Redistribution of Microcirculatory Blood Flow within the Intestinal Wall during Sepsis and General Anesthesia

2003 ◽  
Vol 98 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Luzius B. Hiltebrand ◽  
Vladimir Krejci ◽  
Marcus E. tenHoevel ◽  
Andrej Banic ◽  
Gisli H. Sigurdsson
Keyword(s):  
Septic Shock ◽  
Blood Flow ◽  
Cardiac Output ◽  
Superior Mesenteric Artery ◽  
Intestinal Mucosa ◽  
Mesenteric Artery ◽  
Colonic Mucosa ◽  
Intestinal Wall ◽  
Microcirculatory Blood Flow ◽  
Artery Flow

Background Hypoperfusion of the intestinal mucosa remains an important clinical problem during sepsis. Impairment of the autoregulation of microcirculatory blood flow in the intestinal tract has been suggested to play an important role in the development of multiple organ failure during sepsis and surgery. The authors studied microcirculatory blood flow in the gastrointestinal tract in anesthetized subjects during early septic shock. Methods Eighteen pigs were intravenously anesthetized and mechanically ventilated. Regional blood flow in the superior mesenteric artery was measured with ultrasound transit time flowmetry. Microcirculatory blood flow was continuously measured with a six-channel laser Doppler flowmetry system in the mucosa and the muscularis of the stomach, jejunum, and colon. Eleven pigs were assigned to the sepsis group, while seven animal served as sham controls. Sepsis was induced with fecal peritonitis, and intravenous fluids were administered after 240 min of sepsis to alter hypodynamic sepsis to hyperdynamic sepsis. Results In the control group, all monitored flow data remained stable throughout the study. During the hypodynamic phase of sepsis, cardiac output, superior mesenteric artery flow, and microcirculatory blood flow in the gastric mucosa decreased by 45%, 51%, and 40%, respectively, compared to baseline (P < 0.01 in all). Microcirculatory blood flow in the muscularis of the stomach, jejunum, and colon decreased by 55%, 64%, and 70%, respectively (P < 0.001 in all). In contrast, flow in the jejunal and colonic mucosa remained virtually unchanged. During the hyperdynamic phase of sepsis, there was a threefold increase in cardiac output and superior mesenteric artery flow. Blood flow in the gastric, jejunal, and colonic mucosa also increased (22%, 24%, and 31% above baseline, respectively). Flow in the muscularis of the stomach returned to baseline, while in the jejunum and colon, flow in the muscularis remained significantly below baseline (55% and 45%, respectively, P< 0.01). Conclusions It appears that in early septic shock, autoregulation of microcirculatory blood flow is largely intact in the intestinal mucosa in anesthetized pigs, explaining why microcirculatory blood flow remained virtually unchanged. This may be facilitated through redistribution of flow within the intestinal wall, from the muscularis toward the mucosa.

Effects of Dopamine, Dobutamine, and Dopexamine on Microcirculatory Blood Flow in the Gastrointestinal Tract during Sepsis and Anesthesia

2004 ◽  
Vol 100 (5) ◽  
pp. 1188-1197 ◽  
Author(s):  
Luzius B. Hiltebrand ◽  
Vladimir Krejci ◽  
Gisli H. Sigurdsson
Keyword(s):  
Septic Shock ◽  
Blood Flow ◽  
Gastrointestinal Tract ◽  
Cardiac Index ◽  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Inotropic Agents ◽  
Microcirculatory Blood Flow ◽  
Doppler Flowmetry ◽  
Artery Flow

