Prevalence and characteristics of nonlactate and lactate expressors in septic shock

Purpose: The study's objective was to determine the proportion and patient characteristics of patients in vasopressor-dependent septic shock who presented without lactatemia. Methods: A retrospective review of patients presenting to an urban tertiary-care emergency department between December 2007 and September 2008 was conducted. Patients with a final diagnosis of septic shock requiring vasopressors were divided, based on initial lactate, to nonlactate expressors (0-2.4 mmol/L), intermediate (2.5-3.9 mmol/L), and high (>4.0 mmol/L) lactate groups. Results: Among 123 patients with vasopressor-dependent septic shock, 55 (45%) were nonlactate expressors (lactate ≤2.4 mmol/L). Acute liver injury, history of liver disease, and presence of bacteremia were associated with elevated lactate. Conclusion: Almost one-half of patients with vasopressor-dependent septic shock did not express lactate on presentation, although a high mortality rate remains in this population. We found a significant association between lactate expressors and liver disease and between lactate expressors and positive blood cultures. The use of lactatemia as the sole indicator of need for additional intravenous fluid or an end point of resuscitation in septic shock may be inadequate.