Elective Surgery and Decreased GFR

[BLADEMDA]

I routinely see patients with GFRs less than 60 in the preop holding area. These patients are typically elderly but asymptomatic for both renal and Cardiovascular disease. Some are having moderate to major surgery. Our current approach is to proceed with the case if their mets are over 4 and they asymptomatic.

Recent evidence strongly suggests a deceased GFR is associated with higher postop morbidty and mortality.

http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1918631

Should patients with chronically low GFR get more preop testing such as a stress test? Do any of you view the GFR as a marker for increased perioperative risk?

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[BLADEMDA]

What We Already Know about This Topic

• Estimated glomerular filtration rate is a better estimate of kidney function than increased creatinine concentration
  

What This Article Tells Us That Is New

• This meta-analysis of 49 studies finds that estimated glomerular filtration rate less than 60 ml·min·1.73 m−2 is associated with a three-fold increase in 30-day mortality
  
  
• There was a strong nonlinear increase in mortality at lower preoperative estimated glomerular filtration rates
  

 

[BLADEMDA]

Potential interventions might be to limit the use of perioperative nephrotoxins and/or increase the intensity of postoperative observation in patients identified as being at high risk. In addition, because patients with kidney dysfunction are at increased risk for adverse cardiovascular outcomes after major surgery they may benefit from aggressive treatment of atherosclerotic risk factors and potentially the targeted use of therapeutic interventions such as statin therapy.78 Similarly, interventions such as N-acetyl cysteine79 might potentially be used to prevent renal injury.

http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1918631

 

[BLADEMDA]

http://www.csen.com/renal.pdf

Really not much to add except maintain adequate volume status. Regional anesthesia like SAB may be superior to GA with volatile agent but that hasn't been proven yet.

 

[Arch Guillotti]

Stop checking so many labs.

 

[BLADEMDA]

Perioperative MACCE increase with declining eGFR, primarily when <45 ml min−11.73 m−2. We recommend the use of preoperative eGFR for cardiovascular risk assessment.

Editor's key points

• Chronic kidney disease is an important risk factor for perioperative complications.
  
  
• In a post hoc analysis of a previous outcomes study, estimated glomerular filtration rate (eGFR) was assessed as a predictor of complications after non-cardiac surgery.
  
  
• Major adverse cardiovascular and cerebrovascular events correlated inversely with preoperative eGFR.
  
  
• This index of kidney function is useful for cardiovascular risk assessment in non-cardiac surgery.

https://academic.oup.com/bja/articl...perative-estimated-glomerular-filtration-rate

 

[Mman]

sicker patients have worse outcomes. The only real questions are can you do something to decrease that risk and at what point in the preop process should that decision be made. By the time I see them in preop holding, they are having surgery and there isn't much of anything I can do other than my routine care to change their risk of a bad outcome.

 

[BLADEMDA]

sicker patients have worse outcomes. The only real questions are can you do something to decrease that risk and at what point in the preop process should that decision be made. By the time I see them in preop holding, they are having surgery and there isn't much of anything I can do other than my routine care to change their risk of a bad outcome.

Now you know that low eGFR is another significant marker for CV disease. The evidence is pretty clear on that point. This may or may not change your approach to the case. Perhaps the use of an arterial line to closely monitor the BP?

I realize the limited utility of using the eGFR in making day to day clinical decisions in private practice. Still, it's something to think about when we preop our patients.

 

[Mman]

Now you know that low eGFR is another significant marker for CV disease. The evidence is pretty clear on that point. This may or may not change your approach to the case. Perhaps the use of an arterial line to closely monitor the BP?

I realize the limited utility of using the eGFR in making day to day clinical decisions in private practice. Still, it's something to think about when we preop our patients.

I thought we already knew that significant renal disease was associated with vascular disease. Is this supposed to be something new?

 

[BLADEMDA]

I thought we already knew that significant renal disease was associated with vascular disease. Is this supposed to be something new?

Many of these patients are asymptomatic and unaware they have kidney disease.
An eGFR of 50-55 is something I see quite often but the creatinine itself isn't particularly high. Many times the primary care physician hasn't indicated any CKD (stage 1 or 2) on the chart.

 

[Mman]

Many of these patients are asymptomatic and unaware they have kidney disease.
An eGFR of 50-55 is something I see quite often but the creatinine itself isn't particularly high. Many times the primary care physician hasn't indicated any CKD (stage 1 or 2) on the chart.

Most of my patients are unaware of anything having to do with their health. Do you have diabetes? No? What is this metformin and glyburide for and why is your A1C 7? Because you are "borderline"?

