Clinical Sciences: Medicine, Surgery, Obstetrics and Gynaecology, Paediatrics and Allied Specialties
Clinical questions in INI CET are vignette-shaped: the diagnosis is usually straightforward and the marks sit in the next step, the contraindication, or the time window. Answer the question actually asked - "best next step" is not "best investigation".
Core rules and high-yield facts
- Acute coronary syndrome: primary PCI is preferred if achievable within 90 minutes of first medical contact; fibrinolysis is for when it is not, given within 12 hours of symptom onset in ST-elevation. Aspirin is chewed immediately; oxygen only if saturations are below 90%.
- Stroke: intravenous alteplase within 4.5 hours of onset after excluding haemorrhage on imaging; mechanical thrombectomy up to 24 hours in selected large-vessel occlusion.
- Obstetrics: postpartum haemorrhage is >500 mL after vaginal and >1000 mL after caesarean delivery; uterine atony causes about 70% of cases.
- Paediatrics: WHO dehydration plans - Plan A home fluids, Plan B oral rehydration solution supervised, Plan C intravenous Ringer's lactate for severe dehydration.
Worked example
A woman delivered vaginally 20 minutes ago; the uterus is boggy, estimated loss 700 mL, pulse 110/min, BP 100/60 mmHg. Reasoning: atony until proven otherwise. Sequence: call for help and note time; uterine massage and empty the bladder; oxytocin 10 IU intramuscularly plus infusion; two large-bore cannulae with crystalloid; tranexamic acid 1 g intravenously within 3 hours; then a prostaglandin (carboprost, or misoprostol where available) and balloon tamponade; laparotomy and hysterectomy for failure. Ergot derivatives are withheld if the woman is hypertensive.
Traps that cost marks
- Sending an unstable patient for CT before resuscitation.
- Confusing diabetic ketoacidosis (ketones, acidosis, Kussmaul breathing) with hyperosmolar hyperglycaemic state (very high osmolality, minimal ketosis).
- Forgetting that tranexamic acid is time-critical in obstetric haemorrhage.
- Applying adult drug doses to children - doses are per kilogram, and some drugs (tetracyclines, fluoroquinolones in specific ages) are age-restricted.