摘要:

ObjectiveWe compared tracheobronchial injury following short-term intratracheal pulmonary ventilation (ITPV) and conventional mechanical ventilation (CMV) in a healthy rabbit model. ITPV, a form of tracheal gas insufflation, has been shown to decrease deadspace ventilation and increase CO2removal and therefore may reduce ventilator-induced lung injury.SettingMedical center laboratory.SubjectsTwenty-five rabbits.InterventionsRabbits were randomly assigned to either ITPV or CMV (n = 15 and 10, respectively). Both groups were mechanically ventilated for 8 hrs at the same ventilator settings (Fio2, 0.4; rate, 30 breaths/min; flow, 4 L·min−1; positive end-expiratory pressure, 4 cm H2O; tidal volume, 40 mL). Peak, mean, and end-expiratory carinal pressures, ITPV flow rate, and hemodynamic variables were continuously monitored. Tissue samples for histologic analysis were obtained postmortem from the trachea contiguous to the tip of the endotracheal tube, the distal trachea, the carina, and the main bronchus. The histologic sections were scored, in a single-blind fashion, for ciliary damage, ulceration, hemorrhage, overall inflammation, intraepithelial inflammatory infiltrate, and edema.Measurements and Main ResultsITPV was associated with significantly lower Paco2and deadspace ventilation ratio than CMV. The combined tracheobronchial injury scores for all samples were significantly higher in the ITPV group compared with the CMV group (p< .005; Mann-Whitney U test). The ITPV injury scores, compared with CMV injury scores, were significantly higher at the carina and main bronchus (p< .01; Kruskal-Wallis test followed by Dunn’s multiple comparison test). The area adjacent to the endotracheal tube showed the same degree of damage in both groups. Analysis of the injury scores in individual damage categories demonstrated the greatest difference in the ulceration category (p< .001).ConclusionsIn our study, ITPV, compared with CMV at the same minute ventilation, was associated with a significantly greater difference in tracheobronchial damage at the carina and main bronchus. We postulate that this difference may have been caused by the turbulence of the gas flow generated by the small-caliber ITPV catheter used in our neonatal-size animal model.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveSeveral studies have shown that lipopolysaccharide and lipid A impair red blood cell deformabilityin vitroandin vivo. However, it is unclear whether impaired red blood cell deformability is associated with binding of lipopolysaccharide to the red blood cell membrane.DesignAnalysis of hydroxymyristic acid content in red blood cell membranes and red blood cell deformation in patients with Gram-negative septicemia and afterin vitroincubation of red blood cells from healthy adults with 100 &mgr;g ofEscherichia colilipid A or 1 mg ofE. colilipopolysaccharide per milliliter of red blood cell in buffer solution and in whole blood. Hydroxymyristic acid is a fatty acid of the lipid A part of lipopolysaccharide in most Gram-negative bacteria.SettingUniversity research laboratories.SubjectsTen healthy adults and four patients with clinical and laboratory signs of septicemia.InterventionsBlood sampling.Measurements and Main ResultsRed blood cell deformation was measured with a laser-diffraction shearing device (Rheodyn) and a computerized micropore filtration system (CTA). Lipopolysaccharide and lipid A binding to red blood cell membranes was studied by measuring the amide-linked hydroxymyristic acid by gas chromatography.The detection rates of hydroxymyristic acid were 82% for lipopolysaccharide and 79% for lipid A in buffer solution. In membranes of washed red blood cell, the detection rates of lipopolysaccharide and lipid A were 0.26 ± 0.03% (2.6 ± 0.3 &mgr;g/mL) and 1.3 ± 0.5% (1.3 ± 0.5 &mgr;g/mL), and in red blood cell membranes of whole blood the detection rates were 2.6% (25.5 &mgr;g/mL) and 4.1% (4.1 &mgr;g/mL), respectively. The lipopolysaccharide content in red blood cell membranes of septic patients ranged from 47 to 103 &mgr;g/mL of red blood cell. Red blood cell deformation in the Rheodyn and in the CTA were not influenced by lipopolysaccharide incubated with washed red blood cells. In the Rheodyn, red blood cell deformation was significantly decreased by 18% after lipid A incubation in washed red blood cells, by 26% after lipopolysaccharide incubation in whole blood, and by 31% in septic patients. Similar effects were observed when we used the CTA.ConclusionsRed blood cell deformation is decreased in septic patients, afterin vitroincubation of washed red blood cells with lipid A and of whole blood with lipopolysaccharide. Lipopolysaccharide did not influence red blood cell deformation after incubation with washed red blood cells. The decrease of red blood cell deformation was related to the amount of hydroxymyristic acid measured in red blood cell membranes, suggesting that endotoxin binding directly affects mechanical properties of red blood cells.