Search PubMed⌕ Search

Biomedical subjects

Didier Dreyfuss

Publications and source records attributed to Didier Dreyfuss.

28 records · Page 2Linked to original sources
PubMed2003

Dose-response effect of perfluorocarbon administration on lung microvascular permeability in rats.

The effect of various perflubron doses on overdistension lung injury was evaluated. Rats were given perflubron at 0 ml/kg (control) to 20 ml/kg and ventilated with a VT of 33 ml/kg without or with 5 cm H2O of positive end-expiratory pressure (PEEP). High (20 ml/kg), but not lower, perflubron doses aggravated lung capillary leak in the absence of PEEP. PEEP application aggravated capillary leak in controls, had no effect in those given a low (10 ml/kg) dose, but decreased the leak in rats ventilated with a large dose compared with zero end-expiratory pressure. In the presence of PEEP, this low dose decreased capillary leak compared with controls or with rats given the large dose. Lung computerized tomography scans showed that the large dose increased functional residual capacity by 68% and produced gas trapping that was reduced by PEEP. Thus, large doses predispose to overdistension injury whereas low doses do not and may even have a protective effect in the presence of PEEP. The paradoxical beneficial effect of PEEP when large doses are given may be due to gas trapping reduction. These findings confirm that liquid ventilation does not aggravate volutrauma provided perflubron doses are adjusted. They provide a lead to further investigate partial liquid ventilation in the clinical setting.

Animals↗
PubMed2003

Heat and moisture exchangers in mechanically ventilated intensive care unit patients: a plea for an independent assessment of their performance.

OBJECTIVE: To determine whether use of a hygroscopic and hydrophobic heat and moisture exchanger (HME) for 7 days without change affects its efficiency in long-term, mechanically ventilated, chronic obstructive pulmonary disease (COPD) patients. DESIGN: Prospective, randomized, controlled clinical study comparing two combined HMEs. SETTING: Medical intensive care unit at a university teaching hospital. PATIENTS: Long-term, mechanically ventilated, COPD patients compared with non-COPD patients. INTERVENTIONS: In the first part of the study, COPD patients were studied with the Hygroster HME changed once a week. For the second part, the Hygroster was assessed in non-COPD patients and compared with the Hygrobac HME used in COPD and non-COPD patients for 1 wk without change. Devices could be changed if hygrometric measurements indicated insufficient humidity delivery. MEASUREMENTS AND MAIN RESULTS: Daily measurements were recorded for inspired gas temperature and relative and absolute humidity. Ventilatory variables, clinical indicators of efficient humidification, were also recorded. No tracheal tube occlusion occurred. However, contrary to the manufacturer advertisement, the Hygroster experienced surprisingly low values for absolute humidity in both COPD and non-COPD patients. Such events did not occur with the Hygrobac. Absolute humidity with the Hygroster was constantly and significantly lower during the 7-day study period than with the Hygrobac. Absolute humidity measured in COPD patients was identical to that measured in the rest of the study population with both HMEs. CONCLUSIONS: Manufacturer specifications and bedside measurements of absolute humidity differed considerably for the Hygroster, which in certain instances did not achieve efficient humidification in both COPD and non-COPD patients. This did not occur with the Hygrobac, which performed well throughout the 7-day period in both COPD and non-COPD patients. Our results speak for independent and evaluation of HMEs.

Aged↗
PubMed2003

Long-term mechanical ventilation with hygroscopic heat and moisture exchangers used for 48 hours: a prospective clinical, hygrometric, and bacteriologic study.

OBJECTIVE: To determine whether use of a hygroscopic heat and moisture exchanger (HME) for 48 hrs without change affects its efficiency and the level of bacterial colonization in long-term mechanically ventilated medical intensive care unit patients. DESIGN: Prospective, randomized clinical study evaluating two hygroscopic HMEs. SETTING: Medical intensive care unit at a university teaching hospital. PATIENTS: Long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients. INTERVENTIONS: Patients were randomly allocated to one of the two HMEs studied (Hygrolife and EdithFlex) and changed every 48 hrs. Devices in both groups could be changed if hygrometric measurements indicated insufficient humidity delivery. MEASUREMENTS AND MAIN RESULTS: Daily measurements of inspired gas temperature and relative and absolute humidity. In addition, cultures of tracheal aspirations and both patient and ventilator sides of the device were performed after 48 hrs of use. Ventilatory variables and clinical indicators of efficient humidification were also recorded. Prolonged use of both HMEs was safe and efficient (no tracheal tube occlusion occurred). Mean duration of mechanical ventilation was 20 days. Both clinical indicators and hygrometric measurements showed that both devices performed well during 48 hrs. Absolute humidity with EdithFlex was significantly higher on day 0 and day 1 than with Hygrolife. Absolute humidity measured in chronic obstructive pulmonary disease patients was identical to that measured in the rest of the study population. Tracheal colonization and HME colonization were similar with both HMEs. Bacterial contamination of the ventilator side of both devices was markedly low. CONCLUSIONS: These two purely hygroscopic HMEs provided safe and efficient humidification during a 48-hr period of use in long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients. In addition, they maintained ventilatory circuits clean, despite the absence of filtering media. The cost of mechanical ventilation is consequently reduced.

