ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo examine the influence of positive end-expiratory pressure (PEEP) and posture on the distribution of pulmonary blood flow.DesignExperimental study.SettingUniversity animal laboratory.SubjectsSeven anesthetized and mechanically-ventilated lambs.InterventionsFour conditions were studied in random order: prone or supine position, with or without 5 cm H2O PEEP.Measurements and Main ResultsThe distribution of pulmonary blood flow was assessed using fluorescent-labeled microspheres (15 [micro sign]m) in small ([similar]1.7 cm3) lung regions. Pulmonary blood flow heterogeneity was evaluated using the coefficient of variation of blood flow of the lung regions.The number of regions analyzed were 1290 +/-154 (SD) per animal. PEEP increased pulmonary blood flow heterogeneity in the supine position (47.0 +/- 7.7% to 54.1 +/- 7.3%, p<.01, paired Student's t-test), but not in the prone position (40.4 +/- 8.1% to 39.6 +/- 11.5). Dorsal to ventral (gravitational) flow gradients were present only in the supine position, and increased with PEEP (-7.2%/cm vs. -10.4%/cm, p<.001).ConclusionsPEEP redistributes pulmonary perfusion to dependent lung regions in supine, but not in prone, anesthetized and mechanically-ventilated sheep. (Crit Care Med 1999; 27:37-45)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo determine the relative distribution of fluid within the extracellular fluid volume (ECFV) after infusing either normal saline or 5% albumin in septic, critically ill patients.DesignProspective, randomized, unblinded, interventional study.SettingIntensive care unit in a 450-bed, tertiary care, teaching hospital.PatientsSeptic, critically ill patients (n = 18).InterventionsInfusion of either normal saline or 5% albumin to a hemodynamic end point determined by the patient's clinician.Measurements and Main ResultsPlasma volume (PV), ECFV, cardiac index, and arterial oxygen content were measured immediately before (baseline) and after each fluid infusion. PV and ECFV were measured by dilution of131I-albumin and35S sodium sulfate, respectively. Interstitial fluid volume (ISFV) was calculated as ECFV - PV. Baseline values for PV, ISFV, ECFV, and oxygen delivery index did not differ between treatment groups. Infusion of normal saline increased the ECFV by approximately the volume infused, and the expansion of the PV to ISFV was in a ratio of 1:3. Infusion of 5% albumin increased the ECFV by double the volume infused, with both the PV and ISFV expanding by approximately equal amounts. Oxygen delivery index did not increase after either infusion due to the effect of hemodilution.ConclusionExpansion of the ECFV in excess of the volume of 5% albumin infused suggests that fluid may move from the intracellular fluid volume to the ECFV in septic patients who receive this fluid. (Crit Care Med 1999; 27:46-50)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectivesTo assess mortality and functional health status of patients at 1 yr following admission to a multidisciplinary intensive care unit (ICU) in Hong Kong. To determine which factors are associated with a poor long-term outcome.DesignProspective data collection and review.SettingA 14-bed multidisciplinary ICU in a 1,400-bed tertiary care university hospital.PatientsData from 2,268 consecutive patients admitted over a 2.5-yr period was analyzed, including follow-up at 1 yr in 853 adult survivors.InterventionsNone.Measurements and Main Results15 at 1 yr found increasing age, cardiac/respiratory arrest, intracranial hemorrhage, and trauma to be associated with poor outcomes. A correlation was found between APACHE II scores and SIP scores (Spearman's correlation coefficient = 0.13, p < .001).ConclusionsThe SIP scores indicated that the majority of patients who survived to 1 yr after ICU admission enjoyed reasonable functional health status. A poor functional health status at 1 yr did not relate to the severity of the acute illness suffered, but appeared to relate to the prognosis of the underlying disease process. (Crit Care Med 1999; 27:51-57)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo assess the effects of prognostic estimates, perceived benefit of treatment, and practice style on decision-making in critical care.DesignRandomized assignment of subjects to either of two versions of a questionnaire designed to elicit treatment decisions for six intensive care unit cases based on actual patients. One version offered optimistic survival forecasts; the other, pessimistic forecasts.SubjectsA random sample of 120 clinicians obtained from the Canadian Critical Care Society was contacted by mail. One version of the questionnaire was randomly assigned and mailed to each. Thirty-four replies, 17 for each version (response rate, 28%), were received and analyzed.Measurements and Main ResultsA list of treatment/management options was developed for each case, in three categories: recommended, questionable, and unacceptable. Subjects were also able to list new options that they would order that were not on the list. The dependent variables were the number of actions ordered in each category and the total for each case. Perceived benefit was measured by comparing subjective estimates of the probability of survival with the optimistic/pessimistic forecast given in the case. Practice style was assessed by correlating the total number of actions ordered across all possible pairs of cases. There were no significant differences between the two questionnaires on actions ordered either by category or by amount per category. Perceived benefit did not appear to be an important factor in decision-making. However, statistically significant correlations provide evidence for practice style in intensive care unit decision-making on an interventionist/noninterventionist dimension.ConclusionsThere is no evidence that erroneous or biased prognostic estimates affect intensive care unit treatment choices. Neither