Hot case — the bedside: a septic patient with a metabolic acidosis and a rising lactate

Presentation

You are taken to the bedside of a 66-year-old woman who is on day 1 of septic shock from a urinary-source infection. She was admitted overnight, had 30 mL/kg of balanced crystalloid, broad-spectrum antibiotics and a noradrenaline infusion, and the urinary source is being controlled. On the morning round she is still hypotensive — her mean arterial pressure is 62 mmHg on 0.4 micrograms/kg/min of noradrenaline — her heart rate is 110, her temperature is 38.4, her urine output has fallen to 0.3 mL/kg/h, and the nurse asks you to assess her because the morning blood gas shows a worsening metabolic acidosis: pH 7.22, PaCO2 26, HCO3 11, base excess −14, lactate 5.8 mmol/L (the lactate has risen overnight from 3.2).