Acid and Base Flashcards
Organs associated with Acid Base Balance Regulation
Lungs
Kidneys
Yield hydronium ions (H+) when dissolved in water
Acid
Yield hydroxyl ions (OH-)
Base
Resists changes in pH
Buffer
Normal Blood pH
7.35 - 7.45
pH Level
ACIDOSIS:
ALKALOSIS:
pH Level
ACIDOSIS: < 7.35
ALKALOSIS: > 7.45
Respiratory Regulation
Lungs: Respiration
Metabolic Regulation
Kidneys: Reabsorption & Excretion of bicarbonate
Major Blood Buffer System
Bicarbonate and Carbonic Acid buffer system
Respiratory Regulation
Organ: _________
Regulation: ________
Action/Response: ________
Analytes Controlled: ________
Respiratory Regulation
Organ: Lungs
Regulation: Respiration/Ventilation
Action/Response: Immediate - SHORT term
Analytes Controlled: Oxygen & CO2
Metabolic Regulation
Organ: _________
Regulation: ________
Action: ________
Analytes Controlled: ________
Metabolic Regulation
Organ: Kidney
Regulation: Reabsorption and Excretion of HCO3-
Action/Response: Slow - LONG term
Analytes Controlled: HCO3-
Major Function of Kidney id Acid Base balance
Excretion/Reabsorption of H+ ions and HCO3-
Provide the first line of defense to the changes in acid base status
Lungs
Buffer
Optimum pH level of Arterial Blood
7.40
pH decreases by _______/each Celsius above 37%
0.015
pH range of arterial blood is _______ lower than venous blood
0.003 unit
Evaluates the VENTILATION of Lungs and provide an index of gas exchange
pCO2
Evaluates the DEGREE of OXYGENATION and reflects the availability of O2 in the blood
pO2
Common form of CO2 dissolved in the blood and the CO2 form present in blood circulation
Bicarbonate
HCO3- comprises about _____ of the total CO2 content
95%
Threshold value of Bicarbonate
26 - 30 mmol/L
Metabolic Acidosis
Primary Cause:
Organ Affected:
Compensatory Organ:
Compensation:
Metabolic Acidosis
Primary Cause: Inc. Bicarbonate Excretion, Inc. H+ Reabsorption
Organ Affected: Kidney
Compensatory Organ: Lungs
Compensation: Hyperventilate
Results - Metabolic Acidosis
pH:
HCO3:
pCO2:
Metabolic Acidosis
pH: decreased
HCO3: decreased
pCO2: increased
Metabolic Alkalosis
Primary Cause:
Organ Affected:
Compensatory Organ:
Compensation:
Metabolic Alkalosis
Primary Cause: Inc. Bicarbonate Reabsorption
Organ Affected: Kidney
Compensatory Organ: Lungs
Compensation: Hypoventilation
Results - Metabolic Alkalosis
pH:
HCO3:
pCO2:
Results - Metabolic Alkalosis
pH: Increased
HCO3: Increased
pCO2: Decreased
Respiratory Acidosis
Primary Cause:
Organ Affected:
Compensatory Organ:
Compensation:
Respiratory Acidosis
Primary Cause: Hypoventilation
Organ Affected: Lungs
Compensatory Organ: Kidney
Compensation: Inc. Bicarbonate Reabsorption, H+ excretion
Results - Respiratory Acidosis
pH:
HCO3:
pCO2:
Results - Respiratory Acidosis
pH: decreased
HCO3: decreased
pCO2: increased
Respiratory Alkalosis
Primary Cause:
Organ Affected:
Compensatory Organ:
Compensation:
Respiratory Alkalosis
Primary Cause: Hyperventilation
Organ Affected: Lungs
Compensatory Organ: Kidney
Compensation: Increased Bicarbonate excretion
Results - Respiratory Alkalosis
pH:
HCO3:
pCO2:
Results - Respiratory Alkalosis
pH: increased
HCO3: increased
pCO2: decreased
Causes of Respiratory Acidosis
Alveolar Capillary Diffusion and Perfusion: COPD, Bronchopneumonia, Asthma, Emphysema
