Biomedical subjects

Didier Demory

Publications and source records attributed to Didier Demory.

5 recordsLinked to original sources

PubMed2007

High-frequency oscillatory ventilation following prone positioning prevents a further impairment in oxygenation.

OBJECTIVE: The improvement in oxygenation with prone positioning is not persistent when patients with acute respiratory distress syndrome (ARDS) are turned supine. High-frequency oscillatory ventilation (HFOV) aims to maintain an open lung volume by the application of a constant mean airway pressure. The aim of this study was to show that HFOV is able to prevent the impairment in oxygenation when ARDS patients are turned back from the prone to the supine position. DESIGN: Prospective, comparative randomized study. SETTING: A medical intensive care unit. PATIENTS: Forty-three ARDS patients with a Pao2/Fio2 ratio <150 at positive end-expiratory pressure > or =5 cm H2O. INTERVENTIONS: After an optimization period, the patients were assigned to one of three groups: a) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by a 12-hr period of conventional lung-protective mechanical ventilation in the supine position (CV(prone)-CV(supine)); b) conventional lung-protective mechanical ventilation in the supine position (12 hrs) followed by HFOV in the supine position (12 hrs) (CV(supine)-HFOV(supine)); or c) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by HFOV in the supine position (CV(prone)-HFOV(supine) group). MEASUREMENTS AND MAIN RESULTS: Pao2/Fio2 ratio was higher at the end of the study period in the CV(prone)-HFOV(supine) group than in the CV(prone)-CV(supine) group (p < .02). Venous admixture at the end of the study period was lower in the CV(prone)-HFOV(supine) group than in the two other groups. CONCLUSIONS: HFOV maintained the improvement in oxygenation related to prone positioning when ARDS patients were returned to the supine position.

Aged↗

PubMed2006

Generation of a single pulmonary pressure-volume curve does not durably affect oxygenation in patients with acute respiratory distress syndrome.

INTRODUCTION: It is possible that taking a static pressure-volume (PV) measurement could durably affect oxygenation and thus interfere with early evaluation of a therapeutic intervention delivered just after that measurement. The aim of the present study was to investigate the effects over time of a single static PV measurement on gas exchange and haemodynamics; the PV measurements were taken using a super syringe and by using the constant flow method in patients with acute respiratory distress syndrome. METHOD: We conducted a prospective, randomized and controlled interventional study in an intensive care unit. The study was conducted in 17 patients with early acute respiratory distress syndrome ventilated with a tidal volume of 6.9 +/- 1.0 ml/kg, a plateau pressure of 27 +/- 7 cmH2O and a positive end-expiratory pressure [PEEP] of 10 cmH2O. They were all evaluated for 1 hour after each of the following two measurements was taken and during a control period (in a randomized order): generation of a PV curve using a 2 l super syringe (PVSS; insufflated volume = 1824 +/- 381 ml, plateau pressure = 46 +/- 9 cmH2O); and generation of a PV curve using the constant flow method on the ventilator (PVCF; insufflated volume = 1120 +/- 115 ml in zero end-expiratory pressure after 20 s expiratory pause, plateau pressure = 46 +/- 11 cmH2O). The maximal airway pressure allowed during PV measurement was 60 cmH2O. PEEP was set to 10 cmH2O immediately after PV measurement. Partial arterial oxygen tension (Pao2), partial carbon dioxide tension (Paco2) and mean arterial pressure were recorded each minute. RESULTS: PV measurement did not significantly affect Pao2, Paco2, mean arterial pressure and lung mechanics. Two patients exhibited a sustained increase in Pao2 by more than 20% after PVCF (>60 minutes). Two patients exhibited a decrease in Pao2 by more than 20% after PVSS, which was sustained in one. These latter patients had an upper inflection point identified on the PV curve. After PVSS, Paco2 increased by more than 10 mmHg in two patients and returned to baseline values after 15 minutes. One patient exhibited a decrease in mean arterial pressure by more than 10 mmHg for less than 5 minutes after PVSS and one patient after PVCF. CONCLUSION: Evaluation of the effects of a strategy aimed at improving oxygenation can be reliably recorded early after a single PV measurement that is not followed by a change in PEEP level. PV measurement using the constant flow method improves oxygenation in a limited number of patients.

Adult↗

PubMed2006

[Crohn disease and abdominal tuberculosis: complications related to a diagnostic error].

