REBEL Core Cast 18.0 – DKA Tips and Tricks

Posted by Marco Torres on Sep 25, 2019

Take Home Points

When looking at pH and bicarb, the differences between VBG and ABG are miniscule. For DKA patients, stick with the VBG as is less painful and has fewer complications.
LR is probably a better fluid for the large volume resuscitation required in DKA. Start with a 20 cc/kg bolus and then reassess the patient’s perfusion status.
Stay on top of your electrolyte repletion. If the patient has a working gut, you can aggressively replete potassium orally and don’t forget that when you are repleting potassium you also must replete magnesium.
Bolus dose insulin gets the patient to super-physiologic levels and has been associated with higher potassium requirements and more episodes of hypoglycemia. It’s probably fine to skip the bolus and stick with a drip alone
Don’t forget to think of all possible etiologies of DKA, while we most often find this in patients who have not been taking their home meds for whatever reason, don’t forget a good history to look for sources such as infection and ischemia.

Show Notes

pH mean difference between abg and vbg was 0.02 pH units. PMID: 21143397
Bicarb had a difference of -1.41 mmol/L. PMID: 21143397
pCO2 had a difference of about -6 mmHg
Not important to know the differences but rather the fact that the differences are irrelevant both in diagnosis and treatment

Patients are about 5-10% fluid down which is moderate dehydration
- If hypotensive, more dehydrated and will need more fluid
The standard fluid resuscitation is 20-30cc/kg normal saline. Should it be the standard though?
- NS is 154 mEq of Na & Cl with a pH of ~5.7, not ideal for acidotic patient
- NS bolus can lead to non-anion gap hyperchloremic metabolic acidosis stacking on the anion gap acidosis.
Reach for a more balanced solution like Lactated Ringers or Plasmalyte
- LR is 130 mEq of NA, 130 Cl, 4 K, 1.5 Ca with a pH of ~6.4

Bicarbonate boluses never shown to be beneficial.
Isotonic bicarbonate infusion may be helpful. The BICAR-ICU study showed decreased necessity for dialysis in patients treated with isotonic bicarbonate (secondary endpoint)

Total body potassium deficient
Acidosis causes potassium to shift out of cells and falsely elevated serum levels
If gut working, give PO (40 mEq) & IV (10-20 mEq)
If Low K, then assume Low Mg

K above 3.5, start insulin with K infusion
K less than 3.5, hold insulin and give K
No bolus dosing, just give infusion (0.1 units /kg) and give their basal insulin
Don’t forget to look for underlying cause of DKA!!

Shownotes Written By: Miguel Reyes, MD (Twitter: @miguel_reyesMD)

Post Peer Reviewed By: Salim R. Rezaie, MD (Twitter: @srrezaie)