HCO3- CONTROVERSY

[cbrons]

I been listenin to this here feller (DR. Steve Smith) and he done says that u shouldnt give NaHCO3- like most people give it today. Video is here:
Here is what he says:

Na+ Bicarbonate therapy

• Do not give unless HCO3- very low (less than 5 mEq/L)
• Do NOT base it on pH.
• Base it on HCO3- level UNDER 5.

Reasons:

1. Intracellular acidosis (theoretical risk) via mass action – increase HCO3- binding to H+ to form H2CO3, which subsequently is converted to CO2 and H2O. CO2 is uncharged and can diffuse across cell membranes to reform H2CO3 and subsequently form more protons.
2. Increases PaCO2 and need for ventilation (all newly produced CO2 must be expired eventually)
   1. Carbicarb (NaBicarb + NaCarbonate) or Tris buffer (THAM) can be given, which do not produce CO2.
3. Hypernatremia and fluid overload
   1. One amp (50 mL) has 50 mEq of Na+ (this is 1/3 the Na+ contained in a liter of normal saline)
4. Hypokalemia (aldosterone)
5. Left Shift of oxyhemoglobin dissociation curve

When to give bicarbonate:
Do NOT base it on pH.
Base it on HCO3- level UNDER 5.
For low pH

If bicarb is less than 5, give 1-2 amps of HCO3- and recheck ABG.
ABG: If PaCO2 is greater than = (1.5)(HCO3-) + 8 then ventilate better
In severe respiratory acidosis where pH less than 7.00 (PaCO2 > 100), will not ventilate. Buffer therapy is salvage in extreme asthma.
By pure mass action, will immediately “gobble” up H+ and raise pH.

Why to do this?
- Beta agonists (albuterol) don’t work at low pH

Curious what your thoughts are these insights.

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[Crayola227]

not gonna claim to know that much about this, but none of this seems like new news

I was always told the only time you really give bicarb is as a hail Mary manuveur in certain codes, and that you will have to pay for it later in terms of getting back to good with acid/base status

I could be wrong you just asked for thoughts so there's some thoughts

 

[Psai]

Yeah every time I hear about bicarbonate it's people saying not to use it for respiratory failure and that you should always focus on the underlying cause. The indications I'm thinking of are hyperkalemia, tricyclics od and salicylate od

 

[jdh71]

Stewart already worked out that bicarb actually has zero infulence on pH. You don't "buffer" anything. The physics of it all is pretty straightforward. The pH is actually improved by having the strong cations around. The sodium. Weird. And totaly not how it is taught to us, but true.

Though there are a lot of moving pieces.

If you have a spontaneously breathing patient, wether on the vent or not, they will handle the bicarb load. Especially if the kidneys are working. A point to remember is that THAM requires the beans to be working. Bad hypercapnic resp failure needs ECMO or ECOR and giving bicarb for acidosis is going to be a big problem.

I think about bicarb infusions in patients who are acidotic with a pH <7.2 and a single digit CO2 on the panel if the bicarb doesn't improve after at least three liters of crystalloid resuscitation. I'm not worried about the sodium load. I want it - based on the physical chemistry. I do worry about FLUID overload, however.

I'm not convinced bicarb does anyting for us during a code. I still often give it because nurses get all angsty and want to push something, anything, but the key to a code is really the CPR and cardioversion if appropriate.

Again. To repeat. Profound hypercnapnic resp failure needs a center that can do ECMO or ECOR. Bicarb is moving around deck chairs on a titanic going down in that situation.

 

[lymphocyte]

I been listenin to this here feller (DR. Steve Smith) and he done says that u shouldnt give NaHCO3- like most people give it today.

It's chloride not bicarb that matters for pH. Chloride.

Have you gone down the rabbit hole of Stewart's Strong Ion Difference (SID)? SID explains the video above and also why it's no surprise to keep learning that chloride loading might be no bueno:

http://www.nejm.org/doi/full/10.1056/NEJMra1215672

 

[Teddy.KGB]

I think that bicarb has a very important use in combination with dilute acetic acid to make a volcano. This has been proven to work in every elementary school science fair in the world since the 1980's.

 

[Teddy.KGB]

I'd like to see Dr. Steve Smith debate ESPNs Stephen A. Smith on the utility of bicarb.

Vs.