acid base disorders 8/26

What effects can acid-base disorders have on bodily systems?

Changes in respiratory drive, electrolyte homeostasis, enzyme-mediated homeostasis, and receptor function

What is a pharmacist's role in acid-base disorders?

Assess the disorder

Determine the cause

Prescribe drug therapy

What does an arterial blood gas (ABG) test measure?

Oxygen and carbon dioxide levels

pH balance in oxygenated blood

What does a venous blood gas (VBG) test measure?

Oxygen and carbon dioxide levels

pH balance in deoxygenated blood

Which blood gas test is more reliable, an ABG or a VBG?

a. Arterial blood gas (ABG) test

b. Venous blood gas (VBG) test

Arterial blood gas (ABG) test

How are the results of an ABG structured?

a. pOH/PaO2/PaCO2/HCO3-/SaO2%

b. pH/PaCO2/PaO2/SaO2%/HCO3-

c. pH/PaO2/PaCO2/HCO3-/SaO2%

d. PaO2/PaCO2/pH/HCO3-/SaO2%

pH/PaCO2/PaO2/HCO3-/SaO2%

What is the normal pH range for an ABG test?

7.35-7.45

What is the normal PaCO2 range for an ABG test?

35-45 mmHg

What is the normal PaO2 range for an ABG test?

80-100 mmHg

What is the normal HCO3- range for an ABG test?

22-26 mEq/L

What is the normal SaO2% range for an ABG test?

SaO2% = 99%

What is acidosis?

a pathophysiologic process that acidifies body fluids

What is acidemia?

an increase in the blood's hydrogen ions

What is alkalosis?

a pathophysiologic process that alkalizes body fluids

What is alkalemia?

a decrease in the blood's hydrogen ions

How can acid-base disorders be differentiated?

Primary and secondary changes

What is a primary change in acid-base disorders?

Abnormality in serum [HCO3-] or arterial PCO2 resulting from an issue in body function or metabolism

What is a secondary change in acid-base disorders?

Compensatory response by the body to minimize pH changes produced by the primary disorder

What is compensation in acid-base disorders?

A predictable alteration to normalize pH by altering a non-primary component.

What is a simple acid-base disorder?

Involves one primary disorder with or without compensation

What is a mixed acid-base disorder?

The simultaneous occurrence of two or more primary disorders.

What are the two components needed to name an acid-base disorder?

Primary change/cause (respiratory or metabolic) and pH (acidosis or alkalosis)

How is the primary cause determined in respiratory acid-base disorders?

By using PaCO2, which contrasts with the change in pH

How is the primary cause determined in metabolic acid-base disorders?

By using [HCO3-], which reflects the change in pH

What is the purpose of checking the anion gap in metabolic acidosis?

To determine the etiology (anion gap or non-anion gap acidosis) and guide treatment

How do the lungs compensate in metabolic acidosis?

Eliminating CO2

What is the formula for calculating anion gap?

Na+ - (Cl- + HCO3-)

Sodium - (Chloride + Sodium Bicarbonate)

Which anions are used in the anion gap equation?

Na+

Cl-

HCO3-

How is hypoalbuminemia corrected in the anion gap calculation?

For every 1 g/dL decrease in albumin, add 2.5 to the calculated anion gap

What is the normal range for anion gap?

Between 4-12

What is the clinical presentation of metabolic acidosis?

Hyperventilation (HUGE indicator)

Neurological symptoms

Cardiovascular symptoms

Gastrointestinal symptoms

What are some neurological symptoms associated with metabolic acidosis?

confusion, coma

What are some cardiovascular symptoms associated with metabolic acidosis?

decreased contractility, bradycardia, hypotension

What are some gastrointestinal symptoms associated with metabolic acidosis?

Loss of appetite, N&V

What is the primary change in metabolic acidosis?

Decreased [HCO3-]

What are the possible causes of ANION GAP metabolic acidosis?

GOLDMARK

Glycols

Oxoproline

L-Lactate

D-Lactate

Methanol

Aspirin

Renal Failure

Ketoacidosis

What are some possible drug induced causes of NON-ANION GAP metabolic acidosis?

Carbonic anhydrase inhibitors

Hyperchloremia from NaCl

Cholestyramine

What are some possible non-drug induced causes of NON-ANION GAP metabolic acidosis?

Diarrhea

CKD

Renal tubular acidosis

What are the compensatory mechanisms for metabolic acidosis?

Buffers followed by hyperventilation

What are the treatment options for metabolic acidosis?

Dialysis

Sodium bicarbonate

Insulin

Antibiotics

What is the primary change in respiratory acidosis?

Increased PaCO2 due to impaired ventilation

What are the possible causes of respiratory acidosis?

COPD

Opioid usage

Neurological issues

Obesity

What are the compensatory mechanisms for respiratory acidosis?

Buffers followed by renal compensation

What are the treatment options for respiratory acidosis?

Mechanical ventilation

Naloxone (for opioids)

Corticosteroids (for COPD)

What is the difference between acute and chronic respiratory acidosis?

Acute occurs quickly without proper time for compensation, while chronic occurs gradually with renal compensation

What is the clinical presentation of metabolic alkalosis?

Arrhythmias (if pH>7.6)

Neurological symptoms

Muscular symptoms

What are the neurological symptoms of metabolic alkalosis?

Dizziness

Seizures

Confusion

Coma

What are the muscular symptoms of metabolic alkalosis?

Tetany

Hyperreflexia

Cramps

Weakness

What is the primary change in metabolic alkalosis?

Increased [HCO3-]

What are the compensatory mechanisms for metabolic alkalosis?

Buffers followed by hypoventilation

What are the treatment options for metabolic alkalosis?

Discontinuing the offending agent

Sodium chloride IV

Ketoconazole (for Cushing's)

What are the two types of metabolic alkalosis?

Chloride responsive and chloride resistant

What is the etiology for chloride responsive metabolic alkalosis?

Vomiting

Contraction alkalosis

Loop diuretics

Thiazide diuretics

Antacids

Total parenteral nutrition

What is the etiology for chloride resistant metabolic alkalosis?

Primary aldosteronism

Licorice

Fludrocortisone administration

Gitelman syndrome

Cushing syndrome

Liddle syndrome

What is the clinical presentation of respiratory alkalosis?

Arrhythmias (if pH>7.6)

Neurological symptoms

Muscular symptoms

What are the neurological symptoms of respiratory alkalosis?

Confusion

Dizziness

Paresthesia

Seizures

What are the muscular symptoms of respiratory alkalosis?

Cramps and spasms

What is the primary change in respiratory alkalosis?

Decreased PaCO2 due to hyperventilation

What are the two types of respiratory alkalosis?

Pulmonary and non-pulmonary

What is the etiology for pulmonary respiratory alkalosis?

Asthma

Pulmonary edema

Interstitial fibrosis

What is the etiology for non-pulmonary respiratory alkalosis?

Pregnancy

Brain lesion

High altitude

Cyanotic heart disease

Liver disease

Psychogenic

How does the body compensate for respiratory alkalosis?

Buffers followed by renal compensation

What are some treatment options for respiratory alkalosis?

Bronchodilators and corticosteroids (asthma)

Acetazolamide (high altitude)

Anxiolytics (psychogenic)

Diuresis (pulmonary edema)