answer 147

A lumbar puncture is used to confirm an elevated opening pressure (>25 cmH2O).

Question 148

When is the peak plasma lidocaine concentrations for tumescent lidocaine?

Answer 148

Patients must be informed of the potential signs and symptoms of local anesthetic toxicity because peak plasma lidocaine concentrations occur 12 to 16 hours after initial injection for tumescent liposuction. If tumescent liposuction is performed in an outpatient setting, the patient will most likely be at home during this time.

Question 149

What are the 4T scoring system for HIT?

What scores indicate low probability and what are high probability?

Answer 149

Thrombin level or activity is not a component of the 4T scoring system for heparin-induced thrombocytopenia (HIT).

The 4T clinical scoring system is used to clinically diagnose HIT prior to laboratory confirmation. The 4Ts include:

• *1) Thrombocytopenia
  2) Timing of the reduced platelet count
  3) Presence of Thrombosis
  4) The exclusion of other causes for thrombocytopenia**

A score of 0-3 suggests a low probability

Whereas

Ascore of 6-8 indicates high probability for clinically-relevant HIT.

Question 150

What is the best option for idiopathic intracranial hypertension in labor?

Answer 150

Pregnant patients with idiopathic intracranial hypertension presenting for labor analgesia are an interesting dilemma. If the patient has symptoms, an intrathecal catheter may be a great option to allow for removal of CSF if symptoms worsen during labor.

**I disagree with this**

Question 151

The femoral triangle is bordered by what three structures?

Answer 151

The femoral triangle is bordered by the:

1. Inguinal ligament superiorly
2. Adductor longus muscle medially (ALabama)
3. Sartorius muscle laterally.

Question 152

How does Dantrolene block calcium release from skeletal muscle Sarcoplasmic retriculum?

Answer 152

Dantrolene blocks calcium release from skeletal muscle sarcoplasmic reticulum by interfering with the ability of calcium and calmodulin to activate the voltage-gated ion channels (RYR1 and the L-type calcium channel).

Question 153

According to MHAUS, dantrolene should be administered as in acute phase as what dose?

After acute phase?

Answer 153

According to MHAUS, dantrolene should be administered as a rapid 2.5 mg/kg IV bolus which can be repeated every 5-10 minutes as necessary up to 10 mg/kg.

After the acute phase has resolved, dantrolene should be continued for 24-48 hours either as a 1 mg/kg bolus every 4-6 hours

or

As an infusion of 0.25 mg/kg/hr to prevent recrudescence.

Question 154

PaO2 decreases by what amount per year after 20 years of life?

Answer 154

PaO2 decreases by 0.5 per year after 20 years of life.

Question 155

The NIMS tube uses what technology during thyroid and parathyroid surgery?

Answer 155

EMG - Electromyography

Classically, the gold standard for monitoring the RLN was direct visualization by the surgeon. While this is still important, it lacks the functional information provided by intraoperative nerve monitoring (IONM). IONM is done using a specialized endotracheal tube which has electrodes sitting on the bilateral vocal cords.

During surgery, a surgeon uses a stimulator probe to touch the RLN and surrounding tissues while a neurophysiologist monitors the EMG trends detected by the electrodes on the endotracheal tube. Changes in trends can alert the surgeon of potential nerve injury.

Described here is intermittent IONM. While intraoperative nerve monitoring (as opposed to direct visualization) can give real-time information about nerve function, it is controversial whether employing such an adjunct is able to reduce the number of RLN injuries from thyroid surgery.

Question 156

What is the difference in Lambert Eaton vs. Myasthenia Gravis with anticholinesterases?

Answer 156

Lambert Eaton = Poor response to anticholinesterases

MG = Good response to anticholinesterases

Question 157

What is the benefit of a fructosamine test?

Answer 157

Fructosamine testing in diabetes measures a shorter time interval than hemoglobin A1c and is typically used for patients who have reduced red blood cell lifespans (e.g., in those with hemolytic anemia, sickle cell disease). A

HgA1c level of ≥ 6.5% is diagnostic for diabetes mellitus.

Question 158

What pain modality is utilized when thoracic epidural placement or paravertebral blocks are contraindicated?

Answer 158

TENS - A transcutaneous electrical nerve stimulation​ is an effective modality in pain management of post-thoracotomy pain and can be especially useful in patients in whom neuraxial anesthesia is contraindicated.

