Detailed Instructions: Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
Problem:The microcirculation supplies oxygen (O2) and nutrients to all cells with the red blood cell (RBC) acting as both a deliverer and sensor of O2. In sepsis, a proinflammatory disease with microvascular complications, small blood vessel alterations are associated with multi-organ dysfunction and poor septic patient outcome. We hypothesized that microvascular autoregulation-existing at three levels: over the entire capillary network, within a capillary and within the erythrocyte-was impaired during onset of sepsis. This study had three objectives: 1) measure capillary response time within hypoxic capillaries, 2) test the null hypothesis that RBC O2-dependent adenosine triphosphate (ATP) efflux was not altered by sepsis and 3) develop a framework of a pathophysiological model.', 'This was an animal study, comparing sepsis with control, set in a university laboratory. Acute hypotensive sepsis was studied using cecal ligation and perforation (CLP) with a 6-hour end-point. Rat hindlimb skeletal muscle microcirculation was imaged, and capillary RBC supply rate (SR=RBC/s), RBC hemoglobin O2 saturation (SO2) and O2 supply rate (qO2=pLO2/s) were quantified. Arterial NOx (nitrite+nitrate) and RBC O2-dependent ATP efflux were measured using a nitric oxide (NO) analyzer and gas exchanger, respectively.', "Sepsis increased capillary stopped-flow (p=0.001) and increased plasma lactate (p<0.001). Increased plasma NOx (p<0.001) was related to increased capillary RBC supply rate (p=0.027). Analysis of 30-second SR-SO2-qO2 profiles revealed a shift towards decreased (p<0.05) O2 supply rates in some capillaries. Moreover, we detected a three- to fourfold increase (p<0.05) in capillary response time within hypoxic capillaries (capillary flow states where RBC SO2<20%). Additionally, sepsis decreased the erythrocyte's ability to respond to hypoxic environments, as normalized RBC O2-dependent ATP efflux decreased by 62.5% (p<0.001).
Solution:
Does sepsis impair microvascular autoregulation and delays capillary response within hypoxic capillaries?