Change in brain glucose after enteral nutrition in subarachnoid hemorrhage.

BACKGROUND: The alteration of brain extracellular glucose after enteral nutrition (EN) remains unclear. In this study, we used brain microdialysis methods to estimate whether the physiologic elevation of plasma glucose following EN affects brain glucose metabolism of aneurysmal subarachnoid hemorrhage (SAH) patients. METHODS: Brain extracellular glucose, lactate, glycerol, glutamate, and pyruvate were measured with a brain microdialysis probe in 12 patients (mean age: 60.0 y+/-7.8 y) after SAH. The EN was initially administered a mean of 3.2 d after the onset of SAH. All of the measured parameters were estimated before and after EN. RESULTS: Cerebral perfusion pressure did not significantly change after SAH during the study period. Plasma glucose rose significantly after EN (141.4+/-11.6mg/dL before EN versus 183.8+/-26.2mg/dL immediately after EN (P=0.0006), 177.7+/-30.2mg/dL at 2h after EN (P=0.0033)). The brain extracellular glucose before EN (2.5+/-0.92mmol/L) was significantly lower than the levels measured just after (3.49+/-1.0mmol/L, P=0.0186) and 2h after the end of EN (3.70+/-1.0mmol/L, P=0.0053). Brain extracellular concentrations of lactate, glutamate, pyruvate, and glycerol showed no significant changes. CONCLUSIONS: Brain extracellular glucose increased after the transient elevation of plasma glucose following EN. These results suggest that brief, physiologic elevations in plasma glucose after EN produced no changes in brain extracellular glutamate concentration or lactate/pyruvate ratio. These data may help determine the plasma glucose levels most effective for avoiding brain metabolic acidosis in patients after SAH. It remains unclear, however, how SAH itself influences these findings.

Reduced effectiveness of vasopressin in repeated doses for patients undergoing prolonged cardiopulmonary resuscitation.

INTRODUCTION: The efficacy of repeated administration of vasopressin alone during prolonged cardiopulmonary resuscitation (CPR) remains unconfirmed. This study was conducted to estimate the effectiveness of the repeated administration of vasopressin vs. epinephrine for cardiopulmonary arrest (CPA) patients receiving prolonged CPR. METHODS: We conducted a prospective randomized controlled study on patients who experienced out-of-hospital CPA. The patients were randomly assigned to receive a maximum of four injections of either 40IU of vasopressin (vasopressin group) or 1mg of epinephrine (epinephrine group) immediately after emergency room (ER) admission. Patients who received vasopressors before ER admission or suffered non-cardiogenic CPA were excluded after randomization. RESULTS: In total, 336 patients were enrolled (vasopressin group, n=137; epinephrine group, n=118). No differences were found between these groups (vasopressin group vs. epinephrine group) in the rates of return of spontaneous circulation (ROSC) (28.7% vs. 26.6%), 24-h survival (16.9% vs. 20.3%), or survival to hospital discharge (5.6% vs. 3.8%). In a subgroup analysis by the Fisher's exact test, the rate of ROSC was higher in the vasopressin group than in the epinephrine group, among the patients whose arrests were witnessed (48.1% vs. 27.8%, p=0.010) or who received bystander CPR (68.0% vs. 38.5%, p=0.033). When the independent predictors of ROSC were calculated in the subgroup analysis, however, vasopressin administration (Odds ratio: 0.87-0.28) did not affect the outcome. CONCLUSIONS: This is the first report of a possible vasopressin-alone resuscitation without additional epinephrine. However, repeated injections of either vasopressin or epinephrine during prolonged advanced cardiac life support resulted in comparable survival.

Decreased activated protein C levels as a clinical predictor in patients with ST-elevation myocardial infarction.

BACKGROUND: Circulating markers that indicate atherosclerotic plaque instability may have diagnostic and prognostic value in patients with acute coronary syndromes. We evaluated activated protein C (APC), which has antithrombotic, anti-inflammatory, and profibrinolytic properties, as a possible clinical predictor in ST-elevation myocardial infarction (STEMI), including return of spontaneous circulation after sudden cardiac arrest. METHODS: Patients with STEMI whose APC level was measured upon arrival at the emergency room were enrolled in this study (n=335). The primary end point was inhospital death from any cause. RESULTS: The APC level ranged from 29% to 142% with a median of 80%. The unadjusted death rate increased in a stepwise fashion with decreasing APC levels (33.7% in quartile 1, 12.7% in 2, 6.0% in 3, and 3.6% in 4, P<.001). This association remained significant in subgroups of patients with STEMI only (P=.04) or with return of spontaneous circulation (P=.01). After adjusting for independent predictors of inhospital death, the odds ratio for death among those in the first quartile of APC levels was 9.4 (95% CI 1.1-81.6, P=.04). A cutoff APC level of 65% had the highest combined sensitivity and specificity in predicting death. CONCLUSIONS: Measuring APC levels provides predictive information for use in risk stratification across the STEMI spectrum. Decreased APC levels may be a unifying feature among patients at high risk for death after STEMI.

Resuscitative value of B-type natriuretic peptide in comatose survivors treated with hypothermia after out-of-hospital cardiac arrest due to cardiac causes.

BACKGROUND: Two randomized studies have shown a neurological benefit of therapeutic hypothermia in comatose survivors after out-of-hospital cardiac arrest, but there are no studies of the cardiac neurohormone of B-type natriuretic peptide (BNP) in patients treated with hypothermia. METHODS AND RESULTS: A prospective study was conducted of 109 comatose patients who were treated with mild hypothermia after out-of-hospital sudden cardiac arrest due to cardiac causes and whose BNP level was measured on arrival at the emergency room. The primary endpoint was a favorable neurological outcome at the time of hospital discharge. A total of 45 of the 109 patients had a favorable neurological outcome. The unadjusted rate of a favorable neurological outcome decreased in a stepwise fashion among patients in increasing quartiles of BNP level (p<0.001) and this association remained significant in subgroups of patients. The BNP cutoff value of 80 pg/ml for a favorable neurological outcome had an accuracy of 87.2%. In the multiple logistic-regression analysis, a BNP level of 80 pg/ml or less was an independent predictor of favorable neurological outcome. CONCLUSIONS: The measurement of BNP was found to provide valuable information regarding the neurological outcome of comatose survivors treated with mild hypothermia after out-of-hospital cardiac arrest due to cardiac causes.