Prognostic implications of tissue oxygen saturation in human septic shock

Purpose: To analyze the prognostic value of tissue oxygen saturation (StO2) in septic shock patients with restored mean arterial pressure (MAP). Methods: This was a prospective observational study of patients admitted to the ICU in the early phase of septic shock, after restoration of MAP. Demographic data, severity score, hemodynamics, blood lactate, acid-base status, and StO2 were measured at inclusion followed by a transient vascular occlusion test (VOT) to obtain the StO2-deoxygenation (DeOx) and StO2-reoxygenation (ReOx) rates. Sequential organ failure assessment (SOFA) score was measured at inclusion and after 24 h. Results: Thirty-three patients were studied. StO2 was 76 ± 10%, DeOx -12.2 ± 4.2%/min, and ReOx 3.02 ± 1.70%/s. MAP showed a significant correlation with VOT-derived slopes (r = -0.4, p = 0.04 for DeOx; and r = 0.55, p\0.01 for ReOx). After 24 h, 17 patients (52%) had improved SOFA scores. Patients who did not improve their SOFA showed less negative DeOx values at inclusion. The association between DeOx and SOFA evolution was not affected by MAP. Both DeOx and ReOx impairment correlated with longer ICU stay (r = 0.44, p = 0.05; and r = -0.43, p = 0.05, respectively). Conclusions: In a population of septic shock patients with restored MAP, impaired DeOx was associated with no improvement in organ failures after 24 h. Decrements in DeOx and ReOx were associated with longer ICU stay. DeOx and ReOx were linked to MAP, and thus, their interpretation needs to be made relative to MAP. © Copyright jointly held by Springer and ESICM 2012

Comparison of two different generations of "nIRS" devices and transducers in healthy volunteers and ICU patients

The purpose of this study is to compare Near Infrared Spectroscopy (NIRS) thenar eminence parameters obtained with 2 different devices from the same manufacturer (InSpectra Models 325 and 650, Hutchinson Tech, Min USA), and 2 different probes (15 vs. 25 mm spacing), in healthy volunteers (HV) and ICU patients. Prospective, observational study in ICU setting. Simultaneous, cross over NIRS inter-device comparison and comparison between different probes (25 vs. 15 mm spacing) were done at baseline and during vascular occlusion tests (VOTs). Forty patients (19 septic shock, 21 trauma), and 29 HV were included. NIRS inter-device comparison showed similar baseline StO2 values in HV and patients. The VOT result were significantly different for minimal StO2 value reached during VOT (StO2min) (intraclass concordance coefficient (ICC) = 0.18), the occlusion slope (ICC = 0.16) and the reperfusion slope (StO2reperf) (ICC = 0.26). The probe comparison was also significantly different for VOT parameters (StO2min (ICC = 0.43), occlusion (ICC = 0.50) and StO2reperf (ICC = 0.48). The low concordance, poor agreement and large bias (ICC and Bland & Altman) observed, were related both to the device used and the probe spacing. StO 2 data obtained with NIRS model 650 and 15 mm probe differ from values obtained with the previous device (325 and probe spacing 25 or 15 mm). This difference is not related to the population tested, but to the device and probe spacing. As a consequence, despite similar trends for variations between HV and patients during VOT, threshold and predictive values for outcome should be revisited with the new device before the acceptance for routine clinical use. © 2012 Springer Science+Business Media New York.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Monitoring the microcirculation.

One of the main goals of hemodynamic support is to preserve tissue perfusion. However issue perfusion is related more to microvascular perfusion than aortic blood flow. Monitoring the microcirculation has long been difficult. Recent technologic advances have made feasible monitoring of the microcirculation at bedside of critically ill patients. In this review, we will discuss the relevance of the various tools available to monitor the microcirculation. Videomicroscopic devices such as sidestream darkfield imaging are the most appropriate techniques to evaluate the microcirculation, taking into account the heterogeneous aspect of diseased microcirculation, as in sepsis. The microcirculation can also be indirectly assessed by measuring tissue PCO2. Transcutaneous PCO2 measurement at ear lobe is particularly promising. Finally, near infrared spectroscopy can also provide interesting information, especially using vascular occlusion tests which reactivity of the microcirculation to a transient hypoxic insult. These different devices have provided important data helping us to better understand the pathophysiology of sepsis and multiple organ failure.Journal ArticleReviewinfo:eu-repo/semantics/publishe

Optical Monitoring

SCOPUS: ch.binfo:eu-repo/semantics/publishe

Recovery of right ventricular function after intermediate-risk pulmonary embolism: results from the multicentre Pulmonary Embolism International Trial (PEITHO)-2

Background: Right ventricular (RV) function plays a critical role in the pathophysiology and acute prognosis of pulmonary embolism (PE). We analyzed the temporal changes of RV function in the cohort of a prospective multicentre study investigating if an early switch to oral anticoagulation in patients with intermediate-risk PE is effective and safe. Methods: Echocardiographic and laboratory examinations were performed at baseline (PE diagnosis), 6 days and 6 months. Echocardiographic parameters were classified into categories representing RV size, RV free wall/tricuspid annulus motion, RV pressure overload and right atrial (RA)/central venous pressure. Results: RV dysfunction based on any abnormal echocardiographic parameter was present in 84% of patients at baseline. RV dilatation was the most frequently abnormal finding (40.6%), followed by increased RA/central venous pressure (34.6%), RV pressure overload (32.1%), and reduced RV free wall/tricuspid annulus motion (20.9%). As early as day 6, RV size remained normal or improved in 260 patients (64.7%), RV free wall/tricuspid annulus motion in 301 (74.9%), RV pressure overload in 297 (73.9%), and RA/central venous pressure in 254 (63.2%). At day 180, the frequencies slightly increased. The median NT-proBNP level decreased from 1448 pg/ml at baseline to 256.5 on day 6 and 127 on day 180. Conclusion: In the majority of patients with acute intermediate-risk PE switched early to a direct oral anticoagulant, echocardiographic parameters of RV function normalised within 6 days and remained normal throughout the first 6 months. Almost one in four patients, however, continued to have evidence of RV dysfunction over the long term. Graphical Abstract: [Figure not available: see fulltext.]