摘要:

ObjectiveMyocardial depression, which frequently occurs in the course of septic shock, has been attributed to the cardiodepressant properties of nitric oxide (NO) generated by either the inducible NO synthase (iNOS) or the constitutive isoform (cNOS). We have previously demonstrated that &agr;-toxin fromStaphylococcus aureusinduces thromboxane-mediated vasoconstriction accompanied by severe cardiodepression in isolated rat hearts. In the present study, we investigated the role of NO in the &agr;-toxin-induced vascular and contractile abnormalities.DesignProspective, experimental study.SettingResearch laboratory at a university hospital.SubjectsIsolated hearts from male Wistar rats.InterventionsIsolated hearts were perfused with purified staphylococcal &agr;-toxin for 60 mins.Measurements and Main ResultsAt a concentration of 0.25 and 0.5 &mgr;g/mL, &agr;-toxin induced a rise in coronary perfusion pressure, depressed myocardial contractility, and caused edema formation. Simultaneously, a time- and dose-dependent rapid release of NO into the perfusate was noted as quantified by a chemiluminescence technique. L-NMMA, a nonselective inhibitor of NOS, but not PBITU, an iNOS-selective inhibitor, blocked NO synthesis, markedly increased the rise in coronary perfusion pressure and the loss in contractility, and enhanced edema formation in response to &agr;-toxin. In contrast, zaprinast, a selective inhibitor of phosphodiesterase type V that is used for stabilization of cyclic guanosine monophosphate, attenuated the toxin-induced coronary vasoconstrictor response and the myocardial depression. l-arginine, the substrate of NOS, had similar, yet less potent, effects as zaprinast and slightly increased the release of NO caused by &agr;-toxin. Immunohistochemical analysis of the myocardium at the end of the perfusion period demonstrated a positive staining for cNOS but not for iNOS. In addition, no up-regulation of iNOS mRNA was detected in the tissue of toxin-exposed hearts.ConclusionsStaphylococcal &agr;-toxin provokes NO biosynthesis via activation of cNOS in rat hearts. NO partly antagonizes the deleterious effects of this pathogenicity factor on coronary vasoregulation and myocardial performance.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectivesTo assess the amount of nutrients delivered, prescribed, and required for critically ill patients and to identify the reasons for discrepancies between prescriptions and requirements and between prescriptions and actual delivery of nutrition.DesignProspective cohort study.SettingTwelve-bed medical intensive care unit in a university-affiliated general hospital.PatientsFifty-one consecutive patients, receiving nutritional support either enterally or intravenously for ≥ 2 days. We followed patients for the first 14 days of nutritional delivery.Measurements and Main ResultsThe amount of calories prescribed and the amount actually delivered were recorded daily and compared with the theoretical energy requirements. A combined regimen of enteral and parenteral nutrition was administered on 58% of the 484 nutrition days analyzed, and 63.5% of total caloric intake was delivered enterally. Seventy-eight percent of the mean caloric amount required was prescribed, and 71% was effectively delivered. The amount of calories actually delivered compared with the amount prescribed was significantly lower in enteral than in parenteral administration (86.8% vs. 112.4%,p< .001). Discrepancies between prescription and delivery of enterally administered nutrients were attributable to interruptions caused by digestive intolerance (27.7%, mean daily wasted volume 641 mL), airway management (30.8%, wasted volume 745 mL), and diagnostic procedures (26.6%, wasted volume 567 mL). Factors significantly associated with a low prescription rate of nutritional support were the administration of vasoactive drugs, central venous catheterization, and the need for extrarenal replacement.ConclusionsAn inadequate delivery of enteral nutrition and a low rate of nutrition prescription resulted in low caloric intake in our intensive care unit patients. A large volume of enterally administered nutrients was wasted because of inadequate timing in stopping and restarting enteral feeding. The inverse correlation between the prescription rate of nutrition and the intensity of care required suggests that physicians need to pay more attention to providing appropriate nutritional support for the most severely ill patients.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectivesTo study recombinant human tissue factor pathway inhibitor (rhTFPI) in a superantigen-induced shock model and in a cecal ligation and puncture (CLP) model of peritonitis in mice.DesignProspective, randomized, experimental study.SettingAn experimental animal research laboratory.SubjectsEighty BALB/c mice for the superantigen model, and 56 BALB/c mice for the CLP model.InterventionsIn the superantigen-induced shock model, animals received rhTFPI (350 mg/kg) subcutaneously every 12 hrs (n = 30) or saline control (n = 30) for 60 hrs after staphylococcal enterotoxin B (SEB; 10 &mgr;g iv) and a sublethal dose ofE. coliO111:B4 lipopolysaccharide (LPS; 75 &mgr;g ip). Control groups received SEB alone (n = 10) and LPS alone (n = 10). In the CLP model, rhTFPI or saline was given every 8 hrs for 48 hrs by using a 21-gauge needle (n = 9) or 23-gauge needle (n = 14) for CLP. A sham surgery control group (n = 10) was also included.Measurements and Main ResultsThere was 0% mortality in the SEB and LPS control groups. The mortality rate was 64% in the saline control group that received both SEB and LPS (19 of 30), whereas the rhTFPI- treated animals had a mortality rate of 20% (6 of 30;p< .01). The rhTFPI-treated group had significantly lower interleukin-6 levels (61.8 ± 41 pg/mL vs. 285 ± 63 pg/mL;p< .05) than the control group but no differences in tumor necrosis factor-&agr; or interferon-&ggr; levels.In the CLP experiment, rhTFPI-treated animals did not have any survival advantage over the control group after the large-bore (21-gauge) needle puncture. The rhTFPI group had significantly improved 7-day mortality rate after CLP with the small-bore needle (23-gauge; 21.4% [rhTFPI] vs. 71.4% [control],p< .01). Plasma LPS, interleukin-6, interferon-&ggr;, and tumor necrosis factor-&agr; levels were unchanged by rhTFPI treatment, but significantly reduced LPS (p= .006) and IFN&ggr; (p= .001) levels were found in the peritoneal fluid.ConclusionsTissue factor pathway inhibitor significantly improves the mortality rate in models of superantigen-induced shock and polymicrobial intra-abdominal infection, supporting its potential use in clinical trials for septic shock.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveWe undertook this study to understand the factors at our transplant center that contribute to patients’ return to the ICU after their liver transplant and their initial discharge from that unit. Patients who, after liver transplantation, fail discharge from the Intensive Care Unit (ICU) and must be readmitted to that unit may well utilize many more resources than those patients who are well enough to stay out of the ICU.DesignA retrospective review of a prospectively maintained liver transplant research database followed by a retrospective review of (a subgroup) patient charts and contemporaneous controls.SettingA large metropolitan tertiary care center and adult liver transplant center.PatientsA total of 1,197 consecutive adult patients who underwent their initial liver transplantation from 1984 to 1996.InterventionReadmission to the intensive care unit after adult liver transplantation and discharge from that unit.Main ResultsOnly recipient age, pretransplant synthetic function labs (protime and albumin), bilirubin levels, and intraoperative blood product requirements could be statistically linked to the group requiring ICU readmission. The primary etiology for ICU readmission was cardiopulmonary deterioration. Readmission was associated with significantly lower patient and graft survivals. A detailed review of 23 patients transplanted from October 1994 to June 1996 was made, with special emphasis on cardiopulmonary status (hemodynamics, respiratory variables, and chest radiograph findings). This subgroup was compared with 30 temporally matched controls who were not readmitted to the ICU. Intravascular fluid overload and lower inspiratory capacity were significant factors related to ICU readmission. Readmitted patients had a longer hospitalization with higher hospital charges than the control group.ConclusionsWe conclude that the most important means of preventing ICU readmission in liver transplantation patients is to optimize cardiopulmonary function and status. Close monitoring of fluid balance to avoid hypervolemia is essential. Readmitted patients have a greater resource utilization and have lower survival rates.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveShock in the course of fever is likely caused by septic shock. Because septic shock carries a high mortality rate, early recognition could benefit the patient. We tried to predict the development of shock in medical patients with fever and a clinical infection, on the basis of clinical and microbiological information, and to evaluate the role therein of systemic inflammatory response syndrome (SIRS) criteria: abnormal body temperature, tachycardia, tachypnea, and abnormal white blood cell counts.DesignProspective observational study.SettingDepartment of Internal Medicine at a university hospital.PatientsPatients were 212 consecutive medical patients with newly onset fever (temperature, >38.0°C axillary or >38.3°C rectally) and a clinical source of infection.Measurements and Main ResultsOf the 212 patients enrolled, 14 developed shock (i.e., a decrease in systolic arterial blood pressure of >40 mm Hg) during a maximum follow-up period of 7 days after inclusion. In univariate analyses, advanced age, prior urogenital disease, an abdominal source, nosocomial infections, and bacteremia predisposed