Value of assessment of multivoxel proton chemical shift imaging to predict long term outcome in patients after out-of-hospital cardiac arrest: A preliminary prospective observational study.

BACKGROUND: Existing methods to predict recovery after out-of-hospital cardiac arrest (OHCA) lack of accuracy. The aim of this study was to determine whether quantitative proton chemical shift imaging (1H-CSI) during the subacute stage of OHCA can predict neurological outcome of such patients. METHODS: This monocentric prospective observational study was conducted in a Intensive Care Unit of a teaching hospital. Forty consecutive patients with OHCA were enrolled between January 1st 2011-December 31st 2013. Multivoxel 1H-CSI values were compared to structural magnetic resonance imaging (MRI) sequences (fluid-attenuated inversion recovery and diffusion-weighted imaging). Ratios of N-acetyl-aspartate (NAA) to creatine (Cr) and choline compounds were analyzed using region of interest in bilateral lenticular cores and thalami. The outcome evaluated was the Cerebral Performance Category (CPC) at 6 months, dichotomized as favorable (CPC 1-2) and unfavorable outcome (CPC 3-5). The performance was compared by area under the receiver operating characteristic (ROCAUC) curves analysis. RESULTS: Twenty nine OHCA had an interpretable MRI. Eight patients (28%) had favorable outcome at 6 months. The worst NAA/Cr in lenticular cores was the best 1H-CSI marker, with 80% sensitivity (95% confidence interval (CI), 57-94) and a 100% specificity (95% CI, 63-100) with a positive predictive value of 100%. Prognostic accuracy, as quantified by the ROCAUC, was higher with the worst NAA/Cr in lenticular cores (ROCAUC 0.88; 95% CI, 0.70-0.97) than with the structural MRI sequences. CONCLUSION: In this preliminary study we found that multivoxel 1H-CSI in lenticular cores was highly predictive of unfavorable outcome at 6 months.

Assessment of oxidative stress after out-of-hospital cardiac arrest.

INTRODUCTION: Pathophysiology of cardiac arrest corresponds to a whole body ischemia-reperfusion. This phenomenon is usually associated with an oxidative stress in various settings, but few data are available on cardiac arrest in human. The aim of the present study was to evaluate different oxidative stress markers in out-of-hospital cardiac arrest (OHCA) patients treated with therapeutic hypothermia. MATERIALS AND METHODS: We conducted a prospective study assessing oxidative stress markers (thiobarbituric acid reactive species, carbonyls, thiols, glutathione, and glutathione peroxidase) in OHCA patients treated with therapeutic hypothermia. Measurements were performed during the 4 days after admission and compared between good and poor outcome patients according to Cerebral Performance Category. RESULTS: Thirty-four patients were included, 10 good and 24 poor outcomes at 6 months. Thiobarbituric acid reactive species were higher in the poor outcome group on admission and when therapeutic hypothermia was reached. The other markers were not different between groups. No markers seemed modified by the use of therapeutic hypothermia in each group. CONCLUSIONS: After OHCA, good outcome patients exhibit lower oxidative stress markers than poor outcome patients. Thiobarbituric acid reactive species appears to be an early prognostic parameter. Oxidative stress markers seem not mitigated by therapeutic hypothermia.

Assessment of muscle tissue oxygen saturation after out-of-hospital cardiac arrest.

PURPOSE: Pathophysiology of cardiac arrest corresponds to an ischemia-reperfusion syndrome with deep impairment of microcirculation. Muscular tissue oxygen saturation (StO2) is a noninvasive method of evaluation of microcirculation. Our study was aimed at assessing the prognosis value of muscular StO2 in patients admitted for out-of-hospital cardiac arrest (OHCA) and treated with hypothermia. MATERIALS AND METHODS: We conducted a prospective bicentric observational study including OHCA patients treated with therapeutic hypothermia. Baseline StO2, derived variables (desaturation and resaturation slopes), and lactate levels were compared at different times between patients with good and poor outcomes. Prognosis was assessed by the Cerebral Performance Category (CPC) score at 6 months after admission (CPC 1-2, good outcome; CPC 3-5, poor outcome). RESULTS: Forty-four patients were included, 17 good and 27 poor outcomes at 6 months. At admission, StO2 and lactate levels were lower in good outcome patients. Desaturation and resaturation slopes did not differ between groups. CONCLUSIONS: After an OHCA treated with therapeutic hypothermia, StO2 was correlated with outcome. Further research is needed to better understand the pathophysiological process underlying our results.

Point-of-care ultrasound in intensive care units: assessment of 1073 procedures in a multicentric, prospective, observational study.

OBJECTIVE: To describe current use and diagnostic and therapeutic impacts of point-of-care ultrasound (POCUS) in the intensive care unit (ICU). BACKGROUND: POCUS is of growing importance in the ICU. Several guidelines recommend its use for procedural guidance and diagnostic assessment. Nevertheless, its current use and clinical impact remain unknown. METHODS: Prospective multicentric study in 142 ICUs in France, Belgium, and Switzerland. All the POCUS procedures performed during a 24-h period were prospectively analyzed. Data regarding patient condition and the POCUS procedures were collected. Factors associated with diagnostic and therapeutic impacts were identified. RESULTS: Among 1954 patients hospitalized during the study period, 1073 (55%) POCUS/day were performed in 709 (36%) patients. POCUS served for diagnostic assessment in 932 (87%) cases and procedural guidance in 141 (13%) cases. Transthoracic echocardiography, lung ultrasound, and transcranial Doppler accounted for 51, 17, and 16% of procedures, respectively. Diagnostic and therapeutic impacts of diagnostic POCUS examinations were 84 and 69%, respectively. Ultrasound guidance was used in 54 and 15% of cases for central venous line and arterial catheter placement, respectively. Hemodynamic instability, emergency conditions, transthoracic echocardiography, and ultrasounds performed by certified intensivists themselves were independent factors affecting diagnostic or therapeutic impacts. CONCLUSIONS: With regard to guidelines, POCUS utilization for procedural guidance remains insufficient. In contrast, POCUS for diagnostic assessment is of extensive use. Its impact on both diagnosis and treatment of ICU patients seems critical. This study identified factors associated with an improved clinical value of POCUS.