With regards to patients on antithrombotic agents, paravertebral blocks follow the same guidelines as neuraxial anesthesia.

Question 159

How does Methylene blue mechanically act for vasoplegia?

Answer 159

Methylene blue can block the vasodilatory effect of nitric oxide by inhibiting guanylate cyclase.

However, it is usually considered a last-line medication for vasoplegic shock.

Also it is contraindicated in patients receiving SSRIs because it is a MAO inhibitor and can cause serotonin syndrome.

Question 160

Why should you not give Succinylcholine to Strabismus patients?

Answer 160

Children with strabismus who receive succinylcholine for general anesthesia are 4 times more likely to experience MMR (Masseter Muscle Rigidity)

Question 161

How should you dose Propofol infusions?

Answer 161

Total Body Weight

Question 162

How should you dose induction doses of Propofol?

Answer 162

Lean Body Weight (75-80%)

Question 163

How should you dose induction doses of Fentanyl?

Answer 163

Lean Body Weight

Question 164

How should you dose induction doses of Non-depolarizing paralytics?

Answer 164

Ideal Body Weight (Same as tidal volume)

Question 165

How does the IABP decrease afterload?

Answer 165

In addition, and perhaps more importantly, IABPs improve the myocardial oxygen supply/demand ratio. Because the balloon inflates during diastole, it increases coronary perfusion pressure (increases supply), and because it deflates suddenly right when the ventricle is about to eject blood, it decreases afterload (decreased wall tension -> decreased oxygen demand).

Question 166

SIADH

Serum Level Na?

Serum osmolality?

Urine Na?

Urine Osmolality?

Fluid status?

Answer 166

Serum Level Na - Low

Serum osmolality - Low

Urine Na - High

Urine Osmolality - High

Fluid status - Euvolemic or Hypervolemic

Question 167

What type of cautery should be used when a patient has an uninterrogated pacemaker/defibrillator?

Answer 167

Bipolar - Less energy used

Monocautery is bad

Question 168

With an uninterrogated AICD, where should the dispersive pad be placed?

Answer 168

The dispersive pad should be placed near the surgical field to prevent electrical energy from affecting the AICD.

Question 169

What does a magnet due to an implanted device?

Answer 169

If the operation is an emergency, a magnet can be placed over the device.

The magnet will disable anti-tachyarrhythmia therapy in general, although there is some variability.

Question 170

How does hydrocortisone affect nitric oxide?

Answer 170

Hydrocortisone inhibits nitric oxide synthesis.

Question 171

How do ultrasounds have different penetration and resolution?

Answer 171

Increased wavelength (decreased frequency) ultrasound probes provide better tissue penetration (depth) at the cost of resolution.

Higher frequency means better resolution, but worse penetration.

Question 172

Comment on vessel rich blood flow and how this affects induction of pediatric patients.

Answer 172

Peds have increased proportion of cardiac output going to the vessel-rich groups in infants.

Question 173

What are the diagnostic signs of compartment syndrome?

Include:

1. Compartment Pressure?

2. CK level?

3. Dopplers?

4. Distal pulses?

5. Compartment Perfusion Pressure?

Answer 173

Pulse oximetry and pain are unreliable signs/symptoms of acute compartment syndrome. Diagnostic signs of compartment syndrome described in the literature include:

compartment pressure >30 mmHg

creatine phosphokinase level >5000 U/ml (possibly as little as >1000 U/ml

Loss of normal phasic patterns of tibial venous blood flow

Loss of distal pulses in the setting of closed extremity injury

And compartment perfusion pressure < 21 mmHg.

Question 174

What is the IM dose of phenylephrine?

Answer 174

An IM dose of 2-5 mg will raise blood pressure and lower heart rate typically within 10-15 minutes from injection.

Question 175

What is the IM dose of epinephrine?

Answer 175

An IM dose of 0.1 - 0.5 mg increases heart rate, blood pressure, and produces bronchodilation within 5 minutes from injection.

Question 176

What dose of Phentolamine would you use if you have extravasation?

Answer 176

Should this occur, the degree of necrosis can potentially be decreased by infiltration of the affected area with a phentolamine solution (5-10 mg in 10-15 mL saline).

Question 177

What dose of Ephedrine would you use for IM injectons?

Answer 177

An IM dose of 0.5-0.6 mg/kg (35 mg for 70 kg adult) will produce modest increases in blood pressure and heart rate within 10-15 minutes from the time of injection.

Question 178

Where does Herpes zoster affect most nerve roots?

Answer 178

1. Thoracic nerve roots
2. Ophthalmic division of the trigeminal nerve (V1)
3. Maxillary division of the trigeminal nerve (V2)
4. Cervical spinal roots
5. Sacral spinal roots

Question 179

How is Bicarbonate levels in pyloric stenosis before resuscitation?

Answer 179

Elevated serum bicarbonate is often present along with increased urine specific gravity and decreased urine chloride.

Question 180

How do you diagnose abdominal compartment syndrome?

Answer 180

Abdominal compartment syndrome is diagnosed by observing a tense, distended abdomen and by obtaining bladder pressure readings > 20-25 mm Hg via a urinary catheter.

Question 181

What is the defintion of Heparin resistance?

Answer 181

Heparin resistance is defined as an activated clotting time (ACT) of < 480 seconds after 500 U/kg of IV heparin has been administered or an ACT < 400 seconds at any time during the course of cardiopulmonary bypass (CPB) and heparin administration.

Question 182

What is the dose of antithromobin III levels?

Answer 182

Thrombate III: IV: Initial: 500 units once (dose can be rounded to the nearest vial size)

A repeat dose of 500 units may be considered if activated clotting time remains subtherapeutic after the initial dose.

Question 183

What are the symptoms of Anticholinergic syndrome?

Answer 183

Anticholinergic syndrome:

1. Blind as a bat (cycloplegia and mydriasis)
2. Mad as a hatter (delirium and hallucinations)
3. Red as a beet (skin flushing)
4. Hot as hell (fever)
5. Dry as a bone (anhidrosis)
6. Full as a flask (urinary retention)

Question 184

What is the treatment for anticholinergic syndrome?

Answer 184

Physostigmine (Acetylcholinesterase Inhibitor)

Question 185

What size defib pads should be used?

Answer 185

Defibrillation using Smaller 4.3-cm electrodes can cause damage to the patient including possible myocardial necrosis.

Electrodes that are 12-cm are more effective than smaller electrodes to deliver a shock. Paddle/pad size is inversely proportional to transthoracic resistance.

Paddles of 13-cm diameter reduce transthoracic resistance by 21% as compared with 8.5-cm diameter paddles. Current recommendations by the American Heart Association (AHA) state electrode size of 8-12 cm is reasonable for use in adults. The use of smaller electrodes can injure the patient.

Question 186

What is the treatment for central DI?

Answer 186

Desmopressin

Question 187

What is demeclocycline used for?

Answer 187

Demeclocycline, derived from the tetracycline class of antibiotics, is used in the treatment of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) by actually inducing diabetes insipidus (C) and reducing ADH effects in the collecting duct.

Question 188

What is the American Spinal Injury Association Impairment Score?

Answer 188

A - Complete injury with complete motor and sensory

B - Incomplete - Sensation preserved below injury
C - Incomplete - <3/5 motor strenth in 1/2 of motor groups
D - Incomplete - >3/5 motor strength in 1/2 major groups

E - No evidence of cord injury. Intact motor and sensory innervation

Question 189

What are the labs for primary hyperaldosteronism?

Na?

K?
renin?

Answer 189

High sodium

Low potassium

Reduced renin activity

Metabolic alkalosis

Question 190

What is the thyroid hormone binding ratio in hyperthyroidism vs. hypothyroidism?

Answer 190

Thyroid hormone binding ratio high hyperthyroidism and low in hypothyroidism

Question 191

What is usually the difference between ScvO2 and SvO2?

Answer 191

In normal settings, the ScvO2 is approximately 5% greater than the SvO2 due to the coronary sinus contribution of deoxygenated blood for SvO2.

ScvO2 = Central venous sample

SvO2 = Mixed venous in the Pulmonary Artery

Question 192

What does Dibucaine do?

Answer 192

Dibucaine inhibits normal pseudocholinesterase to a far greater extent than the abnormal enzyme.

Question 193

Understandardized test conditions, dibucaine inhibits the normal enzyme what percent?

dibucaine inhibits the abnormal enzyme what percent?

