摘要:

ObjectiveTo investigate whether gastric intramucosal acidosis is associated with a decreased gastric mucosal blood flow in mechanically ventilated patients.DesignProspective, clinical investigation.SettingUniversity hospital intensive care unit.PatientsSeventeen mechanically ventilated patients with stable hemodynamic status.InterventionsGastric tonometry and endoscopic assessment of mucosal blood flow.Measurements and Main ResultsSix patients had gastric intramucosal acidosis (intramucosal pH [pHi] of 7.24 +/- 0.06), whereas the remaining 11 patients had pHi values within the normal range (7.44 +/- 0.01). No differences were found between intramucosal acidotic and nonacidotic patients with respect to their general and hemodynamic characteristics. Patients with intramucosal acidosis had a lower gastric mucosal blood flow, as assessed by laser-Doppler flowmetry, than nonacidotic patients (1.4 +/- 0.1 vs. 2.1 +/- 0.2 volts, respectively; p < .05). Reflectance spectrophotometry disclosed that patients with low gastric pHi had also a significantly (p < .05) lower hemoglobin content index (61 +/- 4 arbitrary units) than patients with normal pHi (81 +/- 3 arbitrary units), whereas oxygen saturation index was similar for both groups.ConclusionOur results support the hypothesis that gastric mucosal hypoperfusion underlies the development of intramucosal acidosis in mechanically ventilated patients. (Crit Care Med 1998; 26:827-832)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo compare the histopathologic changes observed in a sheep model of oleic acid-induced acute respiratory failure during partial liquid ventilation with perflubron with gas ventilation.DesignRandomized, controlled study.SettingAnimal laboratory and pathology laboratories of a university hospital.SubjectsFourteen healthy adult sheep, weighing 64.9 +/- 6.4 kg.InterventionsLung injury was induced with oleic acid (0.15 mL/kg). A tracheostomy tube was inserted, along with systemic and pulmonary artery monitoring catheters. Animals were randomized to undergo either partial liquid ventilation (n = 7) or gas ventilation (n = 7). Animals underwent euthanasia at the end of the 90-min study period, after which the endotracheal tube was clamped with the lungs in expiratory hold at a positive end-expiratory pressure of 5 cm H2O. En bloc excision of the heart and lungs was performed by thoracotomy. Perfusion of the isolated lung vasculature with 2.5% paraformaldehyde and 0.25% glutaraldehyde in a 0.1-M phosphate buffer was performed. Histologic analysis followed.Measurements and Main ResultsGas exchange increased markedly in the animals that underwent partial liquid ventilation compared with the gas-ventilated animals (PaO2at 90 mins: gas ventilation-treatment group, 40 +/- 8 torr [5.3 +/- 1.1 kPa]; partial liquid ventilation-treatment group, 108 +/- 60 torr [14.4 +/- 8.0 kPa]; p = .004). Lung histologic analysis demonstrated a better overall diffuse alveolar damage score (partial liquid ventilation-treatment group, 12.4 +/- 1.4; gas ventilation-treatment group, 15.0 +/- 1.7; p = .01). In the partial liquid ventilation-treatment group, we observed an increase in mean alveolar diameter (partial liquid ventilation-treatment group, 82.4 +/- 2.9 [micro sign]m; gas ventilation-treatment group, 67.7 +/- 3.9 [micro sign]m; p = .0022) and a decrease in the number of alveoli per high-power field (partial liquid ventilation-treatment group, 25.7 +/- 0.9, gas ventilation-treatment group, 31.4 +/- 2.5; p = .0022), in septal wall thickness (partial liquid ventilation-treatment group, 6.0 +/- 0.6 [micro sign]m; gas ventilation-treatment group, 8.3 +/- 1.0 [micro sign]m; p = .0033), and in mean capillary diameter (partial liquid ventilation-treatment group, 13.0 +/- 0.8 [micro sign]m; gas ventilation-treatment group, 19.9 +/- 1.4 [micro sign]m; p = .0022).ConclusionsPartial liquid ventilation is associated with notable improvement in gas exchange and with a reduction in the histologic and morphologic changes observed in an oleic acid model of acute lung injury. (Crit Care Med 1998; 26:833-843)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectivesTo evaluate and compare the clinical efficacy, impact on hemodynamics, safety profiles, and cost of combined administration of propofol and midazolam (synergistic sedation) vs. midazolam and propofol administered as sole agents, for sedation of mechanically ventilated patients after coronary artery bypass grafting.DesignProspective, controlled, randomized, double-blind clinical trial.SettingIntensive care unit of SCIAS-Hospital de Barcelona.PatientsSeventy-five mechanically ventilated patients who underwent coronary artery bypass graft surgery under low-dose opioid anesthesia.InterventionsAccording to the double-blind method, patients were randomly assigned to receive propofol (n = 25), midazolam (n = 25), or propofol combined with midazolam (n = 25). Infusion rates were adjusted to stay between 8 and 11 points on Glasgow Coma Score modified by Cook and Palma.Measurements and Main ResultsMean +/- SD duration of sedation was 14.4 +/- 1.5 hrs, 14.1 +/- 1.1 hrs, and 14.7 +/- 1.9 hrs for the propofol, midazolam, and synergistic groups, respectively. The induction dose was 0.55 +/- 0.05 mg/kg for propofol as sole agent, 0.05 +/- 0.01 mg/kg for midazolam as sole agent, and 0.22 +/- 0.03 mg/kg for propofol administered in combination with 0.02 +/- 0.00 mg/kg of midazolam (p = .001). The maintenance dose was 1.20 +/- 0.03 mg/kg/hr for propofol as sole agent, 