MEMBER SERVICES  :Login
MEMBER SERVICES  : Logoff
  FAQ FAQ  Forum Search   Register Register  Login Login

BE vs Lactate

 Post Reply Post Reply
Author
  Topic Search Topic Search  Topic Options Topic Options
pjwillis View Drop Down
Pumpling
Pumpling


Joined: May 24 2016
Online Status: Offline
Posts: 3
  Quote pjwillis Quote  Post ReplyReply bullet Topic: BE vs Lactate
    Posted: May 24 2016 at 2:53pm

Adequacy of perfusion is a constant concern in our field. Throughout my perfusion training and career I have used Base Excess testing to aid in the determination of perfusion adequacy, along with venous saturation and cerebral oximetry. An alternative course would be the use of Lactate testing for this determination. In terms of accuracy, testing cost (to the patient and facility), and such limitations as patient weight and BSA, which test would better serve perfusionists as a standard of care when determining adequacy of perfusion?

Thank you in advance for your input.

Paige Teff CCP, LP
Back to Top
pjwillis View Drop Down
Pumpling
Pumpling


Joined: May 24 2016
Online Status: Offline
Posts: 3
  Quote pjwillis Quote  Post ReplyReply bullet Posted: Jun 05 2016 at 11:10am
Post removed.


Edited by pjwillis - Jun 05 2016 at 2:57pm
Paige Teff CCP, LP
Back to Top
pjwillis View Drop Down
Pumpling
Pumpling


Joined: May 24 2016
Online Status: Offline
Posts: 3
  Quote pjwillis Quote  Post ReplyReply bullet Posted: Jun 05 2016 at 11:11am

Posted on behalf of Christopher Lusby, CCP:

Paige,

I would have to agree with Adams response.  There is not one standard value that is going to give us a precise measurement of adequate perfusion.  I find that our patient population is growing sicker and becoming more complex.  We are seeing patients with multiple comorbidities.  Relying on just Lactate or Base Excess for a definitive answer is not the best practice.  I believe that in this current day and age of perfusion practice utilizing all lab values available.  Due to the size of some programs in the country, our attempt to maintain adequate perfusion goes beyond the limits of just cardiopulmonary bypass.

Use of lactate is found to be very effective in our perfusion literature.  We use both oxygen and carbon dioxide-derived parameters. The use of oxygen derived parameters is poor predictors of anaerobic metabolism.  Lactate is produced under anaerobic conditions.  According to study done by Somer et al, we utilize both parameters when interpreting adequate perfusion.  However, a carbon dioxide-derived parameter has a much greater correlation with inadequate tissue perfusion. 

In agreement with Adam base excess cannot be relied upon as a sole predictor of adequate perfusion.  Patients that have been given large amounts of chloride containing fluids can have a false reading when measuring hyperlactatemia.  In my clinical experience base excess has been shown to be insensitive for detecting hyperlactatemia in surgical patients. 

Again, the perfusion literature also states that increased lactate proves to be a good indicator of overall mortality.  Using this lab value in the ICU and ED patient assessment proves to be beneficial.  Li J et al, found that patients with a pre-extracorporeal membrane oxygenation lactate level of 12.6mmol/L are at a higher risk for in hospital death.  Using this lab value further assisted in the utilization of extracorporeal membrane oxygenation

Both tests are beneficial in assessing the patient.  The literature suggests that relying on one value alone is not enough.  We are treating a large and diverse patient population.

Respectfully,

Christopher Lusby, CCP

 

Paige Teff CCP, LP
Back to Top
ablakey86 View Drop Down
Pumpling
Pumpling


Joined: Jun 02 2016
Online Status: Offline
Posts: 1
  Quote ablakey86 Quote  Post ReplyReply bullet Posted: Jun 05 2016 at 12:57pm
Hello Paige,

This is an interesting topic that you bring up. I do not think there is one single “magic bullet” parameter to assess the adequacy of perfusion. I believe we have to look at the global picture of the patient, taking into account all factors: svO2, BE, cerebral oximetry, lactate, etc. As far as blood gas values that determine if there is hypoperfusion occurring, both base excess and lactate have been used in conjunction, or independently to assess perfusion.

The rationale behind using lactate as a marker for adequacy of perfusion is that lactate is produced under anaerobic conditions at the cellular level. The measurement of base excess has been used as a surrogate for lactate production, but that rational has been found to be faulty. In fact, in a study by Milkulaschek et al, it was shown that there is no correlation between lactate and base excess and that lactate must be measured directly.

Using base excess as an independent indicator of hypoperfusion can even lead to an inappropriate clinical intervention believing lactate is rising. Brill et al showed that hyperchloremia can cause a large base deficit in the absence of hyperlactemia. Hyperchloremia occurs when large volumes of normal saline or another chloride containing solution are given to a patient relative to their blood volume (most prevalent in pediatrics and massive transfusion traumas).

