| 1. |
- Borges, João Batista, et al.
(författare)
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Early inflammation mainly affects normally and poorly aerated lung in experimental ventilator-induced lung injury
- 2014
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 42:4, s. e279-e287
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Brauer, Kirk I, et al.
(författare)
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Hypoproteinemia does not alter plasma volume expansion in response to a 0.9% saline bolus in awake sheep
- 2010
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Ingår i: CRITICAL CARE MEDICINE. - : Williams and Wilkins. - 0090-3493 .- 1530-0293. ; 38:10, s. 2011-2015
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To test the hypothesis that hypoproteinemia reduces plasma volume expansion produced by a bolus of crystalloid solution given to awake sheep. Design: Prospective and observational. Setting: Laboratory. Subjects: Five female merino sheep (n = 5) weighing 37 +/- 3 kg were anesthetized. Interventions: Each animal was subjected to a 5-day test period: day 1: 50 mL/min 0.9% saline infusion over 20 mins. Days 2-4: daily plasmapheresis and replacement of the shed plasma with 6 L of 0.9% saline were performed in increments. Measurements and Main Results: Fractional plasma volume expansion after rapid infusion of saline on days 1 and 5 was calculated from changes in hemoglobin concentration. There was a significant reduction in total plasma protein concentration after plasmapheresis (p andlt; .05). Colloid osmotic pressures were also significantly lowered (p andlt; .05). A crystalloid infusion of 0.9% saline did not alter any of these values compared with baseline. The hemodynamic measurements did not show significant differences between the experiments. The plasma volume expansion reached approximately 20% at the end of infusion and stayed at 10-15% during the experiments. No difference was found in plasma volume expansion produced by a bolus of 50 mL/min of 0.9% in the hypoproteinemic state when compared with the euproteinemic state (p = .61). No difference in cumulative urinary output was found between the two states. Conclusions: In contrast to our hypothesis, severe acute hypoproteinemia does not reduce plasma volume expansion in response to 50 mL/min 0.9% saline infusion in nonspleenectomized sheep when compared with the resultant plasma volume expansion after a 50 mL/min of 0.9% infusion in the euproteinemic state.
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| 3. |
- Dankiewicz, Josef, et al.
(författare)
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Safety, Feasibility, and Outcomes of Induced Hypothermia Therapy Following In-Hospital Cardiac Arrest-Evaluation of a Large Prospective Registry
- 2014
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 42:12, s. 2537-2545
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Despite a lack of randomized trials, practice guidelines recommend that mild induced hypothermia be considered for comatose survivors of in-hospital cardiac arrest. This study describes the safety, feasibility, and outcomes of mild induced hypothermia treatment following in-hospital cardiac arrest. Design: Prospective, observational, registry-based study. Setting: Forty-six critical care facilities in eight countries in Europe and the United States reporting in the Hypothermia Network Registry and the International Cardiac Arrest Registry. Patients: A total of 663 patients with in-hospital cardiac arrest and treated with mild induced hypothermia were included between January 2004 and February 2012. Interventions: None. Measurements and Main Results: A cerebral performance category of 1 or 2 was considered a good outcome. At hospital discharge 41% of patients had a good outcome. At median 6-month follow-up, 34% had a good outcome. Among in-hospital deaths, 52% were of cardiac causes and 44% of cerebral cause. A higher initial body temperature was associated with reduced odds of a good outcome (odds ratio, 0.79; 95% CI, 0.68-0.92). Adverse events were common; bleeding requiring transfusion (odds ratio, 0.56; 95% CI, 0.31-1.00) and sepsis (odds ratio, 0.52; 95% CI, 0.30-0.91) were associated with reduced odds for a good outcome. Conclusions: In this registry study of an in-hospital cardiac arrest population treated with mild induced hypothermia, we found a 41% good outcome at hospital discharge and 34% at follow-up. Infectious complications occurred in 43% of cases, and 11% of patients required a transfusion for bleeding. The majority of deaths were of cardiac origin.