 

[BLADEMDA]

Below shows the five stages of CKD and GFR for each stage:

• Stage 1 with normal or high GFR (GFR > 90 mL/min)
• Stage 2 Mild CKD (GFR = 60-89 mL/min)
• Stage 3A Moderate CKD (GFR = 45-59 mL/min)
• Stage 3B Moderate CKD (GFR = 30-44 mL/min)
• Stage 4 Severe CKD (GFR = 15-29 mL/min)
• Stage 5 End Stage CKD (GFR <15 mL/min)

 

[BLADEMDA]

I thought we already knew that significant renal disease was associated with vascular disease. Is this supposed to be something new?

Yes. I've seen this "link" between renal disease and CV disease first hand. At my institution about 4 patients with stage 4 or 5 CKD have coded and died in the O.R. Under anesthesia (in the past 20 years). All were receiving general anesthetics at the time.

In addition, I've had a few renal failure patients die 24-48 hours after surgery in the hospital. This is a high risk population.

The question is how aggressive one gets with undiagnosed Stage 3 CKD in the preop area prior to surgery. We now know that Stage 3 is linked with CV disease and Major coronary events perioperatively.

 

[Planktonmd]

Chronic kidney disease definitely indicates increased risk of perioperative mortality and morbidity because almost always the CKD is a result of other chronic diseases like poorly controlled DM or HTN or heart failure.
So CKD can be seen as a marker of severity for those other chronic diseases that have reached a point of causing end-organ damage.
So as long as these etiologies are addressed adequately pre-op (better control of DM or HTN or heart disease...) there isn't much to do about the CKD itself other than avoid causes of renal hypoperfusion intra-op and minimize surgical stress with multimodal analgesia.

 

[GravelRider]

The question is how aggressive one gets with undiagnosed Stage 3 CKD in the preop area prior to surgery. We now know that Stage 3 is linked with CV disease and Major coronary events perioperatively.

Avoid hypoxia and hypotension.

I think beyond avoiding obvious nephrotoxins, paying closer attention to volume status and maybe having a slightly quicker trigger to transfuse, there isn't much more we can do to mitigate risk of adverse perioperative events. I think treating this patients as if they have CAD is probably the best bet.

 

[drmwvr]

Should patients with chronically low GFR get more preop testing such as a stress test? Do any of you view the GFR as a marker for increased perioperative risk?

If stress testing for patients coming for even moderate risk vascular surgery isn't useful, this wouldn't be. If the risk is present, treat the patient as such and do the case.

 

[BLADEMDA]

If stress testing for patients coming for even moderate risk vascular surgery isn't useful, this wouldn't be. If the risk is present, treat the patient as such and do the case.

Easy to post these things when you haven't had patients die perioperatively on you. I guarantee that after a few of these renal patients (Stage 4 or 5) die in the O.R. the risk will become all too real for you. The screening process is too lax in my opinion as these patients are at high risk of mortality. Despite these deaths nothing has changed in terms of preop testing at my institution. I am very cognizant of their increased risk and avoid GA whenever possible (despite lack of evidence this decreases mortality). In addition, I place arterial lines frequently in this population.

 

[BLADEMDA]

Stop checking so many labs.

Serum creatinine level for people older than 50 years

http://emedicine.medscape.com/article/285191-overview#a3

My patient population is primarily ASA3 and ASA4 as such requires some preop labs.

https://perioperativemedicinejournal.biomedcentral.com/articles/10.1186/s13741-015-0023-y

 

[BLADEMDA]

Conclusions Preoperative non-invasive cardiac stress testing is associated with improved one year survival and length of hospital stay in patients undergoing elective intermediate to high risk non-cardiac surgery. These benefits principally apply to patients with risk factors for perioperative cardiac complications.

http://www.bmj.com/content/340/bmj.b5526

 

[BLADEMDA]

About 20% of my patient population undergoing intermediate operations has at least one risk factor (if not 2 or more) and poor or unknown functional capacity; yet, these patients are not getting any stress tests or TTE/TEE prior to surgery:

"Our results are largely consistent with the position of the American College of Cardiology and American Heart Association guidelines, which emphasise stress testing specifically in individuals who are undergoing intermediate to high risk surgery and have one or more clinical risk factors (for example, ischaemic heart disease, congestive heart failure, cerebrovascular disease, diabetes, or renal insufficiency).5 These guidelines also suggest, however, that testing be restricted to individuals who concurrently have poor or unknown functional capacity"

http://www.bmj.com/content/340/bmj.b5526

I would like to add that eGFR less than 60 may indeed be a risk factor. Certainly, an eGFR less than 45 is a clinical risk factor.

 

[drmwvr]

Easy to post these things when you haven't had patients die perioperatively on you. I guarantee that after a few of these renal patients (Stage 4 or 5) die in the O.R. the risk will become all too real for you. The screening process is too lax in my opinion as these patients are at high risk of mortality. Despite these deaths nothing has changed in terms of preop testing at my institution. I am very cognizant of their increased risk and avoid GA whenever possible (despite lack of evidence this decreases mortality). In addition, I place arterial lines frequently in this population.