Lactate measurement can also be used as a strong indicator of morbidity and mortality. Noval-Padillo et al. measured the lactates of heart transplant patients upon arriving in the ICU, and found that patients with lactates of >4 mmol/L had an 18.7% risk of morbidity and mortality compared to 6.2% for the patients with lactates <4 mmol/L. Lactate clearance in particular correlates strongly with morbidity and mortality. Husain et al found that if lactate could be normalized within 24 hours, survival of shock patients was 90%, compared to 33% if lactate didn’t clear within the first 24 hours.

Base excess measurement still holds value in certain acid-base derangements where lactate does not. Lactate levels have no bearing on other types of acidosis like respiratory, hyperchloremia, or ketoacidosis.

While lactate measurement may be the best blood gas value we have to assess the adequacy of perfusion, it is not perfect, and should be used in conjunction with base excess to assess the patients metabolic needs.

Respectfully,

Adam Blakey, CCP


Mikulaschek A, Henry S, Donovan R, Scalea TM. “Serum Lactate is not predicted by anion gap of base excess after trauma resuscitation.” J of Trauma: Injury, Infection, and Critical Care 1996 Feb;40(2):218-224

Brill SA, Stewart TR, Brundage SI, Schreiber MA. “Base deficit does not predict mortality when secondary to hyperchloremic acidosis.” Shock 2002, 17(6): 459-462

Noval-Padillo et al. “Changes of lactate levels during cardiopulmonary bypass in patients undergoing cardiac transplantation: possible early marker of morbidity and mortality.” Transplant proc. 2011, 43(6): 2249-2250

Husain FA, Martin MJ, Mullenix PS, Steele SR, Elliot DC. “Serum lactate and base deficit as predicators of mortality and morbidity.” AmJSurg 2003, 185(5): 485-491

Back to Top
ShadeBC View Drop Down
Pumpling
Pumpling


Joined: May 25 2016
Location: United States
Online Status: Offline
Posts: 1
  Quote ShadeBC Quote  Post ReplyReply bullet Posted: Jun 06 2016 at 12:28am
Hey Paige,
While many perfusion departments only monitor base deficit, there is significant evidence that intraoperative serum lactate levels may be an indicator of tissue perfusion and also predictor of mortality. Base deficit monitoring alone may not be best practice.


Martin, et al. showed that both lactate and base deficit levels may be used to identify lactic acidosis and predict mortality at admission to the ICU. Increased lactate levels predict mortality and a prolonged course regardless of the associated base deficit level, whereas an increased BD level has no predictive value if the lactate level is normal. This article is somewhat misleading but concludes that base deficit monitoring alone may not be reliable in predicting mortality and care plan.

De Somer published an article in JECT where he investigated principles of cardiac output, anaerobic metabolism, and how to estimate organ perfusion during CPB. While he does not collect or present any data, De Somer recommends that carbon dioxide-derived parameters in combination with intermittent whole blood lactate levels provide inline information regarding tissue perfusion, allowing the perfusionist to proactively intervene to optimize tissue perfusion during CPB.

My thought is that both serum lactate and base deficit monitoring be utilized in ensuring adequacy of perfusion. My recommendation for best practice is that a baseline lactate level be taken prior to CPB, at initiation and every hour. In addition, the base deficit should be monitored and treated accordingly. If lactate levels are >4mmol/L, an increase in flow rate, MAP, or etc should occur to ensure adequacy of perfusion.

Regards,
Brandon C. Shade, CCP

Martin MJ, FitzSullivan E, Salim A, et al. “Discordance between lactate and base deficit in the surgical intensive care unit: which one do you trust?” Am J Surg 2006; 191: 625-630.

De Somer F. “What Is Optimal Flow and How to Validate This.” JECT. 2007; 39: 278–280.
Back to Top
racine View Drop Down
Pumpling
Pumpling


Joined: Aug 26 2007
Location: United States
Online Status: Offline
Posts: 24
  Quote racine Quote  Post ReplyReply bullet Posted: Nov 15 2016 at 2:37pm
Serum Lactate has always been a part of the whole picture. Whether one calculates Op Mort data preop, evaluates all co-morbidities, etc. pH/Base Deficits, and serum lactate, each case is different. I guess I've always read more into the H&P and based my conduct of bypass on all these parameters. What I've found myself doing on occasion is responding to elevated Serum Lactate levels by emphasizing myocardial protection and CI changes despite normal ABG values. It was not uncommon to find Lactate levels approaching high single digits with normal ABGs and even seeing Lactate levels in the double digits on prolonged cases. All in all, I prefer to stay out of deep water and having this value is a vital predictor of outcomes from weaning off CPB to avoiding heavy inotropic support or other mechanical support at the end of the operation.
Just my thoughts...
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.082 seconds.