Medical-Surgical Nursing
Domain 2 covers adult medical and surgical conditions across cardiovascular, respiratory, neurological, renal, endocrine, gastrointestinal and perioperative care. Questions reward prioritisation and early recognition of complications rather than list recall.
Prioritisation rules
- Airway before breathing before circulation; unstable before stable; acute before chronic; actual problems before potential ones.
- When two patients deteriorate, the one with the most reversible threat to life goes first.
Fluids and electrolytes
- Potassium 3.5–5.0 mmol/L. Never give IV push; peripheral infusion is usually limited to about 10 mmol/h, with higher rates requiring central access and cardiac monitoring.
- Isotonic fluids (0.9% sodium chloride, Ringer's lactate) expand the extracellular volume; hypotonic fluids rehydrate cells but risk cerebral oedema; hypertonic fluids are reserved for severe hyponatraemia and raised intracranial pressure.
Diabetes emergencies
- DKA: glucose usually >13.9 mmol/L, ketones present, pH <7.3, Kussmaul breathing, abdominal pain. Start isotonic saline, then insulin infusion, add dextrose when glucose falls below about 13.9 mmol/L, and replace potassium.
- HHS: glucose often >33 mmol/L, minimal ketones, profound dehydration and high osmolality.
Post-operative complications
Atelectasis is the commonest early complication - incentive spirometry, deep breathing, early ambulation. DVT prevention is mobilisation, hydration, compression stockings and prescribed prophylaxis.
Worked example
A 22-year-old with type 1 diabetes presents vomiting, glucose 28 mmol/L, ketones +++ and potassium 3.2 mmol/L. Which order do you question? Reasoning: the insulin infusion started before potassium replacement. Insulin drives potassium into cells and can precipitate fatal hypokalaemia. Give 0.9% saline, replace potassium, then run insulin per protocol, monitoring potassium and ECG.
Traps
Excluding DKA because glucose is near-normal (euglycaemic DKA on SGLT2 inhibitors); accepting a "stat" potassium bolus; treating HHS with insulin before volume.