Have we met? That aside, morbidly ill patients that die perioperatively don't die on "me", they die despite me and the surgeons and whatever other medical staff that are involved in their care. Sounds as though you are as thoughtful with these patients as I am.

Furthermore, would that sending for stress testing were the end of their experience with the cardiologists. That inevitably leads to more coronary angiography which carries it's own risks for these patients and doesn't change a single thing I or the surgeons do.

 

[BLADEMDA]

Have we met? That aside, morbidly ill patients that die perioperatively don't die on "me", they die despite me and the surgeons and whatever other medical staff that are involved in their care. Sounds as though you are as thoughtful with these patients as I am.

Furthermore, would that sending for stress testing were the end of their experience with the cardiologists. That inevitably leads to more coronary angiography which carries it's own risks for these patients and doesn't change a single thing I or the surgeons do.

The evidence isn't as clear cut as you would like to believe. Please respond to the above study which showed IT DID MAKE A DIFFERENCE in the right patient population. The pressure is always on to move the case along even when cardiac evaluation with a stress test is exactly what I would want for my family member especially one with Stage 3 CKD and unknown functional capacity.

http://www.bmj.com/content/340/bmj.b5526

 

[BLADEMDA]

Have we met? That aside, morbidly ill patients that die perioperatively don't die on "me", they die despite me and the surgeons and whatever other medical staff that are involved in their care. Sounds as though you are as thoughtful with these patients as I am.

Furthermore, would that sending for stress testing were the end of their experience with the cardiologists. That inevitably leads to more coronary angiography which carries it's own risks for these patients and doesn't change a single thing I or the surgeons do.

I have more than a few anecdotal stories of patients that I have cancelled for a procedure who got a coronary stent or CABG prior to returning 6 months later for their intermediate surgery. These are real people who would have died perioperatively. The guidelines as published are inadequate in my opinion. The pressure in the system is to "move them along" despite the increased risk regardless of whether coronary interventions would be beneficial.

 

[nimbus]

I have more than a few anecdotal stories of patients that I have cancelled for a procedure who got a coronary stent or CABG prior to returning 6 months later for their intermediate surgery. These are real people who would have died perioperatively. The guidelines as published are inadequate in my opinion. The pressure in the system is to "move them along" despite the increased risk regardless of whether coronary interventions would be beneficial.

On average how many cases do you cancel every year?

 

[nimbus]

Yes. I've seen this "link" between renal disease and CV disease first hand. At my institution about 4 patients with stage 4 or 5 CKD have coded and died in the O.R. Under anesthesia (in the past 20 years). All were receiving general anesthetics at the time.

In addition, I've had a few renal failure patients die 24-48 hours after surgery in the hospital. This is a high risk population.

The question is how aggressive one gets with undiagnosed Stage 3 CKD in the preop area prior to surgery. We now know that Stage 3 is linked with CV disease and Major coronary events perioperatively.

We can agree that patients with ESRD are the sickest of the sick, but to me there's a significant difference between a patient with low GFR and a creatinine of 2 and someone who's been on dialysis. The latter are much more fragile. It's like the COPD patient who plays golf vs the one who lives in a scooter chair on O2.

 

[fakin' the funk]

Bilateral renal venous oximetry catheters for all patients CrCl < 90

 

[dhb]

I have more than a few anecdotal stories of patients that I have cancelled for a procedure who got a coronary stent or CABG prior to returning 6 months later for their intermediate surgery.

Well acording to cards studies the one that got the stent did not get an improvement in mortality and the one that got surgery had maybe a couple of % improvement over medical treatment so technically there was little chance that you saved their lives by not doing the surgery.

 

[BLADEMDA]

Well acording to cards studies the one that got the stent did not get an improvement in mortality and the one that got surgery had maybe a couple of % improvement over medical treatment so technically there was little chance that you saved their lives by not doing the surgery.

Well, I'll never know for certain but I think we get away with a lot of our anesthetics despite the CAD. I'm concerned that these days the attitude is one of "just do the case" even when the functional capacity is unknown and there a lot of risk factors for significant CAD. We are doing patients today that 2 decades ago would have received full work-ups. While the "data" suggests we get away with an awful lot the level of care received by those with primo insurance is significantly better (IMHO) that those who have a governmental payor like CMS.

The fancy hospital up the road will readily order any and all testing like TTE/Stress Test, etc on their private insurance patients (Most of whom are much healthier) vs the public facility where the attitude is "just do the case." Sure, that fancy hospital is "over-testing" their patients to make money but IMHO that is better than "no work-ups whatsoever" in ASA3 and 4 patients undergoing moderate risk surgeries who have several risk factors for CAD along with unknown functional capacity.

 

[BLADEMDA]

On average how many cases do you cancel every year?

I'd say about 1% of cases get "delayed" for additional work-ups. I push REGIONAL heavily on those subgroups at high risk of CAD.

 

[BLADEMDA]

Well acording to cards studies the one that got the stent did not get an improvement in mortality and the one that got surgery had maybe a couple of % improvement over medical treatment so technically there was little chance that you saved their lives by not doing the surgery.

