A 66-year-old man presents with melaena and dizziness. He is tachycardic and hypotensive. Haemoglobin is 78 g/L. What is the single most important initial management step in suspected upper gastrointestinal haemorrhage?AUrgent endoscopy within 2 hoursBImmediate high-dose proton pump inhibitor infusionCAggressive resuscitation with intravenous crystalloids and blood productsDInsertion of a nasogastric tube for lavageEUrgent CT angiographyCheck my answer