SvO2 In Patients Research Articles

Soluble ST2 and mixed venous oxygen saturation for prediction of mortality in patients with pulmonary hypertension.

BackgroundAlthough soluble suppression of tumorigenicity-2 (sST2) has been identified as a clinical biomarker for pulmonary hypertension (PH) by previous studies, the implication of sST2 combined with hemodynamic parameters in PH has not been well studied. This study aimed to evaluate the relationship between sST2 and hemodynamic parameters and to evaluate the predictive value of sST2 for mortality in patients with PH.MethodsOne hundred eighty-four incident patients with PH and 14 healthy controls were retrospectively enrolled by Shanghai Pulmonary Hospital for this retrospective study. After all patients underwent right heart catheterization, blood samples were collected and serum sST2 concentration was assessed by the Presage™ ST2 assay. Kaplan-Meier curve and Cox regression analyses were used to predict survival and the association between survival and different factors such as sST2, SvO2.ResultsDuring a follow-up of 44.9 (IQR 28.5–64.4) months, 65 patients died. The median concentration of sST2 in PH patients was 33.1 ng/mL, which is higher than that in control group (23.1 ng/mL, P=0.005). Furthermore, for PH group, the level of sST2 was higher in non-survivors than that in survivors. Cox regression analyses demonstrated that sST2 and SvO2 were independent risk factors for survival. In Kaplan-Meier curve analyses, elevated sST2 level and reduced SvO2 predicted a poor outcome for patients with PH.ConclusionsHigher sST2 was independently associated with increased mortality, as well as lower SvO2 in patients with PH. Especially, the combination of higher sST2 and lower SvO2 had the strongest predictive value of mortality in patients with PH.

Reduced deep regional cerebral venous oxygen saturation in hemodialysis patients using quantitative susceptibility mapping.

Cerebral venous oxygen saturation (SvO2) is an important indicator of brain function. There was debate about lower cerebral oxygen metabolism in hemodialysis patients and there were no reports about the changes of deep regional cerebral SvO2 in hemodialysis patients. In this study, we aim to explore the deep regional cerebral SvO2 from straight sinus using quantitative susceptibility mapping (QSM) and the correlation with clinical risk factors and neuropsychiatric testing. 52 hemodialysis patients and 54 age-and gender-matched healthy controls were enrolled. QSM reconstructed from original phase data of 3.0T susceptibility-weighted imaging was used to measure the susceptibility of straight sinus. The susceptibility was used to calculate the deep regional cerebral SvO2 and compare with healthy individuals. Correlation analysis was performed to investigate the correlation between deep regional cerebral SvO2, clinical risk factors and neuropsychiatric testing. The deep regional cerebral SvO2 of hemodialysis patients (72.5 ± 3.7%) was significantly lower than healthy controls (76.0 ± 2.1%) (P < 0.001). There was no significant difference in the measured volume of interests of straight sinus between hemodialysis patients (250.92 ± 46.65) and healthy controls (249.68 ± 49.68) (P = 0.859). There were no significant correlations between the measured susceptibility and volume of interests in hemodialysis patients (P = 0.204) and healthy controls (P = 0.562), respectively. Hematocrit (r = 0.480, P < 0.001, FDR corrected), hemoglobin (r = 0.440, P < 0.001, FDR corrected), red blood cell (r = 0.446, P = 0.003, FDR corrected), dialysis duration (r = 0.505, P = 0.002, FDR corrected) and parathyroid hormone (r = -0.451, P = 0.007, FDR corrected) were risk factors for decreased deep regional cerebral SvO2 in patients. The Mini-Mental State Examination (MMSE) scores of hemodialysis patients were significantly lower than healthy controls (P < 0.001). However, the deep regional cerebral SvO2 did not correlate with MMSE scores (P = 0.630). In summary, the decreased deep regional cerebral SvO2 occurred in hemodialysis patients and dialysis duration, parathyroid hormone, hematocrit, hemoglobin and red blood cell may be clinical risk factors.

Decreased susceptibility of major veins in mild traumatic brain injury is correlated with post-concussive symptoms: A quantitative susceptibility mapping study.

