![Anion Gap in Plasma
• The difference between measured major positive
and negative charges. [Na+]+[K+ ] -[Cl- ] +
[HCO3- ]
• The normal value is (3-11) mEq/L
• An increased anion gap indicates that your blood
is more acidic than normal, which may be a sign
of acidosis.](https://image.slidesharecdn.com/acidbasebalance-250114122612-8b355bcf/85/acid-base-balance-by-buffers-systems-ppt-14-320.jpg)
![Compensation of respiratory alkalosis Renal
compensation
• The kidneys decrease plasma [ HCO3 ]:
• Decrease reabsorption of the filtered HCO3.
• The decreased CO2 decreases the generation of
H by the tubular epithelial cells](https://image.slidesharecdn.com/acidbasebalance-250114122612-8b355bcf/85/acid-base-balance-by-buffers-systems-ppt-23-320.jpg)
acid base balance by buffers systems ppt
- 1. ACID-BASE DISTURBANCES & BUFFER SYSTEM Mst. Shazia Yasmeen Senior Lecturer GCON D.G. Khan
- 2. Objectives At the end of this lecture all students will be able to: 1. Define PH ,acid and base. 2. Discuss how the body regulates acid- base balance. 3. Identify the main diagnostic tests used to assess acid- base imbalance. 4. Identify ABG parameters. 5. Differentiate between the respiratory and metabolic imbalances regarding their causes, and clinical manifestations.
- 3. Acid base balance • Acid-base balance is the state of having the right amount of acid and base in the body's fluids, including the blood. It's also known as acid-base equilibrium.
- 4. Definitions Plasma PH represents the hydrogen ions (H+) concentration and measures the acidity or alkalinity of the blood (Pruitt,210) Acidosis: greater the concentration of H+ the more acidic the solution and lower the PH. Alkalosis: lower the H+ concentration more alkaline the solution ands the higher the PH. Buffer System include the substances that reacts with acids and bases to prevent major changes in PH of body fluid by removing or releasing the H+; they prevent excessive changes in H+ concentration and maintain the neutral environment of stable PH.
- 5. Regulation of acid-base balance The body has three mechanisms to maintain acid- base balance: 1- Buffering mechanism. 2- The respiratory compensation mechanism. 3-The metabolic or renal compensation mechanism.
- 6. Types of buffer system 1- Extracellular buffer system • Major EC buffer system is bicarbonate-carbonic acid buffer system. • Normally 20 parts of bicarbonate (HCO-3) to one part of carbonic acid (H2CO3), so that ratio is 20:1. • If the ratio altered the PH will change • CO2 is when dissolved in water it become carbonic acid (Co2+H2O= H2CO3)
- 7. ECF buffer system…… • Less important buffer system in ECF include the inorganic phosphates and the plasma proteins. • The phosphate buffer system is made up of dihydrogen phosphate ions (H2PO4^-) and hydrogen phosphate ions. When a strong acid is added, the dihydrogen phosphate ions accept the protons, preventing a significant change in the concentration of hydrogen ions. When a strong base is added, the hydrogen phosphate ions neutralize the extra hydrogen ions. • Some amino acids in plasma proteins have exposed carboxyl groups that act as weak acids, releasing hydrogen ions when pH rises. Other amino acids have exposed amine groups that act as weak bases, binding hydrogen ions to prevent pH from decreasing.
- 8. Intracellular Buffer system •Proteins •Organic and inorganic phosphates •Red blood cells •Hemoglobin
- 9. Respiratory regulation of acid- base balance • The lungs regulate blood levels of co2 that combine with H2O to form H2CO3 . • Chemo receptors in the medulla of the brain sense those PH changes and vary the rate and depth of breathing to compensate. • Breathing faster or deeper(Hyperventilation) Eliminate more co2 leading to increase PH. • Slow and shallow breathing(Hypoventilation) Lead to accumulation of co2 decrease PH.
- 10. Renal regulation of acid-base balance • Kidneys make long- term adjustment to PH. • They reabsorb acids and bases or excrete them into urine, and can also produce HCO3to replenish lost supply. • Such adjustment to PH take the kidneys days to weeks to complete. If the blood contains too much acids or not enough base, the PH drops and the kidneys in response reabsorb NaHCO3 and excrete (H+) leading to normalization of PH.