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| 4. |
- Derde, Sarah, et al.
(författare)
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Increasing intravenous glucose load in the presence of normoglycemia : Effect on outcome and metabolism in critically ill rabbits
- 2010
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 38:2, s. 602-611
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Endocrine disturbances and a feeding-resistant wasting syndrome, characterized by a negative protein balance, promote delayed recovery and poor outcome of critical illness. Parenteral nutrition alone cannot counteract the hypercatabolic state, possibly in part as a result of aggravation of the hyperglycemic response to illness. In critically ill rabbits, we investigated the impact of varying amounts of intravenous glucose while maintaining normoglycemia on mortality, organ damage, and markers of catabolism/anabolism. Design: Prospective, randomized laboratory investigation. Setting: University animal and molecular laboratory. Subjects: Three-month-old male rabbits. Interventions: Critically ill rabbits were randomized into a fasting group, a standard parenteral nutrition group, and two groups receiving either intermediate or high additional physiological amounts of intravenous glucose while maintained normoglycemic with insulin. These groups were compared with a hyperglycemic group and healthy rabbits. Protein and lipid load was equal for all fed groups. Measurements and Main Results: Varying intravenous glucose load did not affect mortality or organ damage provided hyperglycemia was prevented. Fasted critically ill rabbits lost weight, which was attenuated by increasing intravenous glucose load. As compared with healthy rabbits, mRNA expression and/or activity of several ubiquitin-proteasome pathway components, cathepsin-L and calpain-1, was elevated in skeletal muscle of fasted critically ill rabbits. Intravenous feeding was able to counteract this response. Excessive glucose load and/or hyperglycemia, however, reduced the protective effect of feeding. Genes investigated in the diaphragm and myocardium revealed roughly a similar response. Except in the normoglycemic group with intermediate glucose load, circulating thyroid hormone and insulin-like growth factor-1 levels decreased, most pronounced in hyperglycemic rabbits. Conclusions: Increasing intravenous glucose infusion within the physiological range, while maintaining normoglycemia, was safe for organ function and survival of critically ill rabbits. Concomitantly, it reduced the catabolic responses as compared with fasting. Whether this has a beneficial effect on muscle function and mass remains to be investigated.
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| 5. |
- Derde, Sarah, et al.
(författare)
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Muscle atrophy and preferential loss of myosin in prolonged critically ill patients
- 2012
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 40:1, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Muscle weakness contributes to prolonged rehabilitation and adverse outcome of critically ill patients. Distinction between a neurogenic and/or myogenic underlying problem is difficult using routine diagnostic tools. Preferential loss of myosin has been suggested to point to a myogenic component. We evaluated markers of muscle atrophy and denervation, and the myosin/actin ratio in limb and abdominal wall skeletal muscle, of prolonged critically ill patients and matched controls in relation to insulin therapy and known risk factors for intensive care unit-acquired weakness. DESIGN: Secondary analysis of two large, prospective, single-center randomized clinical studies. SETTING: University hospital surgical and medical intensive care unit. PATIENTS: Critically ill patients and matched controls. INTERVENTIONS: Intensive care unit patients had been randomized to blood glucose control to 80-110 mg/dL with insulin infusion or conventional glucose management, where insulin was only administered when glucose levels rose above 215 mg/dL. MEASUREMENTS AND MAIN RESULTS: As compared with controls, rectus abdominis and vastus lateralis muscle of critically ill patients showed smaller myofiber size, decreased mRNA levels for myofibrillar proteins, increased proteolytic enzyme activities, and a lower myosin/actin ratio, virtually irrespective of insulin therapy. Increased forkhead box protein O1 action may have played a role. Most alterations were more severe in patients treated with corticosteroids. Duration of corticosteroid treatment, independent of duration of intensive care unit stay or other risk factors, was a dominant risk factor for a low myosin/actin ratio. The immature acetylcholine receptor subunit γ mRNA expression was elevated in vastus lateralis, independent of the myosin/actin ratio. CONCLUSIONS: Both limb and abdominal wall skeletal muscles of prolonged critically ill patients showed downregulation of protein synthesis at the gene expression level as well as increased proteolysis. This affected myosin to a greater extent than actin, resulting in a decreased myosin/actin ratio. Muscle atrophy was not ameliorated by intensive insulin therapy, but possibly aggravated by corticosteroids.
