BACKGROUND Hypercapnia abolishes cerebral autoregulation, but little is known about the interaction between hypercapnia and autoregulation during general anesthesia. With normocapnia, sevoflurane (up to 1.5 minimum alveolar concentration) and propofol do not impair cerebral autoregulation. This study aimed to document the level of hypercapnia required to impair cerebral autoregulation during pr...

OBJECTIVE The aims of this study were to document the incidence of impaired cerebral autoregulation in children with traumatic brain injury using transcranial Doppler ultrasonography and to examine the relationship between autoregulatory capacity and outcome in children following traumatic brain injury. DESIGN Prospective cohort study. SETTING Harborview Medical Center (level I pediatric tr...

Experiments were designed to separate effects of myocardial oxygen tension and oxygen consumption on coronary autoregulation. The approach was to measure coronary hemodynamic and metabolic responses to decreases in perfusion pressure during interventions that altered the balance between myocardial oxygen supply and demand. Studies were conducted in anesthetized heart-blocked dogs with the left ...

Cupples WA, Braam B. Assessment of renal autoregulation. Am J Physiol Renal Physiol 292: F1105–F1123, 2007. First published January 16, 2007; doi:10.1152/ajprenal.00194.2006.—The kidney displays highly efficient autoregulation so that under steady-state conditions renal blood flow (RBF) is independent of blood pressure over a wide range of pressure. Autoregulation occurs in the preglomerular mi...

PURPOSE OF REVIEW This review will examine the recent literature on anesthesia and monitoring techniques in relation to cerebral autoregulation. We will discuss the effect of physiologic and pharmacological factors on cerebral autoregulation alongside its clinical relevance with the help of new evidence. RECENT FINDINGS Intravenous anesthesia, such as combination of propofol and remifentanil,...

BACKGROUND AND PURPOSE Cerebral autoregulation can be evaluated by measuring relative blood flow changes in response to a steady-state change in the blood pressure (static method) or during the response to a rapid change in blood pressure (dynamic method). The purpose of this study was to compare the results of the two methods in humans with both intact and impaired autoregulatory capacity. M...

The kidney displays highly efficient autoregulation so that under steady-state conditions renal blood flow (RBF) is independent of blood pressure over a wide range of pressure. Autoregulation occurs in the preglomerular microcirculation and is mediated by two, perhaps three, mechanisms. The faster myogenic mechanism and the slower tubuloglomerular feedback contribute both directly and interacti...

BACKGROUND AND PURPOSE Orthostatic intolerance and falls differ between sexes and change with age. However, it remains unclear what role cerebral autoregulation may play in this response. This study was designed to determine whether cerebral autoregulation, assessed using transcranial Doppler ultrasound, is more effective in elderly females than in males. METHODS We used transcranial Doppler ...

A mathematical model of cerebral blood flow in the form a dynamical system is studied. The autoregulation modeling problem treated as nonlinear control and potential applicability theory techniques are analyzed this respect. It shown that hemodynamics question differentially flat. Then, integrator backstepping approach combined with barrier Lyapunov functions applied to construct laws recover p...

Cerebral autoregulation is impaired in Himalayan high-altitude residents who live above 4,200 m. This study was undertaken to determine the altitude at which this impairment of autoregulation occurs. A second aim of the study was to test the hypothesis that administration of oxygen can reverse this impairment in autoregulation at high altitudes. In four groups of 10 Himalayan high-altitude dwel...