Is thenar tissue hemoglobin oxygen saturation in septic shock related to macrohemodynamic variables and outcome?

Abstract

IntroductionThe study objectives were to evaluate septic shock-induced alterations in skeletal muscle hemoglobin oxygenation saturation (StO2) using near-infrared spectroscopy (NIRS) and forearm skin blood flow velocity using laser Doppler (LD) to determine the relationship of macroperfusion and microperfusion parameters, and to test the relationship of the worst NIRS parameters during the first 24 hours of shock with 28-day prognosis.MethodsA prospective, observational study was performed in a 21-bed university hospital surgical intensive care unit. Forty-three septic shock patients with at least another organ failure underwent a 3-minute, upper arm (brachial artery) vascular occlusion test (VOT). Microperfusion parameters (thenar eminence StO2 and forearm LD skin blood flow) were collected on days 1, 2 and 3, before (baseline StO2 and LD values) and during the 3-minute VOT with calculation of occlusion and reperfusion slopes for StO2 and LD. Daily Sequential Organ Failure Assessment (SOFA) score, macrohemodynamic parameters (systolic arterial blood pressure, cardiac output (pulmonary artery catheter or transesophageal Doppler), mixed venous oxygen saturation (pulmonary artery or superior vena cava catheter)) and metabolic parameters (pH, base excess, lactate) were determined.ResultsBaseline StO2 (82% (75 to 88) vs. 89% (85 to 92), P = 0.04) and reperfusion slope (2.79%/second (1.75 to 4.32) vs. 9.35%/second (8.32 to 11.57), P < 0.0001) were lower in septic shock patients than in healthy volunteers. StO2 reperfusion slope correlated with occlusion slope (P < 0.0001), cardiac output (P = 0.01) and LD reperfusion slope (P = 0.08), and negatively with lactate level (P = 0.04). The worst StO2 reperfusion slope during the first day of shock was lower in nonsurvivors than in survivors (P = 0.003) and improved significantly the predictive value of Simplified Acute Physiology Score II and SOFA scores.ConclusionsThe alteration of StO2 reperfusion slope in septic shock patients compared with healthy volunteers was related with macrohemodynamic, microhemodynamic and metabolic parameters. The addition of the worst value of the day 1 StO2 reperfusion slope improved the outcome prediction of Simplified Acute Physiology Score II and SOFA scores.

Knee area tissue oxygen saturation is predictive of 14-day mortality in septic shock

“…However, the predictive value of thenar StO 2 is still under debate. In a cohort of 43 patients, Payen et al [23] did not find any difference of thenar StO 2 between survivors and non-survivors, whereas Leone et al [8] Knee StO 2 (%) according to mottling score at H6, after initial resuscitation. The higher the mottling score was, the lower the knee StO 2 (P \ 0.01).…”

Prognostic implications of tissue oxygen saturation in human septic shock

“…Thus, VOT-derived parameters seem to have prognostic utility, despite their direct relationship with perfusion pressure. Several studies have explored the usefulness of StO 2 and its derived variables to predict outcome of septic patients [6,7,[13][14][15]. Although steady-state StO 2 values have shown prognostic implications in trauma patients [16], resuscitated septic shock appears not to follow this trend.…”

“…VOT-derived slopes were proposed as dynamic variables to better assess local oxygenation, as an indirect way to evaluate regional perfusion [5,6]. Regarding the usefulness of these slopes, in septic patients, the ReOx slope has proven to show higher value for mortality prediction than absolute StO 2 and DeOx [6,7]. However, this observation has not been supported by other studies [13][14][15].…”

“…In addition to the absolute StO 2 value, evaluation of StO 2 changes in response to a transient ischemic stimuli, by means of a vascular occlusion test (VOT), provides two additional parameters: the StO 2 -deoxygenation rate (DeOx), which has been related to local metabolic rate, and the StO 2 -reoxygenation rate (ReOx), which has been inferred as a reflection of local vascular reactivity and capillary density [4,5]. These VOT-derived slopes have been explored mostly in septic patients, where they have shown some promising prognostic value [6,7]. However, VOT-derived DeOx and ReOx slopes can be significantly affected by global hemodynamic parameters, such as blood pressure, and thus, their interpretation might have an important bias depending on the tissue perfusion pressure [8,9].…”

Actualización del bundle de reanimación inicial y monitorización integral de la perfusión tisular en la sepsis severa

“…Sin embargo, la gran superposición de valores de S t O 2 entre sujetos sanos y pacientes con shock séptico, han limitado su utilidad para la toma de decisiones individuales. Varios investigadores 69,70 han planteado la determinación simultánea de la S t O 2 en la eminencia tenar de pacientes con shock séptico junto con una maniobra dinámica denominada test de oclusión vascular con la finalidad de evaluar la reactividad microvascular e identificar enfermos con alto riesgo de complicaciones y peor desenlace. Lima y cols.…”