June FY22

[kristenhorsman]

This month's journal article is presented by Belinda Gardner. She chose an article about a clinical scenario we face every day: perioperative hypotension.

Please use this link and answer the following two questions:


1). What is the MAP threshold associated with MINS (Myocardial injury after non-cardiac surgery)/ MI for both intraoperative and postoperative and which is more strongly associated with MI or death.

2). What should the MAP cutoff be and and length of time, to prevent increased risk for perioperative AKI and postoperative delirium? Do you have a vasopressor of choice and why? Will you change your management of intraoperative hypotension after reading this article?

[Matthew Soladay]

1- about 65mmHg for intraop. for postop SBP 90 used as threshold for hypotension (figure 5). Postoperative hypotension has greater risk of MI than intraoperative hypotension.
2- MAP < 55 for 5 minutes for AKI. MAP <65 for delirium (although cerebral autoregulation threshold unclear). My vasopressor of choice for intermittent hypotension in adults is phenylephrine, especially if it is secondary to induction of anesthesia. IV push in the prefilled syringes. I prefer norepinephrine for sepsis/shock as an infusion. I believe I will be more likely to treat intraoperative hypotension sooner, however, not by much as giving phenylephrine to bridge towards incision is a common practice.

[Anne McNulty]

(1) This article is definitely thought provoking. According to the article , the MAP threshold associated with MINS is map of 65 MM Hg. I review the patients BP in the preop area and Pre-op H&P. Patients with extensive vascular disease, may have a MAP much greater than MAP of 65 MM HG. The patients cerebral auto-regulation threshold may be much higher than 65 MM hg. The patient's surgical position is also a very serious consideration. I strive to keep the Pt MAP 20% or more than baseline. I find the graphs and figures in this artic difficult to follow. Figure 4 states that post-op hypotension of systolic pressure less than 90 mm hg may be clinically meaningful .Pt evaluation involves much more than a single number. Post-op BP management carries great risk of AKI, MI, cerebral ischemia and delirium. With the large number of out patient surgeries done currently, the statistics will be difficult to review. (2)Map cutoff is less than 55 hg for AKI. I wonder if this was done as a study in lab animals. Post -op delirium is a very complex issue. Prolonged hypotension will definitely be a contribution to this complication. I use phenylephrine and norepi based on pt comorbidities. I hope that in the future we well have cerebral perfusion monitoring devices in every room as well as devices such as clear site CO .

[nanci]

1). What is the MAP threshold associated with MINS (Myocardial injury after non-cardiac surgery)/ MI for both intraoperative and postoperative and which is more strongly associated with MI or death.

MAP threshold associated with MINS/MI intra operative is 65 mmHg
Postoperative hypotension is common and more strongly associated with MI and or death than intra operative hypotension.

2). What should the MAP cutoff be and and length of time, to prevent increased risk for perioperative AKI and postoperative delirium? Do you have a vasopressor of choice and why? Will you change your management of intraoperative hypotension after reading this article?

AKI: MAP cutoff of <55 mmHg for less than 5 minutes below this pressure for AKI
Postoperative delirium: when the MAP is below the lower limits of auto regulation which cerebral auto regulation limits may be unclear and variable between patients with the article stating that some patients base limits can be as high as 85 mmHg.
My current practice is to use Phenylephrine due to availability and that it works in most patients (article states to avoid use in patients with septic shock). Would be nice to see Norepinephrine premixed in our Pyxis machines for use as potentially more providers would use it more frequently or get an infusion running quicker for patients resistant to the larger dosing of Phenylephrine.

[aileenm4]

1. harm threshold MAP is 65 mmHG, , more than 90% of MINS and MI occur within the initial 2 days post op. post op hypotension is common and associated with major vascular events, MI and death and stroke. mortality in the 30 days after surgery is more than 100 times greater than intraoperative mortality.

2. AKI is 18% higher with MAP < 55 for less than 5 minutes, delirium presumed to be from inadequate brain perfusion resulting from MAP less than lower limit of autoregulation, each patient is different and maybe as high as 85mmhg in some patients.
my current practice for pressor is usually ephedrine for children who usually need an increase in HR. First I treat with making sure they are euvolemic and then add Ephedrine and next Phenylephrine unless there is a specific reason to use one over the other like pulm HTN or a specific valve disease. I will continue my management and adjust for patient specific needs and the differences in children who have pristine vasculature over adults

[Jennifer Hannon]

This article definitely made you rethink some things about where you keep your MAP, but I think based on the patient 80-85 is where you want MAPs as well.
Question 1) Keep MAP around 65mmHg intraop. For postop SBP 90 is the guideline more than MAP. Postoperative hypotension has a much greater risk of MI than intraoperative hypotension.
Question 2) A MAP < 55 for 5 minutes can cause AKI and delirium.Phenylephrine is usually first choice unless the HR needs help, the mix in ephedrine and smaller dose phenylephrine. Norepinephrine for sepsis/shock as an infusion (MICU background).