title: Ascending arterial blood flow velocities during cardiac diastole in critical care patients--a characteristic flow pattern with a bad prognosis.
abstract: OBJECTIVE
  Pulsed Doppler ultrasound is a standard noninvasive investigation to measure the velocity and pulsatility of blood flow within the major intracranial and organ-supplying arteries in critical care patients. The normal arterial flow pattern in organ-supplying vessels is characterised by a systolic-diastolic forward flow which is caused by the aortic "Windkessel" function and the low peripheral resistance of the parenchymatous organs. A variety of well known pathological conditions may cause a change of the vascular characteristics within the perfused organs which are diagnosed by the typical changes of the flow pattern in the supplying arteries. In the cardiac diastole, however, there is always a slow decrease of the flow velocity which is terminated by the onset of the following systole.
  
  
  RESULTS
  We report on 11 patients investigated by Doppler ultrasound during their stay in our intensive care unit. All these patients presented a markedly different flow pattern measured in their intra- and/or extracerebral vessels. This very distinctive flow pattern is characterised by a diastolic ascent of the arterial flow velocity and is caused by an excessively increased venous pressure within the draining veins of the affected organs. All patients died due to (multiple) organ failure.
  
  
  CONCLUSIONS
  It is of major importance to be aware of the rare but very characteristic flow pattern described here because of the poor prognosis associated with it.
authors.affiliation: Hospital for Sick Children, Bayreuth, Germany. thomas.rupprecht@kinder.med.uni-erlangen.de
authors.forename: T
authors.initials: T
authors.lastname: Rupprecht
authors.forename: J
authors.initials: J
authors.lastname: Scharf
authors.forename: S
authors.initials: S
authors.lastname: Zink
authors.forename: M
authors.initials: M
authors.lastname: Wagner
mesh_terms: D001158:Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D001783:Blood Flow Velocity; D003422:Critical Care; D003971:Diastole / Q000502:physiology*; D004452:Echocardiography / Q000379:methods*; D006801:Humans; D018617:Ultrasonography, Doppler, Pulsed / Q000379:methods*