Neurological, Renal, and Endocrine Emergencies
Time, glucose and potassium
Stroke care begins with the last known well time. Computed tomography follows within about 25 minutes of arrival to exclude haemorrhage. Intravenous thrombolysis is considered up to 4.5 hours and mechanical thrombectomy up to 24 hours in selected large-vessel occlusion. Check glucose in every altered neurological presentation before labelling it a stroke. Blood pressure is lowered before thrombolysis only if it exceeds 185/110 mmHg. Seizures lasting beyond five minutes constitute status epilepticus: protect the airway, give a benzodiazepine, then a second-line agent. Cushing's triad - hypertension with bradycardia and irregular respiration - is a late, ominous sign of raised intracranial pressure, not an early one.
Diabetic ketoacidosis is managed with fluid first, then insulin. Total body potassium is depleted even when serum potassium looks normal or high, so insulin is withheld when potassium is below 3.3 mmol/L and potassium is replaced. Add dextrose once glucose falls to roughly 200–250 mg/dL so ketone clearance continues. Hyperosmolar hyperglycaemic state shows higher glucose and osmolality with minimal ketosis. Hypoglycaemia is treated with glucose immediately; never delay glucose in a confused patient.
Acute kidney injury is classified as prerenal, intrinsic or postrenal, and urgent dialysis is indicated by the AEIOU mnemonic: acidosis, electrolyte disturbance (refractory hyperkalaemia), intoxication, overload, and uraemia such as encephalopathy or pericarditis.
Worked example: a patient in ketoacidosis with potassium 3.0 mmol/L. Hold the insulin infusion, give intravenous potassium, and recheck before starting insulin.
Traps: giving insulin before checking potassium, lowering blood pressure aggressively in ischaemic stroke, and missing hypoglycaemia as the cause of 'stroke'.