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What are the common causes of gastric outlet obstruction in adults? SpoilerThe causes can be divided into benign and malignant. Benign Peptic ulcer disease causing pyloric stenosis Chronic pancreatitis Caustic ingestion Post-surgical strictures Crohn’s disease Malignant Distal gastric cancer (most common modern cause) Pancreatic head cancer Duodenal carcinoma Periampullary tumours Historically peptic ulcer disease was the commonest cause, but malignancy is now more common. Why does gastric outlet obstruction cause vomiting of undigested food? SpoilerThe obstruction occurs at the pylorus or proximal duodenum, preventing gastric emptying. Food therefore remains in the stomach for prolonged periods and is vomited before reaching the small intestine, so it appears undigested. What electrolyte and acid–base abnormalities are classically seen? SpoilerThe classical abnormality is: Hypochloraemic Hypokalaemic Metabolic alkalosis Often associated with hyponatraemia and volume depletion. Why does vomiting lead to metabolic alkalosis? SpoilerGastric secretions contain hydrochloric acid (HCl). Vomiting causes loss of: Hydrogen ions Chloride ions Loss of hydrogen ions leads to metabolic alkalosis, and loss of chloride contributes to hypochloraemia, which also impairs renal bicarbonate excretion and worsens the alkalosis. Why does hypokalaemia occur in gastric outlet obstruction? SpoilerHypokalaemia occurs due to: Renal potassium loss from activation of the renin–angiotensin–aldosterone system due to dehydration. Hydrogen–potassium exchange in the kidney during metabolic alkalosis, where potassium is excreted to retain hydrogen ions. What clinical signs might you find on examination? SpoilerPossible signs include: Epigastric distension Succussion splash (if stomach contains retained fluid) Visible gastric peristalsis Signs of dehydration (tachycardia, hypotension) Possible weight loss if chronic What investigations would you perform to confirm the diagnosis? SpoilerInvestigations include: Blood tests: FBC, U&E, LFTs, ABG Nasogastric aspiration (large residual volume) Upper GI endoscopy (OGD) – confirms obstruction and allows biopsy CT abdomen – helps identify malignancy or extrinsic compression OGD is the key diagnostic test. How would you manage this patient initially? SpoilerInitial management is resuscitation and decompression: Nil by mouth Nasogastric tube for gastric decompression IV fluids to correct dehydration Correct electrolyte abnormalities IV proton pump inhibitor Arrange urgent endoscopy Definitive treatment depends on the cause (e.g., endoscopic dilation, surgery, or oncological treatment).

Stem2: 78-year-old diabetic woman referred for temporal artery biopsy, having shoulder pain and tender scan for one week. When performing a temporal artery biopsy, you find nodular lesion with some ulcerations in the cheek of the patient suggestive of primary skin carcinoma probably Basal cell carcinoma. Why is temporal artery being biopsy in this case? SpoilerTo test of presence of giant cell arthritis. What is the usual medical treatment of this condition which is started before the biopsy? SpoilerLarge dose of corticosteroid. Why is steroid therapy often started before biopsy is taken? SpoilerTo protect vision from ophthalmic artery insolvent from arthritis. What 4 items of data would you want to see in skin pathology summary report? SpoilerThe type of tumour verification. Tumor diameter. Tumor thickness. Margin clearance, lateral and deep margin. What features of that tumour may give insight into the risk of metastatic disease? SpoilerPresence or absent blood or lymphatic invasion. Six months later the patient readmitted following a mechanical fall in the community. Radiology revealed a fracture neck of femur, requiring surgical intervention. What factors in the scenario can predisposed to this osteoporotic fracture? SpoilerFemale. Age and post menopause. Steroid. From the biochemical perspective, what do you expect the serum calcium and phosphate levels to be, considering this patient is osteoporotic? SpoilerBoth of them will be normal. During surgery, the bone matrix appears to be soft and fragile. A sample sent to the histology and revealed plasmacytoma or myeloma. What will you find in this? SpoilerNeuroplastic, monoclonal, perforations of plasma cell. What may such tumours commonly secrete into the serum? SpoilerMyeloma, immunoglobulins or fragmentation of immunoglobulins. What is Bence Jones protein? SpoilerA light chain or paraprotein, which may be identified in urine. Apart from osteoporosis, what may be the cause of fracture of this patient? SpoilerTumour itself. Bone lysis by the tumour. The screw is required to repair the fracture and some radiotherapy is planned. However, the wound decide heals poorly with a septic breakdown. What 4 factors likely to contribute wound sepsis? SpoilerSteroid. Diabetic. Immunocompromise because plasmacytoma. Foreign body processes. Despite antibiotic treatment, the hip infection persists; excision of the hip, and the fracture site repair followed by a full hip replacement. Patient arrested 24 hours after surgery. What is the cause of this? SpoilerVenous thromboembolism