Transcutaneous oxygen pressure-related variables as noninvasive indicators of low lactate clearance in sepsis patients after resuscitation.

Abstract

The transcutaneous oxygen challenge test (OCT) is associated with central venous oxygen saturation and cardiac output index, and has predictive value for prognosis. Whether the change of transcutaneous oxygen pressure (PtcO2)-related variables can reflect lactate clearance in sepsis patients is worth studying. We conducted a prospective observational study of 79 patients with sepsis or septic shock in the ICU. Immediately after enrollment, PtcO2 monitoring was continuously performed for 6h. The OCT was performed at enrollment (T0) and the sixth hour (T6). The correlation between lactate clearance and PtcO2-related variables such as PtcO2 at T6, ΔPtcO2 (PtcO2 at T6-PtcO2 at T0), ΔPtcO2 index (PtcO2/PaO2 at T6-PtcO2/PaO2 at T0), 10 OCT [(PtcO2 after 10min on FiO2 of 1.0)-(PtcO2 at baseline)], Δ10 OCT (10 OCT at T6-10 OCT at T0) was analyzed. The difference of PtcO2-related variables was compared between the high and low lactate clearance groups. PtcO2 at T6 (r = 0.477, p<0.001), ΔPtcO2 (r = 0.592, p<0.001), ΔPtcO2 index (r = 0.553, p<0.001) and Δ10 OCT (r = 0.379, p = 0.001) were significantly correlated with the lactate clearance. To discriminate low lactate clearance, the area under the ROC curve was largest for ΔPtcO2, which was 0.804. PtcO2 at T6, PtcO2 index, ΔPtcO2, ΔPtcO2 index and Δ10 OCT were significantly different between the two different lactate clearance groups. Low lactate clearance in the initial 6h of resuscitation of septic shock was associated to lower improvements in PtcO2-related variables.