Cerebral venous oxygen saturation (SvO2) is an important biomarker of brain function. In this study, we aimed to explore the relative changes of regional cerebral SvO2 among axonal injury (AI) patients, non-AI patients and healthy controls (HCs) using quantitative susceptibility mapping (QSM). 48 patients and 32 HCs were enrolled. The patients were divided into two groups depending on the imaging based evidence of AI. QSM was used to measure the susceptibility of major cerebral veins. Nonparametric testing was performed for susceptibility differences among the non-AI patient group, AI patient group and healthy control group. Correlation was performed between the susceptibility of major cerebral veins, elapsed time post trauma (ETPT) and post-concussive symptom scores. The ROC analysis was performed for the diagnostic efficiency of susceptibility to discriminate mTBI patients from HCs.The susceptibility of the straight sinus in non-AI and AI patients was significantly lower than that in HCs (P < 0.001, P = 0.004, respectively, Bonferroni corrected), which may indicate an increased regional cerebral SvO2 in patients. The susceptibility of the straight sinus in non-AI patients positively correlated with ETPT (r = 0.573, P = 0.003, FDR corrected) while that in AI patients negatively correlated with the Rivermead Post Concussion Symptoms Questionnaire scores (r = − 0.582, P = 0.018, FDR corrected). The sensitivity, specificity and AUC values of susceptibility for the discrimination between mTBI patients and HCs were 88%, 69% and 0.84. In conclusion, the susceptibility of the straight sinus can be used as a biomarker to monitor the progress of mild TBI and to differentiate mTBI patients from healthy controls.

Oxygen Saturation of Retinal Vessels in All Stages of Diabetic Retinopathy and Correlation to Ultra-Wide Field Fluorescein Angiography.

The purpose of this study was to determine retinal hemoglobin oxygen saturation (SO2) in patients with diabetic retinopathy (DR) using retinal oximetry (RO) and to correlate the degree of retinal ischemia using intravenous fluorescein angiography (IVFA). This is a single-center cross-sectional cohort study. Twenty-seven controls and 60 adult patients with diabetes mellitus (16 without DR and 44 with DR) were enrolled. Patients were stratified according to DR severity. Using RO, SO2 was measured in major retinal arterioles (SaO2) and venules (SvO2). Using IVFA, the percentage of retinal ischemia in 31 patients with DR was calculated and correlated with RO. Pairwise one-way analysis of variance (ANOVA) showed a significant increase in SaO2 and SvO2 in patients with proliferative DR (PDR) compared with controls (SaO2: PDR, 100 ± 7% vs. controls, 91 ± 4% [P = 0.003]; SvO2: PDR, 66 ± 11% vs. controls, 53 ± 6% [P < 0.00001]). The percentage of retinal ischemia also increased with DR severity: ANOVA showed a significant difference in retinal ischemia between all categories of nonproliferative DR vs. PDR: 2.31 ± 2% vs. 7.92 ± 9% (P = 0.017), respectively. Pearson two-tailed correlation showed significant correlation between SaO2 and ischemia (R = 0.467, P = 0.011). Hemoglobin oxygen saturation of retinal arterioles and venules increases with DR severity; SaO2 correlates with increasing ischemia measured by IVFA. Retinal oximetry may complement current imaging strategies to noninvasively augment the diagnosis and risk stratification of patients with diabetes.

Low hemoglobin levels are associated with lower cerebral saturations and poor outcome after cardiac arrest.

Post-cardiac arrest (CA) patients have a large cerebral penumbra at risk for secondary ischemic damage in case of suboptimal brain oxygenation during ICU stay. The aims of this study were to investigate the association between hemoglobin, cerebral oxygenation (SctO2) and outcome in post-CA patients. Prospective observational study in 82 post-CA patients. Hemoglobin, a corresponding SctO2 measured by NIRS and SVO2 in patients with a pulmonary artery catheter (n=62) were determined hourly during hypothermia in the first 24h of ICU stay. We found a strong linear relationship between hemoglobin and mean SctO2 (SctO2=0.70×hemoglobin+56 (R(2) 0.84, p=10(-6))). Hemoglobin levels below 10g/dl generally resulted in lower brain oxygenation. There was a significant association between good neurological outcome (43/82 patients in CPC 1-2 at 180 days post-CA) and admission hemoglobin above 13g/dl (OR 2.76, 95% CI 1.09:7.00, p=0.03) or mean hemoglobin above 12.3g/dl (OR 2.88, 95%CI 1.02:8.16, p=0.04). This association was entirely driven by results obtained in patients with a mean SVO2 below 70% (OR 6.25, 95%CI 1.33:29.43, p=0.01) and a mean SctO2 below 62.5% (OR 5.87, 95%CI 1.08:32.00, p=0.03). Hemoglobin levels below 10g/dl generally resulted in lower cerebral oxygenation. Average hemoglobin levels below 12.3g/dl were associated with worse outcome in patients with suboptimal SVO2 or SctO2. The safety of a universal restrictive transfusion threshold of 7g/dl can be questioned in post-CA patients.

