Reclassifying the spectrum of septic patients using lactate: severe sepsis, cryptic shock, vasoplegic shock and dysoxic shock

Abstract

ObjectiveThe current definition of severe sepsis and septic shock includes a heterogeneous profile of patients. Although the prognostic value of hyperlactatemia is well established, hyperlactatemia is observed in patients with and without shock. The present study aimed to compare the prognosis of septic patients by stratifying them according to two factors: hyperlactatemia and persistent hypotension. MethodsThe present study is a secondary analysis of an observational study conducted in ten hospitals in Brazil (Rede Amil - SP). Septic patients with initial lactate measurements in the first 6 hours of diagnosis were included and divided into 4 groups according to hyperlactatemia (lactate >4mmol/L) and persistent hypotension: (1) severe sepsis (without both criteria); (2) cryptic shock (hyperlactatemia without persistent hypotension); (3) vasoplegic shock (persistent hypotension without hyperlactatemia); and (4) dysoxic shock (both criteria). ResultsIn total, 1,948 patients were analyzed, and the sepsis group represented 52% of the patients, followed by 28% with vasoplegic shock, 12% with dysoxic shock and 8% with cryptic shock. Survival at 28 days differed among the groups (p<0.001). Survival was highest among the severe sepsis group (69%, p<0.001 versus others), similar in the cryptic and vasoplegic shock groups (53%, p=0.39), and lowest in the dysoxic shock group (38%, p<0.001 versus others). In the adjusted analysis, the survival at 28 days remained different among the groups (p<0.001) and the dysoxic shock group exhibited the highest hazard ratio (HR=2.99, 95%CI 2.21-4.05). ConclusionThe definition of sepsis includes four different profiles if we consider the presence of hyperlactatemia. Further studies are needed to better characterize septic patients, to understand the etiology and to design adequate targeted treatments.

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

“…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.…”

“…Overt shock [12,15] was defined as any vasopressor support according to SOFA subscores and further stratified into low-dose (≤0.1 μg/kg per minute norepinephrine) and high-dose (N0.1 μg/kg per minute norepinephrine) vasopressor support. For further analysis, we divided patients into 4 groups according to the presence of hyperlactatemia and vasopressor support: (i) severe sepsis without shock: absence of vasopressor support or hyperlactatemia, (ii) cryptic shock: hyperlactatemia in the absence of vasopressor support [11][12][13], (iii) vasoplegic shock: vasopressor support in the absence of hyperlactatemia [13,15], and (iv) tissue dysoxic shock, defined by the combination of vasopressor support and hyperlactatemia [13,15] (Fig. 1).…”

“…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.…”

“…Different entities within the spectrum of sepsis-induced circulatory dysfunction have been described in recent publications [10]. These include cryptic shock [11][12][13] and occult hypoperfusion [14] (hyperlactatemia without hypotension), overt shock [12,15,16] (sustained hypotension or need for vasopressor support), nonsustained hypotension [16] (short episodes of hypotension), vasoplegic shock [13,15] (sustained hypotension or need for vasopressor support without hyperlactatemia), and (tissue) dysoxic shock [13,15] (sustained hypotension or need for vasopressor support accompanied by hyperlactatemia). None has gained universal acceptance, and there is no consensus about the exact definitions of these terms.…”

Value of serum lactate as a prognostic factor for mortality in patients with sepsis

“…Sin importar cuál de estos mecanismos prima dentro de la elevación de sus valores, se ha observado en diversos estudios que el lactato sérico (4)(5)(6) aumentado al ingreso de los pacientes se asocia con peor pronóstico . Más recientemente, la investigación se ha enfocado en la depuración del lactato como un marcador pronóstico e incluso como una meta en la reanimación del paciente con sepsis.…”