Platelet, Plasma, Urinary Tryptophan-Serotonin-Kynurenine Axis Markers in Hyperacute Brain Ischemia Patients: A Prospective Study.

Background and Purpose: Ischemic stroke is one of the most common causes of morbidity and mortality and has numerous clinical mimics. Previous studies have suggested a potential role of the tryptophan-serotonin (5-HT)-kynurenine (TSK) axis in ischemic stroke. Studies assessing this axis in the hyperacute phase of ischemic stroke (<4.5 h) are lacking. This prospective study thus evaluates the TSK axis in transient ischemic attack (TIA) and hyperacute ischemic stroke (AIS) patients. Methods: This study included 28 patients (24 AIS and 4 TIA) and 29 controls. The blood and urine samples of patient were collected within 4.5 h of symptoms onset (day 0, D0), then at 24 h and 3 months. Control blood and urine samples were collected once (D0). The TSK axis markers measured were platelet serotonin transporter (SERT) and 5-HT2A receptor (5-HT2AR) densities and platelet, plasma, and urinary 5-HT, plasma and urinary 5-hydroxyindole acetic acid (5-HIAA), and plasma kynurenine and tryptophan (TRP) levels. Results: At D0, patients exhibited a lower (p = 10-5) platelet SERT density, higher (p < 10-6) platelet 5-HT2AR density, higher (p = 10-5) plasma kynurenine/tryptophan (K/T) ratio, and higher urinary 5-HT (p = 0.011) and 5-HIAA (p = 0.003) levels than controls. Conclusions: We observed, for the first time, a hyperacute dysregulation of the serotonergic axis, and hyperacute and long-lasting activation of the tryptophan-kynurenine pathway in brain ischemia.

Targeted temperature management after intraoperative cardiac arrest: a multicenter retrospective study.

PURPOSE: Few outcome data are available about temperature management after intraoperative cardiac arrest (IOCA). We describe targeted temperature management (TTM) (32-34 °C) modalities, adverse events, and association with 1-year functional outcome in patients with IOCA. METHODS: Patients admitted to 11 ICUs after IOCA in 2008-2013 were studied retrospectively. The main outcome measure was 1-year functional outcome. RESULTS: Of the 101 patients [35 women and 66 men; median age, 62 years (interquartile range, 42-72)], 68 (67.3%) were ASA PS I to III and 57 (56.4%) had emergent surgery. First recorded rhythms were asystole in 44 (43.6%) patients, pulseless electrical activity in 36 (35.6%), and ventricular fibrillation/tachycardia in 20 (19.8%). Median times from collapse to cardiopulmonary resuscitation and return of spontaneous circulation (ROSC) were 0 min (0-0) and 10 min (4-20), respectively. The 30 (29.7%) patients who received TTM had an increased risk of infection (P = 0.005) but not of arrhythmia, bleeding, or metabolic/electrolyte disorders. By multivariate analysis, one or more defibrillation before ROSC was positively associated with a favorable functional outcome at 1-year (OR 3.06, 95% CI 1.05-8.95, P = 0.04) and emergency surgery was negatively associated with 1-year favorable functional outcome (OR 0.36; 95% CI 0.14-0.95, P = 0.038). TTM use was not independently associated with 1-year favorable outcome (OR 0.82; 95% CI 0.27-2.46, P = 0.72). CONCLUSIONS: TTM was used in less than one-third of patients after IOCA. TTM was associated with infection but not with bleeding or coronary events in this setting. TTM did not independently predict 1-year favorable functional outcome after IOCA in this study.

Predictors of functional outcome after intraoperative cardiac arrest.

BACKGROUND: Few outcome data are available about intraoperative cardiac arrest (IOCA). The authors studied 90-day functional outcomes and their determinants in patients admitted to the intensive care unit after IOCA. METHODS: Patients admitted to 11 intensive care units in a period of 2000-2013 were studied retrospectively. The main outcome measure was a day-90 Cerebral Performance Category score of 1 or 2. RESULTS: Of the 140 patients (61 women and 79 men; median age, 60 yr [interquartile range, 46 to 70]), 131 patients (93.6%) had general anesthesia, 80 patients (57.1%) had emergent surgery, and 73 patients (52.1%) had IOCA during surgery. First recorded rhythms were asystole in 73 patients (52.1%), pulseless electrical activity in 44 patients (31.4%), and ventricular fibrillation/ventricular tachycardia in 23 patients (16.4%). Median times from collapse to cardiopulmonary resuscitation and return of spontaneous circulation were 0 min (0 to 0) and 10 min (5 to 20), respectively. Postcardiac arrest shock was identified in 114 patients (81.4%). Main causes of IOCA were preoperative complications (n = 46, 32.9%), complications of anesthesia (n = 39, 27.9%), and complications of surgical procedures (n = 36, 25.7%). On day 90, 63 patients (45.3%) were alive with Cerebral Performance Category score 1/2. Independent predictors of day-90 Cerebral Performance Category score 1/2 were day-1 Logistic Organ Dysfunction score (odds ratio, 0.78 per point; 95% CI, 0.71 to 0.87; P = 0.0001), ventricular fibrillation/tachycardia as first recorded rhythm (odds ratio, 4.78; 95% CI, 1.38 to 16.53; P = 0.013), and no epinephrine therapy during postcardiac arrest syndrome (odds ratio, 3.14; 95% CI, 1.29 to 7.65; P = 0.012). CONCLUSIONS: By day 90, 45% of IOCA survivors had good functional outcomes. The main outcome predictors were directly related to IOCA occurrence and postcardiac arrest syndrome; they suggest that the intensive care unit management of postcardiac arrest syndrome may be amenable to improvement.

Platelet serotonin level predicts survival in amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a life-threatening neurodegenerative disease involving upper and lower motor neurons loss. Clinical features are highly variable among patients and there are currently few known disease-modifying factors underlying this heterogeneity. Serotonin is involved in a range of functions altered in ALS, including motor neuron excitability and energy metabolism. However, whether serotoninergic activity represents a disease modifier of ALS natural history remains unknown. METHODOLOGY: Platelet and plasma unconjugated concentrations of serotonin and plasma 5-HIAA, the major serotonin metabolite, levels were measured using HPLC with coulometric detection in a cohort of 85 patients with ALS all followed-up until death and compared to a control group of 29 subjects. PRINCIPAL FINDINGS: Platelet serotonin levels were significantly decreased in ALS patients. Platelet serotonin levels did not correlate with disease duration but were positively correlated with survival of the patients. Univariate Cox model analysis showed a 57% decreased risk of death for patients with platelet serotonin levels in the normal range relative to patients with abnormally low platelet serotonin (p = 0.0195). This protective effect remained significant after adjustment with age, gender or site of onset in multivariate analysis. Plasma unconjugated serotonin and 5-HIAA levels were unchanged in ALS patients compared to controls and did not correlate with clinical parameters. CONCLUSIONS/SIGNIFICANCE: The positive correlation between platelet serotonin levels and survival strongly suggests that serotonin influences the course of ALS disease.