Upgrade to remove ads
Only $2.99/month

Metabolic Alkalosis

Terms in this set (18)

What is Metabolic Alkalosis?
Bicarbonate Excess; characterized by a high pH (>7.45) and a high bicarbonate (>28mEq/L)
What can cause metabolic alkalosis?
-a loss of acid (hydrogen ions) typically by vomiting/gastric suctioning (gastric secretions are highly acidic, so when they're lost the alkalinity of body fluid increases)

-a shift of hydrogen ions into cells

-excess bicarbonate in the body (some antacids like Alka-Seltzer contain bicarb, or overzealous administration of bicarb to correct metabolic acidosis)

-hypokalemia (kidneys try to conserve potassium by increasing renal excretion of H+, OR when K+ shifts out of cells to maintain ECF potassium levels, H+ ions shift into the cells to maintain the balance between cations and anions within the cells

-excessive use of potassium-losing diuretics
What does the respiratory system do when metabolic alkalosis develops?
it attempts to return the pH to normal by slowing the respiratory rate, this way carbon dioxide will be retained and the PaCO2 increases (>45mmHg)
True or False: Hypokalemia not only can cause metabolic alkalosis, but can also result from metabolic alkalosis.
TRUE!

H+ ions shift out of the ICF to the ECF to try and balance the pH in alkalosis, this causes more potassium to enter cells, thus depleting ECF K+
Which ion accounts for many of the clinical manifestations associated with metabolic alkalosis?
Calcium (Hypocalcemia)

In alkalosis, calcium combines with serum proteins, reducing the amount of ionized Ca2+ in the blood, this causes the clinical manifestations
What are the clinical manifestations of metabolic alkalosis?
-confusion
-decreased LOC
-hyperreflexia
-tetany
-dysrhythmias
-hypotension
-seizures
-respiratory failure-resp system compensates for alkalosis, depressing RR and rest failure with hypoxemia and resp acidosis may develop
-numbness/tingling of the mouth, fingers, toes
-dizziness
-Trousseau's sign
-muscle spasm
Pharmacologic therapy for metabolic acidosis
restoring normal fluid volume and administering potassium chloride and sodium chloride solution

in severe alkalosis, an acidifying solution such as dilute hydrochloric acid or ammonium chloride may be administered
Why do you administer potassium chloride solution in metabolic alkalosis?
It restores ICF and serum potassium levels, allowing the kidneys to conserve H+ ions more effectively

chloride promotes renal excretion of bicarb
Why do you administer sodium chloride in metabolic alkalosis?
to restore fluid volume deficits
Clinical therapies for metabolic alkalosis
-monitor I&Os
-monitor VS, especially RR and LOC
-administer IV fluids carefully
-administer O2 as ordered
-treat underlying primary disorder thats causing metabolic alkalosis
ABGs for metabolic alkalosis
pH greater than 7.45
bicarb greater than 28

with compensatory hypoventilation, CO2 is retained and PaCO2 is greater than 45mmHg
What will serum electrolytes demonstrate in metabolic alkalosis?

i.e. potassium, chloride, bicarb, and calcium
often demonstrates....

decreased K+ (less than 3.5mEq/L)

decreased Cl+ (less than 95mEq/L)

increased serum bicarb

total serum Ca2+ may be normal, but the ionized fraction of calcium is low
What will the urine pH be with metabolic alkalosis?
may be low (pH 1-3) if its caused by hypokalemia

kidneys will retain potassium and excrete H+ to restore ECF K+ levels

urinary chloride may be normal or greater than 250mEq/24h
What will the ECG pattern be in a person with metabolic alkalosis?
changes similar to those seen with hypokalemia
Health promotion activities for people with metabolic alkalosis
teach clients the risks of taking sodium bicarb as an antacid to relieve heartburn or gastric distress
Nursing Dx for metabolic alkalosis
#1 risk for impaired gas exchange (HIGH priority)

respiratory compensation for metabolic alkalosis depressed the RR and depth of breathing to promote CO2 retention, as a result, the pt is at risk of impaired gas exchange

#2 deficient fluid volume

#3 risk for injury
Appropriate outcomes for pts with metabolic alkalosis
-fix the underlying problem
-O2 sats of 93% or higher
-normal or near normal fluid and electrolyte volumes
Monitor for Impaired Gas Exchange
monitor RR, depth, effort, O2 sats continuously, hypoxemia

assess color, cyanosis, mental status, LOC

place in semi-fowlers or fowlers as tolerated

administed O2 as ordered

schedule nursing care activities to allow rest periods
YOU MIGHT ALSO LIKE...