ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo evaluate French, Swiss, and Belgian Intensive care physicians' knowledge about the pulmonary artery catheter.DesignSurvey study by questionnaire.SettingEighty-six European university and nonuniversity intensive care units (ICUs).SubjectsOne hundred thirty-four ICUs identified from the directories of two European intensive care medicine societies were asked to participate. Five hundred thirty-five critical care physicians working in 86 ICUs participated.InterventionsIn any particular ICU, all physicians were to complete-simultaneously, anonymously and without prior notice-a multiple choice questionnaire consisting of 31 questions regarding all aspects of bedside pulmonary artery catheterization. This questionnaire was the same one already used and extensively validated in a similar study conducted several years earlier in the United States and Canada.Measurements and Main ResultsThe percentage of correct answers per participant (score) was tabulated.Sixty-eight percent of respondents still in training (n = 232) believed that their knowledge of the pulmonary artery catheter was less than adequate; 36% of those who had completed their postgraduate training (n = 294) also believed their knowledge to be inadequate. The mean score of all respondents was 72.2 +/- 14.4%, significantly lower (p < .0001) in case of uncompleted postgraduate training (67.3 +/- 14.7%, lower quartile 56.7%, median 70.0%, upper quartile 76.7%), as compared with completed postgraduate training (76.1 +/- 13.0%, lower quartile 70.0%, median 80.0%, upper quartile 86.7%). When using multivariate analysis, the location of the ICU in a university hospital, the belief of respondent that his/her knowledge of the pulmonary artery catheter was adequate, and the responsibility for supervising catheter insertion were the only independent predictors of good performance on the questionnaire (p < .001 for all three variables). It was impossible to identify any subcategory of physicians with a uniformly good knowledge of the pulmonary artery catheter. The proportion of incorrect answers to some basic items was disturbingly high. For instance, [approximately]50% of the respondents, whether trained or in training, did not correctly identify pulmonary artery occlusion pressure from a clear chart recording.ConclusionsKnowledge of right-heart pulmonary artery catheterization is not uniformly good among ICU physicians. Accreditation policies and teaching practices concerning this technique need urgent revision. (Crit Care Med 1997; 25:213-220)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectivesEndotoxin stimulates platelet-activating factor production and also causes a decrease in myocardial contractility within a few hours in animal models of sepsis. Platelet-activating factor by itself decreases left ventricular contractility. We investigated whether platelet-activating factor contributes substantially to the decrease in left ventricular contractility seen in sepsis.DesignProspective, randomized, controlled animal study.SettingUniversity research laboratory.SubjectsTwenty-two juvenile, cross-bred pigs.InterventionsAnesthetized pigs were pretreated with a platelet-activating factor receptor antagonist (L-659,989) or vehicle (control), and then treated with endotoxin or saline (control). Hemodynamics and left ventricular pressures (Millar catheter) and volumes (conductance catheter) were measured. Left ventricular contractility was assessed using the slope, or maximum elastance (Emax), of the end-systolic pressure-volume relationship.Measurements and Main ResultsIn the control/endotoxin group, 4 hrs after endotoxin administration, Emaxhad decreased by 41 +/- 4% (p < .05) and mean arterial pressure had decreased by 32 +/- 3% (p < .05). In the L-659,989/endotoxin group, the decreases in Emax(26 +/- 2%, p < .05) and mean arterial pressure (16 +/- 7%) were significantly attenuated compared with the control/endotoxin group (p < .05).ConclusionsWe conclude that platelet-activating factor plays a modest but statistically significant role in the early decrease in left ventricular contractility after endotoxin administration. Inhibition of platelet-activating factor during sepsis might be beneficial for left ventricular mechanics and hemodynamics. (Crit Care Med 1997; 25:221-226)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectivesTo directly measure airway pressures proximal and distal to endotracheal tubes during conventional synchronized intermittent mandatory ventilation (SIMV) and pressure controlled-inverse ratio ventilation (PC-IRV), and to compare them with these values measured by the ventilator.DesignProspective, nonrandomized study.SettingSurgical intensive care unit at a trauma center.PatientsGroup 1: Eight intubated adult patients connected to mechanical ventilators in the SIMV mode were studied. All patients required mechanical ventilation following traumatic injuries. Group 2: Five intubated adult patients with adult respiratory distress syndrome connected to mechanical ventilators were studied.InterventionsA small polyethylene catheter was threaded through each endotracheal tube such that it could be positioned to measure pressures proximal and distal to the tubes.Measurements and Main ResultsDuring SIMV, a significant pressure gradient exists across endotracheal tubes. In