Agreement between Central and Mixed Venous Oxygen Saturation Following Cardiac Surgery

Objective: To compare oxygen saturation of blood samples simultaneously taken from superior vena cava (ScvO2) and pulmonary artery (SvO2) in the various hemodynamic conditions that occurs in the early postoperative period following cardiac surgery. Methods: Prospective, observational study in a tertiary cardiac center, 60 ICU patients included following cardiac surgery. 56 patients completed the study with three hundred measurements collected. Exclusion criteria included those with uncorrected valvular incompetence or intracardiac shunting, and frequent arrhythmia interfering with adequate cardiac output measurement. Samples taken simultaneously from the central venous catheter and the distal lumen of pulmonary artery catheter (PAC). Samples were obtained during each cardiac output measurement as requested by the attending intensivist according to his clinical judgment. Results: The correlation between SvO2 and ScvO2 was (r=0.79, p <0.001). The mean bias between SvO2 and ScvO2 was 3.8 %, and the 95% limits of agreement were (+15.8 to – 8.2%). Receiving operating characteristic curves demonstrated that an ScvO2 of 70% or greater can predict SvO2 of 70% or greater with a specificity and sensitivity of 92% and 62% respectively. Conclusion: There is poor agreement between ScvO2 and SvO2 in patients following cardiac surgery. This agreement remains poor regardless changes in cardiac index, type of surgery and type of pharmacological support. We also conclude that a cutoff value of (70% and above) in ScvO2 is a specific –but not sensitive- method to predict adequate mixed venous oxygen saturation.

DECLINES IN MIXED VENOUS O2 SATURATION AFTER EXTUBATION ARE RELATED TO INCREASES IN O2 CONSUMPTION

PURPOSE: Decreases in central and mixed venous O2 (ScvO2 and SvO2, respectively) saturations are accepted markers of deficient oxygen delivery. During weaning from mechanical ventilation others have noted decreases in SvO2 in patients who failed weaning (Jubran et al. AJRCCM 1998; 158:1763). Our aim was to determine the relationship of SvO2 to O2 delivery (DO2) and to consumption (VO2) during the immediate post extubation period in cardiac post-operative patients.

Skeletal muscle oxygen saturation does not estimate mixed venous oxygen saturation in patients with severe left heart failure and additional severe sepsis or septic shock

IntroductionLow cardiac output states such as left heart failure are characterized by preserved oxygen extraction ratio, which is in contrast to severe sepsis. Near infrared spectroscopy (NIRS) allows noninvasive estimation of skeletal muscle tissue oxygenation (StO2). The aim of the study was to determine the relationship between StO2 and mixed venous oxygen saturation (SvO2) in patients with severe left heart failure with or without additional severe sepsis or septic shock.MethodsSixty-five patients with severe left heart failure due to primary heart disease were divided into two groups: groups A (n = 24) and B (n = 41) included patients without and with additional severe sepsis/septic shock, respectively. Thenar muscle StO2 was measured using NIRS in the patients and in 15 healthy volunteers.ResultsStO2 was lower in group A than in group B and in healthy volunteers (58 ± 13%, 90 ± 7% and 84 ± 4%, respectively; P < 0.001). StO2 was higher in group B than in healthy volunteers (P = 0.02). In group A StO2 correlated with SvO2 (r = 0.689, P = 0.002), although StO2 overestimated SvO2 (bias -2.3%, precision 4.6%). In group A changes in StO2 correlated with changes in SvO2 (r = 0.836, P < 0.001; ΔSvO2 = 0.84 × ΔStO2 - 0.67). In group B important differences between these variables were observed. Plasma lactate concentrations correlated negatively with StO2 values only in group A (r = -0.522, P = 0.009; lactate = -0.104 × StO2 + 10.25).ConclusionSkeletal muscle StO2 does not estimate SvO2 in patients with severe left heart failure and additional severe sepsis or septic shock. However, in patients with severe left heart failure without additional severe sepsis or septic shock, StO2 values could be used to provide rapid, noninvasive estimation of SvO2; furthermore, the trend in StO2 may be considered a surrogate for the trend in SvO2. Trial Registration: NCT00384644