Aged↗
PubMed2003

Opinions about surrogate designation: a population survey in France.

OBJECTIVE: Many patients go through periods when they are too ill to give consent or to participate in decisions. When this occurs, patient autonomy is best maintained when a surrogate designated by the patient and familiar with his or her values can speak for the patient. The objective of this study was to determine whether people who are not yet ill are ready to accept surrogate designation. Attitudes toward family participation in care were explored also. DESIGN: Population survey by telephone. Because refusal of life-sustaining treatment is a dramatic example of patient autonomy, the survey used questions about ICU admission. SETTING: General population in France. SUBJECTS: Representative random sample of 8000 residents of France aged 18 yrs or more. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The survey investigated attitudes. RESULTS: Most respondents said they would like to designate a surrogate (7205 [90%]) and to have their family share in their care (6691 [84%] for bathing, 5629 [70%] for feeding, and 4139 [52%] for tracheal suctioning) and in decisions about their management (6120 [76%]). Among respondents with a spouse, 79% said they would designate the spouse to speak for them. The attitudes were not influenced by ethnicity, religion or education level. CONCLUSIONS: Most people living in France would want a surrogate to represent them should they be incompetent and admitted to an ICU. Primary care physicians should inform their patients about the benefits of discussing illness-related issues among friends and family.

Adult↗
PubMed2002

Physicians' attitude to use heat and moisture exchangers or heated humidifiers: a Franco-Canadian survey.

OBJECTIVE: To understand the national utilization pattern of heat and moisture exchangers (HME) and heated humidifiers (HH) in mechanically ventilated ICU patients. DESIGN: Cross-sectional survey. POPULATION: ICU directors in French and Canadian university-affiliated hospitals. Response rate was 89%. MEASUREMENTS: We asked respondents whether they primarily used HME or HH. We recorded whether HME were used in all patients and for how long, how often they were changed, for whom, and why they were not used. RESULTS: HME were used more often in France HH in Canada. HME were more likely to be used for all patients in France than in Canada (63% vs. 13% and for any duration of ventilation (93% vs. 35%). Short-term use of HME was more common in Canada than in France (59% vs. 7%). HME were primarily changed every day in both countries. The patients for whom HME were not used and reasons for nonutilization were similar in France and Canada. The variable of country was the strongest predictor of HME utilization for every patient (France vs. Canada, odds ratio 11) and utilization for periods of 5 days or less (Canada vs. France, odds ratio 22). CONCLUSIONS: HME were reportedly used more in often in France than in Canada for the entire duration of mechanical ventilation. This survey highlights perceptions and practices related to the determinants and consequences of airway humidification and suggests differences in the cost of mechanical ventilation between countries

Attitude of Health Personnel↗
PubMed2002

Ventilator-induced lung injury.

The clinical relevance of experimental ventilator-induced lung injury has recently received a resounding illustration by the Acute Respiratory Distress Syndrome Network trial that showed a 22% reduction of mortality in patients with acute respiratory disease syndrome when lung mechanical stress was lessened by tidal volume reduction during mechanical ventilation. This clinical confirmation of the concept of ventilator-induced lung injury has also undisputedly substantiated the experimental observation that excessive tidal volume and/or end-inspiratory lung volume is the main determinant of ventilator-induced lung injury. More recently, attention has focused on the roles and implication in the pathogenesis of ventilator-induced lung injury of inflammatory cells and mediators that may be activated and released either in the alveolar space or in the systemic circulation because of the rupture of the alveolar-capillary barrier and on the cellular response to mechanical stress.

Cytokines↗