A 62-year-old man on ICU is being treated for septic shock secondary to community-acquired pneumonia. Initial lactate was 5.0 mmol/L. After 6 hours of treatment including antibiotics, 30 mL/kg crystalloid, and noradrenaline, his repeat lactate is 4.8 mmol/L. According to the Surviving Sepsis Campaign 2021, what is the significance of this finding and the recommended response?