I've read all the literature. I know what the experts claim the "standard of care" is for our specialty. But, a perioperative MACE can be lethal to that particular patient. I've seen it more than a few times and I can assure you all these "recommendations" were followed prior to the case:

http://www.clevelandclinicmeded.com...c-risk-stratification-for-noncardiac-surgery/

• For patients with at least one clinical risk factor and poor or unknown functional capacity, who require intermediate-risk or vascular surgery, noninvasive stress testing may be considered if it will change management (class IIb).

At the private hospital the patient gets the stress test while at the public facility (CMS) the patients gets "considered" for about 1 minute before the decision is made not to do the test.

http://riskcalculator.facs.org/RiskCalculator/PatientInfo.jsp

 

[Arch Guillotti]

I have more than a few anecdotal stories of patients that I have cancelled for a procedure who got a coronary stent or CABG prior to returning 6 months later for their intermediate surgery.

I have a few anecdotes of patients who had the full cardiac workup and "clearance" and still managed to have the big one intraop or postop.

 

[BLADEMDA]

I have a few anecdotes of patients who had the full cardiac workup and "clearance" and still managed to have the big one intraop or postop.

I realize "clearance" doesn't guarantee outcome and neither does a stress test. But, the current recommendations are rather vague in this subgroup of patients with unkown or poor functional capacity. As I have posted, my facility just proceeds with the case unless the Anesthesiologist has a valid reason for delaying the case. Unfortunately, 3-4 risk factors and unknown functional capacity for an elective intermediate surgery aren't typically enough at my facility to request a stress test.

Somehow "I followed the guidelines" just doesn't seem to cut the mustard when that subgroup has a MACE intraop or postop. I realize that some of you will just say "it comes with territory" but that doesn't make it any easier after a few of these "events" actually happen to your patients.

 

[Mman]

Somehow "I followed the guidelines" just doesn't seem to cut the mustard when that subgroup has a MACE intraop or postop. I realize that some of you will just say "it comes with territory" but that doesn't make it any easier after a few of these "events" actually happen to your patients.

In the end, high risk patients are going to have bad outcomes if you take care of enough of them. That is what happens. It does come with the territory. No it isn't any easier when you have to tell the family that they died, but that doesn't mean more testing would have made a difference. At some point, you have to use evidence based medicine and when the best evidence says more testing isn't going to change the risk, well then you don't need any more testing.

 

[Ronin2258]

Avoid hypoxia and hypotension.

I think beyond avoiding obvious nephrotoxins, paying closer attention to volume status and maybe having a slightly quicker trigger to transfuse, there isn't much more we can do to mitigate risk of adverse perioperative events. I think treating this patients as if they have CAD is probably the best bet.

Has anyone addressed the chloride load with normal saline and the hypercholremic metabolic acidosis and potential renal damage? The ICU team where I am are paranoid enough about it that they actually use a mix of half-normal saline and sodium acetate to avoid it. Basically, it's Plasmalyte without the potassium (concern for hyperkalemia as well.)

BTW, like copying memes from Facebook, copying Blade's links to an e-mail to read later at my own leisure.

 

[nimbus]

Has anyone addressed the chloride load with normal saline and the hypercholremic metabolic acidosis and potential renal damage? The ICU team where I am are paranoid enough about it that they actually use a mix of half-normal saline and sodium acetate to avoid it. Basically, it's Plasmalyte without the potassium (concern for hyperkalemia as well.)

BTW, like copying memes from Facebook, copying Blade's links to an e-mail to read later at my own leisure.

One of my favorite topics. I hate abnormal saline

https://emcrit.org/pulmcrit/myth-bu...s-safe-in-hyperkalemia-and-is-superior-to-ns/

 

[Robotic Wis-Hipple]

The question isn't if any degree of renal failure impacts perioperative mortality. The question is what would you do about it? If they can reach >4 METS, or have had a recent negative stress test what else are you going to do? A-line everybody, make the surgeon do the case open, etc? What's the NNT to reduce 4 or 5 anecdotally attributed periop deaths in a career to 0? I don't see GFRs of 59 leading to abrupt intraoperative coding.

Patients with renal failure without obstructive CAD despite obvious associated conditions of atherosclerosis, HTN, DM, and +\- smoking make me maintain a realistic perfusion pressure and straddle the line of appropriate fluid rescusitation to maintain euvolemia. I guess the academic answer is an a-line with a minimally invasive CO/SVV/PPV monitor for GDFT, but studies on these are atrocious and again, what's the NNT?.....

 

[BLADEMDA]

The question isn't if any degree of renal failure impacts perioperative mortality. The question is what would you do about it? If they can reach >4 METS, or have had a recent negative stress test what else are you going to do? A-line everybody, make the surgeon do the case open, etc? What's the NNT to reduce 4 or 5 anecdotally attributed periop deaths in a career to 0? I don't see GFRs of 59 leading to abrupt intraoperative coding.