Drug Abuse
Congestive Heart Failure - Cardiac Arrest
Stroke
Causes of Respiratory Alkalosis
CNS Disorders Hypoxia Salicylate or Aspirin Intoxication Pregnancy Physical Exercise Cirrhosis - Hepatic Coma Septicemia - Gram Negative
Causes of Metabolic Acidosis
Increased H+ production: Metabolic Acidosis, Diabetic Ketoacidosis, Lactic Acidosis, Poisoning (methanol & salicylate)
Reduced Acid reduction: RTA, Renal failure
Loss of Bases: Loss of Na, Diarrhea
Causes of Metabolic Alkalosis
Diuretics Antacids Vomiting Diarrhea Mineralocorticoid Activity: Cushing's syndrome, Hyperaldosteronism Excess NaHCO3 administration
Specimen of Choice to measure Acid-Base Status
Arterial Blood
Anticoagulant used
0.05 ml/of blood (Preheparinized - Lithium Heparin)
Syringe Method - Arterial Blood
Collection: Blood Volume: Anticoagulant: Processing: Transport:
Syringe Method
Collection: Anaerobic collection - with rubber stopper
Blood Volume: 3 ml/cc
Anticoagulant: 0.05 ml/ml of blood
Processing: STAT - <30 mins. after collection;
Sample Analysis: 5 mins
Transport: CHILLING (with ice)
Use of Butterfly and ETS is __________________
NOT RECOMMENDED - NEVER USE!!!
Not recommended in Blood Gas Analysis
Do Not Use:
Butterfly needle
ETS
Liquid form of Heparin
Rationale - Chilling with Ice
To maintain Low Temperature in order to:
- Increase solubility of O2, and gases to stay dissolved in the blood.
- Reduce O2 consumption
- Prevent the release of other metabolites that will change pH
Effect if NOT Chilled
pH - _______
pO2 - _______
pCO2 - _______
Effect if NOT Chilled
pH - decrease
pO2 - decrease
pCO2 - increase
Effect: ON STANDING (CLOSE TUBE)
pH - _______
pO2 - _______
pCO2 - _______
HCO3 - _______
Effect: ON STANDING
pH - decreased
pO2 - decreased
pCO2 - increased
HCO3 - increased
Effect: ROOM AIR
pH - _______
pO2 - _______
pCO2 - _______
HCO3 - _______
Effect: ROOM AIR
pH - increased
pO2 - increased
pCO2 - decreased
HCO3 - decreased
Every 1 C rise (37C) in Temperature - Fever:
pO2: _______ 7%
pCO2: ______ 3%
Every 1 C rise (37C) in Temperature - Fever:
pO2: decrease 7%
pCO2: increase 3%
Increased Plasma Proteins
Increased pO2
Increased Bacterial Contamination
Decreased pO2
Glycolysis
Decreased: pH, pO2
Principle: pO2 determination
Amperometry & Polarography
Principle: pH & pCO2 detetmination
Potentiometry
pH Electrode
Measuring Electrode: _______________
Reference electrode: _______________
pH Electrode
Measuring Electrode: Glass Sensing Electrode
Reference electrode: Ag-Ag Cl (internal)/Hg-Hg Cl (external) Electrode
pO2 Electrode
Measuring Electrode: _______________
Reference electrode: _______________
pO2 Electrode
Measuring Electrode: Clarke Electrode
Reference electrode: Ag-Ag Cl Electrode
pCO2 Electrode
Measuring Electrode: _______________
Reference electrode: _______________
pCO2 Electrode
Measuring Electrode: Severinghaus Electrode
Reference electrode: Ag-Ag Cl (internal)/Hg-Hg Cl (external) Electrode
Gasometric Method is used for ______________ determination
Total CO2
Reagents for Gasometric/Van Slyke/Natelson
Lactic acid:
Caprylic Acid:
NaOH:
Reagents for Gasometric/Van Slyke/Natelson
Lactic acid: Release CO2
Caprylic Acid: Prevent Foaming
NaOH: Absorb CO2
Anti-Foam Reagent used in Gasometric Method
Caprylic Alcohol
