How come normal saline for DKA if Chloride causes metabolic acidosis? - USMLE Forums
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Old 05-24-2011
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Help How come normal saline for DKA if Chloride causes metabolic acidosis?

When I was studying Fluid therapy, the book said, Normal saline has high concentration of Cl-. Thus, it will reduce bicarbonate ion and induce metabolic acidosis. (is there anybody who knows how high Cl- level decreases bicarbonate level?)

My question is that when we are treating DKA patients, we give them N/S, according to the above it will exacerbate the acidosis..???
Of course I know it is because of reducing hypovolemia caused by diabetes.
but if we take into consideration the above fact, do we have to use another type of fluid such as Ringer's solution?

thank you !!
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Old 05-24-2011
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An addition to the question : ringer lactate contains lactate which will be metabolized to HCO3, further correcting the acidosis .. why shouldn't we use RL in DKA then ?
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Old 05-24-2011
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Info Why not Sodium Bicarbonate and Why Normal Saline in DKA

You are right, normal saline is hypercholermic and can potentially cause metabolic acidosis but there's another more important priority in the management of DKA, more important than correcting the acidosis.

The priority in the management of DKA is to correct the hypovolemia not the acidosis. Hypovolemia is more critical and more life threatening to the patient. The best volume expander is normal saline. That's why all of the DKA managment protocols insist on initial rescue volume expansion before even giving insulin.

Once you correct the hypovolemia and you give insulin, the acidosis will gradually correct itself.

Giving bicarbonate is not a good idea for three reasons:
First, NaHCO3 will initially convert to CO2 and that will worsen the respiratory acidosis in a DKA patient.
Second, Bicarbonate is given in the form of NaHCO3, and together with NaCl that would constitute too much Sodium load.
Third, Rapid and early correction of acidosis with sodium bicarbonate may worsen hypokalemia and cause paradoxical cellular acidosis.

For these reasons, most DKA protocols indicate that Sodium Bicarbonate should not be given unless the PH is less than 6.9
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drali (05-24-2011), DrSick (05-24-2011), K06100 (05-24-2011), patelMD (05-24-2011), Suneel (03-05-2013)


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