Acid/Base Flashcards
Functions of acid base balance?
homeostasis of body fluids, kidneys, and lungs
what controls Co2?
Respiratory process
what controls bicarbonate?
kidneys (metabolic process)
Carbons dioxide mixes with water to formwhat?
carbonic acid?
bicarbonate and hydrogen ions mix to form what?
carbonic acid
2 ways to make carbonic acid
co2+ h2o
Hco3 + hydrogen ions
what do you need to make carbonic acid in both processes?
carbonic anhydrase
what controls breathing?
Co2
how quickly does respiratory system respond to acid base changes?
quickly- within minutes
is bicarb an acid or a base?
base
is Co2 an acid or a base?
acid
the kindeys control acid-base balance through the retention or excretion of what 2 substances?
hydrogen ions and bicarbonate ions
how quickly does the renal systems respond to acid base changes?
hours to days
-slower than resp but stronger response
how do we figure out acid base status?
ABG -arterial blood gas
most common artery for ABG
radial or femoral
pH range
7.35-7.45
PaCo2 ranges
35-45 mmHg
HCO3 ranges
22-26 mEq/L
Co2 < then 35 =
base
Co2 > 45 =
acid
HCO3 <22=
acid
HCO3 >26=
base
If pH is below 7.35 body will compensate to what range?
7.35-7.39
if pH is above 7.45 body will adjust to
7.41-7.45
when does an UNcompensated acid-base disorder occur?
CO2 or HCO3 = abnormal
pH = normal
when does a PARTIALLY compensated acid-base disorder occur
CO2, HCO3, pH are abnormal
compensated acid-base disorder occurs when
CO2 + HCO3= abnormal
pH = normal
4 types of uncompensated acid-base disorders
metabolic acidosis/alkalosis
respiratory acidosis/alkalosis
causes of metabolic acidosis
-excess carbonic acid productions or bicarb deficit: DKA, lactic acid accumulation with anaerobic exercise, renal disease, severe diarrhea
how does severe diarrhea cause metabolic acidosis ?
- dehydration lead to build up of lactic acid or shock
- stool contains bicarb and severe diarrhea means prolonged loss of bicarb
how does kidney disease cause metabolic acidosis?
kidneys make bicarb so not making enough bicarb
metabolic acidosis compensation
- kidneys make more bicarb
- respiratory hyperventilation to blow off CO2
what is problem with hyperventilation to treat metabolic acidosis?
- resp compensation is relatively weak
- underlying problem is not addressed
s/s metabolic acidosis
- kassmaul’s respiration
- lethargy, fatigue, coma
- hypertension, dysrhythmias
- hyperkalemia
what are kussmaul’s respirations?
deep rapid resps with metabolic acidosis
why have hyperkalemia with metabolic acidosis?
H and K have same 1+ charge so they swap places in the cell
potassium –> out into intravascular
hydrogen –> in to intracellular
–see increase in serum potassium
metabolic acidosis treatment
kidney impairment –> hemodialysis
DKA –> insulin
shock –> fluid replacement/shock treatment
what can be done to treat hyperkalemia?
insulin + dextrose, loop diuretics
metabolic alkalosis causes
- base bicarb excess
- prolonged vomiting / gastric suction (loss of hydrochloric acid)
- bicarb gain
who would be taking bicarbonate supplements and thus be at risk for metabolic alkalosis?
patients with renal insufficiency
metabolic alkalosis compensation
- renal excretion of bicarb
- decrease resp rate (occurs first)
Metabolic alkalosis s/s
- hyperactive reflexes
- paresthiesia
- tetany
- seizures
- resp. depression
- hypocalcemia, hypokalemia
metabolic alkalosis treatment
- for vomiting/gastric suctioning –> adequate hydration, arginine hydrochloride (raises chloride level)
- diuretic: diamox
how does arginine hydrochloride treat metabolic alkalosis?
raises chloride levels which are reduced from gastric loss
what is diamox? how does it help metabolic alkalosis treatment?
carbonic anhydrase inhibitor
- carbonic anhydrase turns bicarb to turn into carbonic acid
- if inhibited –> bicarb no go carbonic acid –> excreted instead
hypoventilation is < ____ resps/minute
12
causes of respiratory acidosis
- hypoventilation
- resp failire
- injury to medulla
- overdose of benzo/opioids (anything with sedative effect)
how does medulla injury cause respiratory acidosis?
- medulla is CNS control of respirations
- if no fxn then result in hypoventilation
respiratory acidosis compensation
- will only have metabolic renal compensations
- -> kidneys retain bicarb ions or excrete H ions
respiratory acidosis s/s
mental status change may occur 1st
- ->irritability, disorientation, lethargy, coma, headache
- tachycardia
why have tachycardia with respiratory acidosis?
trying to get more O2
respiratory acidosis treatment
- -priority it treat underlying cause
- –obstructive condition –> Bipap or mechanical ventilation
- –sedative overdose –> narcan (naloxone)
- O2, HOB elevated, antibiotics in pneumonia
respiratory alkalosis causes
-acid deficit caused by hyperventilation or pulmonary disorders
rapid breathing: anxiety, fever, pain, traums, anemia, asthma, PE, CVA
respiratory alkalosis compensation
bicarb shifts INTO cells in exchange for CHLORIDE ions
-if alkalosis persists –> renal excretion of bicarb
resp alkalosis s/s
neuromuscular: paraesthesia, dizziness, vertigo, tetany
CV: tachy, dysrhythmias, sweating
Resp Alkalosis treatment
- pain/anxiety –> intervention for that
- asthma –> bronchodilator
- anemia –> packed red blood cells, restore Hgb
how is bicarbonate made?
carbonic acid dissociates in the kidneys to make a hydrogen ion and bicarbonate
