Acid

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Acid Base Disorders
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• Respiratory Acidosis
• Respiratory Alkalosis
• Metabolic Acidosis
• Metabolic Alkalosis

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ACIDOSIS

• A pH of 7.4 corresponds to a 201 ratio of HCO3-
  and H2CO3.
• Concentration of HCO3- is 24 meq/liter and H2CO3
  is 1.2 meq/liter.

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RESPIRATORY ACIDOSIS

• Caused by hyperkapnia due to hypoventilation.
• Characterized by a pH decrease and an increase in
  CO2

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RESPIRATORY ACIDOSIS

• Decreased CO2 removal can be the result of
• Obstruction of air passages
• Decreased respiration (depression of respiratory
  centers)
• Decreased gas exchange between pulmonary
  capillaries and air sacs of lungs
• Collapse of lung

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RESPIRATORY ACIDOSIS

• BODYS COMPENSATION
• kidneys conserve HCO3- ions to restore the normal
  ratio (201)
• kidneys eliminate H ion in acidic urine

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RESPIRATORY ALKALOSIS

• Cause is Hyperventilation
• Leads to eliminating excessive amounts of CO2.
• Increased loss of CO2 from the lungs at a rate
  faster than it is produced.
• Decrease in H.

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RESPIRATORY ALKALOSIS

• Can be the result of
• 1) Anxiety, emotional disturbances
• 2) Respiratory center lesions
• 3) Fever
• 4) Salicylate poisoning (overdose)
• 5) Assisted respiration
• 6) High altitude (low PO2)

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RESPIRATORY ALKALOSIS

• Kidneys compensate by
• Retaining hydrogen ions
• Increasing bicarbonate excretion

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METABOLIC ACIDOSIS

• Any acid-base imbalance not attributable to CO2
  is classified as metabolic.
• Metabolic production of Acids
• Or loss of Bases.

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METABOLIC ACIDOSIS

• The causes of metabolic acidosis can be grouped
  into five major categories
• 1) Ingesting an acid or a substance that is
  metabolized to acid
• 2) Abnormal Metabolism
• 3) Kidney Insufficiencies
• 4) Strenuous Exercise
• 5) Severe Diarrhea

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• 1) Ingesting An Acid
• Most substances that cause acidosis when ingested
  are considered poisonous
• Examples includewood alcohol(methanol)
  andantifreeze(ethylene glycol)
• However, even an overdoseof aspirin
  (acetylsalicylic acid)can cause metabolic
  acidosis.

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• 2) Abnormal Metabolism
• One of the most significant is Type I Diabetes
  Mellitus.
• Unregulated diabetes mellitus causes ketoacidosis
• Body metabolizes fat rather than glucose
• Accumulations of metabolic acids
• (Keto Acids) cause an increase in plasma H.

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• 2) Abnormal Metabolism
• The body also produces excess acid in the
  advanced stages of shock, when lactic acid is
  formed through the metabolism of sugar.

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• 3) Kidney Insufficiencies
• Even the production of normal amounts of acid may
  lead to acidosis when the kidneys are not
  functioning normally

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• 4) Strenuous Exercise
• Muscles resort to anaerobic glycolysis during
  strenuous exercise.
• Anaerobic respiration leads to the production of
  large amounts of lactic acid.

Enzymes
C6H12O6 2C3H6O3 ATP (energy)
Lactic Acid
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• 5) Severe Diarrhea
• Fluids rich in HCO3- are released and reabsorbed
  during the digestive process.
• During diarrhea this HCO3- is lost from the body
  rather than reabsorbed.
• Prolonged deep (from duodenum) vomiting can
  result in the same situation.

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METABOLIC ALKALOSIS

• Can be the result of
• 1) Ingestion of Alkaline Substances
• 2) Vomiting ( loss of HCl )

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METABOLIC ALKALOSIS

• Reaction of the body to alkalosis is to lower pH
  by
• Retaining CO2 by decreasing breathing rate.
• Kidneys increase the retention of H.

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ACIDOSIS
deep vomiting from GI tract
increase in plasma H concentration
kidney disease (uremia)
depression of nervous system
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ALKALOSIS
overexcitability of nervous system
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• 1) A 50 year-old man with history of type 2
  diabetes was admitted to the emergency department
  with history of polyuria. On examination he had
  rapid and deep breathing. Blood analysis showed
  glucose level of 400 mg/dl.  
• The following is the arterial blood analysis
  report of this patient  
• pH 7.1, PCO2 40 mmHg and HCO3- 18 mmol/L 
• (Normal reference ranges PCO2 36.0-46.0 mmHg,
  HCO3- 22.0-26.0 mmol/L)
• What is the acid base disturbance in this case?

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• 2) PH 7.12, PaCO2 60mmHg, HCO3? 24meq/L.
• a) Compensated metabolic acidosis.
• b) Uncompensated metabolic acidosis,
• c) Compensated respiratory acidosis,
• d) Uncompensated respiratory acidosis,
• 3) PH 7.51, PaCO2 40mmHg, HCO3? 31meq/L.
• a) Normal,
• c) Compensated respiratory acidosis,
• d) Uncompensated respiratory alkalosis.
• b) Uncompensated metabolic alkalosis,