Persistent Sepsis-Induced Hypotension without Hyperlactatemia: A Distinct Clinical and Physiological Profile within the Spectrum of Septic Shock

Abstract

Introduction. A subgroup of septic shock patients will never develop hyperlactatemia despite being subjected to a massive circulatory stress. Maintenance of normal lactate levels during septic shock is of great clinical and physiological interest. Our aim was to describe the clinical, hemodynamic, perfusion, and microcirculatory profiles associated to the absence of hyperlactatemia during septic shock resuscitation. Methods. We conducted an observational study in septic shock patients undergoing resuscitation. Serial clinical, hemodynamic, and perfusion parameters were registered. A single sublingual microcirculatory assessment was performed in a subgroup. Patients evolving with versus without hyperlactatemia were compared. Results. 124 septic shock patients were included. Patients without hyperlactatemia exhibited lower severity scores and mortality. They also presented higher platelet counts and required less intensive treatment. Microcirculation was assessed in 45 patients. Patients without hyperlactatemia presented higher PPV and MFI values. Lactate was correlated to several microcirculatory parameters. No difference in systemic flow parameters was observed. Conclusion. Persistent sepsis-induced hypotension without hyperlactatemia is associated with less organ dysfunctions and a very low mortality risk. Patients without hyperlactatemia exhibit less coagulation and microcirculatory derangements despite comparable macrohemodynamics. Our study supports the notion that persistent sepsis-induced hypotension without hyperlactatemia exhibits a distinctive clinical and physiological profile.

Hyperlactatemia is an independent predictor of mortality and denotes distinct subtypes of severe sepsis and septic shock

“…Potentially, this hyperlactatemia represents a persistent perfusion deficit. However, 2 groups reported very low mortality rates below 10% in septic shock patients with Lac values below 2.5 mmol/L [10,20] or 2 mmol/L [15]. These data suggest that presence of hyperlactatemia would add significant information to the severity classification of sepsis.…”

“…According to previous publications, cutoff values of 2.5 mmol/L [10,14,20] and 4 mmol/L [13,14,17,18,22], respectively, were chosen. Hyperlactatemia was defined as serum Lac concentration of at least 2.5 mmol/L.…”

“…This association was independent of hypotension in patients with infections in the emergency department [14,18]. Presence of hyperlactatemia was associated with a significantly increased mortality in patients with vasopressor-dependent septic shock [10,13,15,19,20]. Potentially, this hyperlactatemia represents a persistent perfusion deficit.…”

Hyperlactatemia and hypotension: looking at septic shock from different perspectives

“…Mortality was around 20% in both groups at variance with the results by Rivers et al who, as we said before, documented a much higher mortality for hypotensive patients and a clear difference in prognosis for patients in the two groups. To add confusion to the whole story, Hernandez et al 12 recently published an observational study enrolling 124 patients admitted to intensive care unit (ICU) for fluid unresponsive septic shock and treated with vasopressors. Among the 38 patients with lactates <2.5 mmol/L, in-hospital mortality was 7.9% while it was 20.9% among the 86 with lactates >2.5 mmol/L.…”

Vasopressors in shock: are we meeting our target and do we really understand what we are aiming at?

“…Even the largest subgroup of patients with vasodilatory septic shock may actually represent two distinct populations. Despite comparable macrohemodynamics, patients may relevantly differ in their lactate levels and thereby microcirculatory derangements, organ dysfunction, and mortality [15]. Various vasopressors and vasopressor combinations were administered.…”