Renal labs/EKG in dialysis patient for outpatient surgery

[aneftp]

I'm covering an outpatient facility that one of my friends (anesthesiologist also) runs and has partial ownership.

No big deal. But there's a a simple 30 minute hernia case. The patient is a renal patient. It's a free standing outpatient center.

I am pretty shocked they don't do routine renal labs and 12 lead EKG for dialysis patients.

I know most MDs will quote I think the Kaplan (not sure if that's the correct study) study done a few years ago that argued against the routine use of preop labs/tests for low risk outpatient procedures.

But no where in that study does it address high risk patients like dialysis patients needing at least a K level before proceeding.

Obviously some sort of greed is involved when one has a financial stake in a center.

But what's everyone's take on routine renal labs/EKG for a dialysis patient?

Patient currently doesn't have any symptoms (although he did miss yesterday's dialysis). Every hospital/outpatient center I've ever worked at has done renal labs and EKGs for dialysis patients.

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[Idiopathic]

why do you ultimately need a potassium level before proceeding

 

[Idiopathic]

I'm covering an outpatient facility that one of my friends (anesthesiologist also) runs and has partial ownership.

No big deal. But there's a a simple 30 minute hernia case. The patient is a renal patient. It's a free standing outpatient center.

I am pretty shocked they don't do routine renal labs and 12 lead EKG for dialysis patients.

I know most MDs will quote I think the Kaplan (not sure if that's the correct study) study done a few years ago that argued against the routine use of preop labs/tests for low risk outpatient procedures.

But no where in that study does it address high risk patients like dialysis patients needing at least a K level before proceeding.

Obviously some sort of greed is involved when one has a financial stake in a center.

But what's everyone's take on routine renal labs/EKG for a dialysis patient?

Patient currently doesn't have any symptoms (although he did miss yesterday's dialysis). Every hospital/outpatient center I've ever worked at has done renal labs and EKGs for dialysis patients.

i think that came out wrong: i know the answer, but also understand the position you are in. the bolded sentence is the main reason i would be more concerned about pursuing labs, but it depends on how stable the patient has been in the past, i think. you should have access to some labs from the last dialysis visit and assuming they are chronically stable and the patient is well managed, i would probably be okay to proceed with the case. just my opinion. no reason this case couldnt be done with regional or LMA, right?

 

[aneftp]

why do you ultimately need a potassium level before proceeding

Because there's a current lawsuit (which will be settled in a southern state) where the MD didn't check the K level and the hospital next door routinely checked the levels on these dialysis patient.

Patient was executive and they are probably going to settle for 2 million. MD has 3-5 million policy. Obviously they check K+ level during code and it came back very high (of course K levels go up during codes). But MD looked horrible because he can't explain why he didn't check it before besides saying it's not needed based on previous studies but couldn't explain why the hospital next door routinely did renal labs on all their renal patient.

 

[Idiopathic]

then check it and use that as your basis. its absolutely reasonable to have this information before taking a patient for surgery. i can see how you could make a case to take the patient to surgery also.

 

[Idiopathic]

Because there's a current lawsuit (which will be settled in a southern state) where the MD didn't check the K level and the hospital next door routinely checked the levels on these dialysis patient.

Patient was executive and they are probably going to settle for 2 million. MD has 3-5 million policy. Obviously they check K+ level during code and it came back very high (of course K levels go up during codes). But MD looked horrible because he can't explain why he didn't check it before besides saying it's not needed based on previous studies but couldn't explain why the hospital next door routinely did renal labs on all their renal patient.

im not sure how this plays in court (badly, i suppose) but standard of care is not defined as "what the hospital next-door does". unfortunately, it seems that we only get recommendations on what to do when the K+ is above 6 (delay non emergent surgery) rather than recommendations on who/when to check K+.

 

[Jay K]

I'd get the K+. EKG if the K+ is elevated. You've got little ground to stand on if things went awry (and for an elective case at that) and a K+ wasn't drawn irrespective of anesthetic plan. I don't want my hands tied, if I needed to give succ and didn't know the K+ ahead of time.

 

[Laryngophed]

I'd get the K+. EKG if the K+ is elevated. You've got little ground to stand on if things went awry (and for an elective case at that) and a K+ wasn't drawn irrespective of anesthetic plan. I don't want my hands tied, if I needed to give succ and didn't know the K+ ahead of time.

Wouldn't there have been an EKG prior to starting the case? If so, if there are no abnormalities, would it be inappropriate to continue without the K+? At what point does the increase in K+ start to cause electrophysiological changes that are evident on EKG and detrimental to the patient?

ETA - Sorry, I picked EKG because as the anesthesiologist you could quickly read it and it is quick and should be fairly cheap to obtain prior to the operation. It would seem more useful because it would seem that the state of the heart is of the utmost concern with most other measures falling to second place.

