Acid Base Disorders Flashcards
Disorders of acid-base balance are common in clinical practice. They can occur as primary disorders but are often secondary to disturbances in organ functions
To understand these disorders, it’s essential to recall the Henderson-Hasselbalch Equation:
pH = pKa + HCO3/ S.PCO 2
What’s the indicative for metabolic disorders and how does rye body try to compensate in short nd long term? .
Metabolic Disorders
HCO3 Component: Changes in bicarbonate (HCO3 ) levels are indicative of metabolic disorders.
Respiratory Compensatory Changes: In the short term, the body tries to compensate for metabolic disorders through respiratory mechanisms, but this compensation is incomplete.
Long-Term Compensation: In the long term, the kidneys adjust the bicarbonate levels, leading to a complete compensation
What’s the indicative for respiratory disorders and how does the body try to compensate in short nd long term? .
PCO2 Component: Respiratory disorders primarily affect the partial pressure of carbon dioxide (PCO2\text{PCO}_2PCO2).
Renal Mechanisms: The body compensates for respiratory disorders through renal mechanisms.
Interim Compensation: This compensation is partial and incomplete in the short term.
Long-Term Compensation: Over time, the kidneys make adjustments that usually result in complete compensation.
Acidosis: A condition characterized by an excess of acid or a loss of base in the body.
Metabolic Acidosis: Caused by a decrease in bicarbonate.
Respiratory Acidosis: Caused by an increase in PCO2\text{PCO}_2PCO2.
Alkalosis: A condition characterized by an excess of base or a loss of acid in the body.
Metabolic Alkalosis: Caused by an increase in bicarbonate.
Respiratory Alkalosis: Caused by a decrease in PCO2\text{PCO}_2PCO2
What’s the most common acid-base disorder
Metabolic Acidosis
What’s metabolic acidosis?
Metabolic acidosis is a disorder of acid-base homeostasis resulting from any process that lowers the plasma bicarbonate concentration. It is the most common acid-base disorder and involves an increase in hydrogen ions (H+) and carbon dioxide (PCO2), which are primary products of metabolism
What’s Anion Gap
:
Definition: The anion gap is the difference between the measured cations and the measured anions in the plasma.
What’s the formula for anaion gap?
Na+K=Cl+HCO3+A
Here, A\text{A}A represents the anion gap.
What’s normal anion gap?
Normal Anion Gap: 15-20 mmol/L
Anaion gap can be raised in conditions such as? Due to?
The anion gap can be raised in certain causes of metabolic acidosis due to the addition of acids such as lactic acid, urate, sulfate (SO4), and phosphate (PO4
What are the Types of Metabolic Acidosis & therlie common causes?
High Anion Gap Metabolic Acidosis (HAGMA):
This type of metabolic acidosis occurs when there is an addition of acids that are not normally present in the blood, leading to an increase in the anion gap.
Common causes include lactic acidosis, ketoacidosis, and ingestion of toxins (e.g., methanol, ethylene glycol).
Normal Anion Gap Metabolic Acidosis (NAGMA):
this type occurs when there is a loss of bicarbonate or an inability to excrete hydrogen ions, without a significant increase in unmeasured anions.
Common causes include gastrointestinal bicarbonate loss (e.g., diarrhea), renal tubular acidosis, and certain drugs.
What’s another name dir NAGMA?
Also known as hyperchloremic acidosis,
What are they causes of HAGMA?
Causes:
Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD): Impaired kidney function leads to the accumulation of acids.
Diabetic Ketoacidosis (DKA): Results from the breakdown of fats producing ketones, which are acidic.
Ethanol Intoxication: Metabolism of ethanol produces acids such as lactic acid.
Lactic Acidosis: Increased production or decreased clearance of lactic acid.
Salicylate Overdose: Aspirin overdose can lead to an accumulation of salicylates and other acids.
Toxins: Ingestion of substances like methanol, propylene glycol, paraldehyde, and paracetamol (PCM) can produce toxic metabolites.
Muscle Rhabdomyolysis: Breakdown of muscle tissue releases myoglobin and other acids.
Organic Acidurias: Genetic disorders that result in the accumulation of organic acids
What’s the important causes of METABOLIC ACIDOSIS
Important Causes of Metabolic Acidosis
Lactic Acidosis: Can result from conditions that cause increased lactic acid production or decreased clearance (e.g., sepsis, shock, intense exercise).
Renal Tubular Acidosis: A group of disorders where the kidneys fail to properly acidify the urine, leading to acid retention.
What are the Normal Anion Gap Metabolic Acidosis (NAGMA)
Causes:
Ingestion of NH4Cl, Lysine, Sulfuric Acid, or Hydrochloric Acid (HCl): Direct addition of acids to the body.
Renal Tubular Acidosis (RTA): Defects in renal tubules affecting acid excretion.
Diarrhoeal Disease, GI Fistula: Loss of bicarbonate-rich fluids from the gastrointestinal tract.
Ureteric Diversion: Surgical procedures that affect normal urinary drainage.
Excessive Saline Infusion: Large amounts of saline can dilute bicarbonate concentration.
Lactic acidosis causes what type of acidosis?
Metabolic acidosis
Causes if lactic acidosis
Causes:
Hypoxia-Related Causes:
CO Poisoning: Carbon monoxide impairs oxygen delivery.
Severe Anaemia: Reduced oxygen-carrying capacity of blood.
Sepsis: Severe infection leading to tissue hypoxia.
Non-Hypoxia-Related Causes:
Organ Disease:
Liver Cirrhosis: Impaired liver function affects lactate clearance.
Fulminant Hepatic Failure: Acute liver failure leads to lactate accumulation.
Metastatic Disease: Cancer metastases can affect liver and other organ functions.
Inborn Errors of Metabolism:
G-6-PD Deficiency: Leads to hemolysis and lactic acidosis.
Pyr Kinase Deficiency: Affects red blood cell metabolism.
Thiamine Deficiency: Vitamin B1 deficiency affects energy metabolism.
Drugs:
Biguanides (e.g., Metformin): Can cause lactic acidosis, especially in renal failure.
Salicylates: Aspirin overdose.
Methanol: Toxic alcohol.
Ethylene Glycol: Another toxic alcohol.
What’s Renal Tubular Acidosis (RTA)
RTA is a disorder that impairs the kidneys’ ability to acidify urine, leading to metabolic acidosis. It can present as either high anion gap metabolic acidosis (HAGMA) or normal anion gap metabolic acidosis (NAGMA).
What’s Type 1 RTA
Inability of the distal convoluted tubule (DCT) and collecting duct to secrete hydrogen ions (H+), leading to a failure to acidify urine below plasma pH in acidosis.
Causes of type 1 RTA?
Primary/Sporadic: Idiopathic causes.
Wilson’s Disease: Copper accumulation.
Amyloidosis: Protein deposits in kidneys.
Chronic Pyelonephritis (CPN), Post-Transplant: Kidney damage.
Autoimmune Disorders: Sjogren’s syndrome, Churg-Strauss syndrome.
Drugs: Amphotericin, Lithium.
What’s Type 2 RTA?
Type 2 RTA (Proximal RTA):
Pathophysiology: Inability to reabsorb bicarbonate (HCO3-) in the proximal tubule, leading to bicarbonate wasting.