Lactate Level in Kids
Patients’ families often present to us requesting “bloodwork” to make sure that the child is not “sick” or to tell them “what’s wrong.” While we all know that no lab can be used to proclaim complete certainty of a patient’s health or to make a definitive diagnosis on its own, often we perpetuate the myth by ordering labs that do not necessarily direct our actions. By now, most of you know of my disdain for the ubiquitous WBC count (The Last Bastion of the Intellectually Destitute – Amal Mattu), but there is another often ordered test that may also fall into that category — the Lactate Level.
The Lactate Level has grown in popularity over the past decade, particularly in the Adult EDs. Certainly, there is literature that supports its utility with respect to evaluation of SEPSIS and trauma, but this often becomes extrapolated to all patients who “may be sick” as a means to find the covertly ill. This approach (often in a “shotgun” fashion) has steadily crept into the Pediatric EDs as well. What is the known utility of Lactate Level in children? [Thank you @ErnestoAlarco12 for inspiring the question].
Lactate Level – Basic BioChem
- Just in case you don’t recall BioChem class as well as you used to…
- During Glycolysis glucose is converted into Pyruvate.
- Through AEROBIC metabolism, pyruvate is used to generate 2 Acetyl-CoA and eventually many ATPs, H2O, and CO2 (remember the Krebs cycle?).
- When there is not enough Oxygen around (ANAEROBIC metabolism), then pyruvate is converted into Lactate.
- Lactate can be converted back to pyruvate once the oxygen deficit has been corrected.
- Well that was a fun walk down memory lane.
- With this in mind, elevated lactate levels would potentially reflect tissue oxygen deficit.
- Under normal conditions, lactate is rapidly cleared by the liver, with some assistance from the kidneys. (Anderson, 2013)
- There is no standardized levels:
- Most studies use cutoff values of 2.0 to 2.5 mmol/L.
- Many define “High” as a Lactate level > 4.0 mmol/L. (Anderson, 2013)
Lactate Level – Some Causes of Lactate Elevation
Most often elevated Lactate Levels conjure thoughts of tissue hypoperfusion with diminished access to oxygen (SHOCK), but there are others causes to consider. (Anderson, 2013)
- Global ischemia (SHOCK)
- Regional ischemia (ex, mesenteric ischemia, burns, trauma, compartment syndrome)
- High Metabolic States (ex, seizures, heavy exercise, increased work of breathing)
- Drugs (ex, Metformin, epinephrine, propofol, acetominophen, beta-2-agonists)
- Toxins (ex, Cocaine, Cyanide, Carbon monoxide, alcohols)
- Malignancies
- Liver Disease (can’t clear the lactate)
- Diabetic Ketoacidosis
- Thiamine Deficiency (w/o thiamine, anaerobic metabolism predominates)
- Inborn Errors of Metabolism and Mitochondrial Diseases
Lactate Level – Elevation in Kids
- In the PICU:
- Studies of SEPSIS have shown increased mortality in the setting of elevated lactate levels. (Jat, 2011)
- Monitoring serial lactate levels in patients following surgery for congenital heart disease can help discriminate patients at high risk. (Schumacher, 2014; Agrawal, 2012)
- Poor lactate clearance (< 30% at 6 hours) has been associated with increased risk of mortality. (Munde, 2012)
- High lactate level upon admission to the PICU is associated with in-hospital mortality. (Bai, 2014)
- In the ED:
- High lactate levels can be useful to help “rule-in” severe bacterial infection in children in the ED. (Vorwek, 2011)
- High lactate levels identify a population at higher risk for severe outcomes amongst the kids with SIRS in the Peds ED. (Scott, 2012)
- After Return of Spontaneous Circulation following a resuscitation, higher lactate levels are associated with higher likelihood of death, although don’t predict outcomes. (Topjian, 2013)
- Elevated lactate levels obtained in pediatric trauma patients during prehospital transport are associated with increased need for critical care. (Shah, 2013)
Lactate Level – Did it Help You?
- Thus far, we see that, like in adults, an elevated lactate can help identify those patients who are potentially sicker than others, although not perfectly.
- One issue is that, often, an astute clinician would generate a similar assessment of clinical severity. (Scott, 2012)
- That being said, it is known that signs of SHOCK can be under-appreciated in children (see subtle signs of heart failure and palpation of pulse).
- Hypotension is also, generally, a late finding in pediatric patients.
- Another issue is that, when obtained in the “shotgun” approach of obtaining labs, often the confounders (see above) are not taken into account.
- It is only helpful if it alerts you to severe illness presenting subtly or helps direct your resuscitation efforts… which, again, require the astute clinician to determine.
My kid went under hemitruncus surgery, after 14 days of surgery the last lactate level test is 2.5, she only 3 weeks old.
Does it seems to be ok or according to you the lactate seems to be higher?
Thanks in advance
My grandson age 3.5 has complained of severe intermittent pain left arm for the last month. No fractures present or past.his lactate levels are elevated. What could cause this?
I am sorry that your grandson has not been feeling well.
Obviously, I cannot give specific advice out over the internet. I will say that an elevated Lactate level on its own can be related to many, many things and some are not of any concern, while others are. You need to discuss your specific concerns with your grandson’s team of physicians.
All the best,
sean
[…] doctors love to order tests, often only to confirm things we already know. Did that lactate level for the child in SHOCK help your decision to start vasopressors? Better yet, did that WBC count […]
My baby (fimale) age 4.5 years now problem breathing slow & she is not normal when unknown people talk with her, unrest atatute see book & say figer name like birds name, animal name, flower name, see computer or mobile rayms cartoon.Her blood report refarance value Lactate 28 mg/dl & Ammonia refarance value 49 umol/L. Thanks
[…] Lactate Level in Kids BY SEAN FOX · DECEMBER 19, 2014, from Peds EM Morsels–Pediatric Emergency Medical Education. […]
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