Background Insufficient blood flow to the splanchnic organs is believed to be an important contributory factor for the development of organ failure after septic shock. It has been suggested that increasing systemic flow also may improve splanchnic blood flow in septic patients. The aim of this study was to compare the effects of three commonly used inotropic agents, dopamine, dobutamine, and dopexamine, on systemic (cardiac index), regional (superior mesenteric artery), and local (micro-circulatory) blood flow during septic shock in pigs. Methods Eight pigs were intravenously anesthetized, mechanically ventilated, and exposed to sepsis induced by fecal peritonitis. Cardiac index was measured with thermodilution, superior mesenteric artery flow was measured with ultrasound transit time flowmetry, and microcirculatory blood flow was continuously measured with a six-channel laser Doppler flowmetry in the gastric, jejunal, and colon mucosa as well as in the kidney, pancreas, and jejunal muscularis. Each animal received, in a random-order, crossover design, the three test drugs, one at a time: 5 and 10 microg x kg(-1) x min(-1) dopamine, 5 and 10 microg x kg(-1) x min(-1) dobutamine, and 1 and 2 microg x kg(-1) x min(-1) dopexamine. Administration of each drug at each dose continued for 30 min and was followed by a 40- to 60-min recovery period. A new baseline was taken before the next drug was administered. Results All three drugs significantly increased cardiac index; dopamine by 18%, dobutamine by 48%, and dopexamine by 35%, compared with baseline (P < 0.001 for each). At the same time, superior mesenteric artery flow increased by 33% (P < 0.01) with dopamine and 13% (P < 0.01) with dopexamine, whereas it did not change with dobutamine. Microcirculatory blood flow did not change significantly in any of the organs studied with any of the drugs tested. Conclusion All the inotropic agents markedly increased cardiac output in this sepsis model. However, increased systemic flow did not reach the microcirculation in the gastrointestinal tract. This may in part explain why some of the clinical trials, in which systemic oxygen delivery was deliberately increased by administration of inotropic drugs, have failed to improve survival in critically ill patients.

scholarly journals Effects of Vasopressin on Microcirculatory Blood Flow in the Gastrointestinal Tract in Anesthetized Pigs in Septic Shock

2007 ◽  
Vol 106 (6) ◽  
pp. 1156-1167 ◽  
Author(s):  
Luzius B. Hiltebrand ◽  
Vladimir Krejci ◽  
Stephan M. Jakob ◽  
Jukka Takala ◽  
Gisli H. Sigurdsson
Keyword(s):  
Septic Shock ◽  
Blood Flow ◽  
Gastrointestinal Tract ◽  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Jejunal Mucosa ◽  
Microcirculatory Blood Flow ◽  
Group V ◽  
Artery Flow ◽  
Upper Gastrointestinal

Background Vasopressin increases arterial pressure in septic shock even when alpha-adrenergic agonists fail. The authors studied the effects of vasopressin on microcirculatory blood flow in the entire gastrointestinal tract in anesthetized pigs during early septic shock. Methods Thirty-two pigs were intravenously anesthetized, mechanically ventilated, and randomly assigned to one of four groups (n=8 in each; full factorial design). Group S (sepsis) and group SV (sepsis-vasopressin) were made septic by fecal peritonitis. Group C and group V were nonseptic control groups. After 300 min, group V and group SV received intravenous infusion of 0.06 U.kg.h vasopressin. In all groups, cardiac index and superior mesenteric artery flow were measured. Microcirculatory blood flow was recorded with laser Doppler flowmetry in both mucosa and muscularis of the stomach, jejunum, and colon. Results While vasopressin significantly increased arterial pressure in group SV (P<0.05), superior mesenteric artery flow decreased by 51+/-16% (P<0.05). Systemic and mesenteric oxygen delivery and consumption decreased and oxygen extraction increased in the SV group. Effects on the microcirculation were very heterogeneous; flow decreased in the stomach mucosa (by 23+/-10%; P<0.05), in the stomach muscularis (by 48+/-16%; P<0.05), and in the jejunal mucosa (by 27+/-9%; P<0.05), whereas no significant changes were seen in the colon. Conclusion Vasopressin decreased regional flow in the superior mesenteric artery and microcirculatory blood flow in the upper gastrointestinal tract. This reduction in flow and a concomitant increase in the jejunal mucosa-to-arterial carbon dioxide gap suggest compromised mucosal blood flow in the upper gastrointestinal tract in septic pigs receiving low-dose vasopressin.