addition, although initiation of PC-IRV did lead to a lower peak airway pressure measured proximally, intratracheal peak airway pressure was unchanged.ConclusionsA pressure gradient exists during inspiration from the ventilator to the trachea in mechanically ventilated patients. Tracheal pressures cannot be predicted from proximal airway pressure monitors because of marked variation in endotracheal tube resistance in vivo. Initiation of PC-IRV does not result in a decrease in peak airway pressure when measured intratracheally. (Crit Care Med 1997; 25:227-230)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine the accuracy of a bedside glucometer with an enzyme-electrode sensor based on enzyme oxidation by glucose oxidase.DesignProspective, cross-sectional clinical study.SettingOperating room in a public hospital.PatientsFifty-four patients undergoing surgical procedures for a derivation (n = 17) and a validation (n=37) study.InterventionsArterial blood samples were obtained via a 20-gauge cannula inserted into each patient's radial artery.Measurements and Main ResultsGlucose measurements and arterial blood gas analyses were concurrently performed, using 48 blood samples for the derivation study and 45 blood samples for the validation study of this technique. Blood glucose concentrations were measured with both a bedside glucometer using an enzyme-electrode method and a laboratory glucometer based on the colorimetric method. The bedside glucometer consistently underestimated the glucose concentrations and the underestimation was related to the sample oxygen tension but not to hematocrit, plasma protein, creatinine, uric acid, or bilirubin. The present investigation used the following correction formula: (corrected glucose value) = (glucose concentration obtained by a bedside glucometer) + 0.1 x (sample oxygen tension) + 16. The corrected data were in agreement with the laboratory-determined glucose values (i.e., the mean difference and precision were 0.4 and 7.1 mg/dL, respectively). A validation study confirmed the generalization of the present correction formula which facilitates a more accurate estimation of blood glucose concentrations.ConclusionsBlood glucose values measured using a bedside glucometer in this study were influenced by the sample oxygen tension. We used a corrective equation which improved the accuracy of estimating blood glucose values to a clinically acceptable range. (Crit Care Med 1997; 25:231-235)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectivesTo investigate whether the beneficial systemic hemodynamic effects of N-acetylcysteine, an agent that increases cyclic guanosine monophosphate (cGMP) concentration in fulminant hepatic failure, are present in a range of liver disorders and what concurrent effect this agent has on the hepatic-splanchnic circulation.SettingLiver Failure Unit, King's College Hospital, London, UK.PatientsFifteen patients with hepatic dysfunction who were mechanically ventilated, either after liver transplantation or during an acute or decompensated chronic liver disorder.InterventionsProstacyclin was administered at a continuous infusion rate of 5 ng/kg/min for 60 mins. After a washout period, the hemodynamic effects of this infusion were compared with the effects present during infusion of N-acetylcysteine at 150 mg/kg in 250 mL of 5% dextrose in water over 15 mins and then 50 mg/kg in 250 mL of 5% dextrose for 45 mins at an infusion rate of 62.5 mL/hr.Measurements and Main ResultsFollowing N-acetylcysteine infusion, the baseline oxygen delivery (DO2) increased from 667 +/- 154 to 751 +/- 166 (SD) mL/min/m sup 2, and oxygen consumption (VO2) improved in 13 of 15 patients (150 +/- 30 to 169 +/- 25 mL/min/m2) (p < .01). Indocyanine green clearance, as determined by a fiberoptic physiologic monitoring system, also improved in 13 of 15 patients (7.3 +/- 4.2% to 11.8 +/- 4.0% [mean change 100%, 95% confidence interval 9 to 256]) (p = .002). Patients who were defined as responders in relation to systemic hemodynamics (VO210% from baseline [n = 6; 40%]) had a significantly lower baseline consumption compared with that of nonresponders (133 vs. 162 mL/min/m2, p = .04). No clear relationship between the increments in VO2and indocyanine green clearance was observed (r2= .21; p = .08). Prostacyclin resulted in moderate improvements in systemic DO2(but not VO2) and a nonsignificant increase in indocyanine green clearance.ConclusionN-acetylcysteine increases systemic VO2in a proportion of patients with a wide variety of hepatic disorders. In addition, N-acetylcysteine elicits an improvement in indocyanine green clearance. These properties may be clinically useful in a range of critical illnesses where systemic or hepatic-splanchnic circulations are compromised. (Crit Care Med 1997; 25:236-242)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo evaluate the effects of preoperative intentional hemodilution with 4% albumin solution on the extravasation rate of intravascular albumin and fluid in surgical patients.DesignA prospective, randomized, clinical study.SettingUniversity teaching hospital.Patients4 hrs) surgical procedure.InterventionsAutologous technetium-99m (sup 99m Tc)-labeled red blood cells and indium-oxine (sup 111 In)-labeled human serum albumin were injected intravenously during anesthesia at T= 0 min in the two groups for the