| 1. |
- Carlsson, Markus, et al.
(författare)
-
Inflammatory and circulatory effects of the reduction of endotoxin concentration in established porcine endotoxemic shock : a model of endotoxin elimination
- 2009
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 37:3, s. 1031-e4
-
Tidskriftsartikel (refereegranskat)abstract
- Objective:To study whether a reduction of the endotoxin load, once a generalized inflammatory state has been established, reduces the inflammatory response and endotoxin-induced effects on circulation, hypoperfusion, and organ dysfunction.Design:Prospective parallel-grouped placebo-controlled randomized interventional experimental study.Setting:University research unit.Subjects: Healthy pigs.Interventions:The animals were subjected to a continuous endotoxin infusion rate of either 4.0 or 0.063 µg endotoxin × kg-1 × h-1 for 1, 2, or 6 hours. The 1- and 2-hour infusion groups represented the applied therapy by a reduction of the endotoxin load of 5/6 and 2/3, respectively.Measurements and Main Results:During a 6-hour experiment, laboratory and physiologic parameters were recorded hourly in 26 anesthetized and mechanically ventilated pigs. Primary end point was to detect differences in tumor necrosis factor-[alpha] (TNF-[alpha]) concentration during the last 3 hours of the experiment. Despite the early reduction of the endotoxin load, no effect on TNF-[alpha] concentration was observed. Similarly, in circulatory parameters, such as mean arterial pressure and oxygen delivery, and in platelet count and renal function, no effects were noted. However, there was some improvement in pulmonary compliance and function as determined by Pao2, Paco2, and pH. These changes were associated with slight improvements in leukocyte response and capillary leakage.Conclusions:Termination of the endotoxin infusion represents an incontestable model of endotoxin concentration reduction. Endotoxin elimination strategies applied at the TNF-[alpha] peak or later will have very little or no effect on TNF-[alpha]–mediated toxicity. Nevertheless, there was an effect on the leukocyte response that was associated with an improvement in respiratory function and microcirculation, making it impossible to rule out fully the beneficial effect of this strategy. However, the effects were limited in relation to the magnitude of the endotoxin concentration reduction and the very early application of the antiendotoxin measure.
|
|
| 2. |
- Claesson, Jonas, et al.
(författare)
-
Negative mesenteric effects of lung recruitment maneuvers in oleic acid lung injury are transient and short lasting.
- 2007
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 35:1, s. 230-238
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To test the hypothesis that repeated recruitment maneuvers (RMs) have sustained negative effects on mesenteric circulation, metabolism, and oxygenation 60 mins after RMs in pigs with oleic acid lung injury. Further, we aimed to test the hypothesis that an infusion of prostacyclin (PC) at 33 ng.kg.min would attenuate such possible negative mesenteric effects. DESIGN: Randomized, experimental, controlled study. SETTING: University hospital animal laboratory. SUBJECTS: A total of 31 anesthetized, fluid-resuscitated pigs with oleic acid lung injury. INTERVENTIONS: Animals were randomized to one of the following four groups: a control group (n = 7) that received no intervention, recruitment group (n = 8) that underwent the RM sequence, a prostacyclin group (n = 8) that received an infusion of PC, and a recruitment-prostacyclin group (n = 8) that received an infusion of PC and concomitant RM sequence. MEASUREMENTS AND MAIN RESULTS: We measured systemic and mesenteric hemodynamic variables, jejunal mucosal perfusion, mesenteric lactate flux, jejunal tissue oxygen tension, and mesenteric oxygen delivery, uptake, and extraction ratio. Five minutes after RMs, mesenteric oxygen extraction ratio and mesenteric lactate flux were more prominently increased in the recruitment group, giving evidence of worsened mesenteric conditions after RMs. These signs of worsened conditions were further supported by more decreased jejunal tissue oxygen tension and portal vein oxygen saturation in the recruitment group. PC preserved mesenteric oxygenation, as indicated by less of a decrease in portal vein oxygen saturation at the time corresponding to 5 mins after RM and less of a decrease in mesenteric oxygen delivery at the time corresponding to 15 mins after RM. PC preserved mesenteric oxygenation as indicated by less of a decrease in portal vein oxygen saturation at 5 mins after RM and an attenuated increase in mesenteric oxygen extraction ratio at 5 mins after RM. There was a trend toward worsened jejunal mucosal perfusion, although not significant. CONCLUSIONS: In an oleic acid lung injury model, three repeated RMs did not improve systemic oxygenation or lung mechanics. Negative effects on mesenteric oxygenation and metabolism were transient and short lasting. The intestinal effects of PC during RMs were minor and opposing, showing preserved oxygenation but a trend toward worsened mucosal perfusion.
|
|
| 3. |
- Da, Jiping, et al.