0.08 +/- 0.01 mg/kg/hr for midazolam as sole agent, and 0.50 +/- 0.09 mg/kg/hr for propofol administered in combination with 0.03 +/- 0.01 mg/kg/hr of midazolam (p < .001). All sedative regimens achieved similar efficacy in percentage of hours of adequate sedation (93% for propofol, 88% for midazolam, and 90% for the synergistic group, respectively). After induction, both propofol and midazolam groups had significant decreases in systolic blood pressure, diastolic blood pressure, left atrial pressure, and heart rate. Patients in the synergistic group had significant bradycardia throughout the study, without impairment in other hemodynamic parameters. Patients sedated with propofol or synergistic regimen awoke sooner and could be extubated before those patients sedated with midazolam (0.9 +/- 0.3 hrs and 1.2 +/- 0.6 hrs vs. 2.3 +/- 0.8 hrs, respectively, p = .01). Synergistic sedation produced cost savings of 28% with respect to midazolam and 68% with respect to propofol.Conclusions68% reduction in maintenance dose, and lower pharmaceutical cost. (Crit Care Med 1998; 26:844-851)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectivesTo compare the performance of four severity scoring systems: the Acute Physiology and Chronic Health Evaluation (APACHE) II, the new versions of the Mortality Prediction Model (MPM0 and MPM24), and the Simplified Acute Physiology Score (SAPS) II.DesignA prospective cohort study.SettingThree Tunisian intensive care units (ICUs).PatientsConsecutive, unselected adult patients (n = 1325).InterventionsNone.Measurements and Main ResultsOverall, observed death rates were higher than predicted by all models except MPM0. All the evaluated scoring systems had good discrimination power as expressed by area under the receiver operating characteristics curve, but their calibration was less perfect when compared with original valldation reports. There were no major differences between the models with regard either to discrimination or calibration performance.ConclusionDespite an overall good discrimination, APACHE II, MPM0, MPM24, and SAPS II showed a less satisfactory calibration in our Tunisian sample of ICU patients. Part of the models inaccuracy could be related to quality of care problems in our ICUs, but this issue needs further analysis. (Crit Care Med 1998; 26:852-859)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo compare the effects of isocaloric, isonitrogenous carbohydrate nutrition vs. lipid-based total parenteral nutrition on respiratory gas exchange and intermediary metabolism in critically ill patients.DesignProspective, clinical trial.SettingSurgical intensive care unit in a major university hospital in Switzerland.PatientsSixteen patients admitted to the surgical intensive care unit.InterventionsPatients were randomized to receive isocaloric isonitrogenous total parenteral nutrition (TPN) containing 75% (TPN-glucose) or 15% (TPN-lipid) glucose over a 5-day period.Measurements and Main ResultsIndirect glucose metabolism was assessed from plasma carbon-13 (13) C)-labeled glucose and13C-labeled CO2production during a tracer infusion of uniformly13C-labeled glucose, and de novo lipogenesis was estimated from the incorporation of13C into palmitate-very low density lipoproteins (VLDL) during a tracer infusion of 1-(13) C acetate.Compared with TPN-lipid, TPN-glucose increased plasma glucose more (by 26% vs. 7%, p < .05), increased insulin more (by 284% vs. 40%, p < .01), and increased total CO2more (by 15% vs. 0%, p < .01). Both nutrient mixtures failed to inhibit endogenous glucose production and net protein oxidation, suggesting absence of suppression of gluconeogenesis. Fractional de novo lipogenesis was markedly increased by TPN-glucose to 17.4% vs. 3.3% with TPN lipids.ConclusionsThe rate of glucose administration commonly used during TPN of critically ill patients does not suppress endogenous glucose production or net protein loss, but markedly stimulates de novo lipogenesis and CO2production. Increasing the proportion of fat may be beneficial, provided that lipid emulsion has no adverse effects. (Crit Care Med 1998; 26:860-867)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo continuously monitor PCO2during two different protocols for apnea testing as part of the determination of brain death.DesignProspective comparative study using continuous transcutaneous PCO2(tcPCO2) monitoring in 54 apnea tests with or without artifical CO2augmentation. Another 53 apnea tests were not continuously monitored.SettingIntensive care wards in Northern Bavaria.PatientsNinety-six consecutive patients with suspected brain death.InterventionsApnea tests guided by transcutaneous monitoring during a PaCO (2or=to8 kPa).Measurements and Main ResultsThe mean of the difference between tcPCO2and PaCO2was -0.26 +/- 1.16 (SEM) torr (-0.035 +/- 0.15 kPa). Seventy percent of all transcutaneous measurements were within +/- 10% of the PaCO2values. The individual differences ranged from -25.8 to 16.9 torr (-3.44 to 2.25 kPa).ConclusionsWhile not as precise as could be desired in individual cases, the overall agreement between tcPCO2and PaCO2was good. Transcutaneous monitoring aided in effectively reducing the CO2target overshoot with artificial CO2augmentation, reduced the necessary number of blood gas checks compared with a former study, using predetermined time-locked evaluations, and prolonged only tests with artificial CO2augmentation. (Crit Care Med 1998; 26:868-872)

ISSN:0090-3493    

出版商:OVID    

年代:1998

数据来源: OVID