In an 82-year-old patient with hypertension and acute onset of breathlessness, the first step would be to administer oxygen inhalation and antibiotics, particularly if there is a concern about an infectious cause, such as pneumonia or an acute exacerbation of a chronic condition like heart failure. Vasodilators and IV nitroglyceryl may be considered if there is a suspicion of acute heart failure or ischemia, while nebulized salbutamol would be useful if the patient is presenting with a wheezing or obstructive component. The chest X-ray would help to further guide the management.