Effect of increased cardiac output on hepatic and intestinal microcirculatory blood flow, oxygenation, and metabolism in hyperdynamic murine septic shock

2005 ◽  
Vol 33 (10) ◽  
pp. 2332-2338 ◽  
Author(s):  
Gerd Albuszies ◽  
Peter Radermacher ◽  
Josef Vogt ◽  
Ulrich Wachter ◽  
Sandra Weber ◽  
...  
Keyword(s):  
Septic Shock ◽  
Blood Flow ◽  
Cardiac Output ◽  
Microcirculatory Blood Flow

Splanchnic haemodynamic changes during acute hypoglycaemia in man

1991 ◽  
Vol 81 (s25) ◽  
pp. 519-524 ◽  
Author(s):  
G. D. Braatvedt ◽  
P. G. Newrick ◽  
M. Halliwell ◽  
P. N. T. Wells ◽  
A. E. Read ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Blood Glucose Concentration ◽  
Peripheral Resistance ◽  
Artery Blood Flow ◽  
Ultrasound Technique ◽  
Haemodynamic Changes ◽  
Mesenteric Artery Blood Flow

1. Splanchnic haemodynamic changes were studied in seven healthy subjects during hypoglycaemia induced by the intravenous infusion of insulin. Superior mesenteric artery blood flow and cardiac output were examined non-invasively by a Doppler ultrasound technique. 2. Blood glucose concentration fell from 4.5 (0.14) mmol/l basally to 1.5 (0.09) mmol/l [mean (sem), P < 0.003] at the hypoglycaemic reaction (‘R’) and recovered to baseline by ‘R’ + 60 min. There was an associated rise in plasma glucagon, adrenaline and noradrenaline levels. 3. Superior mesenteric artery blood flow rose at ‘R’ from a basal value of 532 (38) ml/min to a peak of 803 (73) ml/min at ‘R’+10 min [mean (sem), P < 0.005] and remained significantly elevated until ‘R’ + 40 min. Resistance in this vessel fell by 33% at ‘R’+ 10 min (P < 0.005) and remained significantly low until ‘R’ + 40 min. 4. Cardiac output rose by 33% at ‘R’ (P < 0.004) and returned to normal by ‘R’ + 20 min. This was associated with a 24% rise in pulse rate (P 0.03), but no change in stroke volume or mean arterial pressure. Total peripheral resistance fell by 21% at ‘R’ (P 0.005) and had returned to normal by ‘R’ + 20 min. 5. The sustained rise in splanchnic blood flow during hypoglycaemic recovery may be of homoeostatic importance by providing metabolic fuel to the liver for gluconeogenesis.

Effects of small intestinal glucose load on blood pressure, splanchnic blood flow, glycemia, and GLP-1 release in healthy older subjects

2011 ◽  
Vol 300 (6) ◽  
pp. R1524-R1531 ◽  
Author(s):  
Lora Vanis ◽  
Diana Gentilcore ◽  
Christopher K. Rayner ◽  
Judith M. Wishart ◽  
Michael Horowitz ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Splanchnic Blood Flow ◽  
Glucose Load ◽  
Postprandial Hypotension ◽  
Older Subjects ◽  
Small Intestinal ◽  
Artery Flow

