Jan 15, 2018
Should I give bicarbonate to DKA patients with severe
acidemia? I've certainly been admonished for NOT doing it.
The reason for withholding bicarb has been that I've heard that it
doesn't help and may actually be a bad idea. I can't say the action
(or inaction) was based on a deep understanding.
How could bicarb in DKA be a bad idea if even
the American Diabetes Association (ADA) recommends we give a bicarb
to DKA patients with pH under 6.9? The argument in favor of giving
bicarb is that the more acidemic the patient, the higher the risk
of circulatory collapse and cardiac arrest. Even though there is no
evidence of benefit, the ADA gives
a very specific set of steps to take in the low pH
- Because severe acidosis may lead to numerous adverse
vascular effects, it is recommended that adult patients with a pH
less than 6.9 should receive bicarbonate. Specially 100 mmol sodium
bicarbonate, two ampules, in 400 mL sterile water with 20 mEq KCL
admitted at a rate of 200ml/hr for 2 hours until the venous pH is
over 7. If the ph isn’t over 7 at that point, they say repeat the
bicarb infusion every 2 hours until the ph is over
With that sort of exact guidance, you'd think there would be
evidence to back it up, but here is the sentence that precedes the
- No prospective randomized studies concerning the use of
bicarbonate in DKA with pH values <6.9 have been
Because of the lack of evidence, the
UK guidelines say this
- Adequate fluid and insulin therapy will resolve the
acidosis in diabetic ketoacidosis and the use of bicarbonate is not
But as the saying goes, "absence of evidence is not evidence of
absence", so is there a downside to giving bicarb to DKA patients?
It turns out there there may be. Several FOAMed bloggers have
tackled this in great detail: Pulm Crit,
Life in the Fast Lane, emdocs, and
Jacobi EM. (just to name a few)
Here are just of few of the problems with bicarb in DKA
Giving bicarb drives potassium into the intracellular
- DKA patients are total body potassium depleted.
- Once the IV fluid and insulin get going the potassium is likely
to drop quickly. In a patient already at risk for hypokalemia,
administration of bicarb can drop the serum potassium even
Does bicarbonate infusion in DKA improve
- The preponderance of evidence, albeit small numbers of
patients, suggests that bicarb does not improve outcome, even in
those with low pH.
- The most widely cited article on this is a
2011 systematic review from Annals of Intensive Care that
found no evidence of benefit for either neurologic or hemodynamic
outcome. There was some evidence of a transient improvement in
acidosis with the first 2 hours but no evidence of clinical
Bicarb slows ketone clearance.
- A 1996
study found that giving bicarb slowed the clearance of ketones
and AND transiently increased acetoacetate and beta
Bicarb may cause CSF acidosis. This goes back
to a 1967
study by Posner and Plum.
- A series of 7 severely acidotic patients.
- Some were obtunded and some weren't
- The authors postulated that it’s the degree of CSF acidosis
that determines coma more than peripheral acidosis.
- To study this, whenever blood ph was studied, they did a
neurologic exam and a lumbar puncture.
- Lower CSF pH correlated with a lower level of
- In 2 patients with DKA, they found that giving IV bicarbonate
infusion, while it improved serum pH, was associated with more
- Other studies have called the importance or even validity of
bicarb infusion causing CSF acidosis into question and found
treating DKA how we regularly do can itself cause the CSF pH to
George Willis, ED doc and DKA expert, uses bicarb in DKA
in three scenarios
- DKA with cardiac arrest
- Persistent hypotension despite vasopressors
- Hyperkalemia with arrhythmia
So should ANY DKA patients get
bicarbonate? I think there are several choices
- You can follow the US/ADA guidelines and use bicarb if the pH
is under 6.9. This is not based on solid evidence, more-so the
worry that severe acidemia can lead to circulatory collapse (and
bicarb may mitigate that)
- You can follow the UK guidelines and just not give bicarb at
- I like the Willis rule of 3. Hyper K with arrhythmia, severe
hypotension despite pressors, cardiac arrest -because these are
patients who are about to die. With hypo-K, you might push just
enough potassium into the cells to make a difference. In cardiac
arrest, you might give a quick bump up in pH to improve the
cardiovascular situation, then again, you might not.
Mentioned in the intro
Kitabchi, Abbas E., et al. "Hyperglycemic crises in adult
patients with diabetes." Diabetes care 32.7
Dyer, P. H., and M. S. Hamersley. "Diabetes UK Position
Statements and Care Recommendations Joint British Diabetes
Societies guideline for the management of diabetic ketoacidosis."
Chua, Horng Ruey, Antoine Schneider, and Rinaldo Bellomo.
"Bicarbonate in diabetic ketoacidosis-a systematic
review." Annals of intensive care 1.1 (2011):
Savage, M. W., et al. "Joint British Diabetes Societies
guideline for the management of diabetic
ketoacidosis." Diabetic Medicine 28.5 (2011):
Okuda, Y. U. K. I. C. H. I., et al. "Counterproductive effects
of sodium bicarbonate in diabetic ketoacidosis." The
Journal of Clinical Endocrinology & Metabolism 81.1
Posner, Jerome B., and Fred Plum. "Spinal-fluid pH and
neurologic symptoms in systemic acidosis." New England
Journal of Medicine 277.12 (1967): 605-613.