Mixed Deck — All SMLE Topics Flashcards

A patient with gout is prescribed allopurinol. What is its mechanism of action?

Answer: Inhibits xanthine oxidase

Allopurinol is a xanthine oxidase inhibitor that blocks the conversion of hypoxanthine to xanthine and xanthine to uric acid, thereby reducing uric acid production. It should not be started during an acute gout attack as it can worsen the flare.

A 55-year-old male with a 30-pack-year smoking history presents with painless gross haematuria. Cystoscopy reveals a papillary mass in the bladder. What is the most likely histological type?

Answer: Transitional cell carcinoma (urothelial)

Transitional cell carcinoma (urothelial carcinoma) is the most common type of bladder cancer, strongly associated with cigarette smoking. It typically presents as a papillary lesion on cystoscopy.

A patient is prescribed gentamicin for a serious gram-negative infection. Which two adverse effects require monitoring?

Answer: Nephrotoxicity and ototoxicity

Aminoglycosides (gentamicin, tobramycin, amikacin) require monitoring for nephrotoxicity (elevated creatinine, reduced GFR) and ototoxicity (vestibular and cochlear damage causing dizziness and hearing loss). Trough and/or peak levels guide dosing to minimise toxicity.

A 6-year-old child presents with polydipsia, polyuria, weight loss, and a blood glucose of 22 mmol/L. Blood pH is 7.15 and ketones are strongly positive. What is the immediate priority in management?

Answer: IV fluid resuscitation with normal saline

In paediatric diabetic ketoacidosis, the immediate priority is IV fluid resuscitation with 0.9% normal saline to correct dehydration and restore circulation. IV insulin infusion (NOT bolus) is started after the first hour of fluid resuscitation to avoid cerebral oedema.

A 35-year-old woman experiences recurrent, unexpected panic attacks with palpitations, shortness of breath, chest pain, and fear of dying. She now avoids crowded places. What is the most accurate diagnosis?

Answer: Panic disorder with agoraphobia

Panic disorder is characterised by recurrent unexpected panic attacks with persistent concern about future attacks. When the patient develops avoidance of situations where escape might be difficult (crowded places), agoraphobia is diagnosed as a comorbid condition.

A patient on isoniazid for tuberculosis develops peripheral neuropathy. Which vitamin deficiency is responsible and what supplement prevents this?

Answer: Vitamin B6 (pyridoxine)

Isoniazid inhibits pyridoxal phosphokinase and competes with pyridoxal phosphate (active form of vitamin B6), leading to pyridoxine deficiency. This manifests as peripheral neuropathy. Prophylactic pyridoxine (10-25 mg/day) prevents this complication.

A 55-year-old male presents with a change in bowel habit, rectal bleeding, and a palpable mass on digital rectal examination at 6 cm from the anal verge. What is the most likely diagnosis?

Answer: Rectal carcinoma

A palpable rectal mass with change in bowel habit and rectal bleeding in a patient over 50 is rectal carcinoma until proven otherwise. Digital rectal examination can detect low rectal tumours, and further assessment with rigid sigmoidoscopy and biopsy is essential.

A 12-month-old infant presents with pallor, irritability, and a haemoglobin of 7 g/dL. Peripheral smear shows microcytic hypochromic anaemia with target cells. HPLC shows HbS 80% and HbF 15%. What is the diagnosis?

Answer: Sickle cell disease (HbSS)

HbS of 80% with HbF 15% on HPLC is diagnostic of sickle cell disease (homozygous HbSS). Sickle cell disease is prevalent in Saudi Arabia, particularly in the Eastern Province and southwestern regions. HbF levels above 10% in SCD are common in the Saudi variant.

A patient on metformin is scheduled for a CT scan with IV contrast. What precaution should be taken?

Answer: Hold metformin for 48 hours after the contrast study

Metformin should be held at the time of or before contrast administration and withheld for 48 hours after the procedure. IV contrast can rarely cause contrast-induced nephropathy, and impaired renal function combined with metformin increases the risk of lactic acidosis.

A trauma patient arrives with paradoxical chest wall movement on the right side. Oxygen saturation is 88% on room air. What is the diagnosis and initial management?

Answer: Flail chest — intubation and mechanical ventilation if needed

Paradoxical chest wall movement indicates flail chest (≥3 consecutive ribs fractured in ≥2 places). Management focuses on adequate analgesia, oxygen supplementation, and mechanical ventilation if respiratory failure develops. The underlying pulmonary contusion often determines the clinical course.