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine the effects of an anti-CD14 monoclonal antibody on the clearance of a bacteremicEscherichia colichallenge in the presence or absence of antimicrobial agents.DesignProspective randomized animal study.SettingUniversity-affiliated research laboratory.SubjectsNew Zealand White rabbits weighing 1.5–2.5 kg.InterventionsAnimals were pretreated with either an anti-lapine CD14 monoclonal antibody (immunoglobulin G2a, 5 mg/kg intravenously) or an isotype control monoclonal antibody. The animals then were challenged with 1 × 106E. coli018:K1 in the presence or absence of ceftazidime (50 mg/kg intravenously). There were four groups of six animals randomized to receive either anti-CD14 monoclonal antibody without ceftazidime, isotype control monoclonal antibody without ceftazidime, anti-CD14 monoclonal antibody with ceftazidime, or isotype control antibody with ceftazidime.Measurements and Main ResultsSerial measurement of quantitative bacteremia and endotoxemia was performed over 24 hrs after the administration of the bacterial challenge. Animals also underwent necropsy with quantitative bacterial cultures from multiple organ tissue samples. The anti-lapine CD14 monoclonal antibody significantly impaired the bloodstream clearance ofE. coli(p< .01) and increased quantitative counts ofE. coliin tissue culture samples when compared with isotype control antibody in the absence of simultaneous administration of ceftazidime. No differences in quantitative bacteremia, endotoxemia, or organ tissue counts were found after anti-CD14 antibody and control antibody-treated animals in the presence of ceftazidime treatment.ConclusionsAnti-CD14 monoclonal antibody has the capacity to interfere with the innate immune response and systemic microbial clearance in experimental animals withE. colibacteremia. The concomitant administration of effective antimicrobial therapy eliminated differences in the rate of microbial clearance between the control antibody and the CD14 monoclonal antibody. These results indicate that care should be taken in clinical trials with anti-CD14 monoclonal antibodies to ensure that adequate antimicrobial therapy is administered in the presence of systemic bacterial infection.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjetiveThis study was performed to examine both brain and systemic interleukin-6 (IL-6) release in patients with an acute brain injury (ABI), to study whether a correlation exists between the transcranial IL-6 gradient during the first days after injury and prognosis, and finally, to investigate the relationship between a nucleotide polymorphism at position −174 in the promoter of the gene encoding IL-6, IL-6 responsiveness, and clinical evolution.DesignProspective clinical investigation.SettingA 19-bed intensive care unit in a university hospital.Patients and MethodsA total of 62 patients were followed up for 3 days after acute brain injury, and both their arterial and jugular IL-6 levels were measured serially and at the moment of brain death diagnosis. Genetic polymorphism of IL-6 was also determined in all patients. Data were correlated with those from score procedures for clinical severity. Neurologic outcome was graded according to the Glasgow Outcome Scale 6 months after injury. IL-6 levels and IL-6 genotyping was performed in control healthy individuals.Main ResultsThere is a significant transcranial IL-6 gradient at admission and at the moment of brain death. The gradient is higher in those patients who evolved toward a fatal outcome during the first 6 months after injury (p< .001). There is significant correlation between the transcranial IL-6 gradient and the acute brain injury severity.ConclusionsIL-6 is elevated in patients with acute brain injury, and a significant relationship exits between the severity of acute brain injury and the transcranial IL-6 gradient at admission. It can be considered to be a prognosis marker at admission. When data at the moment of brain death are considered, venous IL-6 (p< .01) and the transcranial IL-6 gradient (p< .005) are significantly higher than at the time of admission. Although the IL-6 C allele is associated with significantly lower concentrations of IL-6, there was no correlation between low or high IL-6 responders and patient outcome.