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Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic.

ABSTRACT: The rate of weaning of vasopressors drugs is usually an empirical choice made by the treating in critically ill patients. We applied fuzzy logic principles to modify intravenous norepinephrine (noradrenaline) infusion rates during norepinephrine infusion in septic patients in order to reduce the duration of shock.Septic patients were randomly assigned to norepinephrine infused either at the clinician's discretion (control group) or under closed-loop control based on fuzzy logic (fuzzy group). The infusion rate changed automatically after analysis of mean arterial pressure in the fuzzy group. The primary end-point was time to cessation of norepinephrine. The secondary end-points were 28-day survival, total amount of norepinephine infused and duration of mechanical ventilation.Nineteen patients were randomly assigned to fuzzy group and 20 to control group. Weaning of norepinephrine was achieved in 18 of the 20 control patients and in all 19 fuzzy group patients. Median (interquartile range) duration of shock was significantly shorter in the fuzzy group than in the control group (28.5 [20.5 to 42] hours versus 57.5 [43.7 to 117.5] hours; P < 0.0001). There was no significant difference in duration of mechanical ventilation or survival at 28 days between the two groups. The median (interquartile range) total amount of norepinephrine infused during shock was significantly lower in the fuzzy group than in the control group (0.6 [0.2 to 1.0] microg/kg versus 1.4 [0.6 to 2.7] microg/kg; P < 0.01).Our study has shown a reduction in norepinephrine weaning duration in septic patients enrolled in the fuzzy group. We attribute this reduction to fuzzy control of norepinephrine infusion.Trial registration: Clinicaltrials.gov NCT00763906.

SUBMITTER: Merouani M

PROVIDER: S-EPMC2646320 | biostudies-literature | 2008

REPOSITORIES: biostudies-literature

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Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic.

Merouani Mehdi M Guignard Bruno B Vincent François F Borron Stephen W SW Karoubi Philippe P Fosse Jean-Philippe JP Cohen Yves Y Clec'h Christophe C Vicaut Eric E Marbeuf-Gueye Carole C Lapostolle Frederic F Adnet Frederic F

Critical care (London, England) 20081209 6

<h4>Introduction</h4>The rate of weaning of vasopressors drugs is usually an empirical choice made by the treating in critically ill patients. We applied fuzzy logic principles to modify intravenous norepinephrine (noradrenaline) infusion rates during norepinephrine infusion in septic patients in order to reduce the duration of shock.<h4>Methods</h4>Septic patients were randomly assigned to norepinephrine infused either at the clinician's discretion (control group) or under closed-loop control b ...[more]

PMID: 19068113

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Project description:IntroductionMost experts recommend norepinephrine as the first-line agent in septic shock. Our objective was to determine the effectiveness and safety of norepinephrine in patients with septic shock.MethodsWe searched the Cochrane Central Register of Controlled Trials and Epistemonikos, as well as MEDLINE from 1966 till August 2019. Screening of full texts, evaluation for eligibility, and data extraction were done by four independent reviewers. We estimated risk ratios (RR) and mean differences (MD) using a random-effects model with 95% confidence intervals (CI). The primary outcomes included the number of participants who achieved the target mean arterial pressure (MAP), time to achieve the target MAP, and number of participants with all-cause 28-day mortality. The secondary outcomes included the length of stay in the intensive care unit, length of hospital stay, incidence of arrhythmia and myocardial infarction, vasopressor-free days, and number of participants with all-cause 90-day mortality.ResultsWe identified 11 randomized controlled trials with a total of 4,803 participants. There was no difference in the number of participants who achieved the target MAP between those patients receiving norepinephrine and other vasopressors (RR 1.44; 95% CI, 0.32 to 6.54; P = 0.640; I2 = 94%; two trials, 116 participants). There was no significant difference in time to achieve the target MAP (MD -0.05; 95%, CI, -0.32 to 0.21; P = 0.690; I2 = 26%; two trials, 1763 participants) and all-cause 28-day mortality (RR 0.95; 95% CI, 0.89 to 1.02; P = 0.160; I2 = 0%; seven trials, 4,139 participants). Regarding the secondary outcome, norepinephrine may significantly reduce the incidence of arrhythmia as compared to other vasopressors (RR 0.64; 95% CI, 0.42 to 0.97; P = 0.030; I2 = 64%; six trials, 3974 participants). There was no difference in the incidence of myocardial infarction (RR 1.28; 95% CI, 0.79 to 2.09), vasopressor-free day (RR 0.46; 95% CI, -1.82 to 2.74) and all-cause 90-day mortality (RR 1.08; 95% CI, 0.96 to 1.21) between norepinephrine and vasopressors.ConclusionIn minimizing the occurrence of an arrhythmia, norepinephrine is superior to other vasopressors, making it safe to be used in septic shock. However, there was insufficient evidence concerning mortality and achievement of the target MAP outcomes.

Project description:BackgroundClosed-loop resuscitation can improve personalization of care, decrease workload and bring expert knowledge in isolated areas. We have developed a new device to control the administration of fluid or simultaneous co-administration of fluid and norepinephrine using arterial pressure.MethodWe evaluated the performance of our prototype in a rodent model of haemorrhagic shock. After haemorrhagic shock, rats were randomized to five experimental groups: three were resuscitated with fluid and two with co-administration of fluid and norepinephrine. Among groups resuscitated with fluid, one was resuscitated by a physician and two were resuscitated according to two different closed-loop algorithms. Among groups resuscitated with fluid and norepinephrine, one was resuscitated by a physician and the other one by the closed-loop device. The precision of arterial pressure during the resuscitation period was assessed using rising time, time passed in the target area and performance error calculations.ResultsGroups resuscitated with fluid had similar performances and passed as much time in the target area of 80-90 mmHg as the manual group [manual: 76.8% (67.9-78.2), closed-loop: 64.6% (45.7-72.9) and 80.9% (59.1-85.3)]. Rats resuscitated with fluid and norepinephrine using closed-loop passed similar time in target area than manual group [closed-loop: 74.4% (58.4-84.5) vs. manual: 60.1% (46.1-72.4)] but had shorter rising time to reach target area [160 s (106-187) vs. 434 s (254-1081)] than those resuscitated by a physician. Rats resuscitated with co-administration of fluid and norepinephrine required less fluid and had less hemodilution than rats resuscitated with fluid alone. Lactate decrease was similar between groups resuscitated with fluid alone and fluid with norepinephrine.ConclusionsThis study assessed extensively the performances of several algorithms for closed-loop resuscitation of haemorrhagic shock with fluid alone and with co-administration of fluid and norepinephrine. The performance of the closed-loop algorithms tested was similar to physician-guided treatment with considerable saving of work for the caregiver. Arterial pressure closed-loop guided algorithms can be extended to combined administration of fluid and norepinephrine.