determination of total blood volume and albumin diffusion space, respectively. In addition, body tetrapolar electrical impedance was used to assess extracellular fluid volume. In the hemodiluted group (group 2), 15 mL/kg of blood was withdrawn over 30 mins (T = 20 mins to T = 50 mins) and simultaneously replaced by an equal volume of 4% albumin solution (0.6 g/kg).Measurements and Main Results3 mL/kg. Urine output was significantly lower in group 2 than in group 1 (0.7 +/- 0.4 vs. 1.4 +/- 1.0 mL/min, respectively; p < .05). A comparable decrease in colloid oncotic pressure and in plasma albumin concentration was observed in both groups.ConclusionsThese results suggest that preoperative hemodilution using 4% albumin on a 1:1 volume basis for blood substitution during a prolonged surgical procedure with reduced blood losses enhances the extravasation rate of albumin and fluid to the interstitial tissues, impeding the maintenance of isovolemia. These findings support the use of a volume of infused colloid solution higher than that of withdrawn blood during preoperative hemodilution. (Crit Care Med 1997; 25:243-248)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo determine whether replacement of human albumin will improve a patient's prognosis.DesignA randomized, double-blind, controlled study in which 25 g of human albumin vs. placebo was administered intravenously daily.SettingA university-affiliated hospital.PatientsThirty-six patients with hypoalbuminemia (serum albumin of <2.5 g/dL), receiving total parenteral nutrition. None of the patients had known cancer, cirrhosis, or nephrotic syndrome.InterventionsEach patient received at least 6 days of therapy (6 to 24 days of albumin; 7 to 32 days of placebo). Four subjects were excluded from the study since they received therapy for <6 days. One patient was excluded from the study after nephrotic syndrome was identified. Albumin metabolic rates for those patients receiving albumin were estimated using the formula: Metabolism of albumin = 25 g/day + (albumin 1 - albumin 2)(Vd)/days, where albumin 1 and 2 are the serum albumin concentrations (g/L) at the beginning and end of the serum sampling intervals, respectively; Vd is the volume of distribution (L); and days relates to the number of days of the sampling interval.Measurements and Main ResultsSixteen patients received albumin; 15 patients received placebo. One patient receiving placebo and two patients receiving albumin died within 30 days. One patient who received placebo and three patients who received albumin developed sepsis or bacteremia; four patients who received placebo and seven patients who received albumin developed pneumonia during the study (NS). The serum albumin increased in all patients receiving intravenous albumin, but one patient received intravenous albumin for only 6 days. The mean serum albumin concentration increased by 1.42 g/dL in the albumin patients, and increased by 0.29 in the placebo patients (p < .0001 by unpaired t-test). Mean initial albumin metabolism was 17.4 g/day (0.3 g/kg/day). At the end of therapy, albumin metabolism was 20.5 g/day (0.36 g/kg/day) (paired t-test, p = .4, NS).Conclusionsa) The administration of intravenous albumin to hypoalbuminemic patients receiving total parenteral nutrition does not improve morbidity or mortality. b) Albumin metabolic rates, initially related to the catabolic state, are high; later, these rates are high related to filling of the albumin space and gluconeogenesis. c) On the basis of the high albumin catabolic rates at the end of the infusion, doses of albumin of <25 g/day might be sufficient to replace albumin stores. (Crit Care Med 1997; 25:249-252)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo evaluate the accuracies of the respiratory rate/tidal volume ratio (rate/volume ratio), minute volume, and negative inspired force in predicting weaning outcome in postoperative mechanically ventilated patients.DesignA prospective, observational study.SettingSurgical intensive care unit of a 270-bed community teaching hospital.PatientsOne hundred eighty-three postoperative, mechanically ventilated patients.InterventionsNone.Measurements and Main Results24 hrs. Predictive characteristics were computed using threshold values of 100 breaths/min/L, 10 L/min, and -20 cm H2O for the rate/volume ratios, minute volume, and negative inspired force, respectively. Receiver operating characteristic curves were also constructed to assess each parameter.Sensitivities for the initial rate/volume ratio, rate/volume ratio after 30 mins, minute volume, and negative inspired force were 0.97, 0.96, 0.76, and 0.96, respectively. Specificities were 0.33, 0.31, 0.40, and 0.07, respectively. Areas (+/- SD) for receiver operating characteristic curves were 0.76 +/- 0.08, 0.75 +/- 0.06, 0.54 +/- 0.08, and 0.62 +/- 0.07, respectively. The rate/volume ratio after 30 mins correlated with the initial rate/volume ratio; the rate/volume ratio after 30 mins did not add significant, additional predictive information.ConclusionsThe rate/volume ratio measured at the beginning and after 30 mins of weaning is more highly predictive of weaning outcome than the negative inspired force and minute volume. The principal weakness of the rate/volume ratio is false-positive results. (Crit Care Med 1997; 25:253-257)

ISSN:0090-3493    

出版商:OVID    

年代:1997

数据来源: OVID