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo describe normal serum levels of S-100&bgr; in healthy children and determine whether serum S-100&bgr; levels after traumatic brain injury are associated with outcome.DesignProspective cohort study.SettingUrban, tertiary care, children’s teaching hospital.PatientsA total of 136 healthy children and 27 children with traumatic brain injury.MethodsSerum S-100&bgr; levels were measured in 136 healthy children. A total of 27 children with traumatic brain injury had S-100&bgr; levels collected within 12 hrs of injury. Other indices of severity of injury measured were admission Glasgow Coma Scale score, and Pediatric Risk of Mortality score at 24 hrs (PRISM 24). Outcome was measured by the Pediatric Cerebral Performance Category (PCPC) score at hospital discharge and 6 months postinjury or at death.Measurements and Main ResultsS-100&bgr; levels in healthy children had a mean of 0.3 &mgr;g/L (90% confidence interval, 0.03–1.47) and inversely correlated with age, (r= −.32,p< .001). In children with traumatic brain injury, 6-month postinjury outcome inversely correlated with Glasgow Coma Scale score (r= −.47,p= .01) and correlated with PRISM 24 score (r= .83,p< .001) and S-100&bgr; levels (r= .75,p< .001). Six months postinjury, comparing good outcome (PCPC ≤ 3, n = 20) vs. poor outcome (PCPC ≥ 4, n = 7), median admission Glasgow Coma Scale scores were 8 (range, 3–15) and 3 (range, 3–7,p= .01), median PRISM 24 scores were 7 (range, 0–19) and 30 (range, 18–35,p< .001), and median S-100&bgr; levels were 0.85 &mgr;g/L (range, 0.08–4.8 &mgr;g/L) and 3.6 &mgr;g/L (range, 1.4–20 &mgr;g/L,p< .001), respectively. A serum S-100&bgr; level of ≥2.0 &mgr;g/L is associated with poor outcome, with a sensitivity of 86% and a specificity of 95%. The area under the receiver operating curve for S-100&bgr; was 0.94 (±0.05).ConclusionsSerum S-100&bgr; levels in healthy children have a moderate inverse correlation with age. After traumatic brain injury in children, the acute assessment of serum S-100&bgr; levels seems to be associated with outcome.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo measure and compare critical care physicians’ and nurses’ attitudes about teamwork.DesignCross-sectional surveys.SettingEight nonsurgical intensive care units in two teaching and four nonteaching hospitals in the Houston, TX, metropolitan area.SubjectsPhysicians and nurses who worked in the intensive care units.Measurements and Main ResultsThree hundred twenty subjects (90 physicians and 230 nurses) responded to the survey. The response rate was 58% (40% for physicians and 71% for nurses). Only 33% of nurses rated the quality of collaboration and communication with the physicians as high or very high. In contrast, 73% of physicians rated collaboration and communication with nurses as high or very high. By using factor analysis, we developed a seven-item teamwork scale. Multivariate analysis of variance of the items yielded an omnibus (F[7, 163] = 8.37;p< .001), indicating that physicians and nurses perceive their teamwork climate differently. Analysis of individual items revealed that relative to physicians, nurses reported that it is difficult to speak up, disagreements are not appropriately resolved, more input into decision making is needed, and nurse input is not well received.ConclusionsCritical care physicians and nurses have discrepant attitudes about the teamwork they experience with each other. As evidenced by individual item content, this discrepancy includes suboptimal conflict resolution and interpersonal communication skills. These findings may be the result of the differences in status/authority, responsibilities, gender, training, and nursing and physician cultures.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectivesA systematic review of somatosensory evoked potentials performed early after onset of coma, to predict the likelihood of nonawakening. The pooled results were evaluated for rates of awakening, confidence intervals, and the possibility of rare exceptions.Data SourcesForty-one articles reporting somatosensory evoked potentials in comatose patients and subsequent outcomes, from 1983 to 2000.Study SelectionStudies were included if they reported coma etiology, age group, presence or absence of somatosensory evoked potentials, and coma outcomes.Data ExtractionWe separated patients into four groups: adults with hypoxic-ischemic encephalopathy, adults with intracranial hemorrhage, adults and adolescents with traumatic brain injury, and children and adolescents with any etiologies. Somatosensory evoked potentials were categorized as normal, abnormal, or bilaterally absent. Outcomes were categorized as persistent vegetative state or death vs. awakening.Data SynthesisFor each somatosensory evoked potential result, rates of awakening (95% confidence interval) were calculated: adult hypoxic-ischemic encephalopathy: absent 0% (0%–1%), abnormal 22% (17%–26%), normal 52% (48%–56%); adult intracranial hemorrhage: absent 1% (0%–4%), present 38% (27%–48%); adult-teen traumatic brain injury: absent 5% (2%–7%), abnormal 70% (64%–75%), normal 89% (85%–92%); child-teen: absent 7% (4%–10%), abnormal 69% (61%–77%), normal 86% (80%–92%).ConclusionsSomatosensory evoked potential results predict the likelihood of nonawakening from coma with a high level of certainty. Adults in coma from hypoxic-ischemic encephalopathy with absent somatosensory evoked potential responses have <1% chance of awakening.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID