ABA Basic sample questions

[cricoidcommander]

Wondering if anyone can help me with some explanations for some of the answers to the ABA Basic sample questions. I'm a CA1 getting ready to take basic and a few of these I don't understand.

An induction dose of ketamine is MOST likely to have which of the following effects?

A. Analgesia (correct)

B. Decreased cerebral metabolic rate

C. Preservation of laryngeal reflexes

I was stuck between A and C for this one, not sure why the answer is A over C.


A healthy 42-year-old man has an increase in heart rate from 60 bpm to 120 bpm during

induction of anesthesia. Which of the following factors is MOST likely to satisfy the increased

metabolic demand of the myocardium?

A. Decreased coronary artery resistance (correct)

B. Increased coronary perfusion pressure

C. Increased O2 extraction by the myocardium
Honestly just didn't know which to put for this one, I figured it's not B becuase perfusion pressure is probably decreased on induction. But wasn't sure why A vs C.

A 36-year-old woman is receiving general anesthesia for a diagnostic laparoscopy in the

Trendelenburg position with CO2 insufflation. During a 15-minute period after induction, her

SpO2 decreases from 99% to 90% and the partial pressure of ETCO2 increases from 38 to 43. mmHg. FiO2 is 0.3; all ventilator settings have been constant. Which of the following etiologies

is the MOST likely cause of the decrease in SpO2?

A. CO2 embolus

B. Compression of the vena cava

C. Right mainstem endobronchial intubation (correct)

I put A for this, I'm not really sure why it couldn't be A or B. With right main stem I thought we usually see a decreased end tidal so I actually crossed that one off first but it ended up being the answer.

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[CopaceticOne]

Not to be a jerk, but have you talked with your attendings about these? That will be waaaaay more useful in determining where are your individual knowledge gaps.

Edit: I say that because the third question is a softball question so I wonder where your knowledge level really is at. That scenario is a basic trouble shoot that you should have experienced as a CA1.

 

[Onefellswoop87]

Wondering if anyone can help me with some explanations for some of the answers to the ABA Basic sample questions. I'm a CA1 getting ready to take basic and a few of these I don't understand.

An induction dose of ketamine is MOST likely to have which of the following effects?

A. Analgesia (correct)

B. Decreased cerebral metabolic rate

C. Preservation of laryngeal reflexes

I was stuck between A and C for this one, not sure why the answer is A over C.


A healthy 42-year-old man has an increase in heart rate from 60 bpm to 120 bpm during

induction of anesthesia. Which of the following factors is MOST likely to satisfy the increased

metabolic demand of the myocardium?

A. Decreased coronary artery resistance (correct)

B. Increased coronary perfusion pressure

C. Increased O2 extraction by the myocardium
Honestly just didn't know which to put for this one, I figured it's not B becuase perfusion pressure is probably decreased on induction. But wasn't sure why A vs B.

A 36-year-old woman is receiving general anesthesia for a diagnostic laparoscopy in the

Trendelenburg position with CO2 insufflation. During a 15-minute period after induction, her

SpO2 decreases from 99% to 90% and the partial pressure of ETCO2 increases from 38 to 43

212. 13. 14. 15. 16. mmHg. FiO2 is 0.3; all ventilator settings have been constant. Which of the following etiologies

is the MOST likely cause of the decrease in SpO2?

A. CO2 embolus

B. Compression of the vena cava

C. Right mainstem endobronchial intubation (correct)

I put A for this, I'm not really sure why it couldn't be A or B. With right main stem I thought we usually see a decreased end tidal so I actually crossed that one off first but it ended up being the answer.

1. Ketamine does not preserve airway reflexes. It does not cause apnea, which I think is where the confusion comes from. But consider using it as a sole induction agent - if regurgitation occurs, then aspiration is possible because the patient does not have airway reflexes to cough, close epiglottis, etc.
2. Can’t have decreased coronary resistance and increased perfusion pressure. They are directly correlated. If decreased resistance, then less pressure. Can’t have A and B at same time.
3. You’d see decreased end-tidal if tension pneumothorax causing one-lung ventilation but that’s from very different physiology and does not apply to inadvertent one-lung ventilation from right mainstream without tension. A and B are just less likely in general and could cause other derangements to physiology. Compression of vena cava impairs RV return so if catastrophic would cause decreased cardiac output and then decrease end tidal as a marker of circulation, not directly ventilation. CO2 embolus in insufflation directly into circulation. Very rare complication. And end-tidal CO2 would rise much more than 5 points over 15 minutes.

But agree with above poster. Talk to your attending. I don’t work with residents any more but if I had one come to me and said “I was reviewing basic questions and don’t understand these, can we discuss them?” then I’d be happy to and I’d hope that any attending at a residency program would also. These are the attending who theoretically know you well so these questions coupled with your thought process in the OR should be illuminating to your academic progress.

 

[cricoidcommander]

Not to be a jerk, but have you talked with your attendings about these? That will be waaaaay more useful in determining where are your individual knowledge gaps.

Edit: I say that because the third question is a softball question so I wonder where your knowledge level really is at. That scenario is a basic trouble shoot that you should have experienced as a CA1.

unfortunately at my program our attendings don’t stay with us in the OR for more than 5 minutes for me to even have time to discuss anything like this with them. We are expected to almost entirely learn on our own

 

[cricoidcommander]

1. Ketamine does not preserve airway reflexes. It does not cause apnea, which I think is where the confusion comes from. But consider using it as a sole induction agent - if regurgitation occurs, then aspiration is possible because the patient does not have airway reflexes to cough, close epiglottis, etc.
2. Can’t have decreased coronary resistance and increased perfusion pressure. They are directly correlated. If decreased resistance, then less pressure. Can’t have A and B at same time.
3. You’d see decreased end-tidal if tension pneumothorax causing one-lung ventilation but that’s from very different physiology and does not apply to inadvertent one-lung ventilation from right mainstream without tension. A and B are just less likely in general and could cause other derangements to physiology. Compression of vena cava impairs RV return so if catastrophic would cause decreased cardiac output and then decrease end tidal as a marker of circulation, not directly ventilation. CO2 embolus in insufflation directly into circulation. Very rare complication. And end-tidal CO2 would rise much more than 5 points over 15 minutes.

But agree with above poster. Talk to your attending. I don’t work with residents any more but if I had one come to me and said “I was reviewing basic questions and don’t understand these, can we discuss them?” then I’d be happy to and I’d hope that any attending at a residency program would also. These are the attending who theoretically know you well so these questions coupled with your thought process in the OR should be illuminating to your academic progress.

I had reviewed on open anesthesia and a few other sources that ketamine does generally preserve airway reflexes

 

[Onefellswoop87]

I had reviewed on open anesthesia and a few other sources that ketamine does generally preserve airway reflexes

Sorry, I think I misread the question. Or didn’t answer well. Analgesia is still the best answer choice for an induction dose. Ketamine likely preserves airway reflexes for sedation or if an analgesic/non-dissociative dose is given. But I’d argue not for an induction dose, which is what is asked, A is the best test answer.
Open anesthesia also says it is generally preserved but maybe not protective. So “preserved” but not clinically present airway reflexes?