Acidosis/Alkalosis

[queenjulie, RN]

I'm studying for a test that is going to include a lot of acidosis and alkalosis information, and I'm trying to come up with a general idea of what patients would look like with metabolic and respiratory acidosis and alkalosis. Can you guys help? I'm sure I'm missing plenty of signs and symptoms. These are my ideas:

Metabolic acidosis: S/S: Possibly breathing fast (to blow off CO2), disorientation/confusion, poor kidney function, low pH and bicarbonate in ABGs. Can be from diabetic ketoacidosis, severe diarrhea, or major exercising (in lactic acidosis).

Metabolic alkalosis: S/S: vomiting, diarrhea, changes in level of consciousness, hypertension, poor kidney function. High pH and bicarbonate.

Respiratory acidosis: S/S: Depressed respirations (not blowing off enough CO2), lethargy, fatigue. Can be from respiratory disease, like COPD, or narcotics. ABGs will have low pH and high CO2. Bicarbonate may increase to compensate. Put them in high Fowler's if possible to help respirations.

Respiratory alkalosis: S/S: Tachypnea, often d/t hyperventilation or overuse of ventilators, as well as dizziness and light-headedness. ABGs will have high pH and low CO2. Use a paper bag or turn down the ventilator settings.

[Zookeeper3]

It's all in the ABG

what is the PH...... figure that out

now your acidotic or alkolotic. what is causing it?

look at co2 and bicarb.... what do they tell you?

low ph and acidotic... is the co2 high? it resp.... your kidney's take two days to compensate without bicarb push, thats why they're breathing 50 times a minute to blow off the hydrogen ion.... don't knock off that drive

low ph, co2 normal and the bicarb is in the toilet, usually with your renal patients... no kidney's to fix it... it's metabolic and unless the ph is under 7.2, not treated and these guys live there unless new acute renal failure and they do just fine until hemo fixes them by lowering their Kcl lvl.

high ph... alkilotic... worse, shift in the oxyhemoglobin curve... are they an OD? if not... what is the bicarb and co2... is it metabolic.. the bicarb or the co2 the rapid breathing blowing off the hydrogen ion making them alkolotic.

The lungs immediately try to fix this... you need to know when to act to intervene... or let the lungs go to have at it until the kidneys can try to get a grip on it.

Any PH lower than 7.2 or higher than 7.6 needs intervention of the opposing end.

Hope that made sense, worked last night and exhausted, if I've screwed it up, someone will correct me pretty quickly, bank on it.

[Esme12, ASN, BSN, RN]

acid-base imbalance: a disruption to the normal acid-base equilibrium in the body. there are four main groups of disorder involving an acid-base imbalance: respiratory acidosis or alkalosis and metabolic acidosis or alkalosis. obviously the severity of symptoms is determined by the degree of imbalance

http://www.wrongdiagnosis.com/a/acid_base_imbalance/symptoms.htm#symptom_list

http://www.merckmanuals.com/home/sec12/ch159/ch159b.html

[color=#0e774a]www.clt.astate.edu/mgilmore/.../acid%20and%20base.ppt

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[color=#0e774a]http://www.enotes.com/nursing-encyclopedia/acid-base-balance

[color=#767676]here are a couple of good sites

[sewnew]

This is one of the best articles out there on ABGs.

http://www.ncbi.nlm.nih.gov/pubmed/7624703

ABG Article.pdf

[Cinquefoil]

I'm not the most knowledgable person on all these topics, but I believe (and Merck's manual http://www.merckmanuals.com/professional/sec12/ch157/ch157d.html#CIHCIAFF backs me up) that:

1) Vomiting is a CAUSE of metabolic alkalosis, not a symptom. When you suddenly lose your stomach contents, especially repeatedly, your stomach's parietal cells go hey, too little acid here, I must make more! and more,,,,and more...as the vomiting repeats. And what is a byproduct of stomach acid production? Bicarb ions, which then build up in the rest of your body faster than you can get rid of them. Then you have metabolic alkalosis.

2) A big s/sx of metabolic alkalosis I didn't see you mention was hypoventilation. Your body is metabolically less motivated than usual to blow off CO2, because the trigger for letting go of CO2 is set off by the acidic end of your acid/base balance, so the urge to breathe comes less frequently, and your respiratory rate is slower.

When I took A&P a few years ago, the textbook said that you could tell different forms of acidosis/alkalosis apart by how they were being compensated. If it was a metabolic imbalance, it would be most visibly compensated through the respiratory system. If it was respiratory imbalance, it would be compensated most visibly by metabolic routes.

Also, alkalosis in all its forms is relatively rare since the causes of alkalosis happen less frequently.

Does all that help?

And now I have a question of my own: I remember one professor saying that our bicarb buffer system buffers Xes better than Y's but I forget which one of those was acids and which one was bases. And, just through a 10 minute internet search, I couldn't puzzle out which one it was. I think it has to do with the relative concentrations of all substances in that equilibrium reaction in the body. Anyone know?

[XingtheBBB, BSN, RN]

Good stuff in those links, I've used many before- just a few things to add to the OP

Beside DKA, much of the Met Acidosis I've seen results from non-compliance in ESRD therapy- pts skipping dialysis, etc- and rhabdomyelosis, not from over exertion (it happens but not often in your day to day population) but from accidental neglect... think of those elderly folks found on the floor 12 hours after their fall.

Echoing the above poster, renal failure, like vomiting, is a cause of met acidosis, not a s/s. Expect to be pulling out a hefty bolus syringe of bicarb. Maybe start a drip. K will be out of wack, too, so be careful! It's exchanged across the cell wall for hydrogen... leaves the cells in acidosis and bicarb will push it back in.

Just be aware (I doubt it will be testable, and many of our residents have a poor grasp on this) that in Resp Alkalosis in a vent pt, it will usually take more adjustments to the vent then turning down the rate... many critically ill patients still take "extra" breaths that aren't given by the vent. So if the pt is breathing 30X a minute even though the vent is set for a rate of 16, turning the vent down to 10 won't help. Yet, I see newer residents try it all the time. Usually these are patients who are in Met Acidosis and trying to compensate.

That said, treat the primary imbalance before treating the compensation.

Lungs start to compensate for metablic imbalance right away. Kidneys compensate by altering bicarb levels much more slowly- onset of effect in hours, peak in about 3 days!

[GilaRRT]

Just to clarify, do not EVER use a paper bag to treat a patient. You must always assume a respiratory alkalosis is the result of an underlying problem or a compensatory process. The paper bag practice should be considered generally useless and even harmful.

[ImThatGuy, BSN, RN]

This is one of the best articles out there on ABGs.

http://www.ncbi.nlm.nih.gov/pubmed/7624703

Anyone else having trouble opening the attached pdf?