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| 6. |
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| 7. |
- Lennmyr, Fredrik, et al.
(författare)
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Cerebral effects of hyperglycemia in experimental cardiac arrest
- 2010
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 38:8, s. 1726-1732
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the effects of cardiac arrest on cerebral perfusion and oxidative stress during hyperglycemia and normoglycemia. Design: Experimental animal model. Setting: University laboratory. Subjects: Triple-breed pigs (weight, 22-27 kg). Interventions: Thirty-three pigs were randomized and clamped at blood glucose levels of 8.5-10 mM (high) or 4-5.5 mM (normal) and thereafter subjected to alternating current-induced 12-min cardiac arrest followed by 8 mins of cardiopulmonary resuscitation and direct-current shock to restore spontaneous circulation. Measurements and Main Results: Hemodynamics, regional near-infrared light spectroscopy, regional venous HbO(2), and biochemical markers (Protein S100 beta, troponin I, F-2-isoprostanes reflecting oxidative stress and inflammation) were monitored and/or sampled throughout an observation period of 4 hrs. No significant differences were seen in hemodynamics or biochemical profile. The cerebral oxygenation by means of regional near-infrared light spectroscopy was higher in the hyperglycemic (H) than in the normal (N) group after restoration of spontaneous circulation (p < .05). However, tendencies toward increased protein S100 beta and 15-keto-dihydro-prostaglandin F-2 alpha were observed in the H group but were not statistically significant. Conclusions: The responses to 12-min cardiac arrest and cardiopulmonary resuscitation share large similarities during hyperglycemia and normoglycemia. The higher cerebral tissue oxygenation observed in the hyperglycemia needs to be confirmed and the phenomenon needs to be addressed in future studies.
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| 8. |
- Miclescu, Adriana, et al.
(författare)
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Methylene blue protects the cortical blood-brain barrier against ischemia/reperfusion-induced disruptions
- 2010
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 38:11, s. 2199-2206
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the effects of cardiac arrest and the reperfusion syndrome on blood-brain barrier permeability and evaluate whether methylene blue counteracts blood-brain barrier disruption in a pig model of controlled cardiopulmonary resuscitation. Design: Randomized, prospective, laboratory animal study. Setting: University-affiliated research laboratory. Subjects: Forty-five piglets. Interventions: Forty-five anesthetized piglets were subjected to cardiac arrest alone or 12-min cardiac arrest followed by 8 mins cardiopulmonary resuscitation. The first group (n = 16) was used to evaluate blood-brain barrier disruptions after untreated cerebral ischemia after 0, 15, or 30 mins after untreated cardiac arrest. The other two groups received either an infusion of saline (n = 10) or infusion of saline with methylene blue (n = 12) 1 min after the start of cardiopulmonary resuscitation and continued 50 mins after return of spontaneous circulation. In these groups, brains were removed for immunohistological analyses at 30, 60, and 180 mins after return of spontaneous circulation. Measurements and Main Results: An increase of injured neurons and albumin immunoreactivity was demonstrated with in-creasing duration of ischemia/reperfusion. Less blood-brain barrier disruption was observed in subjects receiving methylene blue as demonstrated by decreased albumin leakage (p<.01), water content (p<.05), and neuronal injury (p<.01). Methylene blue treatment reduced cerebral tissue nitrite/nitrate content (p<.05) and the number of inducible and neuronal nitric oxide synthase-activated cortical cells during administration (p<.01). Meanwhile, the number of cortical endothelial nitric oxide synthase-activated cells increased over time (p<.001). Conclusion: Cerebral tissue water content, blood-brain barrier permeability and neurologic injury were increased early in reperfusion after cardiac arrest. Methylene blue exerted neuroprotective effects against the brain damage associated with the ischemia/reperfusion injury and ameliorated the blood-brain barrier disruption by decreasing nitric oxide metabolites. (Crit Care Med 2010; 38: 2199-2206)
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| 9. |
- Nielsen, Niklas, et al.