A diabetic mother delivers a macrosomic baby. During delivery, the fetal head delivers but the shoulders do not. What is this obstetric emergency called?

Answer: Shoulder dystocia

Shoulder dystocia occurs when the fetal shoulders become impacted behind the maternal symphysis pubis after delivery of the head. It is more common with fetal macrosomia and maternal diabetes. The McRoberts manoeuvre is the first-line intervention.

A child presents with a unilateral, painless abdominal mass that does not cross the midline. CT shows an intrarenal mass with areas of haemorrhage and necrosis. What is the most likely diagnosis?

Answer: Wilms tumour (nephroblastoma)

Wilms tumour is the most common renal malignancy in children, typically presenting between 3-5 years of age as a painless abdominal mass arising from the kidney. Unlike neuroblastoma, it does not cross the midline and is intrarenal in origin.

A 60-year-old patient with chronic atrial fibrillation and a CHA2DS2-VASc score of 4 is not on anticoagulation. What is the most appropriate anticoagulant?

Answer: Direct oral anticoagulant (e.g., rivaroxaban)

Direct oral anticoagulants (DOACs) such as rivaroxaban, apixaban, or dabigatran are now preferred over warfarin for stroke prevention in non-valvular atrial fibrillation due to their predictable pharmacokinetics and lower intracranial bleeding risk.

Which drug is the antidote for opioid overdose?

Answer: Naloxone

Naloxone is a competitive opioid receptor antagonist used to reverse opioid overdose. It rapidly reverses respiratory depression, sedation, and miosis. Due to its shorter half-life compared to many opioids, repeated doses or an infusion may be needed.

A 45-year-old patient presents with progressive exertional dyspnoea, bilateral basal crackles, and an S3 gallop. Echocardiogram shows an ejection fraction of 30%. What is the initial pharmacological management?

Answer: ACE inhibitor and beta-blocker

For heart failure with reduced ejection fraction (HFrEF), first-line pharmacological therapy includes ACE inhibitors (or ARBs) and beta-blockers, which reduce mortality. These should be initiated together with diuretics for symptom relief.

A 4-month-old infant is found to have developmental hip dysplasia on screening. What is the most appropriate initial treatment?

Answer: Pavlik harness

For infants under 6 months with developmental dysplasia of the hip (DDH), the Pavlik harness is the first-line treatment. It maintains the hip in flexion and abduction, promoting concentric reduction and acetabular development. Success rate is approximately 90% when started early.

A 22-year-old woman presents with lower abdominal pain, fever, purulent vaginal discharge, and cervical motion tenderness. What is the most likely diagnosis?

Answer: Pelvic inflammatory disease (PID)

The triad of lower abdominal pain, fever, and cervical motion tenderness (chandelier sign) is classic for pelvic inflammatory disease. PID is usually caused by ascending infection from Neisseria gonorrhoeae or Chlamydia trachomatis.

A 4-year-old child presents with easy bruising, petechiae, and a platelet count of 15,000/μL. WBC and haemoglobin are normal. Peripheral smear shows large platelets. What is the most likely diagnosis?

Answer: Immune thrombocytopenic purpura (ITP)

ITP in children typically presents after a viral infection with isolated thrombocytopenia, petechiae, and bruising. WBC and haemoglobin are normal, and peripheral smear shows large platelets indicating increased platelet destruction with compensatory bone marrow production.

A 25-year-old male sustains a penetrating injury to the neck in Zone II. He is haemodynamically stable with an expanding haematoma. What is the recommended approach?

Answer: Mandatory surgical exploration

Zone II penetrating neck injuries (between the cricoid and angle of mandible) with hard signs (expanding haematoma, active bleeding, airway compromise) require mandatory surgical exploration regardless of imaging. An expanding haematoma is a hard sign indicating vascular injury.

A patient with rheumatoid arthritis on methotrexate develops pancytopenia. What supplement should have been co-prescribed to prevent this complication?

Answer: Folic acid

Folic acid supplementation (5 mg weekly, taken on a different day from methotrexate) reduces the incidence of methotrexate side effects including pancytopenia, stomatitis, and GI upset. Methotrexate inhibits dihydrofolate reductase, causing folate depletion.