I don't know jack, (man, med school has almost made that my surname. Hi, I'm XX, I don't know jack...) but it was just a thought.

 

[pgg]

At what point does the increase in K+ start to cause electrophysiological changes that are evident on EKG and detrimental to the patient?

It depends. Chronic aberrations don't have nearly the physiologic effect that acute aberrations do. The 'why' and the context matter more when weighing the risks and benefits of continuing with surgery or postponing.

ETA - Sorry, I picked EKG because as the anesthesiologist you could quickly read it and it is quick and should be fairly cheap to obtain prior to the operation.

Just because a test is noninvasive, fast, safe, and relatively inexpensive (though keep in mind the "cost" of an ECG isn't just the cost of an 8.5 x 11 sheet of pink paper and a minute of the anesthesiologist's time) ... that doesn't mean everyone should get it.

As a general theme (which applies to every field of medicine) if you get in the habit of ordering unnecessary tests because they're cheap/fast/safe at some point luck and the bell curve are going to guarantee that you'll get abnormal results. 5% of the population by definition has lab values more than 2 standard deviations from the mean; many people have nonspecific findings on ECGs or radiology studies.

What do you do with an abnormal result from a test that wasn't indicated in the first place? You're obligated to follow up on it, or document why you don't care. Even if the initial test was safe and cheap, the followup studies or the consequences of delaying surgery may be risky and expensive.

The ideal we should all strive for is to never order a test without a compelling reason. A corollary to that is to not order a test if it doesn't have the potential to change your management.


ETA - to answer the original question, I'd want to see a K unless (as Idiopathic noted) there was evidence that the patient has been consistently well managed and stable.

 

[proman]

I wouldn't do a case in an HD patient who missed a treatment without knowing the K. Maybe overly cautious but the missing treatment makes me suspect.

 

[Arch Guillotti]

I wouldn't do a case in an HD patient who missed a treatment without knowing the K. Maybe overly cautious but the missing treatment makes me suspect.

agree completely.

If they were recently dialyzed, are reliable compliant and for a minor procedure then i probably wouldn't get one. Unless there was some compelling reason I wouldn't get an ekg.

I think a lot of the labs that are ALWAYS ordered are silly but a pre-op K+ in noncompliant dialysis patient is a no-brainer for me.

 

[Laryngophed]

It depends. Chronic aberrations don't have nearly the physiologic effect that acute aberrations do. The 'why' and the context matter more when weighing the risks and benefits of continuing with surgery or postponing.



Just because a test is noninvasive, fast, safe, and relatively inexpensive (though keep in mind the "cost" of an ECG isn't just the cost of an 8.5 x 11 sheet of pink paper and a minute of the anesthesiologist's time) ... that doesn't mean everyone should get it.

As a general theme (which applies to every field of medicine) if you get in the habit of ordering unnecessary tests because they're cheap/fast/safe at some point luck and the bell curve are going to guarantee that you'll get abnormal results. 5% of the population by definition has lab values more than 2 standard deviations from the mean; many people have nonspecific findings on ECGs or radiology studies.

What do you do with an abnormal result from a test that wasn't indicated in the first place? You're obligated to follow up on it, or document why you don't care. Even if the initial test was safe and cheap, the followup studies or the consequences of delaying surgery may be risky and expensive.

The ideal we should all strive for is to never order a test without a compelling reason. A corollary to that is to not order a test if it doesn't have the potential to change your management.


ETA - to answer the original question, I'd want to see a K unless (as Idiopathic noted) there was evidence that the patient has been consistently well managed and stable.

Understood and thanks!

 

[Idiopathic]

you assume hes noncompliant but what if hes a T/TH/Sa patient, its Friday and hes never missed an appt before, has good exercise tolerance and is clearly not volume overloaded. I think barring anything crazy on the monitor, I do this case (hell, I probably even give sux)

most of the problems with hyperK are with acute rapid changes in potassium. A bag of blood can have 80mEq of potassium in it at its peak. Ive given 4 units rapidly and seen acute hyperkalemic arrest, and the Mayo clinic reported on a series a few years back where they had several arrests from similar scenarios and the K usually peaked in the 4.5 range, so there you have it, a jump from 2.5 to 5.0 is way more concerning than someone who lives at 5.2 and goes to 6.0

 

[proman]

you assume hes noncompliant but what if hes a T/TH/Sa patient, its Friday and hes never missed an appt before, has good exercise tolerance and is clearly not volume overloaded. I think barring anything crazy on the monitor, I do this case (hell, I probably even give sux)

Ignore his noncompliance at your own peril. The scenario presented is a ESRD patient who has skipped a treatment. It's a judgement call, but like Arch said, this one, to me, is a no brainer.

