Combination of arterial lactate levels and venous-arterial CO2 to arterial-venous O2 content difference ratio as markers of resuscitation in patients with septic shock

Abstract

PurposeTo evaluate the prognostic value of the Cv-aCO2/Da-vO2 ratio combined with lactate levels during the early phases of resuscitation in septic shock.MethodsProspective observational study in a 60-bed mixed ICU. One hundred and thirty-five patients with septic shock were included. The resuscitation protocol targeted mean arterial pressure, pulse pressure variations or central venous pressure, mixed venous oxygen saturation, and lactate levels. Patients were classified into four groups according to lactate levels and Cv-aCO2/Da-vO2 ratio at 6 h of resuscitation (T6): group 1, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; group 2, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0; group 3, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; and group 4, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0.ResultsCombination of hyperlactatemia and high Cv-aCO2/Da-vO2 ratio was associated with the worst SOFA scores and lower survival rates at day 28 [log rank (Mantel–Cox) = 31.39, p < 0.0001]. Normalization of both variables was associated with the best outcomes. Patients with a high Cv-aCO2/Da-vO2 ratio and lactate <2.0 mmol/L had similar outcomes to hyperlactatemic patients with low Cv-aCO2/Da-vO2 ratio. The multivariate analysis revealed that Cv-aCO2/Da-vO2 ratio at both T0 (RR 3.85; 95 % CI 1.60–9.27) and T6 (RR 3.97; 95 % CI 1.54–10.24) was an independent predictor for mortality at day 28, as well as lactate levels at T6 (RR 1.58; 95 % CI 1.13–2.22).ConclusionComplementing lactate assessment with Cv-aCO2/Da-vO2 ratio during early stages of resuscitation of septic shock can better identify patients at high risk of adverse outcomes. The Cv-aCO2/Da-vO2 ratio may become a potential resuscitation goal in patients with septic shock.Electronic supplementary materialThe online version of this article (doi:10.1007/s00134-015-3720-6) contains supplementary material, which is available to authorized users.

Effects of dobutamine on intestinal microvascular blood flow heterogeneity and O2 extraction during septic shock

“…Such increased CO 2 -to-O 2 relationship has been proposed as reflection of anaerobic metabolism, since under aerobic steady-state conditions, CO 2 production (V̇ co 2 ) approximates O 2 consumption (V̇ o 2 ), and, consequently, the mixed venous-to-arterial CO 2 content difference ($\text{C}\stackrel{true¯}{\text{v}}\text{-}{\text{a}}_{\text{C}{\text{O}}_2}$) approximates the arterial-to-mixed-venous O 2 content difference ($\text{Ca-}{\stackrel{true¯}{\text{v}}}_{{\text{O}}_2}$). Accordingly, the V̇ co 2 -to-V̇ o 2 ratio (i.e., the respiratory quotient) should not be higher than 1.0, whereby nonsymmetric decreases in V̇ o 2 and V̇ co 2 with subsequent rises in the respiratory quotient could reflect nonaerobic CO 2 generation (30, 32). Importantly, models subjected to dobutamine infusion in our experiment showed a progressive improvement in microvascular blood flow distribution that was in turn related to decreases in the $\text{Pvmes-}{\text{a}}_{\text{C}{\text{O}}_2}$/$\text{Ca}{\text{-vmes}}_{{\text{O}}_2}$ ratio (a regional surrogate of the V̇ co 2 /V̇ o 2 ratio), suggesting the reversal of anaerobic metabolism while mesenteric lactate levels also decreased.…”

The ten pitfalls of lactate clearance in sepsis

“…We recently proposed that a simultaneous analysis of three flow-sensitive parameters such as central venous O 2 saturation, central venous–arterial pCO 2 gradient (Pcv-aCO 2 ), and peripheral perfusion (capillary refill time, peripheral perfusion index, skin temperature, mottling) might be helpful in suggesting the presence of hypoperfusion in the context of hyperlactatemia [15, 16]. In addition to the Pcv-aCO 2 one could use the Pcv-aCO 2 to arterial–venous O 2 content difference as a marker of tissue hypoperfusion as a cause of hyperlactatemia [17]. Persistent hyperlactatemia without a hypoperfusion context is associated with a better prognosis and might suggest non-hypoperfusion-related sources [15] (Fig.…”

Arter Kan Gazlari Ve Asi̇t Baz Dengesi̇

“…6 mmHg'nın üzerindeki değerler, doku perfüzyonu bozuk olan hastada doku perfüzyonunun bozulmasında kalp debisinin azalmasının da katkısı olduğunu göstermektedir (4 …”