the principle of maximizing expected utility nor the Rule of Rescue appear to affect these decisions systematically, but practice style does. (Crit Care Med 1999; 27:58-65)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo obtain further insight into the constitutional, phenotype-dependent changes of T-helper-1 and T-helper-2 signature lymphokine synthesis after trauma.DesignProspective, descriptive study.SettingIntensive care unit of a burn center in a community hospital.PatientsTen patients 1, 3, 5, and 7 days after major burn injury and 15 healthy individuals.InterventionsPeripheral blood mononuclear cells were separated and incubated (5 hrs) for cytokine production induced by the accessory cell-independent stimulus of ionomycin and phorbol 12-myristate 13-acetate. After fixation and permeabilization, cell samples were immunofluorescently stained for cell surface antigens (CD4 and CD8), intracellular interferon (IFN)-gamma, and interleukin (IL)-4 synthesis. Results were correlated with corresponding enzyme-linked immunosorbent assay measurements of the culture supernatants.Measurements and Main ResultsThe phenotypic analysis of the composition of the helper (CD4) and suppressor/cytotoxic (CD8) T-cell subset demonstrated that patients suffering from major burns and healthy controls express these antigens in similar percentages. The ratio of CD4 positive to CD8 positive/CD16 negative T-cell subsets showed no significant changes after trauma compared with controls. The production of IL-4 was excessively up-regulated while the release of IFN-gamma was only slightly increased. The predominant cell source of IL-4 after burn trauma was the CD8+ cell with nearly five-fold increased production on day 5 (7.2 +/- 2.6%) vs. 1.5 +/- 0.4% in controls. While CD8+ cells are also capable of enhancing their IFN-gamma synthesis under stress by about 60% due to the significant participation of the naive CD45RA+ subset, the CD4+ IFN-gamma release remained largely unchanged. With this study, we demonstrated that in nonsurvivors the number of CD8+ IL-4-producing cells was significantly higher compared with controls; also, the number of IFN-gamma-releasing memory/effector CD45RO+ cells was lower compared with survivors.ConclusionsIn previous experiments, we show that a shift to TH2 dominated phenotypes increases the risk for postburn infection. The current study confirms that major burns induce a significant shift of cytokine response in the TH2 direction and demonstrates that the CD8+, rather than the CD4+ phenotype, is present. Increased IL-4 production is associated with the TH2 lymphocyte. These diagnostic tests may help to differentiate patients with compensatory anti-inflammatory response syndrome and immunosuppression from those patients in the proinflammatory state associated with the systemic inflammatory response syndrome. The profile described in this article is associated with immunosuppression and may contraindicate attempts at anti-inflammatory therapy for sepsis. (Crit Care Med 1999; 27:66-72)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo describe and analyze patient responses to rapid terminal weaning from mechanical ventilation.DesignA prospective, descriptive, correlational study.SettingAn urban, university-affiliated, trauma/emergency hospital.PatientsA convenience sample of 31 adult patients experiencing withdrawal of mechanical ventilation.InterventionsNone.Measurements and Main ResultsPhysiologic (peripheral oxygen saturation, end-tidal CO2, heart rate, and respiratory rate) and comfort (electroencephalogram [EEG], Bizek Agitation Scale, and the COMFORT scale) measures were collected at baseline, during, and after the terminal weaning procedure. Clinical status was measured using the Acute Physiology and Chronic Health Evaluation score, Glasgow Coma Scale, and PaO2/FIO2. Duration of survival after the wean inversely correlated with illness severity but did not correlate with consciousness, use of analgesia/sedation, or pulmonary function. Respiratory rate and oxygen saturation changed significantly during the wean but not end-tidal CO2. Patients remained comfortable with little or no analgesia/sedation, in a predominantly comatose sample. Subjective measures of comfort strongly correlated with objective data from bispectral analysis of EEG.ConclusionsPatients with altered consciousness or coma can be kept comfortable during a rapid terminal weaning procedure with morphine and benzodiazepines in low doses. Comfort can be reliably evaluated using subjective scales. (Crit Care Med 1999;27:73-77)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo investigate cost effectiveness of administration of flumazenil to patients presenting with suspected acute drug overdose.DesignDouble-blind, prospective, placebo-controlled randomized study.SettingUniversity teaching hospital.PatientsForty-three adults presenting with suspected drug overdose and having a Glasgow Coma Scale (GCS) score of <13. Patients with known benzodiazepine/tricyclic ingestion were excluded.InterventionsIntravenous administration of flumazenil (up to 2 mg) or placebo.Measurements and Main ResultsIndividual patient costs were assessed and data aggregated for each treatment group. Major diagnostic and therapeutic interventions were recorded and between group comparisons performed. Clinical response to study drug administration was assessed by obtaining pre- and post-drug GCS scores and observation of the patient for at least 180 mins for signs of resedation.Aggregate cost or number of major diagnostic and therapeutic interventions were not different between groups.Patients randomized to the flumazenil group showed a marked increase in GCS score (7.4 to 11.8) compared with those in the placebo group (8.2 to 8.6).ConclusionUse of flumazenil in intentional drug overdose of unknown etiology is not cost effective. (Crit Care Med 1999; 27:78-81)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID