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- Antonsson, J B, et al.
(author)
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Changes in gut intramucosal pH and gut oxygen extraction ratio in a porcine model of peritonitis and hemorrhage.
- 1995
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In: Critical Care Medicine. - : Ovid Technologies (Wolters Kluwer Health). - 0090-3493 .- 1530-0293. ; 23:11, s. 1872-81
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To establish the relationship between gut intramucosal pH and blood flow to the gut, gut oxygen delivery, and gut oxygen extraction ratio in a porcine model of peritonitis and hemorrhage.DESIGN: Prospective, controlled study.SETTING: Experimental laboratory in a university teaching hospital.SUBJECTS: Thirty pigs of both sexes, weighing 15 to 22 kg.INTERVENTIONS: Animals were anesthetized, intubated, and mechanically ventilated. A flow probe was placed around the superior mesenteric artery for registration of blood flow. A tonometer was placed in the lumen of midileum for calculation of gut intramucosal pH. Hourly, for 5 hrs, blood samples were taken from mixed venous, mesenteric venous, and arterial blood. Five animals served as controls, ten animals had peritonitis induced by fecal instillation in the abdominal cavity, five were bled stepwise, five were bled rapidly (to a mean arterial pressure of 30 mm Hg), and five were bled rapidly and reinfused after 3 hrs.MEASUREMENTS AND MAIN RESULTS: Both peritonitis and hemorrhage caused decreases in gut blood flow and intramucosal pH. In mild peritonitis, the intramucosal pH decrease preceded that of blood flow. In all experimental groups, oxygen delivery decreased over time; in both mild and severe peritonitis, this decrease was preceded by a decrease of intramucosal pH. Intramucosal pH correlated well with gut oxygen extraction ratio in peritonitis (r2 = .86). In hemorrhage, there was a correlation of r2 = .66, but in intramucosal pH of < 7.12, a further decrease was accompanied only by minor changes in extraction ratio.CONCLUSIONS: Since a reduction in blood flow was preceded by a decrease in intramucosal pH, low intramucosal pH in peritonitis cannot be explained by low flow alone. Gut oxygen delivery proved to be a poor indicator of gut acidosis (i.e., low intramucosal pH). In peritonitis, a decreasing intramucosal pH was associated with an increasing oxygen extraction ratio. In hemorrhage, this association had a sharp deflection point below which a further decrease in intramucosal pH occurred concomitantly with an unchanged gut oxygen extraction ratio. Increased extraction ratio was not sufficient, not even initially, to maintain aerobic metabolism (i.e., unchanged intramucosal pH).
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- Arctaedius, Isabelle, et al.
(author)
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2021 European Resuscitation Council/ European Society of Intensive Care Medicine Algorithm for Prognostication of Poor Neurological Outcome After Cardiac Arrest—Can Entry Criteria Be Broadened?
- 2024
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In: Critical Care Medicine. - 0090-3493. ; 52:4, s. 531-541
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To explore broadened entry criteria of the 2021 European Resuscitation Council/European Society of Intensive Care Medicine (ERC/ ESICM) algorithm for neuroprognostication including patients with ongoing sedation and Glasgow Coma Scale-Motor score (GCS-M) scores 4–5. DESIGN: Retrospective multicenter observational study. SETTING: Four ICUs, Skane, Sweden. PATIENTS: Postcardiac arrest patients managed at targeted temperature 36°C, 2014–2018. Neurologic outcome was assessed after 2–6 months according to the Cerebral Performance Category scale. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In 794 included patients, median age was 69.5 years (interquartile range, 60.6–77.0 yr), 241 (30.4%) were female, 550 (69.3%) had an out-of-hospital cardiac arrest, and 314 (41.3%) had a shockable rhythm. Four hundred ninety-five patients were dead at follow-up, 330 of 495 died after a decision on withdrawal of life-sustaining therapies. At 72 hours after cardiac arrest 218 patients remained unconscious. The entry criteria of the original algorithm (GCS-M 1–3) was fulfilled by 163 patients and 115 patients with poor outcome were identified, with false positive rate (FPR) of 0% (95% CI, 0–79.4%) and sensitivity of 71.0% (95% CI, 63.6–77.4%). Inclusion of patients with ongoing sedation identified another 13 patients with poor outcome, generating FPR of 0% (95% CI, 0–65.8%) and sensitivity of 69.6% (95% CI, 62.6–75.8%). Inclusion of all unconscious patients (GCS-M 1–5), regardless of sedation, identified one additional patient, generating FPR of 0% (95% CI, 0–22.8) and sensitivity of 62.9% (95% CI, 56.1–69.2). The few patients with true negative prediction (patients with good outcome not fulfilling guideline criteria of a poor outcome) generated wide 95% CI for FPR. CONCLUSION: The 2021 ERC/ESICM algorithm for neuroprognostication predicted poor neurologic outcome with a FPR of 0%. Broadening inclusion criteria to include all unconscious patients regardless of ongoing sedation identified an additional small number of patients with poor outcome but did not affect the FPR. Results are limited by high rate of withdrawal of life-sustaining therapies and few patients with true negative prediction.
