Comparison Between Transcranial Color-Coded Duplex Doppler and Contrast Enhanced Transcranial Color-Coded Duplex Doppler After Subarachnoid Aneurysmal Hemorrhage.

BACKGROUND: Transcranial color-coded duplex Doppler (TCCD) is commonly used to detect and monitor vasospasm in subarachnoid aneurysmal hemorrhage (aSAH). However, contrast enhanced TCCD (CE-TCCD) may be more effective. The objective of this study was to compare the accuracy of TCCD and CE-TCCD in the detection of vasospasm. METHODS: This study was a prospective comparison of TCCD and CE-TCCD for the detection of vasospasm, using computed tomography angiography (CT Angio) as a reference examination. The setting was the Department of Anesthesiology and Intensive Care at the Bicêtre University Hospital in Le Kremlin Bicêtre, France. TCCD and CE-TCCD were performed in 47 patients admitted to the intensive care unit (ICU) following aSAH over a 7-month period. TCCD and CE-TCCD were performed at ICU admission and between days 7 and 10. We aimed to visualize the seven intracranial arteries of the circle of Willis. Vasospasm diagnosis was assessed by CT Angio  and graded as moderate when the percentage change in arterial diameter since admission was between 25 and 50% or as severe when the percentage change was greater than 50%. RESULTS: On ICU admission, TCCD allowed visualization of all intracranial arteries in 16 (34%) of 47 patients, whereas CE-TCCD allowed visualization of all vessels in 37 (79%) of 47 patients (p < 0.001). These results were consistent between days 7 and 10. The proportions of middle cerebral arteries (MCAs), anterior cerebral arteries (ACAs) and posterior cerebral arteries (PCAs) visualized were greater with CE-TCCD. There was no difference in the visualization of basilar arteries (BAs). We performed vasospasm analysis on 67 of 94 MCAs in 47 patients. Area under the curve (AUC) of mean flow velocity to detect MCA vasospasm (moderate and severe) was 0.86 (0.58-1.00) for TCCD and 0.90 (0.77-1.00) for CE-TCCD. AUC of mean velocity to detect severe MCA vasospasm was 0.86 (0.58-1.00) for TCCD and 0.90 (0.77-1.00) for CE-TCCD, without any significant difference between the two techniques. For other arteries, the accuracy of TCCD and CE-TCCD to diagnose vasospasm was poor. CONCLUSIONS: CE-TCCD allows better visualization of intracranial arteries in patients with aSAH. The accuracy of CE-TCCD to screen severe MCA vasospasm is similar to that of TCCD. CE-TCCD is an alternative tool for monitoring patients with aSAH without a temporal bone window for an ultrasound.

Comparison of Pressure Reactivity Index and Mean Velocity Index to Evaluate Cerebrovascular Reactivity During Induced Arterial Blood Pressure Variations in Severe Brain Injury.

OBJECTIVES: To compare the assessment of cerebral autoregulation by cerebrovascular reactivity indices based on intracranial pressure (Pressure Reactivity Index, PRx) and on transcranial Doppler (Mean Velocity Index, Mx) during controlled variations of arterial blood pressure in severe brain injury. Primary outcome was the agreement between both cerebrovascular reactivity indices measured by the Bland-and-Altman method. Secondary outcomes were the association of cerebrovascular reactivity indices with arterial blood pressure variation, and the comparison of optimal cerebral perfusion pressures determined by both indices. METHODS: All consecutive comatose (Glasgow Coma Scale < 8) patients from the surgical intensive care unit of Bicetre Hospital who had an acute brain injury on computerized tomography and needed vasopressor support were prospectively included. Step-by-step arterial pressure variations using vasopressors were performed to compare PRx and Mx and to calculate optimal cerebral perfusion pressure (CPPopt). MEASUREMENTS AND MAIN RESULTS: 15 patients were included. Mean difference between both indices measured by Bland-and-Altman plot was - 0.07 (IC 95% [- 1.02 to 0.87]). Mx was significantly associated with arterial pressure variation (one-way ANOVA test, p = 0.007), whereas PRx was not (p = 0.44). Optimal cerebral perfusion pressure calculated with PRx and Mx was respectively 11 and 15mmHg higher than the mean perfusion pressure prescribed. Optimal cerebral perfusion pressure calculation was possible in all cases. CONCLUSIONS: Cerebral vasoreactivity indices calculated with intracranial pressure or transcranial Doppler show only moderate agreement. Both indices nonetheless suggest substantially higher optimal cerebral perfusion pressure than those currently provided by international guidelines.