Patients with renal failure without obstructive CAD despite obvious associated conditions of atherosclerosis, HTN, DM, and +\- smoking make me maintain a realistic perfusion pressure and straddle the line of appropriate fluid rescusitation to maintain euvolemia. I guess the academic answer is an a-line with a minimally invasive CO/SVV/PPV monitor for GDFT, but studies on these are atrocious and again, what's the NNT?.....

I think you need to re-read my posts. My venting here on this thread was in reference to patients presenting for Intermediate Surgery with poor (less than 4) or unknown functional capacity in addition to several risk factors for CAD. Many of my patients (20%) are in this category and have received NO WORK-UP whatsoever prior to their intermediate surgery. Some on SDN have posted that they think a work-up doesn't make one bit of difference; that is the consensus at my facility as well so unless I "delay" the case for a TTE (3% or so of the time in this subgroup) or cancel for a stress test (rare) the patient proceeds for surgery.

Every death or near death is seared into my memory forever. It's almost like anesthesia PTSD in the sense I will never forget those patients. I am a better Anesthesiologist as a result of these experiences but I'd be just fine, if not elated, to never have another one of them in my career.

 

[AdmiralChz]

I think someone has mentioned (or at least I am mentioning now) postoperative care - should we be monitoring these patients more closely for longer? Need more ICU TLC? Blade do you think this would have made a difference in your cases that had bad postoperative outcomes?

 

[BLADEMDA]

I think someone has mentioned (or at least I am mentioning now) postoperative care - should we be monitoring these patients more closely for longer? Need more ICU TLC? Blade do you think this would have made a difference in your cases that had bad postoperative outcomes?

Those with Renal Failure on dialysis or about to start dialysis are extremely high risk. Many have undiagnosed CAD and the stress of the surgery/anesthestic combined with the prothombotic nature of the operative period really puts them at risk. I've had 3 of these patients with borderline BP preoperatively (less than 100 systolic) die in the postop period (within 24 hours).

 

[BLADEMDA]

OCTOBER 14, 2015
Low Blood Pressure Greater Peri-op Risk for Death Than High BP
Very Large Database Finds:


BERLIN—Anesthesiologists are working harder to better understand preoperative risks that may influence perioperative care. According to one intriguing study of surgical risks, preoperative low blood pressure—as opposed to high blood pressure—is a risk factor for death.

The study, conducted by researchers in the United States and United Kingdom, looked at data from 250,000 patients to investigate the relationship between preoperative blood pressure and 30-day mortality after noncardiac surgery. They looked for hypertension as a risk factor, and were interested in understanding how the change in risk relates to increasing and decreasing blood pressure values. They expected to see drops in blood pressure as a risk factor but didn’t think the effects would present as strongly as they did.

“While we expected the extremes of blood pressure to be associated with increased risk, the lack of effect of hypertension was surprising. We were additionally surprised that only small drops in blood pressure exerted an effect, especially as these small changes survived the risk-factor adjustment,” said Robert Sanders, MBBS, PhD, FRCA, assistant professor of anesthesiology at the University of Wisconsin–Madison, who worked with Puja Myles, PhD, MPH, and Sudhir Venkatesan, MPH, at The University of Nottingham, in England, and other collaborators at the University of Southampton, Oxford University and University College London, also in England. “We think that lower blood pressure is underrecognized as a factor.”

ADVERTISEMENT
Sample Size Allows Precise Measurements

The large sample size gave them the statistical power to detect small differences, Dr. Sanders said. The study’s design prioritized a large number so that the researchers wouldn’t have arbitrary thresholds for blood pressure numbers. “To identify blood pressure thresholds for the change in postoperative risk, we focused on a data-driven approach to avoid biases,” Dr. Sanders said. Findings from the study were released at the Euroanaesthesia 2015 conference.

The group took two statistical approaches to the data, which analyzed 252,278 patients from the U.K. Clinical Practice Research Datalink. First, they identified 29 risk factors, such as age, sex, race, comorbidities, medications and surgical risk score, and adjusted for them in various regression models. Second, they adjusted for significant confounders to combat overadjusting for risk factors, which can lead to a loss of statistical power.

After the adjustment, the effects of preoperative systolic and diastolic hypertension were no longer associated with increased postoperative mortality. However, preoperative hypotension was associated with statistically significant increases. For example, the likelihood of death increased by 40% for patients with a systolic number below 100 mm Hg. For those with a diastolic number under 40 mm Hg, the likelihood of death increased 2.5 times. Values below 100/40 mm Hg showed the greatest risk.

At the Euroanaesthesia 2015 conference, other researchers were intrigued and surprised as well, Dr. Sanders said. His research team is developing a full manuscript to report on additional findings in the large database.

“Our working hypothesis is that patients with low blood pressure drop below a critical limit during the perioperative period and become vulnerable,” Dr. Sanders said. “The question is, what do we do about this?”

In the future, the team hopes to study how to modify risk to improve patient outcomes. Dr. Sanders and others want to amass a continuum of data to combine what they know about preoperative and perioperative states to understand the differences for patients who are injured. Then, the next step is to move into preoperative hemodynamics.

“My caution is that these are observational data, and it can’t prove causation,” he said. “But it’s a step toward causality, and it seems reasonable to me to consider these patients at an increased risk.”

Dr. Sanders and his colleagues don’t yet have recommendations or intervention guidelines for how this should be managed, but he noted that anesthesiologists at the bedside should be wary about patients who have low blood pressure before surgery.

“These patients are already potentially at a threshold where further drops could be problematic,” Dr. Sanders said. “Control of blood pressure remains important.”

 

[nimbus]

Those with Renal Failure on dialysis or about to start dialysis are extremely high risk. Many have undiagnosed CAD and the stress of the surgery/anesthestic combined with the prothombotic nature of the opeartive period really puts them at risk. I've had 3 of these patients with borderline BP preoperatively (less than 100 systolic) die in the postop period (within 24 hours).

We often don't think of ESRD as a terminal illness like advanced cancer but it is. I remember reading years ago the the average life expectancy after starting dialysis is 7 years. These patients have started the process of dying beginning with their kidneys. Then a toe here and a leg there. As for me I hope to go all at once.

 

[BLADEMDA]

We often don't think of ESRD as a terminal illness like advanced cancer but it is. I remember reading years ago the the average life expectancy after starting dialysis is 7 years. These patients have started the process of dying beginning with their kidneys. Then a toe here and a leg there. As for me I hope to go all at once.

The group you really need to worry about the most:

1. Renal Failure on Dialysis
2. DM
3. High Cholesterol
4. History of CAD (this really doesn't matter as they likely have it)

Then, the starting SBP is less than 100 in the holding area. If the bells aren't ringing yet they should be. My advice is to proceed with caution as this is one of the highest subgroups for periop mortality I have ever encountered.

 

[Mman]

Many of my patients (20%) are in this category and have received NO WORK-UP whatsoever prior to their intermediate surgery.

Can I assume they've at least had a 12 lead EKG? I mean that's some sort of workup. It isn't a stress test or echo, but it's something. From an evidence based POV, when you are referring to preop testing in a patient with risk factors for CAD (such as the DM2, HTN, ESRD patient) and poor functional status, what kind of further testing (if any) is indicated depends on the surgery. Low risk surgeries don't require any further preop testing, even if the patient has horrible functional status and lots of risk factors. High risk surgeries require further testing. Then again, it also depends on if you are going to change management. If the patient is coming in for revision of their dialysis access because it isn't really working, you can't really delay that for months without putting them at significant risk of other complications.


So does a poorly function ESRD patient coming for major vascular surgery require a stress test if they haven't had one in a while? Of course. If they are coming for declot of their arm graft? No way.

To me the biggest question in these patients is what constitutes "recent" in terms of cardiac testing. I mean I see patients that have had several caths and stress tests over the last 15 years. At what point is one recent enough that I don't need another. I tend to use changes in functional status or changes in their baseline 12 lead EKG as indicators for additional testing if it's been greater than 12 months since last. But if it's the same old gomer with nothing new and they had a stress echo 24 months ago? What is doing another going to add?

 

[deleted171991]

Then, the starting SBP is less than 100 in the holding area. If the bells aren't ringing yet they should be. My advice is to proceed with caution as this is one of the highest subgroups for periop mortality I have ever encountered.

A lot of young/middle-aged females have low baseline BP with no problems. I think the lowest preop BP for GA I have done was around 70 mmHg.

But I agree, if I see low BP in a patient where I expect hypertension, that can be bad news. The same way as a now normotensive but usually hypertensive inpatient might be cooking a sepsis.

Kidney disease is well known to increase mortality big time in everything, including the ICU. That's why avoiding AKI is one of the best things you can do for your patient. Which, by the way, means an intraop MAP of at least 75-80, even higher for hypertensives, not 65. I would almost argue that a touch of phenylephrine infusion is a good routine, especially in the absence of enough surgical stimulation.

Chronic kidney disease, especially ESRD, is associated with accelerated atherosclerosis, which means every CKD patient is a vascular patient. Same as with DM, but that's something most people know. That's why a creatinine of >2 mg/dl has been included in the RCRI for a long time, at the same level of significance with CAD, CHF, cerebrovascular disease, DM, and intermediate-risk/high-risk surgery. At 2 out of 6 risk factors, meaning most surgeries plus CKD, the MACE risk is 6.6%.

 

[BLADEMDA]

A lot of young/middle-aged females have low baseline BP with no problems. I think the lowest preop BP for GA I have done was around 70 mmHg.

But I agree, if I see low BP in a patient where I expect hypertension, that can be bad news. The same way as a now normotensive but usually hypertensive inpatient might be cooking a sepsis.

Kidney disease is well known to increase mortality big time in everything, including the ICU. That's why avoiding AKI is one of the best things you can do for your patient. Which, by the way, means an intraop MAP of at least 75-80, even higher for hypertensives, not 65. I would almost argue that a touch of phenylephrine infusion is a good routine, especially in the absence of enough surgical stimulation.

Chronic kidney disease, especially ESRD, is associated with accelerated atherosclerosis, which means every CKD patient is a vascular patient. Same as with DM, but that's something most people know. That's why a creatinine of >2 mg/dl has been included in the RCRI for a long time, at the same level of significance with CAD, CHF, cerebrovascular disease, DM, and intermediate-risk/high-risk surgery. At 2 out of 6 risk factors, meaning most surgeries and CKD, the MACE risk is 6.6%.

I'm with you on the MEAN BP issue: 75 is the new 65 in terms of the low end of the BP scale for many patients especially those with a history of HTN.

 

[BLADEMDA]

FEBRUARY 3, 2017
Hypotension During Bypass Increases Adverse Effects

Vancouver, british columbia—In one of the first studies of its kind, researchers at the University of Ottawa Heart Institute have found that hypotension during cardiopulmonary bypass is associated with postoperative cardiovascular accidents, such as stroke. The researchers also found evidence of a dose–response relationship with increasing severity and duration of hypotension.

“Although the etiology of stroke is multifactorial, hypotension is thought to play a key role,” began Amy M. Chung, MSc, a medical student at the University of Ottawa Faculty of Medicine, in Ontario. “However, no model to date has investigated the role of hypotension during distinct phases of cardiac surgery. Accordingly, our work sought to examine whether hypotension before, during and after bypass was associated with postoperative strokes.” Cerebrovascular accidents, she added, can occur in up to 10% of patients undergoing major cardiac surgery.

A Retrospective Study

To investigate the potential association between varying magnitudes and durations of intraoperative hypotension and postoperative cardiovascular accidents, Ms. Chung and her colleagues conducted a retrospective cohort study of 7,779 patients, all of whom underwent major cardiac surgery requiring cardiopulmonary bypass between November 2009 and June 2014. Patients undergoing off-pump procedures were excluded.

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The study’s primary exposure was longest duration of mean arterial pressure (MAP) less than 55, less than 65, and less than 75 mm Hg before, during and after bypass. The primary outcome was a postoperative ischemic cardiovascular event, defined as new focal or global neurologic deficit of cerebrovascular origin lasting at least 24 hours and nonhemorrhagic in nature.

The diagnosis of a cardiovascular event was verified by reviewing reported postoperative brain CT or MRI studies. Intraoperative invasive blood pressure measurements were recorded every 15 seconds in an electronic patient record; artifacts were removed using an automated algorithm.

As Ms. Chung reported at the 2016 annual meeting of the Canadian Anesthesiologists’ Society (abstract 151847), cardiovascular accidents occurred in 148 patients (1.9%) and were associated with any duration of MAP less than 75 mm Hg during cardiopulmonary bypass. What’s more, each additional 10 minutes of intraoperative hypotension with MAP less than 55 mm Hg was associated with a 17% increased odds of cardiovascular accidents (propensity-adjusted odds ratio [OR], 1.17; 95% CI, 1.07-1.28).

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Similar results were found for each additional 10 minutes of MAP less than 65 and less than 75 mm Hg, which were respectively associated with 9% (OR, 1.09; 95% CI, 1.03-1.16) and 5% (OR, 1.05; 95% CI, 1.01-1.10) increased odds of cardiovascular accidents. Pre– and post–cardiopulmonary bypass intraoperative hypotension were not associated with cardiovascular accidents.

Independent Risk Factors

“We also found that there was a dose-dependent relationship for greater deviations of mean arterial pressure from baseline,” Ms. Chung reported. “For a MAP decrease of 30%, there was a 10% increase in cardiovascular events for the during-bypass period. And for a MAP decrease of 50%, there was a 21% increase in events.”

The researchers also identified a variety of other independent risk factors for cardiovascular accidents. According to Ms. Chung, these included:

 

[BLADEMDA]

Anesthesiology. 2015 Aug;123(2):307-19. doi: 10.1097/ALN.0000000000000756.
Association between Intraoperative Hypotension and Hypertension and 30-day Postoperative Mortality in Noncardiac Surgery.
Monk TG1, Bronsert MR, Henderson WG, Mangione MP, Sum-Ping ST, Bentt DR, Nguyen JD, Richman JS, Meguid RA, Hammermeister KE.
Author information

Erratum in

• Association between Intraoperative Hypotension and Hypertension and 30-day Postoperative Mortality in Noncardiac Surgery: Erratum. [Anesthesiology. 2016]

Abstract
BACKGROUND:
Although deviations in intraoperative blood pressure are assumed to be associated with postoperative mortality, critical blood pressure thresholds remain undefined. Therefore, the authors estimated the intraoperative thresholds of systolic blood pressure (SBP), mean blood pressure (MAP), and diastolic blood pressure (DBP) associated with increased risk-adjusted 30-day mortality.

METHODS:
This retrospective cohort study combined intraoperative blood pressure data from six Veterans Affairs medical centers with 30-day outcomes to determine the risk-adjusted associations between intraoperative blood pressure and 30-day mortality. Deviations in blood pressure were assessed using three methods: (1) population thresholds (individual patient sum of area under threshold [AUT] or area over threshold 2 SDs from the mean of the population intraoperative blood pressure values), (2). absolute thresholds, and (3) percent change from baseline blood pressure.

RESULTS:
Thirty-day mortality was associated with (1) population threshold: systolic AUT (odds ratio, 3.3; 95% CI, 2.2 to 4.8), mean AUT (2.8; 1.9 to 4.3), and diastolic AUT (2.4; 1.6 to 3.8). Approximate conversions of AUT into its separate components of pressure and time were SBP < 67 mmHg for more than 8.2 min, MAP < 49 mmHg for more than 3.9 min, DBP < 33 mmHg for more than 4.4 min. (2) Absolute threshold: SBP < 70 mmHg for more than or equal to 5 min (odds ratio, 2.9; 95% CI, 1.7 to 4.9), MAP < 49 mmHg for more than or equal to 5 min (2.4; 1.3 to 4.6), and DBP < 30 mmHg for more than or equal to 5 min (3.2; 1.8 to 5.5). (3) Percent change: MAP decreases to more than 50% from baseline for more than or equal to 5 min (2.7; 1.5 to 5.0). Intraoperative hypertension was not associated with 30-day mortality with any of these techniques.

CONCLUSION:
Intraoperative hypotension, but not hypertension, is associated with increased 30-day operative mortality.


http://anesthesiology.pubs.asahq.org/article.aspx?articleid=2343033

 

[BLADEMDA]

Any time spent with a MAP of less than 55 mmHg during noncardiac surgery was independently associated with an increased risk of acute kidney injury and myocardial injury. As the time with a MAP of less than 55 mmHg increased so too did the risk for acute kidney injury and myocardial injury.

http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1918179

 

[BLADEMDA]

Anesthesiology. 2015 Sep;123(3):515-23. doi: 10.1097/ALN.0000000000000765.
Association of intraoperative hypotension with acute kidney injury after elective noncardiac surgery.
Sun LY1, Wijeysundera DN, Tait GA, Beattie WS.
Author information

• 1From the Department of Anesthesia, Toronto General Hospital and University of Toronto, Toronto, Ontario, Canada (L.Y.S., D.N.W., G.A.T., W.S.B.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (D.N.W.); Institute of Health Policy Management and Evaluation, Toronto, Ontario, Canada (D.N.W.); and Cardiovascular Research Program, Institute for Clinical Evaluative Sciences, Totonto, Ontario, Canada.

Abstract
BACKGROUND:
Intraoperative hypotension (IOH) may be associated with postoperative acute kidney injury (AKI), but the duration of hypotension for triggering harm is unclear. The authors investigated the association between varying periods of IOH with mean arterial pressure (MAP) less than 55, less than 60, and less than 65 mmHg with AKI.

METHODS:
The authors conducted a retrospective cohort study of 5,127 patients undergoing noncardiac surgery (2009 to 2012) with invasive MAP monitoring and length of stay of 1 or more days. Exclusion criteria were preoperative MAP less than 65 mmHg, dialysis dependence, urologic surgery, and surgical duration less than 30 min. The primary exposure was IOH. The primary outcome was AKI (50% or 0.3 mg/dl increase in creatinine) during the first 2 postoperative days. Multivariable logistic regression was used to model the exposure-outcome relationship.

RESULTS:
AKI occurred in 324 (6.3%) patients and was associated with MAP less than 60 mmHg for 11 to 20 min and MAP less than 55 mmHg for more than 10 min in a graded fashion. The adjusted odds ratio of AKI for MAP less than 55 mmHg was 2.34 (1.35 to 4.05) for 11- to 20-min exposure and 3.53 (1.51 to 8.25) for more than 20 min. For MAP less than 60 mmHg, the adjusted odds ratio for AKI was 1.84 (1.11 to 3.06) for 11- to 20-min exposure.

CONCLUSIONS:
In this analysis, postoperative AKI is associated with sustained intraoperative periods of MAP less than 55 and less than 60 mmHg. This study provides an impetus for clinical trials to determine whether interventions that promptly treat IOH and are tailored to individual patient physiology could help reduce the risk of AKI.

 

[Noyac]

I lost interest about post #10. But thanks for the info.

I check GFR on almost every pt. At least every one that has had labs. Been doing this for years.