"Basic" oral board knowledge answers

[Anes2010]

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Can someone help me with the following? These are relatively basic topics, but I just can't find a concrete answer and want to give a reasonable answer if I get asked any at the oral boards.

1) Sux - how soon after crush injury, burn, spinal cord injury should you avoid it? After what period of time IS it safe to give?

2) Time requirement for ELECTIVE surgery following MI?

3) Time requirement to delay elective case following
a) angioplasty
b) bare metal stent

4) When "safe" to go off of plavix for elective procedure after drug eluting stent?

5) Hypo/hyperkalemia at which you would cancel elective case?

6) Hyperglycemia at which you would cancel elective case?

7) Blood pressure at which you would cancel elective case.

I think I know most of the answers, but if I get pinned on them during the exam I want to make sure my answers are consistent with general practice.

Thanks!

 

[Idiopathic]

many of these answers are arbitrary

1) Sux - how soon after crush injury, burn, spinal cord injury should you avoid it? After what period of time IS it safe to give?

safe within 24 hours, equivocal 24-48 hours after and wouldnt use it after 48 hours in burns/crushes; denervation injury a little different and id probably just elect not to use it in someone with a clinically significant spinal cord injury more than 2 days out

2) Time requirement for ELECTIVE surgery following MI?

6 months

3) Time requirement to delay elective case following
a) angioplasty
b) bare metal stent

a - dont know about this, i would say that it should be long enough to establish a new functional baseline, assuming NSTEMI, maybe 2-4 weeks.
b - Id wait at least a month on a BMS but if you can wait 90 days I think outcomes are better

4) When "safe" to go off of plavix for elective procedure after drug eluting stent?

not such an easy question. if patient is on plavix monotherapy it may never be safe to stop it as there is evidence of a rebound phenomenon (ive seen instent thrombosis after 4 years on plavix) but guidelines are one year. id feel better if the remained on aspirin

5) Hypo/hyperkalemia at which you would cancel elective case?

at any value where you are seeing EKG changes. <3 or >6 with no good reason for it to be out of bounds I would be concerned and would research previous labs or history

6) Hyperglycemia at which you would cancel elective case?

you will get asked about your concern for DKA when above 200, probably, id just be ready to talk about that

7) Blood pressure at which you would cancel elective case.

>180? I would try and get it down below 150 preop but depends on the patient.

I think the key is just to be able to back up your answers with rational medical thought.

 

[cchoukal]

With regard to 3 and 4:

Anesthesiology. 2008 Oct;109(4):588-95.
Time and cardiac risk of surgery after bare-metal stent percutaneous coronary intervention.
Nuttall GA, Brown MJ, Stombaugh JW, Michon PB, Hathaway MF, Lindeen KC, Hanson AC, Schroeder DR, Oliver WC, Holmes DR, Rihal CS.

Department of Anesthesiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905, USA. [email protected]
Comment in:

Anesthesiology. 2008 Oct;109(4):573-5.
Abstract
BACKGROUND: The duration of time that elective noncardiac surgery (NCS) should be delayed after percutaneous coronary intervention (PCI) with bare metal stents (BMSs) is unknown. METHODS: This large, single-center, retrospective study examined the relation between complication rate in patients with BMSs undergoing NCS and the duration of time between PCI and NCS. Primary endpoints included in-hospital major adverse cardiac events (death, myocardial infarction, stent thrombosis, or repeat revascularization with either coronary artery bypass grafting or PCI of the target vessel) and bleeding events. The relation between the events and the timing of noncardiac surgery after PCI with BMS was assessed using univariate analysis and multiple logistic regression. RESULTS: From January 1, 1990, to January 1, 2005, a total of 899 patients were identified. The frequency of major adverse cardiac events was 10.5% when NCS was performed less than 30 days after PCI with BMS, 3.8% when NCS was performed between 31 and 90 days after PCI with BMS, and 2.8% when NCS was performed more than 90 days after PCI with BMS. In univariate and multivariate analyses, a shorter time interval between PCI with BMS and noncardiac surgery was significantly associated with increased incidence of major adverse cardiac events (univariate: P < 0.001; odds ratio = 4.0; 95% confidence interval, 2.0-8.3; multivariate: P = 0.006; odds ratio = 3.2; 95% confidence interval, 1.5-6.9). Bleeding events were not associated with time between PCI with BMS and NCS or with the use of antiplatelet therapy in the week before NCS. CONCLUSIONS: The incidence of major adverse cardiac events is lowest when NCS is performed at least 90 days after PCI with BMS.


That same issue also had a similar article w/ regard to drug-eluting stents. Not practice standards, by any stretch, but they provide some guidance. There was also a commentary on both articles in that issue, and that might put some of this into context.

 

[cchoukal]

Here's the DES paper:

Anesthesiology. 2008 Oct;109(4):596-604.
Cardiac risk of noncardiac surgery after percutaneous coronary intervention with drug-eluting stents.
Rabbitts JA, Nuttall GA, Brown MJ, Hanson AC, Oliver WC, Holmes DR, Rihal CS.

Department of Anesthesiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905, USA.
Comment in:

Anesthesiology. 2008 Oct;109(4):573-5.
Abstract
BACKGROUND: The American College of Cardiology released a scientific advisory that included a recommendation to delay elective of noncardiac surgery (NCS) for 1 yr after percutaneous coronary intervention (PCI) with a drug-eluting stent (DES). METHODS: This single-center, retrospective study examined the risk for complications of NCS performed within 2 yr after DES placement and examined whether this risk changed based on the time between procedures. The primary endpoint was major adverse cardiac events (MACEs) during the hospitalization for NCS. Bleeding events were analyzed as a secondary endpoint. RESULTS: From April 22, 2003, to December 31, 2006, a total of 520 patients underwent NCS within 2 yr after PCI with a DES at Mayo Clinic. The majority, 84%, of the DES placed were Cypher stents. The frequency of MACE was not found to be significantly associated with the time between PCI and NCS (rate of MACEs 6.4, 5.7, 5.9, and 3.3% at 0-90, 91-180, 181-365, and 366-730 days after PCI with DES, respectively; P = 0.727 for comparison across groups). Characteristics found to be associated with MACEs in univariate analysis were advanced age (P = 0.031), emergent NCS (P = 0.006), shock at time of PCI (P = 0.035), previous history of myocardial infarction (P = 0.046), and continuation of a thienopyridine (ticlopidine or clopidogrel) into the preoperative period (P = 0.040). The rate of transfusion did not seem to be associated with antiplatelet therapy use. CONCLUSIONS: The risk of MACEs with NCS after DES placement was not significantly associated with time from stenting to surgery, but observed rates of MACEs were lowest after 1 yr.

 

[Breezee]

Can someone help me with the following? These are relatively basic topics, but I just can't find a concrete answer and want to give a reasonable answer if I get asked any at the oral boards.

1) Sux - how soon after crush injury, burn, spinal cord injury should you avoid it? After what period of time IS it safe to give?

2) Time requirement for ELECTIVE surgery following MI?

3) Time requirement to delay elective case following
a) angioplasty
b) bare metal stent

4) When "safe" to go off of plavix for elective procedure after drug eluting stent?

5) Hypo/hyperkalemia at which you would cancel elective case?

6) Hyperglycemia at which you would cancel elective case?

7) Blood pressure at which you would cancel elective case.

I think I know most of the answers, but if I get pinned on them during the exam I want to make sure my answers are consistent with general practice.

Thanks!

1. Can give Sux within 24 hours of burn but don't give after 24 hours because of the upregulation of the extrajunctional receptors allowing Sux to cause widespread depolarization and excess K+ release. How long after is it safe to give? I don't know.

2. Two trains of thought: 1) Delay elective surgery 6 months as risk for reinfarction is more likely soon after MI and less after 6 months or 2) Delay 4-6 weeks after MI then decide if surgery is safe based on medical optimization, clinical risk factors, and surgical risk.

3. PTCA= 2-4 weeks, BMS= 4-6 weeks

4. DES= 1 year

5. No clear cut numbers for this one. Some would say 3.5-5.5 mEq/L but higher may be tolerated in your chronic renal patient. I think the decision lies in whether the abnormal value in question is causing cardiac disturbances/EKG changes that may cause intraop and postop issues.

6. Don't know if there is a definite number. Maybe delay and treat if greater than 250.

7. Don't know if there is a definite number. Maybe delay/cancel elective case and treat if greater than 180/110 to prevent possible intraop BP lability and adverse cardiac outcomes.


Good luck. 10 days for me until D-day.

 

[Noyac]

Can someone help me with the following? These are relatively basic topics, but I just can't find a concrete answer and want to give a reasonable answer if I get asked any at the oral boards.

1) Sux - how soon after crush injury, burn, spinal cord injury should you avoid it? After what period of time IS it safe to give?

2) Time requirement for ELECTIVE surgery following MI?

3) Time requirement to delay elective case following
a) angioplasty
b) bare metal stent

4) When "safe" to go off of plavix for elective procedure after drug eluting stent?

5) Hypo/hyperkalemia at which you would cancel elective case?

6) Hyperglycemia at which you would cancel elective case?

7) Blood pressure at which you would cancel elective case.

I think I know most of the answers, but if I get pinned on them during the exam I want to make sure my answers are consistent with general practice.

Thanks!

1) I'm not sure when to avoid sux after a crush but it's pretty early on as best I can remember. Something like 24 hrs maybe. But burns are more difficult to predict so I skip it after 24 hrs. In SC injuries the risk grows with time. You are generally safe up to 3-4 days.

2) 6 months
3) Bare metal- 6months
DES- 1 yr
4) never safe but after a year if it is necessary
5) ECG changes is a good gauge.
6) Start thinking about it around 300 would be my answer but who knows.
7) DBP >110 is the board answer if I remember but I try to treat it first. GA usually treats it just fine.

 

[seinfeld]

with regards to bp preop it all depends. DId they stop their usual bp meds? What is there nl BP? What type of case is it? If its a carotid or beachchair case i am more reluctant to treat it preop and tend to wait until the pt is induced then deal with BP issues.