- 11. Diagnosis of acid base imbalance 1-Arterial Blood Gases(ABG). 2-Anion gap estimation
- 12. Arterial blood gases Parameters Parameters • PH • HCO-3 • PCO2 • PO2 • Base excess/deficit • O2 Saturation % Arterial blood • 7.35 to 7.45 • 22 to 28 mEq/L • 35 to 45mmHg • >8o mmHg • ±2 mEq/L • >94% • g
- 13. Base excess(B/E The base excess indicates the amount of excess or insufficient level of bicarbonate in the system. The normal range is –2 to +2 mEq/liter. (A negative base excess indicates a base deficit in the blood).
- 14. Anion Gap in Plasma • The difference between measured major positive and negative charges. [Na+]+[K+ ] -[Cl- ] + [HCO3- ] • The normal value is (3-11) mEq/L • An increased anion gap indicates that your blood is more acidic than normal, which may be a sign of acidosis.
- 15. Acid –base imbalance •Respiratory acidosis. •Respiratory alkalosis. •Metabolic acidosis. •Metabolic alkalosis.
- 17. Arterial Blood Gases Interpretation • Step1: Classify the PH • Step 2: Assess the PCO2 level • Step 3: Assess the HCO3 Level • Step 4: Determine the presence of compensation Total compensation Partial compensation Uncompensation
- 18. Respiratory Acidosis It occur with any mechanism that decreases the rate of alveolar ventilation. It is characterized by: PH< 7.35 PaCO2 > 45 mmHg compensatory increase in HCO3 Causes of respiratory acidosis: Depression of respiratory center Narcotics / over sedation. Anesthesia: Respiratory arrest, Paralysis of respiratory muscles Impaired ventilation, Airway obstruction: Foreign body.
- 19. Signs and Symptoms associated with Acidosis • Decrease excitability of CNS • Restlessness, • Headache, • Drowsiness, • Disorientation, • Coma, • Cardiovascular: • Dysrhythmias, • Decreased cardiac contractility • Hypotension.
- 20. Compensation of respiratory acidosis • Renal compensation: • Increased the plasma HCO3concentration . • The increased PaCO2acts as a stimulus to increase the formation of H and HCO3 from CO2+ H2O in the renal tubular cells. • The renal H is secreted and the new HCO3 is returned to the plasma.
- 21. Respiratory Alkalosis • It is defined as a decrease in PaCo2 caused by increase alveolar ventilation. • It is characterized by: PH > 7.45 , PaCO2 < 35 mmHg ,compensatory decrease in HCO3 Causes of Respiratory Alkalosis: • Hyperventilation: o Hypoxemia o Anemia o Fever o Psychological dyspnea o Early in exercises o Angry
- 22. Signs and Symptoms associated with Alkalosis • Increase excitability of CNS: o Light headedness, o Numbness, o Tingling, o Confusion, o Inability to concentrate o Blurred vision.
- 23. Compensation of respiratory alkalosis Renal compensation • The kidneys decrease plasma [ HCO3 ]: • Decrease reabsorption of the filtered HCO3. • The decreased CO2 decreases the generation of H by the tubular epithelial cells
- 24. Metabolic acidosis • It is defined as a primary decrease in plasma bicarbonate concentration(HCO3). • It is characterized by: • PH < 7.35 • HCO3 < 22 mEq/ L • Compensatory decrease in PaCO2
- 25. Causes of metabolic acidosis 1)Loss of HCO3: • Prolonged severe diarrhea 2)Decreased elimination of acids: • Renal failure 3)Excess production of Acids: • Starvation - Shock • Cardiac arrest - Alcoholic Ketoacidosis • Tissue hypoxia • Sepsis • Diabetic Ketoacidosis
- 26. . Metabolic alkalosis • It results from an increase in bicarbonate in ECF. • It is characterized by: • PH > 7.45 • HCO3 > 26 mEq/ L • Compensatory increase in PaCO2
- 27. Causes of metabolic alkalosis • Excess of base /loss of acid. • Acute H ion loss: • Vomiting, • Gastric suction. • diuretics as: Frusemide. • Excess intake of Alkali • Diet rich H in fruits and vegetables. • IV NaHCO3administration.
Editor's Notes
- #4: A solution of acetic acid and sodium acetate (CH3COOH + CH3COONa) is an example of a buffer that consists of a weak acid and its conjugate base, whereas a solution of ammonia and ammonium chloride (NH3 + NH4Cl) is an example of a buffer that consists of a weak base and its conjugate acid.
- #8: Origin: Organic substances are derived from living organisms, while inorganic substances are derived from nonliving components. Chemical bonds: Organic substances have carbon-hydrogen covalent bonds, while inorganic substances generally have ionic bonds. Carbon content: Organic substances contain carbon, while inorganic substances rarely contain carbon. However, some inorganic substances, like carbonates, cyanides, and cyanates, do contain carbon