Answer 193

Under standardized test conditions, dibucaine inhibits the normal enzyme about 80 percent and the abnormal enzyme about 20 percent, thus the DN is the percent of PChE enzyme activity that is inhibited by dibucaine.

Question 194

Normal Dibucaine number?

Answer 194

70-80

Question 195

Heterozygote for Atypical Pseudocholinesterase enzyme Dibucaine number?

Answer 195

heterozygous atypical yields a DN of 50-60

Question 196

Homozygous Atypical Pseudocholinesterase Enzyme Dibucaine number?

Answer 196

Homozygous atypical yields a DN of 20-30

Question 197

When should specimens should be collected 48 hours after the administration of succinylcholine to test for dibucaine number?

Answer 197

Specimens should be collected 48 hours after the administration of succinylcholine

Question 198

Mivacurium

What class?

Metabolism?

Answer 198

Mivacurium, a benzylisoquinolinium short-acting nondepolarizing skeletal muscle relaxant, is also metabolized via hydrolysis by pseudocholinesterase.

Question 199

90-95% of an intravenous dose of succinylcholine occurs when?

The remaining 5-10% of the succinylcholine dose acts where?

Answer 199

Pseudocholinesterase hydrolyzes succinylcholine to succinylmonocholine and then to succinic acid. In individuals with normal plasma levels of normally functioning pseudocholinesterase enzyme, hydrolysis and inactivation of approximately 90-95% of an intravenous dose of succinylcholine occurs before it reaches the neuromuscular junction.

The remaining 5-10% of the succinylcholine dose acts as an acetylcholine receptor agonist at the neuromuscular junction, causing prolonged depolarization of the postsynaptic junction of the motor-end plate.

Question 200

What organisms are most commonly seen in Ventilator Associated Pneumonia?

Answer 200

antibiotic-sensitive flora

1. methicillin-sensitive Staphylococcus aureus

2. Haemophilus influenzae

3. Streptococcus pneumoniae

4. Proteus, Klebsiella, and Enterobacter species

Question 201

What are the main differences between coma vs. Persistent Vegetative State?

Answer 201

They may have spontaneous eye movement

They may have sleep-wake cycle

They may vocalize or have non-purposeful sound

Question 202

What are similar between coma vs. persistent vegetative state?

Answer 202

Cannot follow commands

Cannot communicate

Cannot have purposeful movement

Question 203

How does reducing contractility help with SAM / HOCM / LVOTO pathologies?

Answer 203

Reducing cardiac contractility:

1. Improves diastolic filling

2. Increases LV end diastolic volume

3. Increases LV chamber size

ALL = reduces LVOT obstruction.

Question 204

How does increasing afterload help in SAM/LVOTO/HOCM?

Answer 204

Maintaining or increasing the afterload on the left heart lengthens the systolic ejection time, therefore reducing the incidence of coaptation between the mitral valve leaflets and the ventricular septum.

Incidentally, SAM may occur due to coaptation of both MV leaflets or only the anterior MV leaflet with the septum; this is dependent on the spatial relationship between the MV apparatus and the LVOT during systole.

Question 205

How would dual chamber sensing help a HOCM patient’s hemodynamics?

Answer 205

The mechanism likely involves the paradoxical motion of the ventricular septum during systole, which serves to reduce coaptation with the mitral valve leaflet(s).

Question 206

Can you use succinylcholine in cerebral palsy patients?

Answer 206

Yes

Succinylcholine has been used in children with CP for more than 50 yr without a single report of a hyperkalaemic response.

Question 207

What pulm and GI considerations need to be in place for cerebral palsy cases?

Answer 207

CP patients have an increased incidence of gastroesophageal reflux and esophageal dysmotility. Pulmonary aspiration is increased in CP patients and places them at a greater risk for postoperative pulmonary complications.

Question 208

How do Spinal Cord Stimulators work?

Answer 208

Spinal cord stimulators activate the larger Aα and Aβ fibers to a greater degree compared with the smaller nociceptive Aδ and C fibers.

Directly acts at dorsal horn of the spinal cord (Ascending)

This closes the gate in and impedes conduction of pain sensation past the substantia gelatinosa of the dorsal horn of the spinal cord.

Question 209

For metabolic acidosis, how would you predict compensatory change in PaCO2?

Answer 209

Winter formula to predict the compensatory change in PaCO2.

