Children & medico-legal for MRCS Part A

What the paper tends to test

• Questions typically describe an infant with vomiting and ask for the diagnosis from the detail — bilious in the first days of life, projectile and non-bilious at 4–6 weeks, with colic and red-currant jelly stool at 6–9 months.
• Expect the undescended testis, the hydrocele and the inguinal hernia to be tested on timing: which resolve, which are referred, and when orchidopexy or herniotomy is done.
• Paediatric fluid questions use weight-based maintenance (the 4-2-1 rule or 100-50-20 ml/kg/day), a 10 ml/kg bolus and the circulating volume of a child.
• The acute scrotum is examined as torsion until proved otherwise, with the window for exploration as the discriminator.
• Consent questions ask who can consent for a child, what Gillick competence means, and what happens when a competent young person refuses treatment.
• Capacity questions apply the Mental Capacity Act 2005 — the presumption of capacity, the two-stage test and best-interests decisions — and the duty of candour after a notifiable safety incident.
• Expect negligence to be tested through Bolam, Bolitho and Montgomery, and confidentiality through the circumstances in which it may be breached.

Classic traps and discriminators

• Bilious vomiting in a neonate is malrotation with midgut volvulus until proved otherwise and needs an urgent upper gastrointestinal contrast study and surgical review; pyloric stenosis presents at 4–6 weeks with non-bilious projectile vomiting, a palpable ‘olive’ and a hypochloraemic, hypokalaemic metabolic alkalosis that must be corrected before pyloromyotomy.
• Intussusception peaks at 6–9 months with colicky pain, drawing up of the legs, a sausage-shaped mass and red-currant jelly stool; ultrasound shows the target sign, and the first-line treatment is air (pneumatic) reduction under radiological control provided there is no peritonitis or perforation.
• A paediatric inguinal hernia is repaired by herniotomy alone, and promptly in infants because of the risk of incarceration; a congenital hydrocele usually resolves by about 2 years and is left until then. An undescended testis is referred for orchidopexy by about 6–12 months of age, not watched into childhood.
• Children under 16 can consent to treatment if Gillick competent; those of 16 and 17 are presumed to have capacity under the Family Law Reform Act 1969. In England and Wales a refusal by a competent child can be overridden by a person with parental responsibility or by the court; the position in Scotland is governed by the Age of Legal Capacity (Scotland) Act 1991.
• Capacity is decision-specific and time-specific, is presumed in adults, and is not lost because a decision is unwise; a patient lacks capacity only if an impairment of the mind or brain means they cannot understand, retain, use or weigh the information, or communicate the decision — and even then the decision is made in their best interests, not by their relatives.
• The statutory duty of candour (Regulation 20 of the Health and Social Care Act 2008 (Regulated Activities) Regulations 2014) applies to notifiable safety incidents: tell the patient what happened, apologise, explain what will be done to find out more and follow up in writing. An apology is not an admission of liability.

Children & medico-legal questions, answered