objective 4 (2) Flashcards
produced with normal metabolic processes
acids
what is the organ that plays an essential role in acid/base balance?
kidneys
what conditions can lead to acid base imbalances?
diabetes, COPD, kidney disease, vomiting and diarrhea
what is the normal blood pH?
7.35-7.45
pH less than 7.35
acidosis
pH greater than 7.45
alkalosis
an increased in H+ concentration lead to…
acidity
a decrease in H+ concentration leads to…
alkalinity
the higher the pH…
the lower the H+ concentration
the lower the pH…
the higher the H+ concentration
1
most ACIDIC
14
most BASIC
ADDITION of H+ will…
increase ACIDITY and lower pH
ELIMINATION of H+ will…
promote ALKALINITY and rise pH
what are the 4 mechanisms that the body will use to maintain normal balance of acids and bases in the blood?
buffer system
respiratory system
renal system
is the fastest-acting system and the primary
regulator of acid–base balance
buffer system
act chemically to change
strong acids into weaker acids or to bind to acids and neutralize
their effect
buffers
what is the major buffer system for acid base balance?
bicarbonate-carbonic acid system
carbonic acid
chief acid
bicarbonate
chief base
- The amount of CO2 in the blood directly relates to carbonic acid concentration
and subsequently to H+ concentration - CO2 is a potential acid; when dissolved in water, it becomes carbonic acid (CO2
+ H2O = H2CO3). Increase in CO2 = increase in acid in bloodstream (LOWER
pH) & decrease in CO2 = decrease in acid in bloodstream (HIGHER pH). - As a compensatory mechanism, the respiratory system acts on the CO2 + H2O
side of the reaction by altering the rate and depth of breathing to “blow off”
(through hyperventilation) or “retain” (through hypoventilation) CO2. - will respond within couple minutes to change in pH, maximal
effectiveness seen within hours.
respiratory response
- Under normal conditions, the kidneys reabsorb and conserve all of
the bicarbonate they filter. The kidneys can generate additional
bicarbonate and eliminate excess H+ as compensation for acidosis. - The body depends on the kidneys to excrete a portion of the acid
produced by cellular metabolism. Thus the kidneys normally excrete
an acidic urine (average pH is 6).
*is relatively slow (hours or days), but in chronic
conditions (COPD) can maintain balance indefinitely
renal response
what are the normal plasma pH levels?
7.35-7.45
acidosis
6.8-7.35
alkalosis
7.45-7.8
when will death occur?
<6.8 >7.8
what is normal HCO3?
21-28
what is the normal CO2?
35-45
is how we can measure
the acidity/alkalinity of
blood
* Used to determine acid
base imbalances, their
cause, if there is any
compensation
happening, and the
severity
* Usually drawn through
radial artery by
respiratory therapist
arterial blood gas
occurs with
hypoventilation – retention of CO2
* Hypoventilation results in a buildup of
CO2; subsequently, carbonic acid
accumulates in the blood. Carbonic
acid dissociates, causing liberation of
H−, and the pH decreases
respiratory acidosis
what are the causes of respiratory acidosis?
asthma, pneumonia, COPD, overdose, pulmonary edema
what are the S&S of respiratory acidosis?
- Extreme respiratory insufficiency
(Hypoventilation) - Cyanosis
- Dizziness / drowsiness
- Increased pulse / Decreased BP
- Warm flushed skin
- Possible Seizures
- Cardiac arrythmias (Due to subsequent
Hyperkalemia)
how do we manage respiratory acidosis>
Individualized treatment dependent upon cause, acute or chronic.
Treatment aimed at improving ventilation - o2 admin, hydration,
BiPAP, bronchodilators, steroids, possible mechanical ventilation
occurs with hyperventilation – loss of CO2
* The decrease in the arterial CO2 level leads to a decrease in carbonic
acid concentration in the blood and an increase in pH
* Always caused by hyperventilation; blowing off CO2 and so lowering
carbonic acid concentrations
respiratory alkalosis
what are the causes of respiratory alkalosis?
Pneumonia, Pulmonary Embolus, Pain, Anxiety
what are the S&S of respiratory alkalosis?
increased respiratory rate
lightheadedness
numbness/tingling of hands and feet
sweating
panic
tinnitus
tachycardia
dysthymias
how do we manage respiratory alkalosis?
Treatment varies, dependent upon cause
If temporary anxiety is the issue, the patient is
instructed to breathe into a paper bag to allow
rebreathing of expired air (CO2)
Sedation if the patient is very anxious.
Kidneys compensate by retaining
H+ and excreting HCO3-
occurs when
an acid other than carbonic acid accumulates in the body
or when bicarbonate is lost from body fluids. In both
cases, a bicarbonate deficit results.
* pH decreased
* HcO3 decreased
metabolic acidosis
what are the causes of metabolic acidosis?
Shock, cardiac arrest, starvation, DKA, renal failure
(chronic metabolic acidosis), severe diarrhea, diuretic
overuse, lactic acidosis (working out too much!)
what are the S&S of metabolic acidosis?
- Kussmaul’s breathing (increased rate and
depth) - N/V
- Headache / confusion / lethargy
- Dangerous cardiac dysrhythmias
- Cold clammy skin
- Hyperkalemia (shift of K+ out of cells)
- If DKA is cause – Will have fruity smelling
breath
how do we manage metabolic acidosis?
- Eliminating the cause, if possible
- Replacing lost fluids and electrolytes
- Severe: IV bicarbonate
- Insulin if cause is DKA
occurs when
acid is lost (as a result of prolonged vomiting or gastric
suction) or when bicarbonate increases (from ingestion of
things like baking soda) occurs
* Increased pH
* Increased HCO3
metabolic alkalosis
what are the causes of metabolic alkalosis?
: Diuretic therapy, prolonged gastric suctioning,
pyloric stenosis with emesis, vomiting, hypokalemia,
antacids, sodium bicarb administration, steroid use
what are the S&S of metabolic alkalosis?
- Depressed respirations to retain CO2 may
cause hypoxemia in patients with
decreased LOC - Dizziness
- Confusion
- Tachycardia
- Dysrhythmia (caused by hypokalemia)
- Tetany
- Muscle cramps
how do we manage metabolic alkalosis?
Monitor I&O carefully
Restore fluid balance
Administer chloride (IV
fluids with K+ if necessary)
to aid in elimination of
bicarbonate.
what is ROME?
respiratory
opposite
metabolic
equal
low pH, high PaCO2
respiratory acidosis
high pH, low PaCO2
respiratory alkalosis
low pH, low HCO3
metabolic acidosis
high pH, high HCO3
metabolic alkalosis
Returning the bicarbonate/carbolic acid ratio back to 20:1
compensation
KIDNEYS: Increased renal acid (H+) excretion and HCO3 is
retained in the blood serum
respiratory acidosis compensation
KIDNEYS: Increased renal HCO3 excretion and H+ is
retained in the blood serum.
respiratory alkalosis compensation
LUNGS: Increased ventilation expels CO2 and renal retention of
HCO3.
metabolic acidosis compensation
LUNGS: Decreased ventilation to retain CO2.
metabolic alkalosis compensation