 

[proman]

Ive given 4 units rapidly and seen acute hyperkalemic arrest, and the Mayo clinic reported on a series a few years back where they had several arrests from similar scenarios and the K usually peaked in the 4.5 range, so there you have it, a jump from 2.5 to 5.0 is way more concerning than someone who lives at 5.2 and goes to 6.0

The 4.2 value was mean preoperative K level. I question the notion that chronic hyper or hypokalemia is protective or harmful in the event of an acute rise from baseline. Is there evidence that supports this?


Anesth Analg. 2008 Apr;106(4):1062-9, table of contents.
Cardiac arrests associated with hyperkalemia during red blood cell transfusion: a case series.
Smith HM, Farrow SJ, Ackerman JD, Stubbs JR, Sprung J.

Department of Anesthesiology, College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Abstract
BACKGROUND: Transfusion-associated hyperkalemic cardiac arrest is a serious complication of rapid red blood cell (RBC) administration. We examined the clinical scenarios and outcomes of patients who developed hyperkalemia and cardiac arrest during rapid RBC transfusion.

METHODS: We retrospectively reviewed the Mayo Clinic Anesthesia Database between November 1, 1988, and December 31, 2006, for all patients who developed intraoperative transfusion-associated hyperkalemic cardiac arrest.

RESULTS: We identified 16 patients with transfusion-associated hyperkalemic cardiac arrest, 11 adult and 5 pediatric. The majority of patients underwent three types of surgery: cancer, major vascular, and trauma. The mean serum potassium concentration measured during cardiac arrest was 7.2 +/- 1.4 mEq/L (range, 5.9-9.2 mEq/L). The number of RBC units administered before cardiac arrest ranged between 1 (in a 2.7 kg neonate) and 54. Nearly all patients were acidotic, hyperglycemic, hypocalcemic, and hypothermic at the time of arrest. Fourteen (87.5%) patients received RBC via central venous access. Commercial rapid infusion devices (pumps) were used in 8 of 11 (72.7%) of the adult patients, but RBC units were rapidly administered (pressure bags, syringe pumped) in all remaining patients. Mean resuscitation duration was 32 min (range, 2-127 min). The in-hospital survival rate was 12.5%.

CONCLUSION: The pathogenesis of transfusion-associated hyperkalemic cardiac arrest is multifactorial and potassium increase from RBC administration is complicated by low cardiac output, acidosis, hyperglycemia, hypocalcemia, and hypothermia. Large transfusion of banked RBCs and conditions associated with massive hemorrhage should raise awareness of the potential for hyperkalemia and trigger preventative measures.

 

[Idiopathic]

ill have to go back and revisit that article, i did get the impression that the authors argued the absolute K was not as important as the delta, and more than one textbook supports the claim that chronic elevations in K are much better tolerated than acute rises, even those that may be to lower absolute values.

 

[aneftp]

Update: So I went ahead and just got K level (it was 5.8); my cutoff for renal patients is usually 6.0; it could be slightly higher since they probably tolerate higher K levels and EKG was non-specific. Did the case under general, no issues.

 

[Idiopathic]

nice, although i am surprised the K was that high

 

[sevoflurane]

ill have to go back and revisit that article, i did get the impression that the authors argued the absolute K was not as important as the delta, and more than one textbook supports the claim that chronic elevations in K are much better tolerated than acute rises, even those that may be to lower absolute values.

This is correct.

Ironically, hypokalemia is more common than hyperkalemia with blood transfusions.

 

[cchoukal]

Knowing the K was borderline, did you use an LMA and risk an elevated K from the respiratory acidosis?

 

[dhb]

A bag of blood can have 80mEq of potassium in it at its peak.

Do you mean 80mEq/l because 80mEq per bag is kinda dangerous?

 

[proman]

This is correct.

Ironically, hypokalemia is more common than hyperkalemia with blood transfusions.

I'm not sure it's correct. It's definitely the common thinking. Today I curbsided a nephrologist I know who thinks it's a myth. I've found an article that shows the OR of mortality in chronic kidney disease with hyperkalemia is 2.7. There is one paper:

Eight cases had clear documentation that the case proceeded with hyperkalemia. Anesthesia techniques were one general anesthetic, one regional block, five monitored anesthesia care (MAC), and one local infiltration only. Mean potassium was 6.9 mmol·L−1 (range 6.1–8.0). In this series of selected asymptomatic hyperkalemic patients undergoing low risk surgery, no adverse results occurred.

Is this the best evidence showing chronic hyperkalemia is well tolerated? Just looking for something more convincing.

 

[Idiopathic]

Do you mean 80mEq/l because 80mEq per bag is kinda dangerous?

yeah sorry, I think they give 100mEq during lethal injection so 80 per bag would be pretty ridiculous huh