hypokalemia and ng suctioning

Shorty11, BSN, RN · Dec 15, 2012

I am a nursing student, not a nurse. From what I understand the hypokalemia is caused directly from the fluid and electrolytes being suctioned out of the body. Potassium should NEVER be given IV push (bolus). I have heard of IV infusions of potassium being given for severe hypokalemia, but it requires very careful monitoring. Never seen this done though. Potassium can cause significant dysrhythmias if too much is given or if it is given too fast. It can be fatal. Hypokalemia and hyperkalemia both affect the musculoskeletal and cardiac systems. Conduction of the heart is greatly affected by imbalances of potassium. Oral is the preferred method of administration.

(Someone will surely correct me if I am wrong.)

Shorty11, BSN, RN · Dec 15, 2012

Well, NG suctioning can cause metabolic alkalosis also.. Removal of stomach acid through the suctioning raises the pH to alkaline. This suctioning also directly removes fluid and electrolytes. So I am not sure how exactly to answer part of your question. The suctioning can cause hypokalemia and/or metabolic alkalosis both. Sorry if I confused you! I would wait and see what other posters have to say as well.

HollyGoLightlyRN · Dec 16, 2012

You are correct that the hypokalemia occurs from depletion of the fluid and electrolytes from the stomach. Potassium is given IV, but never IV push or undiluted. Serum potassium is always checked per agency protocol after administration.

psu_213, BSN, RN · Dec 16, 2012

hey everyone!
I have a question concerning ng suctioning and hypokalemia. How does it cause hypokalemia? just that the ng tube is suctioning the fluid and electrolytes out of the stomach and causing an electrolyte imbalance, or would it be related to the metabolic alkalosis that the ng tube can cause? I would assume these individuals do not get oral potassium to correct the problem, more like a K IV infusion correct?
thanks everyone!

A couple questions to get you to think about this. Why would an NG tube to suction cause electrolyte imbalance? Specifially, what is the NG tube suctioning out? As for what is being suctioned out--how does this effect acid-base balance? If you want to take it to another level, what is the relationship between hypokalemia and alkalosis (this can be any case of alkalosis/hypokalemia whether or not caused by an NG tube)?

As for replacing the K, why do you think that oral K would probably not help if the gastric contents are being suctioned out through the NG tube (OK, that kinda answered the question)?

Newgraduatenurse2012 · Dec 16, 2012

it is the same concept as when you throw up # Hypokalemia. The NG put the pt. at risk for Hypokalemia and metabolic Alkalosis because alot of the acid it is being sucked out of the stomach. for example, vomit is acidic!

HouTx, BSN, MSN, EdD · Dec 17, 2012

This is a wonderful example of critical thinking in action - good job PPs!

As for the concern that IV K+ can be fatal.... yessireee Bob, it certainly can. That's why it is done in very careful allotments (10 meq/hr) & with continuous EKG monitoring to detect the characteristic waveform changes that happen with K+ imbalances. FYI, an IV K+ bolus used to be part of the "lethal injection" cocktail for TX. Don't know if it still is or not. . . just interesting trivia.

akulahawkRN, ADN, RN, EMT-P · Dec 17, 2012

This is a wonderful example of critical thinking in action - good job PPs!
As for the concern that IV K+ can be fatal.... yessireee Bob, it certainly can. That's why it is done in very careful allotments (10 meq/hr) & with continuous EKG monitoring to detect the characteristic waveform changes that happen with K+ imbalances. FYI, an IV K+ bolus used to be part of the "lethal injection" cocktail for TX. Don't know if it still is or not. . . just interesting trivia.

IV K+ can be fatal if given as a bolus. I believe that K+ has been removed as a part of the lethal injection cocktail as it's highly irritating to veins (think very painful) when given that way. At a rate of 10 mEq/hr, up to 40 mEq total dose, I've rarely seen an EKG used. When the 40 mEq has to be given over 2 hours, the EKG seems to always be used, and such replacement is done with someone watching the Tele all the time. I start watching for an increase in the T wave size first.

As far as why K+ is reduced with gastric suctioning, gastric juice has a bit of KCl in it, so when you remove the gastric contents, you take the gastric juice and the K+ that's in it and remove it from the body. Over time, without replacement, you can very easily cause hypoK. There's some NaCl in there too, but you'll see hypoK before Hyponatremia.

jbrennan101 · Nov 13, 2015

So, yes you would want to replete K+ via IV to someone with an NGT connected to suctioning. The hypokalemia results from both processes you mentioned. You lose some potassium chloride and a lot of hydrogen chloride via suctioning. Remember also, as the blood becomes more alkaline, extracellular K+ will move into cells in an attempt to maintain electroneutrality with a corresponding movement of intracellular H+ ions out.