Postprandial hypotension is an important problem, particularly in the elderly. The fall in blood pressure is dependent on small intestinal glucose delivery and, possibly, changes in splanchnic blood flow, the release of glucagon-like peptide-1 (GLP-1), and sympathetic nerve activity. We aimed to determine in healthy older subjects, the effects of variations in small intestinal glucose load on blood pressure, superior mesenteric artery flow, GLP-1, and noradrenaline. Twelve subjects (6 male, 6 female; ages 65–76 yr) were studied on four separate occasions, in double-blind, randomized order. On each day, subjects were intubated via an anesthetized nostril, with a nasoduodenal catheter, and received an intraduodenal infusion of either saline (0.9%) or glucose at a rate of 1, 2, or 3 kcal/min (G1, G2, G3, respectively), for 60 min ( t = 0–60 min). Between t = 0 and 60 min, there were falls in systolic and diastolic blood pressure following G2 and G3 ( P = 0.003 and P < 0.001, respectively), but no change during saline or G1. Superior mesenteric artery flow increased slightly during G1 ( P = 0.01) and substantially during G2 ( P < 0.001) and G3 ( P < 0.001), but not during saline. The GLP-1 response to G3 was much greater ( P < 0.001) than to G2 and G1. Noradrenaline increased ( P < 0.05) only during G3. In conclusion, in healthy older subjects the duodenal glucose load needs to be > 1 kcal/min to elicit a significant fall in blood pressure, while the response may be maximal when the rate is 2 kcal/min. These observations have implications for the therapeutic strategies to manage postprandial hypotension by modulating gastric emptying.

scholarly journals The intensity of mesenterial blood flow and the degree of intestinal maturity in newborns at risk of necrotizing enterocolitis

2021 ◽  
Vol 16 (1) ◽  
pp. 27-32
Author(s):  
T.K. Znamenska ◽  
O.V. Vorobiоva ◽  
A.A. Vlasov
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Superior Mesenteric Artery ◽  
Necrotizing Enterocolitis ◽  
Vascular Resistance ◽  
Wall Thickness ◽  
Mesenteric Artery ◽  
Abdominal Ultrasound ◽  
Intestinal Wall ◽  
Premature Babies

Background. In recent years, the use of abdominal ultrasound for the diagnosis of necrotizing enterocolitis (NEC) in newborns has spread. At the initial stages of the disease, intestinal wall thickness, echogenicity and perfusion increase due to intestinal inflammation and mucosal edema. With the progression of NEC, thinning of the intestinal wall, lack of perfusion and peristalsis prevail and warn of the risk of intestinal perforation. This is the evidence of the diagnostic advantage of ultrasound in assessing the progression of NEC. The article presents some results of our own experience of using abdominal ultrasound to diagnose NEC in premature babies. The purpose was to assess the degree of intestinal maturity and the relationship between Doppler indices of intestinal perfusion and vascular resistance in the superior mesenteric arterial bed in premature newborns on day 1–5 of life who are at risk of developing NEC. Materials and methods. The authors examined 34 randomly selected premature babies with low and very low body weight and gestational age from 28 to 36 weeks who were born to mothers with complications of pregnancy. Maximum systolic velocity, end-diastolic velocity, and mean blood flow velocity were assessed at ≥ 5 consecutive heartbeats. Based on these indicators, the pulse index was calculated. Results. After the study on days 1–5 of life the newborns were divided retrospectively into groups depending on clinical diagnoses at the end of the early neonatal period. Babies born with severe asphyxia, with high vascular resistance in the superior mesenteric artery on day 1–5 of life, as well as with a bowel wall thickness of less than 1.6 mm, have an increased risk of developing NEC. Conclusions. The revealed high vascular resistance in the superior mesenteric artery on day 1–5 of life in premature infants with very low body weight and with a high risk of developing NEC will help make correct clinical decisions on ma­nagement and treatment, including the initiation of enteral nutrition and expanding its volume.

scholarly journals The use of pulse pressure variation for predicting impairment of microcirculatory blood flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christoph R. Behem ◽  
Michael F. Graessler ◽  
Till Friedheim ◽  
Rahel Kluttig ◽  
Hans O. Pinnschmidt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Reperfusion Injury ◽  
Pulse Pressure ◽  
Pulse Pressure Variation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Pressure Variation ◽  
Volume Loading ◽  
Microcirculatory Blood Flow

AbstractDynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg−1 bodyweight−1. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia–reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min−1) 1.68 (1.02–2.35) versus 2.84 (2.15–3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65–38.12) versus 52.34 (43.55–61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45–32.22) versus 9.59 (1.68–17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18–534.72) versus 327.21 (206.95–447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73–1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

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