Mid-regional pro-adrenomedullin (MR-proADM), a marker of positive fluid balance in critically ill patients: results of the ENVOL study.

BACKGROUND: The optimal control of blood volume without fluid overload is a main challenge in the daily care of intensive care unit (ICU) patients. Accordingly this study focused on the identification of biomarkers to help characterize fluid overload status. METHODS: Sixty-seven patients were studied from ICU admission to day 7 (D7). Blood and urine samples were taken daily and sodium and water balance strictly calculated resulting in a total cumulative assessment of ∆Na+ and ∆H2O. Furthermore, plasmatic biomarkers (cortisol, epinephrine, norepinephrine, renin, angiotensin II, aldosterone, pro-endothelin, copeptine, atrial natriuretic peptide, erythropoietin, mid-regional pro-adrenomedullin (MR-proADM)) and Sequential Organ Failure Assessment (SOFA) scores were measured at D2, D5 and D7. Blood volumes were measured with 51Cr fixed on red blood cells at D2 and D7. RESULTS: The ∆Na+ or ∆H2O were increased in all patients but never related to blood volumes at D2 nor D7. Total blood volumes were at normal values with constantly low red blood cell volumes and normal or decreased plasmatic volume. Weight, plasmatic proteins, and hemoglobin were weakly related to ∆Na+ or ∆H2O. Amongst all tested biomarkers, only MR-proADM was related to sodium and fluid overload. This biomarker was also a predictor of SOFA scores. CONCLUSIONS: Plasmatic concentration in MR-proADM seems to be a good surrogate for evaluation of ∆Na+ or ∆H2O and predicts sodium and extracellular fluid overload. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01858675 in May 13, 2013.

Determinants and significance of cerebral oximetry after cardiac arrest: A prospective cohort study.

AIM OF THE STUDY: To study the determinants and the evolution of cerebral oximetry determined by near-infrared spectroscopy after out-of-hospital cardiac arrest of cardiac origin during therapeutic hypothermia and rewarming, and to compare cerebral oximetry values between patients with good and bad prognosis. METHODS: In this prospective, non-interventional, single center study, all consecutive patients between 18 and 80 years admitted for out-of-hospital cardiac arrest (OHCA) with a no flow less than 10min, a low flow of less than 50min and a persistent coma after ROSC with Glasgow score equal or less than seven at baseline were included. RESULTS: Between February 2012 and January 2013, 43 patients were admitted for OHCA in our ICU. Twenty-two patients (51%) were discharged with no or minimal neurologic complications (CPC 1-2). Mortality rate in the ICU was 46.5%. Cerebral oximetry (rSO2) was correlated with temperature, heart rhythm, PaO2, hemoglobin, and mean arterial pressure. Mean rSO2 during the 48 first hours was not different between patients with good and bad neurologic outcomes, respectively, 61.8 (5.9) vs. 58.1 (8.8), P=0.13, as during the period of hypothermia. The minimal value of rSO2 during the first 48h was significantly different between patients with good prognosis and those with bad prognosis, respectively, 45.0 (6.8) vs. 31.7 (15.0), P=0.0009. CONCLUSIONS: In this prospective cohort of OHCA patients, main determinants of rSO2 were systemic variables. Monitoring of rSO2 does not allow discriminating patients with good or bad outcome, but could be useful for identifying vulnerable periods for the development of neurologic injury.