Fluid & Electrolytes Part 3 Flashcards
Homeostasis of Hydrogen (H+) concentration in body fluids =
Acid Balance
When a hydrogen imbalance occurs, what happens?
The H+ shifts between the intracellular & extracellular compartments to compensate for the imbalance
A minor hydrogen change can have major effects on-
Cellular Function
For optimal cell function, we need a steady balance of -
Acids & Bases
Used to evaluate acid-base balance =
Arterial Blood Gas (ABG)
This is an indirect measurement of H+ ion concentration =
Arterial pH
What is the arterial pH a result of?
Respiratory & Kidney Compensation Function
What is your pH an expression of?
The balance between Carbon Dioxide (CO2) and Bicarbonate (HCO3)
CO2 is regulated by-
The Lungs
HCO3 is regulated by-
The Kidneys
The greater the H+ concentration =
The more acidic bodily fluids are and the lower the pH
The lower the H+ concentration =
More alkaline the bodily fluids are and the higher the pH
The normal pH of Arterial Blood (Serum) =
7.35 - 7.45
Whenever your pH is lower than 7.35 it is-
Acidosis
Whenever your pH is higher than 7.35 it is-
Alkalosis
What is Acidosis?
An increase in H+ ions
Lose base (Bicarbonate / HCO3)
What is Alkalosis?
A decrease in H+ ions
Gain base (Bicarbonate / HCO3)
When does death occur due to a poor pH?
Less than or equal to 6.8
Greater than or equal to 7.8
How do you treat an acid base imbalance?
You have to fix whatever the problem is that’s causing the acid base imbalance to fix the acid base imbalance
To maintain acid base balance, what are the 3 different bodily mechanisms to compensate for it?
Chemical Buffers (Carbonic Acid-Bicarbonate System)
Respiratory Regulation & Compensation
Renal Regulation & Compensation
How do the lungs impact the acid-base balance?
The lungs can release or retain acid
How does the Carbonic Acid-Bicarbonate System impact the acid-base balance?
It can send out chemical buffers to neutralize excess acid or excess base
How do the kidneys impact the acid-base balance?
They can either retain or excrete acids and bases
What are the chemical buffers and protein buffers that can be released to regulate acid-base balance?
Chemical Buffers = Bicarbonate & Intracellular Fluid
Protein Buffers = Albumin & Globulins
This buffer is the first line of defense for the acid-base balance =
Chemical Buffers
How do chemical buffers neutralize excess acid or base?
They either bind or release hydrogen ions as needed
How fast is the response from chemical buffers?
It’s a quick response (reacts within seconds of imbalance)
What is the benefit of chemical buffers?
It allows very little change in your pH and it keeps the ratio of 1 to 20 acid bicarbonate
What should your ratio of Carbonic Acid be to your Base Bicarbonate?
1 Carbonic Acid to 20 Base Bicarbonate
This is the secondary buffer to respond to pH imbalance =
Respiratory Buffer
This buffer works within minutes =
Respiratory Buffer
How does the respiratory buffer control hydrogen levels?
By the blood via CO2 level control
The receptors can sense a change in CO2 level =
Chemoreceptors
Once Chemoreceptors sense a change in CO2 level, what occurs?
A signal is sent to the brain to alter rate and depth of the pt’s respirations
What does Hyperventilation do?
It blows off excess hydrogen ions thus decreasing hydrogen ions
What does Hypoventilation do?
Increases hydrogen ions or retains the H+ ions
What does carbon dioxide control?
Hydrogen levels
What is the last buffer to respond to pH imbalance?
Kidney Buffers
How long do Kidney Buffers take to respond?
Much slower to respond (3-5 days)
What is the benefit of kidney buffers?
It’s more efficient and long-term
Kidneys control bicarbonate movement in the -
Urine
The kidneys can cause bicarbonate to be-
Reabsorbed into the bloodstream or excreted in the urine dependent upon the blood levels of H+
What can the kidneys produce to impact a hydrogen imbalance if needed?
Bicarbonate
What can cause bicarbonate reabsorption and production?
A higher level of Hydrogen ions
If the level of hydrogen is high, what will the pH be?
Under 7.35
If the level of hydrogen is low, what will the pH be?
Over 7.45
Impaired renal function =
Impaired renal compensation
Why is it so important to keep a person who is incontinent dry?
Urine is acidic. This can cause pressure ulcers & tissue breakdown
The average pH value for urine =
A pH of 6
What pH would be considered acidic for urine?
A pH of 5 or below
HCO3 =
Bicarbonate
What’s the normal pH look like?
Between 7.35 and 7.45
What’s the normal pCo2 look like?
35-45 mm Hg
What’s the normal po2 look like?
80-100 mm Hg
Sao2 =
Less than 95%
What should a base deficit look like?
-2
What should base excess look like?
+2 mEq/L
Where is an ABG drawn from?
Straight from the artery
Who can carry out a ABG?
A Lab Tech
A Respiratory Tech
Whenever a lab tech or respiratory tech finishes taking an ABG, how long do they need to hold pressure for?
Five Minutes
What needs to be done if an ABG sample is not taken straight to the lab and there’s any kind of delay?
The sample needs to be put on ice
What are the different types of acid-base imbalances?
Respiratory Acidosis
Respiratory Alkalosis
Metabolic Acidosis
Metabolic Alkalosis