 

[Anes2010]

Thanks for your thoughts. I'm a bit more aggressive (in real life), but want to be able to have a good board answers - particularly when backed with evidence (thanks for the bare metal/drug eluting stent articles).

I thought in burn sux was safe up to week, but 3 days was conservative. 24 hours is certainly much more conservative. I think it's safe after a year. Not sure if this is true for hemiparesis/CVA/spinal cord injury though.

Anybody else free free to post some of their basic questions/answers.

Two more I would add.

1) Uncomplicated URI in children - cancel case? My response will be if it is a minor case such as a BMT, there is likely no need to cancel. The incidence of laryngospasm is likely slightly higher, but no worse outcome. Other cases - equivical. I might consider particularly if I can avoid ETT with a LMA. A more major case or ETT planned, would delay for 4 weeks. Anyone do anything different?

2) Tight glycemic control - controversial. Anyone have a good goal range for postop sugar in the ICU.

3) Regional for difficult airway? I would consider it in cases where I had easy access to the head, where the surgery can be halted abrupted (or at least paused), and I had a backup plan to induce GA. Though certainly a more conservative answer (possibly for the orals) would be awake fiberoptic regardless, because even if I can do 1000 spinals in real life without respiratory paralysis, if it's going to happen, it'll happen on the boards.

4) Hyperventilation for elevated ICP intraop - out of vogue. Wouldn't do it.

5) Beta blockers - continue if they are on them, avoid them if they have not and have no CAD (worse outcomes by blunting physiologic response). If CAD not on BB, consider periop, but ideally would start preoperative (2-4 weeks?)

6) Any significant changes with the newly released 2010 ASRA guidelines. I had the old ones memorized. Just learned yesterday that new ones had been published. Haven't read yet.

Any other things you can think of?

 

[Noyac]

Your on the right track. All of these scenarios are debatable. The approach you take is up to you. Just don't be dogmatic or inflexible. Be able to change your approach on the fly and discuss the critical points. What the examiners are looking for is a well educated doc with a good sense of how to practice. They know you are smart and that you know the material because you have passed the written exam. Now they want to know if you can discuss the material with a cool head and be a "diplomat" of the ABA. If you go in there with any ego or attitude you will be doomed to fail.

 

[Sapdaddy]

Can someone help me with the following? These are relatively basic topics, but I just can't find a concrete answer and want to give a reasonable answer if I get asked any at the oral boards.

1) Sux - how soon after crush injury, burn, spinal cord injury should you avoid it? After what period of time IS it safe to give?

2) Time requirement for ELECTIVE surgery following MI?

3) Time requirement to delay elective case following
a) angioplasty
b) bare metal stent

4) When "safe" to go off of plavix for elective procedure after drug eluting stent?

5) Hypo/hyperkalemia at which you would cancel elective case?

6) Hyperglycemia at which you would cancel elective case?

7) Blood pressure at which you would cancel elective case.

I think I know most of the answers, but if I get pinned on them during the exam I want to make sure my answers are consistent with general practice.

Thanks!

"knocking out the boards"
it's in there.
and if it's not, let me know, i'll make sure it gets in there in 2nd ed.

 

[supahfresh]

Board stiff III has most of this stuff.

with regard to BP, Yao states to delay if SBP is > 200 or if DBP > 110 but the key is to know their range. Nearly a quarter of my patients have poorly controlled HTN and if we were more conservative than this, a significant number of people in this region would not get their surgeries.

Ranges in BP is crucial. The HTN patient will have exaggerated high's and low's in response to stress and anesthetics which is important to keep in mind when you see them anxious in the pre-op area.

 

[sevoflurane]

Good quick read. DES/BMS =12months/1month.

http://www.asahq.org/Newsletters/2008/04-08/sweitzer04-08.html#ref

 

[CambieMD]

BSIII is a great book . It helps you to process information as you work to develop your own answers to the stated questions and others that tend to pop up on exams and in clinical practice.

The hand book to Anesthesia an Co-existing Diseases is also an excellent book for the orals.

Cambie

 

[michigangirl]

A few important points:

1. You can never go wrong just not giving sux period to an acute burn/crush injury patient-- unless it's an airway edema/anticipated airway emergency, roc will work just fine in all cases. Either way, the first 24 hours it's ok, after that, no go! You're setting yourself up if you try to give it up to the first 48 hours...not worth the risk. So if it's an airway issue in the first 24 hours, use it, otherwise, lose it. When you can resume use is controversial, depends on the severity of the initial burns. One year is good and conservative.

2. Peds URIs- the key is UNCOMPLICATED. If you canceled cases for URI, however big the case is, we'd never get any cases done in the peds world. ASA refresher course-- URI only-- proceed with the case. URI with fever greater than 38.3- proceed with caution, discuss with surgeons. URI with wheezes or rales or any evidence of lower respiratory disease-- cancel case and reschedule in 4-6 weeks.

Some folks would advocate for using an endotracheal tube if the patient has a URI with no history of asthma simply because of the laryngospasm risk with LMA.

Good luck!