For clinical reference only — does not replace local trust guidelines or clinical judgement.
Reference

Acid-Base Causes

Quick jump
🔴

Metabolic Acidosis

Increased Acid Production
🩸
Lactic Acidosis
  • Sepsis
  • Shock
  • Hypoperfusion
🍬
Ketoacidosis
  • DKA
  • Alcoholic ketoacidosis
  • Starvation ketosis
☠️
Toxins
  • Methanol
  • Ethylene glycol
  • Salicylates
Reduced Acid Excretion
🩺
Acute Kidney Injury
🩺
Chronic Kidney Disease
Bicarbonate Loss
💩
Diarrhoea
🩺
High-output stoma
🩺
Fistula losses
Quick Memory Aid
MUDPILES — Methanol, Uraemia, DKA, Paraldehyde, Iron/INH, Lactate, Ethylene glycol, Salicylates
🟢

Metabolic Alkalosis

Causes
🤮
Vomiting
🩺
NG losses
💊
Diuretics
🩺
Hyperaldosteronism
💉
Excess bicarbonate
🩺
Volume depletion
Quick Memory Aid
"Loss of acid or gain of bicarbonate"
🔵

Respiratory Acidosis

Causes
🫁
COPD Exacerbation
🫁
Severe Asthma
💊
Opioid Toxicity
💊
Sedative Overdose
🧠
Reduced Conscious Level
🫁
Neuromuscular Disease
🫁
Obesity Hypoventilation
🫁
Severe Pneumonia
Core Concept
Hypoventilation
CO₂ Retention
Respiratory Acidosis
🟣

Respiratory Alkalosis

Causes
😰
Anxiety
🫁
Pulmonary Embolism
🤒
Sepsis
🤰
Pregnancy
🫁
Hypoxia
🧠
Pain
🧠
Early Salicylate Toxicity
Core Concept
Hyperventilation
Excess CO₂ Loss
Respiratory Alkalosis
🟠

Mixed Disorders

⚠️
Always suspect mixed disorders when results do not fit the expected compensation.
Common Mixed Disorders
🫁
COPD + Sepsis
🫁
COPD + Vomiting
🍬
DKA + Vomiting
☠️
Salicylate Toxicity
🩸
Cardiac Arrest