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- Baker, Tim, et al.
(author)
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Single Deranged Physiologic Parameters Are Associated With Mortality in a Low-Income Country
- 2015
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In: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 43:10, s. 2171-2179
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Journal article (peer-reviewed)abstract
- Objective: To investigate whether deranged physiologic parameters at admission to an ICU in Tanzania are associated with in-hospital mortality and compare single deranged physiologic parameters to a more complex scoring system. Design: Prospective, observational cohort study of patient notes and admission records. Data were collected on vital signs at admission to the ICU, patient characteristics, and outcomes. Cutoffs for deranged physiologic parameters were defined a priori and their association with in-hospital mortality was analyzed using multivariable logistic regression. Setting: ICU at Muhimbili National Hospital, Dar es Salaam, Tanzania. Patients: All adults admitted to the ICU in a 15-month period. Measurements and Main Results: Two hundred sixty-nine patients were included: 54% female, median age 35 years. In-hospital mortality was 50%. At admission, 69% of patients had one or more deranged physiologic parameter. Sixty-four percent of the patients with a deranged physiologic parameter died in hospital compared with 18% without (p < 0.001). The presence of a deranged physiologic parameter was associated with mortality (adjusted odds ratio, 4.64; 95% CI, 1.95-11.09). Mortality increased with increasing number of deranged physiologic parameters (odds ratio per deranged physiologic parameter, 2.24 [1.53-3.26]). Every individual deranged physiologic parameter was associated with mortality with unadjusted odds ratios between 1.92 and 16.16. A National Early Warning Score of greater than or equal to 7 had an association with mortality (odds ratio, 2.51 [1.23-5.14]). Conclusion: Single deranged physiologic parameters at admission are associated with mortality in a critically ill population in a low-income country. As a measure of illness severity, single deranged physiologic parameters are as useful as a compound scoring system in this setting and could be termed danger signs. Danger signs may be suitable for the basis of routines to identify and treat critically ill patients.
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- Bassford, Christopher R., et al.
(author)
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U.K. Intensivists' Preferences for Patient Admission to ICU : Evidence From a Choice Experiment
- 2019
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In: Critical Care Medicine. - : Lippincott Williams & Wilkins. - 0090-3493 .- 1530-0293. ; 47:11, s. 1522-1530
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Deciding whether to admit a patient to the ICU requires considering several clinical and nonclinical factors. Studies have investigated factors associated with the decision but have not explored the relative importance of different factors, nor the interaction between factors on decision-making. We examined how ICU consultants prioritize specific factors when deciding whether to admit a patient to ICU.DESIGN: Informed by a literature review and data from observation and interviews with ICU clinicians, we designed a choice experiment. Senior intensive care doctors (consultants) were presented with pairs of patient profiles and asked to prioritize one of the patients in each task for admission to ICU. A multinomial logit and a latent class logit model was used for the data analyses.SETTING: Online survey across U.K. intensive care.SUBJECTS: Intensive care consultants working in NHS hospitals.MEASUREMENTS AND MAIN RESULTS: Of the factors investigated, patient's age had the largest impact at admission followed by the views of their family, and severity of their main comorbidity. Physiologic measures indicating severity of illness had less impact than the gestalt assessment by the ICU registrar. We identified four distinct decision-making patterns, defined by the relative importance given to different factors.CONCLUSIONS: ICU consultants vary in the importance they give to different factors in deciding who to prioritize for ICU admission. Transparency regarding which factors have been considered in the decision-making process could reduce variability and potential inequity for patients.
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- Berg, Sören, et al.
