Dynamic cerebral autoregulation in acute intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Cerebral autoregulation (CA) is not universally impaired in acute intracerebral hemorrhage (ICH); however, the dynamic components of CA are probably more vulnerable. This study, therefore, evaluates the time course of dynamic CA in acute ICH and its relationship to clinical outcome. METHODS: Twenty-six patients with ICH were studied on days 1, 3, and 5 after ictus. Dynamic CA was measured from spontaneous fluctuations in blood pressure and middle cerebral artery flow velocity by transfer function phase (reflecting rapidity of CA) and gain (reflecting damping characteristics of CA) in the low frequency range. Results were compared with those from 55 controls and related with clinical factors and 90-day outcome (modified Rankin scale). RESULTS: Phase did not fluctuate significantly over time, nor did it differ between sides or differ from controls. Gain was always higher in patients than in controls but showed no significant association with outcome or other clinical factors. At day 1, poorer ipsilateral phase was associated with lower blood pressure and higher ICH volume. Poorer phase always coincided with lower Glasgow Coma Scale values. Poorer ipsilateral phase on day 5 was related with poorer clinical outcome according to multivariate analysis (P=0.013). CONCLUSIONS: Dynamic temporal characteristics of CA (phase) are not generally altered in acute ICH. Poorer individual phase values are, however, associated with larger ICH volume, lower blood pressure, and worsened outcome. Dampening characteristics of CA (gain) are generally impaired in acute ICH but not related to clinical factors or outcome.

Urine tested positive for ethyl glucuronide and ethyl sulphate after the consumption of "non-alcoholic" beer.

In abstinence maintenance programs, for reissuing the driving licence and in workplace monitoring programs abstinence from ethanol and its proof are demanded. Various monitoring programs that mainly use ethyl glucuronide (EtG) as alcohol consumption marker have been established. To abstain from ethanol, but not from the taste of alcoholic beverages, in particular non-alcoholic beer has become more and more popular. In Germany, these "alcohol-free" beverages may still have an ethanol content of up to 0.5vol.% without the duty of declaration. Due to severe negative consequences resulting from positive EtG tests, a drinking experiment with 2.5L of non-alcoholic beer per person was performed to address the question of measurable concentrations of the direct metabolites EtG and EtS (ethyl sulphate) in urine and blood. Both alcohol consumption markers - determined by LC-MS/MS - were found in high concentrations: maximum concentrations in urine found in three volunteers were EtG 0.30-0.87mg/L and EtS 0.04-0.07mg/L, i.e., above the often applied cut-off value for the proof of abstinence of 0.1mg EtG/L. In the urine samples of one further volunteer, EtG and EtS concentrations cumulated over-night and reached up to 14.1mg/L EtG and 16.1mg/L EtS in the next morning's urine. Ethanol concentrations in blood and urine samples were negative (determined by HS-GC-FID and by an ADH-based method).

Secondary decline of cerebral autoregulation is associated with worse outcome after intracerebral hemorrhage.

PURPOSE: Blood pressure management in acute intracerebral hemorrhage (ICH) relies on functioning cerebral autoregulation. The time course of autoregulation in acute ICH and its relation with clinical outcome are not known. METHODS: Twenty-six patients with spontaneous ICH were studied on days 1, 3 and 5 after ictus. Autoregulation was noninvasively measured from spontaneous fluctuations of blood pressure and middle cerebral artery flow velocity (assessed by transcranial Doppler) using the correlation coefficient index Mx. From the same signals, non-invasive cerebral perfusion pressure was calculated. Results were compared with 55 healthy controls and related with clinical and radiological factors and 90-day outcome (modified Rankin scale). RESULTS: Average Mx values of all patients did not differ across days or from controls. Higher Mx (i.e., poorer autoregulation) on day 5 was significantly related with lower Glasgow coma score, ventricular hemorrhage (both sides) and lower noninvasive cerebral perfusion pressure (ipsilateral). Increasing ipsilateral Mx between days 3 and 5 was related with lower Glasgow coma score and ventricular hemorrhage. In a multivariate analysis controlling for other hemodynamic factors, higher ipsilateral Mx on day 5 (p = 0.013) was a significant predictor for poor 90-day outcome. CONCLUSIONS: Cerebral autoregulation is primarily preserved in acute ICH, but a secondary decline mainly ipsilateral to the ICH can occur. This is associated with poor clinical status, ventricular hemorrhage, lower cerebral perfusion pressure and worse clinical outcome.