Acid- Base disorders.pptx Acid-base balance refers to the balance between input (intake and production) and output (elimination) of hydrogen ion.

Acid-base balance refers to the balance between input (intake and production) and output (elimination) of hydrogen ion. The body is an open system in equilibrium with the alveolar air where the partial pressure of carbon dioxide pCO2 is identical to the carbon dioxide tension in the blood.

1. ACID BASE DISORDER

2. Specific Learning Objectives At the end of this lecture all students will be able to: Explain the acid- Base Disorders

3. Definition Acid – base imbalance  is an abnormality of the human body's normal   balance  of  acids  and  bases  that causes the plasma pH to deviate out of the normal range (7.35 to 7.45).

4. Acid –base imbalance

5. 25

6. Respiratory Acidosis -1 It occur with any mechanism that decreases the rate of alveolar ventilation. It is characterized by: PH< 7.35 PaCO 2 > 45 mmHg compensatory increase in H 2 CO 3 -

7. Causes of respiratory acidosis Depression of respiratory centre: Narcotics / over sedation. Anesthesia. Respiratory arrest. Paralysis of respiratory muscles Impaired ventilation. Airway obstruction: Foreign body.

8. Signs and Symptoms associated with Acidosis Decrease excitability of CNS Restlessness, Headache, Drowsiness, Disorientation, Coma, Cardiovascular: Dysrhythmias, Decreased cardiac contractility Hypotension.

9.  Increase electrolytes : -Hyperkalemia -Hyper calcemia

10. Compensation of respiratory acidosis Renal compensation: Increased the plasma H 2 CO 3 concentration . The increased PaCO 2 acts as a stimulus to increase the formation of H and HCO 3 from CO 2 + H 2 O in the renal tubular cells. The renal H is secreted and the new H 2 CO 3 is returned to the plasma.

11. Respiratory Alkalosis It is defined as a decrease in PaCo2 caused by increase alveolar ventilation. It is characterized by: PH > 7.45 PaCO 2 < 35 mmHg compensatory decrease in H2CO 3

12. Causes of Respiratory Alkalosis H y p er v e n t i l a t i on: H y p o x e m ia Anemia Fever Psychological dyspnea Early in exercises Angry

13. Signs and Symptoms associated with Alkalosis Increase excitability of CNS Light headedness, Numbness, Tingling, Confusion, Inability to concentrate Blurred vision. Decrease electrolytes: Hypokalemia Hypertension

14. Compensation of respiratory alkalosis Renal compensation The kidneys decrease plasma [ H 2 CO 3 ]: Decrease reabsorption of the filtered H 2 CO 3 . The decreased CO 2 decreases the generation of H by the tubular epithelial cells.

15. Metabolic acidosis It is defined as a primary decrease in p l a s m a bicarbonate concentration(HCO3). It is characterized by: PH < 7.35 HCO 3 < 22 mEq/ L Compensatory decrease in PaCO 2

16. Causes of metabolic acidosis Loss of HCO3: Prolonged severe diarrhea Decreased elimination of acids: Renal failure Excess production of Acids: Starvation Cardiac arrest Tissue hypoxia Sepsis Diabetic Ketoacidosis Shock Alcoholic Ketoacidosis

17. Metabolic alkalosis It results from an increase in bicarbonate in EC F. It is characterized by: PH > 7.45 HCO 3 > 26 mEq/ L Compensatory increase in PaCO 2

18. 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 NaHCO 3 administration.