Project description:Background:Use of high-dose norepinephrine is thought to have an immunosuppressive action that increases mortality. This study aimed to evaluate the correlation between norepinephrine dosage and prognosis of patients with septic shock. Methods:This study was a nested cohort of the DExmedetomidine for Sepsis in Intensive Care Unit Randomized Evaluation (DESIRE) trial. We evaluated 112 patients with septic shock and an initial Sequential Organ Failure Assessment Cardiovascular (SOFA-C) category score >?2 and initial lactate level >?2 mmol/L. We divided the patients into two groups according to the norepinephrine dosage administered over the initial 7 days: high dose (??416 ?g/kg/week) (H group, n?=?56) and low dose (<?416 ?g/kg/week) (L group, n?=?56). The primary outcome of interest was 28-day mortality. Secondary outcomes were ventilator-free days, initial 24-h infusion volume, initial 24- to 48-h infusion volume, and the need for renal replacement therapy. For comparisons between the H group and L group, we used the chi-square test or Fisher's exact test for categorical variables and the t test or Wilcoxon rank sum test for continuous variables. For time-to-event outcomes, Cox proportional hazards models were used. Kaplan-Meier survival curves were created for graphical representation. Results:Patient characteristics appeared to be similar between the two groups except for the SOFA-C score and fibrinogen degradation product level. The cumulative incidence of death at 28 days was 29.9% (16 patients) in the L group and 29.7% (15 patients) in the H group (p?=?0.99). The median number of 28-day ventilator-free days was 20 (0, 25) in the L group and 16 (0, 22) in the H group (p?<?0.05). Initial infusion volume at 0-24 h in the H group was significantly higher than that in the L group (p?=?0.004). Infusion volume at 24-48 h in the H group was also significantly higher than that in the L group (p?=?0.03). Conclusions:No statistically significant difference was observed in 28-day mortality between patients with septic shock treated with high-dose norepinephrine compared with those treated with low-dose norepinephrine. However, the number of ventilator-free days in the L group was higher than that in the H group. Trial registration:clinicaltrials.gov Identifier: NCT01760967 Date of trial registration: January 4, 2013.

Project description:BACKGROUND:Optimal timing for the start of vasopressors (VP) in septic shock has not been widely studied since it is assumed that fluids must be administered in advance. We sought to evaluate whether a very early start of VP, even without completing the initial fluid loading, might impact clinical outcomes in septic shock. METHODS:A total of 337 patients with sepsis requiring VP support for at least 6 h were initially selected from a prospectively collected database in a 90-bed mixed-ICU during a 24-month period. They were classified into very-early (VE-VPs) or delayed vasopressor start (D-VPs) categories according to whether norepinephrine was initiated or not within/before the next hour of the first resuscitative fluid load. Then, VE-VPs (n = 93) patients were 1:1 propensity matched to D-VPs (n = 93) based on age; source of admission (emergency room, general wards, intensive care unit); chronic and acute comorbidities; and lactate, heart rate, systolic, and diastolic pressure at vasopressor start. A risk-adjusted Cox proportional hazard model was fitted to assess the association between VE-VPs and day 28 mortality. Finally, a sensitivity analysis was performed also including those patients requiring VP support for less than 6 h. RESULTS:Patients subjected to VE-VPs received significantly less resuscitation fluids at vasopressor starting (0[0-510] vs. 1500[650-2300] mL, p < 0.001) and during the first 8 h of resuscitation (1100[500-1900] vs. 2600[1600-3800] mL, p < 0.001), with no significant increase in acute renal failure and/or renal replacement therapy requirements. VE-VPs was related with significant lower net fluid balances 8 and 24 h after VPs. VE-VPs was also associated with a significant reduction in the risk of death compared to D-VPs (HR 0.31, CI95% 0.17-0.57, p < 0.001) at day 28. Such association was maintained after including patients receiving vasopressors for < 6 h. CONCLUSION:A very early start of vasopressor support seems to be safe, might limit the amount of fluids to resuscitate septic shock, and could lead to better clinical outcomes.