_Expected PaCO2 = (1.5 * [HCO3]) + 8 +/- 2_

If Measured > Expected = Then respiratory acidosis also

If measured < expected = Respiratory alkalosis compensating

If the PaCO2 is significantly different then expected, suspect a mixed disorder.

Question 210

How does the upslope change in different arterial line waveforms?

Answer 210

Steeper upstroke the more distal you go

Question 211

How does mixed venous oxygen saturation change with hyperdynamic state?

Answer 211

Increases

Question 212

How does the dicrotic notch change as arterial line changes?

Answer 212

Dicrotic notch later the more peripheral you go

Question 213

What are the mechanisms of high frequency jet ventilation?

Answer 213

Cardiogenic mixing describes the movement of lung tissue directly surrounding the pumping heart results in further molecular diffusion and mixing of gases.

Pendelluft ventilation involves the redistribution and mixing of gas as a result of local differences in airway and alveolar resistance and compliance.

Venturi effect describes the entrainment of room air along with each delivered jet ventilation cycle. In the setting of supraglottic jet ventilation, this will always result in the delivered gas containing less than 100% oxygen.

Taylor Dispersion

Question 214

How does the appearance of dicrotic notch change the more peripheral you go?

Answer 214

Later and less sharp

Question 215

What is lid lag? When is it seen?

Answer 215

Patients can also have lid lag which is due to adrenergic hyperactivity leading to spasming of the levator palpebrae superioris muscle.

Seen in Hyperthyroidism

Question 216

How does TLC (Total Lung Capacity) change in restrictive lung diseases

Answer 216

Drops

Question 217

Why can myotonic dystrophy patients not receive Neostigmine?

Answer 217

Neostigmine inhibits acetylcholinesterase, thereby increasing acetylcholine at the neuromuscular junction. This increase in acetylcholine causes increased muscle activation and has been associated with myotonias.

Question 218

What is SpO2 during 1st minute of life?

10 minutes of life?

Answer 218

60-65% by 1 minute of life

85-95% by 10 minutes of life.

Question 219

Is nasal congestion or rhinoorhea with stellate ganglion block?

Answer 219

Nasal congestion

Question 220

How will temperature change in stellate ganglion block?

Answer 220

A temperature increase in the ipsilateral arm is evidence of a successful stellate ganglion block. Temperature increases in the leg can be seen with a lumbar sympathetic block.

Question 221

How will low phosphate shift the Oxy-Hemoglobin curve?

Answer 221

Shift to left (Decreased 2,3 DPG)

Question 222

What is the metabolite of cisatracurium?

What is the clinical significance of this?

Answer 222

Cisatracurium (and atracurium) is primarily metabolized (80%) to laudanosine.

This renally-cleared excitatory amine can precipitate seizures, but does not have neuromuscular blocking activity.

The clinical significance of laudanosine was more important with atracurium since it is much less potent than cisatracurium, and thus more of the metabolite is produced.

Question 223

What end organ does vecuronium have clinical signficance and why?

Answer 223

Vecuronium has an active metabolite, 3-desacetyl-vecuronium, that has 80% of the potency of vecuronium. Accumulation of this renally-cleared metabolite can significantly prolong the duration of action of the drug, particularly when an infusion is used in a patient with renal failure.

Question 224

When do you see alpha effects from Dopamine?

Answer 224

>10 mcg/kg/min

Question 225

What is the genetics of Malignant hyperthermia?

Answer 225

MH is often caused by a mutation in the ryanodine receptor (RYR1) of skeletal muscle found on chromosome 19

Question 226

WHAT is the treatment of choice for methemoglobinemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency?

Answer 226

Ascorbic acid is the treatment of choice for methemoglobinemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Question 227

What are the indications for Fenoldopam?

Answer 227

Severe hypertension: Short-term treatment of severe hypertension (up to 48 hours in adults while in hospital), including patients with malignant hypertension with deteriorating end-organ function

AND

Short-term (up to 4 hours while in hospital) blood pressure reduction in pediatric patients while in hospital

Question 228

What is the equation for Wall Tension?

Answer 228

Wall tension = (LVEDP x radius) / (2 x LV wall thickness)

T = P * R / LVH

Question 229

When does the RV recevive its greatest perfusion peak in the cardiac cycle?

Answer 229

The right ventricle is perfused throughout the cardiac cycle but receives its greatest perfusion during peak/late systole and early diastole.