Acid-Base causes CC

Question 1

Normal anion gap metabolic acidosis

Answer 1

• Renal tubular acidosis
• Addison’s disease
• Diarrhoea
• Ureterosigmoidostomy
• Fistula
• Carbonic anhydrase inhibitors (e.g., topiramate, acetazolamide)
• Ammonium chloride injection
• Chemotherapy (e.g, ifosfamide, cisplatin)
• Antibiotics (e.g., aminoglycosides, trimethoprim/sulfamethoxazole)
• Amphotericin B
• Lithium
• Pentamidine
• Rifampin
• Inhaled toluene

MCQs

Question 2

Raised anion gap metabolic acidosis

Answer 2

• Renal failure
• Hypoxia
• Diabetic ketoacidosis
• Alcohol poisoning
• Shock
• Salicylate poisoning

MCQs

Question 3

Causes of combined respiratory and metabolic acidosis

Answer 3

• Acute cardiac failure
• Severe exacerbation of obstructive airways disease and pre-renal failure from diuretics
• Aspirin poisoning
• Severe pneumonia with renal failure due to septicaemia or interstitial nephritis (Legionnaire’s disease)
• Septicaemia from any cause complicated by ARDS
• Malaria complicated by pneumonia
• Acute renal failure and fluid overload
• Renal pulmonary syndromes: anti-GBM disease, Wegener’s granulomatosis, microscopic polyarteritis nodosa
• Acute massive pulmonary embolism
• Cardiac arrest (before ventilation)

Question 4

Metabolic alkalosis

Answer 4

• Bartter’s syndrome
• Hypokalaemia
• Carbenoxolone
• Primary hyperaldosteronism
• Congenital adrenal hyperplasia
• Diuretics
• Cushing’s syndrome
• Vomiting / aspiration
• Liquorice

Question 5

Causes of Metabolic Alkalosis in the ICU

Answer 5

• Acute alkali administration
• Gastric fluid losses
• Postdiuretic therapy
• Posthypercapnic states
• Massive transfusions
• Hyperaldosteronism
• Cushing’s syndrome
• Nonresorbable anions

MCQs

Question 6

Hypokalemia with alkalosis

Answer 6

• Vomiting
• Diuretics
• Cushing’s syndrome
• Conn’s syndrome (primary hyperaldosteronism)
• Reduction in effective arterial blood volume
• Volume contraction: vomiting, NG suction, bleeding, or diuretics (thiazides and loops)
• Renovascular disease: renal artery stenosis or fibromuscular dysplasia
• 2° hyperaldosteronism: severe HF, cirrhosis, nephrotic syndrome
• 1° aldosteronism
• Renin-secreting tumor
• Cushing syndrome
• Liddle’s, Bartter’s, and Gitelman’s

Question 7

Hypokalemia with acidosis

Answer 7

• Diarrhoea
• Renal tubular acidosis
• Acetazolamide
• Partially treated diabetic ketoacidosis

Question 8

Causes of respiratory alkalosis

Answer 8

• Due to stimulation of the central nervous system: Anxiety, Hypoxia, Salicylate poisoning, Encephalitis, Brainstem injury
• Due to pulmonary disease: Asthma, Pneumonia, Lung fibrosis, Pulmonary oedema, Pulmonary embolus