Project description:IntroductionThe present study was designed to determine the effects of continuously infused norepinephrine (NE) plus (1) terlipressin (TP) or (2) arginine vasopressin (AVP) or (3) placebo on sublingual microcirculation in septic shock patients. The primary study end point was a difference of ≥ 20% in the microvascular flow index of small vessels among groups.MethodsThe design of the study was a prospective, randomized, double-blind clinical trial. NE was titrated to maintain mean arterial pressure (MAP) between 65 and 75 mmHg after establishment of normovolemia in 60 septic shock patients. Thereafter patients (n = 20 per group) were randomized to receive continuous infusions of either TP (1 μg/kg/hour), AVP (0.04 U/minute) or placebo (isotonic saline). In all groups, open-label NE was adjusted to maintain MAP within threshold values if needed. The sublingual microcirculatory blood flow of small vessels was assessed by sidestream dark-field imaging. All measurements, including data from right heart catheterization and norepinephrine requirements, were obtained at baseline and 6 hours after randomization.ResultsTP and AVP decreased NE requirements at the end of the 6-hour study period. The data are medians (25th and 75th interquartile ranges (IQRs)): 0.57 μg/kg/minute (0.29 to 1.04) vs. 0.16 μg/kg/minute (0.03 to 0.37) for TP and 0.40 μg/kg/minute (0.20 to 1.05) vs. 0.23 μg/kg/minute (0.03 to 0.77) for AVP, with statistical significance of P < 0.05 vs. baseline and vs. placebo. There were no differences in sublingual microcirculatory variables, systemic hemodynamics, oxygen transport and acid-base homeostasis among the three study groups during the entire observation period. The proportions of perfused vessels increased in relation to baseline within all study groups, and there were no significant differences between groups. The specific data were as follows (median (IQR)): 9.7% (2.6 to 19.8) for TP, 8.9% (0.0 to 17.8) for AVP, and 6.9% (3.5 to 10.1) for placebo (P < 0.05 vs. baseline for each comparison), as well as perfused vessel density 18.6% (8.6 to 36.9) for TP, 20.2% (-3.0 to 37.2) for AVP, and 11.4% (-3.0 to 19.4) for placebo (P < 0.05 vs. baseline for each comparison).ConclusionsThe present study suggests that to achieve a MAP of 65 to 75 mmHg in septic patients treated with NE, the addition of continuously infused low-dose TP or AVP does not affect sublingual microcirculatory blood flow. In addition, our results suggest that microcirculatory flow abnormalities are mainly related to other factors (for example, volume status, timing, hemodynamics and progression of the disease) rather than to the vasopressor per se.Trial registrationClinicalTrial.gov NCT00995839.

Project description:BackgroundVasopressors are a cornerstone for the management of vasodilatory hypotension. Vasopressor infusions are currently adjusted manually to achieve a predefined arterial pressure target. We have developed a closed-loop vasopressor (CLV) controller to help correct hypotension more efficiently during the perioperative period. We tested the hypothesis that patients managed using such a system postcardiac surgery would present less hypotension compared to patients receiving standard management.MethodsA total of 40 patients admitted to the intensive care unit (ICU) after cardiac surgery were randomized into 2 groups for a 2-hour study period. In all patients, the objective was to maintain mean arterial pressure (MAP) between 65 and 75 mm Hg using norepinephrine. In the CLV group, the norepinephrine infusion was controlled via the CLV system; in the control group, it was adjusted manually by the ICU nurse. Fluid administration was standardized in both groups using an assisted fluid management system linked to an advanced hemodynamic monitoring system. The primary outcome was the percentage of time patients were hypotensive, defined as MAP <65 mm Hg, during the study period.ResultsOver the 2-hour study period, the percentage of time with hypotension was significantly lower in the CLV group than that in the control group (1.4% [0.9-2.3] vs 12.5% [9.9-24.3]; location difference, -9.8% [95% CI, -5.4 to -15.9]; P < .001). The percentage of time with MAP between 65 and 75 mm Hg was also greater in the CLV group (95% [89-96] vs 66% [59-77]; location difference, 27.6% [95% CI, 34.3-19.0]; P < .001). The percentage of time with an MAP >75 mm Hg (and norepinephrine still being infused) was also significantly lower in patients in the CLV group than that in the control group (3.2% [1.9-5.4] vs 20.6% [8.9-32.5]; location difference, -17% [95% CI, -10 to -24]; P < .001).The number of norepinephrine infusion rate modifications over the study period was greater in the CLV group than that in the control group (581 [548-597] vs 13 [11-14]; location difference, 568 [578-538]; P < .001). No adverse event occurred during the study period in both groups.ConclusionsClosed-loop control of norepinephrine infusion significantly decreases postoperative hypotension compared to manual control in patients admitted to the ICU after cardiac surgery.

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Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic.

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Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic.

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