(author)
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Proinflammatory cytokines increase the rate of glycolysis and adenosine-5'-triphosphate turnover in cultured rat enterocytes
- 2003
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In: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 31:4, s. 1203-1212
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Journal article (peer-reviewed)abstract
- Objective: Measurements of steady-state adenosine-5'-triphosphate (ATP) levels in tissue samples from patients or experimental animals with sepsis or endotoxemia provide little information about the rate of ATP production and consumption in these conditions. Accordingly, we sought to use an in vitro "reductionist" model of sepsis to test the hypothesis that proinflammatory cytokines modulate ATP turnover rate. Design: In vitro "reductionist" model of sepsis. Setting: University laboratory. Subjects: Cultured rat enterocyte-like cells. Interventions: IEC-6 nontransformed rat enterocytes were studied under control conditions or following incubation for 24 or 48 hrs with cytomix, a mixture of tumor necrosis factor-a (10 ng/mL), interleukin-1ß (1 ng/mL), and interferon-? (1000 units/mL). To measure ATP turnover rate, ATP synthesis was acutely blocked by adding to the cells a mixture of 2-deoxyglucose (10 mM), potassium cyanide (8 mM), and antimycin A (1 µM). ATP content was measured at baseline (before metabolic inhibition) and 0.5, 1, 2, 5, and 10 mins later. Log-linear ATP decay curves were generated and the kinetics of ATP utilization thereby calculated. Measurements and Main Results: ATP consumption rate was higher in cytomix-stimulated compared with control cells (3.11 ± 1.39 vs. 1.25 ± 0.66 nmol/min, respectively, p < .01). Similarly, the half-time for ATP disappearance was shorter in cytomix-stimulated compared with control cells (2.63 ± 1.00 vs. 6.21 ± 3.49, p < .05). In contrast to these findings, the rate of ATP disappearance was similar in cytokine-naïve and immunostimulated IEC-6 cells when protein and nucleic acid synthesis were inhibited by adding 50 µg/mL cycloheximide and 5 µg/mL actinomycin D to cultures for 4 hrs. The rates of glucose consumption and lactate production were significantly greater in cytomix-stimulated compared with controls cells. Conclusions: Incubation of IEC-6 cells with cytomix significantly increased ATP turnover. Increased ATP turnover rate was supported by increases in the rate of anaerobic glycolysis. These findings support the view that proinflammatory mediators impose a metabolic demand on visceral cells. In sepsis, cells may be more susceptible to dysfunction on the basis of diminished oxygen delivery and/or mitochondrial dysfunction.
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- Borges, João Batista, et al.
(author)
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Early inflammation mainly affects normally and poorly aerated lung in experimental ventilator-induced lung injury
- 2014
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In: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 42:4, s. e279-e287
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Journal article (peer-reviewed)abstract
- OBJECTIVE: The common denominator in most forms of ventilator-induced lung injury is an intense inflammatory response mediated by neutrophils. PET with [F]fluoro-2-deoxy-D-glucose can be used to image cellular metabolism, which, during lung inflammatory processes, mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. The aim of this study was to assess the location and magnitude of lung inflammation using PET imaging of [F]fluoro-2-deoxy-D-glucose in a porcine experimental model of early acute respiratory distress syndrome.DESIGN: Prospective laboratory investigation.SETTING: A university animal research laboratory.SUBJECTS: Seven piglets submitted to experimental ventilator-induced lung injury and five healthy controls.INTERVENTIONS: Lung injury was induced by lung lavages and 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressure and high inspiratory pressures. All animals were subsequently studied with dynamic PET imaging of [F]fluoro-2-deoxy-D-glucose. CT scans were acquired at end expiration and end inspiration.MEASUREMENTS AND MAIN RESULTS: [F]fluoro-2-deoxy-D-glucose uptake rate was computed for the whole lung, four isogravitational regions, and regions grouping voxels with similar density. Global and intermediate gravitational zones [F]fluoro-2-deoxy-D-glucose uptakes were higher in ventilator-induced lung injury piglets compared with controls animals. Uptake of normally and poorly aerated regions was also higher in ventilator-induced lung injury piglets compared with control piglets, whereas regions suffering tidal recruitment or tidal hyperinflation had [F]fluoro-2-deoxy-D-glucose uptakes similar to controls.CONCLUSIONS: The present findings suggest that normally and poorly aerated regions-corresponding to intermediate gravitational zones-are the primary targets of the inflammatory process accompanying early experimental ventilator-induced lung injury. This may be attributed to the small volume of the aerated lung, which receives most of ventilation.
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