ACIDOSIS
The urgent indications are acidosis, electrolyte problems, overload, uraemia and toxins that do not respond to treatment.
What our notes say
- The urgent indications are acidosis, electrolyte problems, overload, uraemia and toxins that do not respond to treatment. (Internal Medicine (MBIM 4100) main exam, Paper One: 3 July 2019)
- Hold or change the offending ARV if lactic acidosis or renal injury is the cause, after discussion with the HIV specialist, and restart ART once stable. (Internal Medicine (MBIM 4100) special/supplementary exam, Paper Two: 14 August 2)
- The acidosis shifts potassium out of cells, so the measured potassium is often high even though total body potassium is low. (Paediatrics end of fourth year special supplementary exam: August 2019, Paper On)
- In a tet spell, knee-chest position, oxygen, morphine, bicarbonate for acidosis, fluids and propranolol are used. (Paediatrics end of second semester exam (MBPE 4300): 4 October 2022, cardiology,)
- Sodium bicarbonate is indicated in a patient with metabolic acidosis associated with respiratory failure (Paediatrics Year 6 MBChB end of semester CAT: clinical case MCQs, 29 of 30 quest)
- Non-invasive ventilation (NIV) if respiratory acidosis persists (pH below 7.35 with PaCO2 above 6.5 kPa) despite treatment; intubation if NIV fails. (Chronic Obstructive Pulmonary Disease (COPD))
Study material on ACIDOSIS
- Chemical Pathology MCQs: Clinical Chemistry, Endocrine & Renal
- Chemical Pathology MCQs
- Chemical Pathology MCQs: Diabetes, Renal & Liver Disease
- Chemical Pathology Sem 1
- Chemical Pathology Practice Examination
- Liver Function Tests (LFTs)
- Medical MCQs: Chemical Pathology & Haematology Exam Review
- Chemical path 2021
- Renal, Liver, Cardiac & Adrenal Function Tests for Year 3
- Paediatrics Year 6 MBChB end of semester CAT: clinical case MCQs, 29 of 30 questions
- ACIDOSIS AND ALKALOSIS MCQs
- Chemical Pathology MCQs
- ADRENAL NEOPLASMS — Adenoma vs Carcinoma
- Weekly Year 2: Physiology Exam - June 5, 2026 (Section A: MCQs)
- Weekly Year 2: Physiology Exam - May 29, 2026 (Section A: MCQs)
Practice questions on ACIDOSIS
Which of the following is a component of the renal response to metabolic acidosis?
- reabsorption of H+
- secretion of HCO3- into the tubular lumen
- secretion of ammonium into the tubular lumen
- secretion of glutamine into the interstitial fluid
- Usually mediated by non-specific mechanisms
Answer: C. During metabolic acidosis, the kidneys compensate by increasing acid excretion and bicarbonate regeneration. Ammonium (NH4+) secretion into the tubular lumen is a major mechanism for eliminating excess acid from the body. ---
A 19-year-old with abdominal pain, Kussmaul breathing, high ketones and metabolic acidosis most likely has:
- Hyperosmolar hyperglycaemic state
- Diabetic ketoacidosis
- Addison crisis
- Thyroid storm
- SIADH ✅ Answer: B
Answer: A. Abdominal pain, Kussmaul breathing, high ketones, and metabolic acidosis are the hallmark features of diabetic ketoacidosis (DKA).
An increased anion gap metabolic acidosis can be caused by
- Diarrhea
- Lactic acidosis
- Renal tubular acidosis
- Hyperaldosteronism Correct
Answer: B. Lactic acidosis causes increased anion gap metabolic acidosis due to organic acid accumulation. Diarrhea and RTA typically cause normal anion gap acidosis. ---
Which of the following causes a normal anion gap metabolic acidosis?
- Lactic acidosis
- Methanol toxicity
- Renal tubular acidosis
- Diabetic ketoacidosis Correct
Answer: C. RTA causes normal anion gap acidosis due to impaired renal acid excretion. Other options cause high anion gap acidosis. ---
A patient with metabolic acidosis and an increased anion gap likely has
- Renal tubular acidosis
- Diabetic ketoacidosis
- Hyperaldosteronism
- SIADH Correct
Answer: B. DKA produces ketoacids, causing high anion gap metabolic acidosis. RTA causes normal anion gap acidosis. ---
Which compensatory response occurs in metabolic acidosis?
- Decreased respiratory rate
- Increased respiratory rate
- Increased bicarbonate
- Increased CO₂ retention Correct
Answer: B. Metabolic acidosis triggers hyperventilation to blow off CO₂ and partially compensate for the acidosis. ## Case-Based MCQs Section 1: Electrolytes & Acid-Base Disorders ---