patients to shock (p< .05). For clinical variables, obtained daily for 2 days after inclusion, a low performance (p< .001), the peak respiratory rate (p< .05), the peak heart rate (p< .05), the nadir score on the Glasgow Coma Scale (p< .005), the peak and nadir white blood cell counts (p< .005), and the nadir albumin (p< .01) and peak creatinine concentrations in blood (p< .001) predicted shock development. In multivariate analysis, the presence of bacteremia, the peak respiratory rate, the nadir Glasgow Coma Scale score, and the peak white blood cell count positively and the peak erythrocyte sedimentation rate negatively contributed to prediction of shock development. In contrast, SIRS had less predictive value, mainly because of lack of predictive value of peak heart rate and temperature in multivariate models.ConclusionIn febrile medical patients with a clinical infection, the development of shock involves an interaction between circulating microbial products and the host response, which can be recognized clinically by variables easily obtained at the bedside and partly different from the set used to define SIRS.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo evaluate the effects of high-dose almitrine infusion on gas exchange and right ventricular function in patients with severe hypoxemia related to acute respiratory distress syndrome (ARDS).DesignProspective study.SettingMedicosurgical intensive care department (ten beds).PatientsNine patients with ARDS and severe hypoxemia (Pao2/Fio2ratio, <150 torr [20 kPa]).InterventionHigh-dose almitrine infusion (16 &mgr;g/kg/min for 30 mins).Measurements and Main ResultsGas exchange and hemodynamic parameters were recorded before and after almitrine infusion. Right ventricular function was evaluated by using a fast response thermistor pulmonary artery catheter that allowed measurement of right ventricular ejection fraction and calculation of right ventricular end-diastolic and end-systolic volumes. Almitrine did not significantly alter arterial oxygenation and intrapulmonary shunt. Almitrine increased mean pulmonary arterial pressure (MPAP) from 31 ± 4 to 33 ± 4 mm Hg (p< .05), pulmonary vascular resistance index from 353 ± 63 to 397 ± 100 dyne·sec/cm5·m2(p< .05), and right ventricular end-systolic volume index from 71 ± 22 to 77 ± 21 mL/m2(p< .05); almitrine decreased right ventricular ejection fraction from 36% ± 7% to 34% ± 8% (p< .05). Stroke volume index and cardiac index did not change. The almitrine-induced changes in right ventricular ejection fraction were closely correlated with the baseline MPAP (r2= .71,p< .01).ConclusionIn patients with severe hypoxemia related to ARDS, high-dose almitrine infusion did not improve arterial oxygenation and impaired the loading conditions of the right ventricle. The decrease in right ventricular ejection fraction induced by almitrine was correlated with the baseline MPAP. Thus, high-dose almitrine infusion may be harmful in ARDS patients with severe hypoxemia and pulmonary hypertension.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThe aim of this study was to estimate the agreement between superior vena caval pressure (SVCP) and femoroiliac venous pressure (FIVP) measurements by using short (<20 cm) femoral catheters commonly used in an adult intensive care unit. In addition, the effects of two modes of ventilation on agreement were assessed.DesignMeasurements of central venous pressure were recorded from both sites by using the same pressure transducer connected to the catheters via a three-way stopcock. SVCP and FIVP were recorded at 5-min intervals for 40 mins with the patient in the supine position. Recordings were taken from ventilated patients during a randomized crossover sequence of normal and inverse ratio ventilation (IRV). Analyses included Pearson’s correlation (r), intraclass correlation (ri), Bland-Altman plots, and repeated measures analysis of variance with crossover tests for period and period-treatment interactions.SettingAdult intensive care unit.PatientsAdult intensive care patients.MeasurementsCentral venous pressure.ResultsTwenty-two patients were enrolled in the study, giving 162 paired measurements;rwas .97 (p< .0001), andriwas .96. The bias for SVCP-FIVP measurements was −0.75 mm Hg (95% confidence interval = −1.31 to −0.18), with 95% limits of agreement of −3.30 to 1.81 mm Hg. Seventeen patients were suitable for randomization to normal ratio ventilation and IRV. IRV significantly increased SVCP and FIVP (p< .002). Tests for the effect of mode of ventilation on agreement (p= .36), for period (p= .26), and for period-treatment interaction (p= .84) were not significant.ConclusionThe study showed excellent overall agreement with acceptable clinical agreement for SVCP and FIVP measurements that was not affected by changing the mode of ventilation. IRV significantly increased central venous pressure measurements from both catheter sites but had no effect on overall agreement.

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:2001

数据来源: OVID