December FY21

[clawry]

December's article Blood Pressure and the Brain: How Low Can You Go? has been submitted by LaSharVea Bailey, CRNA. This article provides an excellent review of cerebral blood flow, autoregulation, and CNS blood flow reserve and how these factors are affected by blood pressure. This article is pertinent to neuroanesthesia as well as general cases.

Here is a link to the article.

journals.lww.com/anesthesia-analgesia/fulltext/2019/04000/blood_pressure_and_the_brain__how_low_can_you_go_.21.aspx


1. Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article?


2. Are the findings in this article significant such that it prompts a modification of your practice?

[LarSharVeA Bailey]

Pushing the lower limits of the customarily recommended mean arterial pressures (MAPs) can be dangerous. The article places emphasis on the cerebral blood flow reserve phenomenon, which can be compromised in patients with recent CNS injury, chronic hypertension, loss or impairment of collateral blood flow pathways, raised local tissue pressure, and vertical positioning. Although the article seeks to distinguish this phenomenon from autoregulation, the principle is very much the same. Thus, my recommendation for a MAP > 70 persists, with the exception for vibrant, healthy patients who exist with a MAP substantially lower on a day-to-day basis.

There are cases where a temporary reduction in MAPs are necessary, orthopedic surgery being chief amongst those. Poor visibility from an increased hydrostatic pressure impedes the ability to see under the scope. Still, I am a huge proponent of esmolol where a reduction in MAP is ephemeral, thus little compromise to cerebral perfusion. A MAP of 70 is a decent buffer to avoid ischemic symptoms, sometimes even higher is necessary.

[Jessica Switzman]

The Cerebral Blood Flow Reserve phenomenon in this article is very similar to the principle of autoregulation. I practice striving for a MAP of 70 except with young, healthy patients. Patients with underlying co morbidities can be compromised when MAP are allowed to trend lower. Of course, temporary reductions in BP are exceptable with certain procedures; i.e. orthopedic surgery on healthy patients. I will not be modifying my practice based on this article.

[kels]

I agree that the principles of cerebral blood flow regulation and autoregulation are similar. I too aim to keep maps towards the 70 mark in patients with comorbidities. In cases where lower BP s are requested I do have a discussion with the surgery team and my attending to make sure we are all on board with lowering a persons blood pressure who has comorbidities. I will not be changing my practice.

[Dahlia Rouchon]

After review and consideration of the article, the lower limits of MAP should always still be patient specific, cognizant we are working in anesthetized patients not un-anesthetized patients, and positioning should always be a factor when managing BP readings. It does not change my manner of practice in that I attempt to keep MAPs at 70 but also within 20% of baseline BP for hypertensive patients, or those with cardiac and CNS disease. BPs must be corrected before the next BP reading is presented.

[Ben Waldbaum]

1. Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article?
interesting, but hard to apply to a specific patient.


2. Are the findings in this article significant such that it prompts a modification of your practice?
I have never been willing to go as low as suggested in this article. In fact, I don't think most are willing to go that low. As the author admits, it is patient specific and his suggestions are not based on outcome data, which he also admits. This article will not change my practice in any way.

[Amy Swank CRNA]

The article presented some excellent thoughts and review of cerebral blood flow autoregulation.  However, with anesthesia and an otherwise healthy individual with a baseline MAP of 70 fully alert, I would hesitate to chase the MAP of 70 or above with anesthesia. The article did refer to considerable inter-subject variability, which is always good to keep in mind, although the gist of the article really didn't support that view.  
I will be more cognizant of the science and the auto-regulation, but will continue to give individual's some leeway when the patient's health status supports it.  

[christine velarde]

The article sheds light to the MAP of 70 and what previous thoughts on cerebral perfusion MAPS should be. I think I would now aim for a higher MAP and keep in mind all confounding factors that exist for each patient.
I think that I would like to see higher MAPS and see what expectations of MAPS may be for the surgical procedure, depending on position and type of procedure (Neuro).

[nanci]

1) Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article? I don't feel comfortable going below a MAP 65 and tend to keep them higher if possible. Thoughts on a lower level of MAP presented in the article may be patient specific but not something I would routinely do intentionally.



2. Are the findings in this article significant such that it prompts a modification of your practice?
No, I don't think I will change my practice based on this article.

[Wai-Ling Lo]

1. Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article?
It is good to know about the cerebral blood flow reserve phenomenon. But like many other have said, the lower level of MAPs should be patient/procedure specific. Given the risks of all potential complications with hypoperfusion to various organs from lower MAP, I will not feel comfortable to allow lower MAPs deliberately.


2. Are the findings in this article significant such that it prompts a modification of your practice?
No, I won't change my practice based on this article.

[Soo-Ok Kim]

1. Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article?
It is interesting and gives different approach to manage BP during anesthesia. But, BP control should be patient and case specific. It is hard to general to all cases. 


2. Are the findings in this article significant such that it prompts a modification of your practice?
No. The evidence from the article doesn't convince to change my current practice. 

[mary clothier]

1 The article gives great information on the cerebral blood flow phenomenon, the lower levels of MAPs should probably only be approached deliberately when the exigencies of the surgical situation absolutely require it.

2. The article findings confirm my current practice to keep the MAP at 70 mm Hg in normotensive human beings for autoregulation.

[clawry]

1. Given the presentation of the cerebral blood flow reserve phenomenon, what are your thoughts on the lower levels of MAP presented in the article?


I will still maintain appropriate MAP's for the specific patient. We nee to assess patient's baseline and make sure that we customize MAP levels for that particular patient. MAP levels going to low is dangerous and I will avoid that practice.




2. Are the findings in this article significant such that it prompts a modification of your practice?

No, I will continue to be vigilant in maintaining appropriate MAP levels for the individual patient for whom I am caring for.