(författare)
-
Nitric oxied up-regulates the glucocorticoid receptor and blunts the inflammatory reaction in porcine endotoxin sepsis
- 2007
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 35:1, s. 26-32
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Nitric oxide inhibits the expression of many genes involved in inflammatory diseases. Glucocorticoids inhibit similar transcription factors. We hypothesized that there may be an interaction between nitric oxide and glucocorticoids, with the potential to enhance the anti-inflammatory effect when administered simultaneously. Design: Prospective, randomized, controlled study. Setting: Animal research laboratory. Subjects: A total of 45 anesthetized and mechanically ventilated pigs. Interventions: Lung and systemic injury was induced by intravenous infusion of endotoxin (lipopolysaccharide) for 6 hrs. After 2.5 hrs, one group received 3.5 mg/kg hydrocortisone, another group inhaled nitric oxide (30 ppm), and still another group received both steroid and nitric oxide. Control groups of healthy and endotoxin-exposed piglets were also studied. Measurements and Main Results: Central hemodynamics and gas exchange were measured. Detection of the glucocorticoid receptor and inflammatory markers in lung, liver, and kidney tissue were made by immunohistochemistry, and morphology was studied with light microscopy. Endotoxin infusion markedly reduced glucocorticoid receptor expression in lung, liver, and kidney and up-regulated activator protein-1 and the inflammatory markers nuclear factor-κB and tumor necrosis factor-a. When administered separately, steroids and nitric oxide had modest effect on the inflammatory response. However, nitric oxide up-regulated the glucocorticoid receptor expression. Simultaneous administration of steroids and nitric oxide attenuated the inflammatory response and almost preserved or restored normal histology of both lung and systemic organs. When the glucocorticoid receptor was blocked by a receptor antagonist (mifepristone, 600 mg) and inhaled nitric oxide was subsequently administered, no increase in the expression of the glucocorticoid receptor was seen. Conclusion: We suggest that up-regulation of glucocorticoid receptor expression by nitric oxide made steroid therapy more effective.
|
|
| 4. |
- Gedeborg, Rolf, 1962-, et al.
(författare)
-
The impact of clinically undiagnosed injuries on survival estimates
- 2009
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 37:2, s. 449-55
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES:: Missed injury diagnoses may cause potentially preventable deaths. To estimate the effect of clinically undiagnosed injuries on injury-specific survival estimates and the accuracy of an injury severity score. To also estimate the potentially preventable mortality attributable to these injuries. DESIGN, SETTING, AND PATIENTS:: In a nation-wide, population-based study, data were collected from all hospital admissions for injuries in Sweden between 1998 and 2004. We studied 8627 deaths in hospital among 598,137 incident hospital admissions. MEASUREMENTS AND MAIN RESULTS:: New specific-injury categories were added in 7.4% (95% confidence interval [CI] 6.8-8.0) of all deaths with an autopsy rate of 24.2%. It was estimated that this proportion would have increased to 25.1% (95% CI 23.0-27.2), if all deaths had been autopsied. The most pronounced effect of clinically undiagnosed injuries was found for internal organ injury in the abdomen or pelvis, where they reduced the estimated survival from 0.83 to 0.69 (95% CI for the difference: 0.09-0.20). Autopsy diagnoses also revealed substantial bias of survival estimates for vascular injuries in the thorax and crush injuries to the head. The performance of the International Classification of Diseases Injury Severity Score improved when autopsy diagnoses were added to hospital discharge diagnoses. The maximum proportion of injury deaths attributable to missed injuries was estimated to be 6.5%. CONCLUSIONS:: Maintaining a high autopsy rate and merging accurate hospital discharge data and autopsy data are effective ways to improve the accuracy of survival estimates and mortality prediction models, and to estimate mortality attributable to diagnostic failures.
|
|
| 5. |
|
|
| 6. |
- Larsson, Lars
(författare)
-
Experimental animal models of muscle wasting in intensive care unit patients
- 2007
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 35:9, s. S484-S487
-
Tidskriftsartikel (refereegranskat)abstract
- The muscle wasting and loss of muscle function associated with critical illness and intensive care have significant negative consequences for weaning from the respirator, duration of hospital stay, and quality of life for long periods after hospital discharge. There is, accordingly, a significant demand for focused research aiming at improving our understanding of the mechanisms underlying the impaired neuromuscular function in intensive care unit (ICU) patients. However, the study of generalized muscle weakness in critically ill ICU patients is further complicated by the coexistence of multiple independent factors, such as different primary diseases, large variability in pharmacologic treatment, collection of muscle samples several weeks after admission to the ICU, and exposure to causative agents. This has led to the design of specific animal models mimicking ICU conditions. These models have often been used to study the mechanisms underlying the paralysis and muscle wasting associated with acute quadriplegic myopathy in ICU patients. This short review aims at presenting existing and recently introduced experimental animal models mimicking the conditions in the ICU (i.e., models designed to determine the mechanisms underlying the muscle wasting associated with ICU treatment).
|
|
| 7. |
- Lattuada, Marco, et al.
(författare)
-
Abdominal lymph flow in an endotoxin sepsis model : Influence of spontaneous breathing and mechanical ventilation
- 2006
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 34:11, s. 2792-2798
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Lymph flow from the abdomen was investigated in a sepsis model. We also compared the effect on thoracic duct lymph flow of mechanical ventilation with different levels of positive end-expiratory pressure (PEEP) and spontaneous breathing with continuous positive airway pressure (CPAP). DESIGN: Experimental study. SETTING: Research laboratory in a university hospital. SUBJECTS: Thirty-two pigs. INTERVENTIONS: Animals were anesthetized. In study 1 (n = 18), an ultrasonic flow probe was put around the intact thoracic duct just caudal to the diaphragm, and animals were randomized to receive mechanical ventilation with a PEEP of 5 cm H2O or 15 cm H2O or breathed spontaneously in CPAP with a PEEP of 5 cm H2O. In study 2 (n = 6), the thoracic duct was cannulated and the cannula externalized through the abdominal wall for lymph collection; animals were then ventilated as in study 1. In all animals, endotoxin was infused at 15 μg/kg/hr for 2.5 hrs and then continued at 5 μg/kg/hr. In study 3, healthy (n = 4) and endotoxin-exposed (n = 4) pigs had intra-abdominal pressure increased to 27 cm H2O for 2 hrs by pneumoperitoneum. Lymph flow was measured as in study 1. MEASUREMENTS AND MAIN RESULTS: Lymph flow (mean ± se) was 2.5 ± 0.4 mL/min at baseline and increased to 3.9 ± 0.8 mL/min after 90 mins and 6.3 ± 1.6 mL/min after 150 mins (p < .005) of endotoxin exposure. PEEP 15 cm H2O decreased lymph flow in pigs with intact thoracic duct (flow probe recording) and in pigs with cannulated lymph duct when drained against the central venous pressure. However, when drained against atmospheric pressure, PEEP increased flow. Spontaneous breathing increased flow both in intact and in cannulated animals. CONCLUSIONS: Endotoxin increases lymph flow from the abdomen. Mechanical ventilation with high PEEP impedes lymph drainage and could increase lymph production. Spontaneous breathing increases flow and improves drainage of abdominal edema.
|
|
| 8. |
- Lipcsey, Miklós, et al.
(författare)
-
Effect of a single dose of tobramycin on systemic inflammatory response-induced acute kidney injury in a 6-hour porcine model
- 2009
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 37:10, s. 2782-2790
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:To evaluate whether the addition of tobramycin further compromises renal function in inflammatory response-induced acute kidney injury. Effective antibiotic treatment in septic shock is crucial for the outcome. The combination of aminoglycosides with different beta-lactam antibiotics offers a broad antimicrobial coverage, rapid bacterial killing, synergistic effects, and low antibiotic-induced endotoxin release. However, aminoglycosides have nephrotoxic effects that may aggravate sepsis-induced acute kidney injury.DESIGN:Prospective, randomized, placebo-controlled experimental study.SETTING:University research unit.SUBJECTS:Twenty-four healthy pigs.INTERVENTIONS:The animals were anesthetized and randomized to four groups. Groups I (n = 8) and II (n = 8) received endotoxin infusion for 6 hrs, whereas groups III (n = 4) and IV (n = 4) received saline. Groups I and III received 7 mg/kg of tobramycin 20 mins after the initiation of the protocol, whereas groups II and IV received saline.MEASUREMENTS AND MAIN RESULTS:The renal elimination rate of a bolus dose of cefuroxime was chosen as the primary end point. Renal function was also evaluated by urine output, creatinine clearance, plasma cystatin C, plasma urea, and urine NAG (N-acetyl-beta-D-glucoaminidase). After 3 hrs, there were significantly lower cefuroxime elimination rates in the two endotoxin groups than in the nonendotoxin groups. No difference in cefuroxime elimination rates between groups I and II could be detected at any time point. Similarly, there were changes indicating acute kidney injury in urine output, creatinine clearance, and plasma cystatin C in the endotoxin groups with no differences between groups I and II. Plasma urea and urine NAG did not differ between any of the groups.CONCLUSIONS:The result of this study does not lend any support to the hypothesis that a single dose of tobramycin enhances the risk of acute renal failure in cases with systemic inflammatory response-induced acute kidney injury.
|
|
| 9. |
- Miclescu, Adriana, et al.
(författare)
-
Methylene blue added to a hypertonic-hyperoncotic solution increases short-term survival in experimental cardiac arrest
- 2006
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 34:11, s. 2806-2813
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Methylene blue (MB), a free-radical scavenger inhibiting the production and actions of nitric oxide, may counteract excessive vasodilatation induced by nitric oxide during cardiac arrest. Effects of MB in cardiac arrest and cardiopulmonary resuscitation were investigated. DESIGN: Randomized, prospective, laboratory animal study. SETTING: University animal research laboratory. SUBJECTS: A total of 63 piglets of both sexes. INTERVENTIONS: A pig model of extended cardiac arrest (12 mins of untreated cardiac arrest and 8 mins of cardiopulmonary resuscitation) was employed to assess the addition or no addition of MB to a hypertonic saline-dextran solution. These two groups (MB and hypertonic saline-dextran group [MB group] and hypertonic saline-dextran-only group) of 21 animals were each compared with a group receiving isotonic saline (n = 21). MEASUREMENTS AND MAIN RESULTS: Although the groups were similar in baseline values, 4-hr survival in the MB group was increased (p = .02) in comparison with the isotonic saline group. Hemodynamic variables were somewhat improved at 15 mins after restoration of spontaneous circulation in the MB group compared with the other two groups. The jugular bulb levels of 8-isoprostane-prostaglandin F2alpha and 15-keto-dihydro-prostaglandin F2alpha (indicators of peroxidation and inflammation) were significantly decreased in the MB group compared with the isotonic saline group. Significant differences were recorded between the three groups in levels of protein S-100beta (indicator of neurologic injury), with lower levels in the MB group compared with the isotonic saline and hypertonic saline-dextran-only groups. Troponin I and myocardial muscle creatine kinase isoenzyme arterial concentrations (indicators of myocardial damage) were also significantly lower in the MB group. CONCLUSIONS: MB co-administered with a hypertonic-hyperoncotic solution increased 4-hr survival vs. saline in an experimental porcine model of cardiac arrest and reduced oxidative, inflammatory, myocardial, and neurologic injury.
|
|
| 10. |
- Olofsson, Pia, et al.
(författare)
-
Gastrointestinal microcirculation and cardiopulmonary function during experimentally increased intra-abdominal pressure
- 2009
-
Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 37:1, s. 230-239
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to assess gastric, intestinal, and renal cortex microcirculation parallel with central hemodynamics and respiratory function during stepwise increase of intra-abdominal pressure (IAP). Design: Prospective, controlled animal study. Setting: Research laboratory, University Hospital. Subjects: Twenty-six anesthetized and mechanically ventilated pigs. Interventions: Following baseline registrations, CO2 peritoneum was inflated (n = 20) and IAP increased stepwise by 10 mm Hg at 10 mins intervals up to 50 mm Hg and subsequently exsufflated. Control animals (n = 6) were not insufflated with CO2. Measurements and Main Results: The microcirculation of gastric mucosa, small bowel mucosa, small bowel seromuscular layer, colon mucosa, colon seromuscular layer, and renal cortex were selectively studied at all pressure levels and after exsufflation using a four-channel laser Doppler flowmeter (Periflex 5000, Perimed). Central hemodynamic and respiratory function data were registered at each level and after exsufflation. Cardiac output decreased significantly at IAP levels above 10 mm Hg. The microcirculation of gastric mucosa, renal cortex and the seromuscular layer of small bowel and colon was significantly reduced with each increase of IAP. The microcirculation of the small bowel mucosa and colon mucosa was significantly less affected compared with the serosa (p < 0.01). Conclusions: Our animal model of low and high IAP by intraperitoneal CO2-insufflation worked well for studies of microcirculation, hemodynamics, and pulmonary function. During stepwise increases of pressure there were marked effects on global hemodynamics, respiratory function, and microcirculation. The results indicate that intestinal mucosal flow, especially small bowel mucosal flow, although reduced, seems better preserved in response to intra-abdominal hypertension caused by CO2-insufflation than other intra-abdominal microvascular beds.
|
|
