A 76-year-old man with known heart failure presents acutely breathless. He is sitting upright, tachypnoeic with widespread crackles, pink frothy sputum, BP 150/90 mmHg and SpO2 86% on air. What is the most appropriate immediate management?AHigh-flow oxygen, sit him upright, intravenous Frusemide and consider intravenous nitratesBRestrict fluids and start oral RamiprilCGive a large rapid fluid bolusDStart long-acting oral Nitrates and dischargeEArrange elective echocardiography onlyCheck my answer