A 73-year-old man presents with fever, productive cough, pleuritic chest pain and confusion. He is hypotensive with a systolic BP of 88 mm Hg, tachycardic and has a lactate of 4.0 mmol/L. Chest radiograph shows right lower lobe consolidation. You suspect septic shock secondary to community-acquired pneumonia. According to the 2021 Surviving Sepsis Campaign guidelines, what is the most appropriate immediate management priority?