(författare)
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Adverse events and their relation to mortality in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia
- 2011
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 39:1, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the association between adverse events recorded during critical care and mortality in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia. Design: Prospective, observational, registry-based study. Setting: Twenty-two hospitals in Europe and the United States. Patients: Between October 2004 and October 2008, 765 patients were included. Interventions: None. Measurements and Main Results: Arrhythmias (7%-14%), pneumonia (48%), metabolic and electrolyte disorders (5%-37%), and seizures (24%) were common adverse events in the critical care period in cardiac arrest patients treated with therapeutic hypothermia, whereas sepsis (4%) and bleeding (6%) were less frequent. Sustained hyperglycemia (blood glucose >8 mmol/L for >4 hrs; odds ratio 2.3, 95% confidence interval 1.6-3.6, p < .001) and seizures treated with anticonvulsants (odds ratio 4.8, 95% confidence interval 2.9-8.1, p < .001) were associated with increased mortality in a multivariate model. An increased frequency of bleeding and sepsis occurred after invasive procedures (coronary angiography, intravascular devices for cooling, intra-aortic balloon pump), but bleeding and sepsis were not associated with increased mortality (odds ratio 1.0, 95% confidence interval 0.46-2.2, p = .91, and odds ratio 0.30, 95% confidence interval 0.12-0.79, p = .01, respectively). Conclusions: Adverse events were common after out-of-hospital cardiac arrest. Sustained hyperglycemia and seizures treated with anticonvulsants were associated with increased mortality. Bleeding and infection were more common after invasive procedures, but these adverse events were not associated with increased mortality in our study.
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| 10. |
- Nilsson, Manja C, et al.
(författare)
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Distant effects of nitric oxide inhalation in endotoxemic pigs
- 2010
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 38:1, s. 242-248
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Inhalation of nitric oxide (INO) has distant effects. By a blood- borne factor, INO down-regulates endogenous nitric oxide production in healthy pig lungs, resulting in vasoconstriction in lung regions not directly reached by INO. The aim of this study was to investigate whether INO has distant effects in endotoxemic pig lungs. The hypothesis was that INO down-regulates endogenous NO production in lung regions not reached by INO. DESIGN: Prospective, randomized animal study. SETTING: University hospital research laboratory. SUBJECTS: Twenty-two pairs of domestic pigs. INTERVENTIONS: Cross-circulation was established in 22 pairs of anesthetized pigs. Nine pairs received endotoxin (control group) and 13 pairs received endotoxin, with one pig inhaling NO (80 ppm) and one pig receiving blood from that pig (NO-blood recipient group). MEASUREMENTS AND MAIN RESULTS: NO in exhaled air, NO synthase activity in lung tissue, endothelin-1 in the blood, ETA and ETB receptor immunoreactivity in lung tissue, vital parameters, and blood gases were measured. Endotoxin per se increased NO in exhaled air by 100% compared to baseline (control group). In the NO-blood recipient group, i.e., pigs receiving blood from the NO-inhaling pigs, NO in exhaled air increased by 300% (p = .03). The Ca-dependent NO synthase activity was higher in these pigs (p = .02), indicating increased endogenous NO production. The ET B receptor immunoreactivity was higher in the NO-blood recipient group (p = .004). CONCLUSIONS: As opposed to findings in healthy pigs, INO in endotoxemic pigs causes an increase in endogenous NO production in lung regions not reached by INO. Increased NO production in nonventilated lung regions may cause vasodilatation, counteracting the INO-induced increase in blood flow to the ventilated lung regions.
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