Acid-Base Disorders Flashcards

Vocabulary flashcards reviewing the mechanisms and clinical causes of respiratory acidosis, respiratory alkalosis, metabolic acidosis, metabolic alkalosis, mixed acidosis, and mixed alkalosis.

Respiratory Acidosis (↑CO₂)

An acid-base disorder caused by hypoventilation leading to CO₂ retention.

Causes of Respiratory Acidosis

COPD (acute or chronic), asthma attack, airway obstruction, opioid/sedative overdose, neuromuscular failure (MG crisis, Guillain-Barré, ALS), obesity hypoventilation syndrome, chest wall restriction (kyphoscoliosis), underventilation on mechanical ventilation, and supplemental O₂ in chronic CO₂ retainers (hyperoxemia + CO₂ narcosis).

Respiratory Alkalosis (↓CO₂)

An acid-base disorder caused by hyperventilation leading to blowing off CO₂.

Causes of Respiratory Alkalosis

Anxiety/panic, pain, fever, early sepsis, pulmonary embolism, pneumonia with tachypnea, pregnancy (chronic mild respiratory alkalosis), high altitude, liver disease, early salicylate toxicity, and hyperventilation while receiving supplemental O₂.

Metabolic Acidosis (↓HCO₃)

An acid-base disorder caused by acid gain or bicarbonate loss.

Causes of Metabolic Acidosis

Diabetic ketoacidosis, lactic acidosis (shock, sepsis, hypoxia), renal failure (cannot excrete acids), diarrhea (loss of bicarbonate), toxins (methanol, ethylene glycol, salicylates), and chronic metabolic acidosis (renal failure, chronic diarrhea).

Metabolic Alkalosis (↑HCO₃)

An acid-base disorder caused by acid loss or bicarbonate excess.

Causes of Metabolic Alkalosis

Vomiting, NG suction, diuretics (loop/thiazide), hypokalemia, excess bicarbonate administration, mineralocorticoid excess (Conn syndrome, Cushing’s), post-hypercapnic alkalosis (after correcting chronic CO₂ retention), chronic diuretic therapy, and chronic vomiting with renal compensation.

Mixed Acidosis (↑CO₂ + ↓HCO₃)

An acid-base disorder characterized by respiratory failure and metabolic acidosis occurring simultaneously.

Causes of Mixed Acidosis

Cardiac arrest, severe sepsis with respiratory failure, multi-organ failure, COPD exacerbation + lactic acidosis, respiratory failure + renal failure, and severe trauma/shock.

Mixed Alkalosis (↓CO₂ + ↑HCO₃)

An acid-base disorder characterized by hyperventilation and metabolic alkalosis occurring together.

Causes of Mixed Alkalosis

Hyperventilation + vomiting, anxiety + diuretic use, pain + NG suction, and pregnancy + bicarbonate administration.

Post-hypercapnic Alkalosis

A metabolic alkalosis that develops after correcting chronic CO₂ retention.

Neuromuscular Failure (Respiratory Acidosis)

A cause of hypoventilation and respiratory acidosis including MG crisis, Guillain-Barré, and ALS.