Acid-Base Disorders Flashcards
Normal human pH is ____
7.35 - 7.45
Even small alterations in pH can result in ____ or _____ of proteins.
misconfiguration or denaturing
the activities of almost all enzyme system throughout the body are influenced by the ____ concentration
H+
Acid vs. a Base
Acid: Molecules that contain Hydrogen and can release H+ (HCl, H2CO3)
Base: Ion or molecule that can accept or bind free H+ (HCO3-, HPO4-)
Acidosis vs. Alkalosis
Acidosis is excess addition of H+ to body fluids (pH under 7.35)
Alkalosis is excess removal of H+ from body fluids (pH over 7.45)
To defend against changes in the concentration of hydrogen ions, the body uses three main defense mechanisms:
Buffering of Hydrogen Ions
Respiratory Regulation
Renal Regulation
the body must continually dispose of ___ to keep the arterial pH within normal limits.
acid
There are several buffering systems utilized in the body to manage the pH, the main one being the _____
Carbonic Acid - Bicarbonate System
H20 + Co2 <—> H2CO3 <—-> HCO3- + H+
When looking at labs, think of CO2 as the ___
Respiratory Acid
By adjusting how much HCO3- is reabsorbed and how much H+ is secreted, the ____ can manage the net loss of either acid or base.
kidneys
When looking at labs, think of HCO3- as the ____
Metabolic Base
By ____ back and forth on the Carbonic Acid System, the body maintains the pH
Compensating
Acid-Base disorders include
Metabolic Acidosis
Metabolic Alkalosis
Respiratory Acidosis
Respiratory Alkalosis
Metabolic Acidosis Results from_____ or_____
decreased HCO3-; increased Acid concentration
Clinical causes of metabolic acidity
- Failure of the kidneys to excrete extracellular acids (due to renal diseases, whether acute or chronic)
- Formation of excess metabolic acids in the body (such as diabetic ketoacidosis, lactic acidosis, etc)
- Loss of base from body fluids (such as severe diarrhea, which results in loss of large amounts of bicarbonate in the feces)
Metabolic Alkalosis Results from ____ or _____
increased HCO3- concentration; loss of excess H+.
Clinical causes of metabolic alkalosis
- Increased ingestion of alkaline drugs, such as Sodium Bicarbonate.
- Excessive vomiting can result in loss of large amounts of acid from the gastric hydrochloric acid (HCl).
- Excessive Aldosterone secretion results in increased renal Na+ reabsorption, which also causes increased urinary excretion of H+.
Respiratory Acidosis Results from ____ and ____
decreased ventilation; increased PCO2
Clinical causes of Hypoventilation:
- Damage to respiratory center in the medulla oblongata
- Obstructive lung conditions, such as COPD, chest trauma, etc
- Factors that interfere with pulmonary gas exchange, such as pneumonia, pulmonary embolism, cardiac arrest, etc
- Other causes of hypoventilation, such as narcotic overdose
Treatment for Respiratory Acidosis:
Treat underlying condition and hyperventilate.
Respiratory Alkalosis Results from ___and ____
increased ventilation; decreased PCO2
Clinical causes of Hyperventilation:
Anxiety, panic attacks, fever, some head injuries, COPD, asthma, pneumonia, pulmonary fibrosis, etc.
An acute metabolic complication of diabetes characterized by
- Hyperglycemia, hyperketonemia, and metabolic acidosis
- DKA occurs mostly in individuals with Type 1 DM
What is Ketogenesis?
Glucagon stimulates mitochondrial conversion of free fatty acids into ketones, mostly in the liver
ketone bodies are oxidized by several enzymes in the cells to produce ____, which can then be used for cellular energy
ATP
Breakdown of ketones is called ____
ketolysis
DKA is an important form of ____
metabolic acidosis
T/F Ketones are Acids
T
In situations when tissues are being deprived of oxygen (such as shock, sepsis, heart failure, COPD, etc.), ____ Respiration may be needed.
Anaerobic
During Anaerobic Respiration, ____ can still occur
glycolysis
However, in order to keep glycolysis going, enzymatic processes need to occur in the absence of oxygen.
Anaerobic Respiration produces _____
Lactate (lactic acid)
____ is a diagnostic assessment that can be used to evaluate a patient’s Acid-Base status, and diagnose Hypoxia
ABG = Arterial Blood Gas
An ABG provides the clinician with
Arterial pH
Arterial PCO2
Arterial PO2
Percentage of O2 Saturation
Bicarbonate (HCO3-)
ABG collection is not significantly invasive but does have a few potential complications including:
Arterial thrombosis or occlusion, and Bleeding
The ____ is almost always the artery sampled for an ABG
Radial Artery
6 steps to ABG interpretation
- pH - is there acidosis or alkalosis?
- Is the CO2 normal?
- Is the HCO3 normal?
- Match the CO2 or the HCO3 with the pH.
- Does CO2 or HCO3 go the opposite direction of the pH?
- Are the PO2 and O2 Saturation normal?
Assessing if the CO2 is normal
35-45 is normal
Greater than 45 is considered Acidic.
Less than 35 is considered Alkalotic.
Assessing the HCO3
Normal range is 22-26
Greater than 26 is considered Alkalotic.
Less than 22 is considered Acidic.
Assessing if PO2 and O2 saturation are normal
Normal PO2 is 80-100 mmHg, O2 sat is 95-100%
A PO2 of 60 mmHg generally correlates with an O2 Saturation of about 90%.
If PO2 or O2Sat are low, your patient is Hypoxic and should be placed on O2.