INTRODUCTION: We report the case of a patient with abdominal tuberculosis initially treated as Crohn disease. CASE: A 50-year-old man, diagnosed with Crohn disease, was admitted to the intensive care unit for acute respiratory failure. After a new diagnosis of pulmonary and ileocecal tuberculosis and appropriate treatment for it, he improved. DISCUSSION: It is difficult - but essential - to differentiate intestinal tuberculosis and Crohn disease, for the immune suppression necessary to treat the latter can induce severe complications of the former. Management of intestinal tuberculosis is primarily medical, with surgery reserved for complications such as obstruction, fistulization, perforation, and bleeding.

Antitubercular Agents↗

PubMed2006

Neuromuscular blocking agents decrease inflammatory response in patients presenting with acute respiratory distress syndrome.

OBJECTIVE: To evaluate the effects of neuromuscular blocking agents (NMBAs) on pulmonary and systemic inflammation in patients with acute respiratory distress syndrome ventilated with a lung-protective strategy. DESIGN: Multiple-center, prospective, controlled, and randomized trial. SETTING: One medical and two medical-surgical intensive care units. PATIENTS: A total of 36 patients with acute respiratory distress syndrome (Pao2/Fio2 ratio of < or =200 at a positive end-expiratory pressure of > or =5 cm H2O) were included within 48 hrs of acute respiratory distress syndrome onset. INTERVENTIONS: Patients were randomized to receive conventional therapy plus placebo (n = 18) or conventional therapy plus NMBAs (n = 18) for 48 hrs. Both groups were ventilated with a lung-protective strategy (tidal volume between 4 and 8 mL/kg ideal body weight, plateau pressure of < or =30 cm H2O). MEASUREMENTS AND MAIN RESULTS: Bronchoalveolar lavages and blood samples were performed, before randomization and at 48 hrs, to determine the concentrations of tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, and IL-8. Pao2/Fio2 ratio was evaluated before randomization and at 24, 48, 72, 96, and 120 hrs. A decrease over time in IL-8 concentrations (p = .034) was observed in the pulmonary compartment of the NMBA group. At 48 hrs after randomization, pulmonary concentrations of IL-1beta (p = .005), IL-6 (p = .038), and IL-8 (p = .017) were lower in the NMBA group as compared with the control group. A decrease over time in IL-6 (p = .05) and IL-8 (p = .003) serum concentrations was observed in the NMBA group. At 48 hrs after randomization, serum concentrations of IL-1beta (p = .037) and IL-6 (p = .041) were lower in the NMBA group as compared with the control group. A sustained improvement in Pao2/Fio2 ratio was observed and was reinforced in the NMBA group (p < .001). CONCLUSION: Early use of NMBAs decrease the proinflammatory response associated with acute respiratory distress syndrome and mechanical ventilation.

Cytokines↗

PubMed2005

Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome.

OBJECTIVE: Both prone position and high-frequency oscillatory ventilation (HFOV) have the potential to facilitate lung recruitment, and their combined use could thus be synergetic on gas exchange. Keeping the lung open could also potentially be lung protective. The aim of this study was to compare physiologic and proinflammatory effects of HFOV, prone positioning, or their combination in severe acute respiratory distress syndrome (ARDS). DESIGN: : Prospective, comparative randomized study. SETTING: A medical intensive care unit. PATIENTS: Thirty-nine ARDS patients with a Pao2/Fio2 ratio <150 mm Hg at positive end-expiratory pressure > or =5 cm H2O. INTERVENTIONS: After 12 hrs on conventional lung-protective mechanical ventilation (tidal volume 6 mL/kg of ideal body weight, plateau pressure not exceeding the upper inflection point, and a maximum of 35 cm H2O; supine-CV), 39 patients were randomized to receive one of the following 12-hr periods: conventional lung-protective mechanical ventilation in prone position (prone-CV), HFOV in supine position (supine-HFOV), or HFOV in prone position (prone-HFOV). MEASUREMENTS AND MAIN RESULTS: Prone-CV (from 138 +/- 58 mm Hg to 217 +/- 110 mm Hg, p < .0001) and prone-HFOV (from 126 +/- 40 mm Hg to 227 +/- 64 mm Hg, p < 0.0001) improved the Pao2/Fio2 ratio whereas supine-HFOV did not alter the Pao2/Fio2 ratio (from 134 +/- 57 mm Hg to 138 +/- 48 mm Hg). The oxygenation index ({mean airway pressure x Fio2 x 100}/Pao2) decreased in the prone-CV and prone-HFOV groups and was lower than in the supine-HFOV group. Interleukin-8 increased significantly in the bronchoalveolar lavage fluid (BALF) in supine-HFOV and prone-HFOV groups compared with prone-CV and supine-CV. Neutrophil counts were higher in the supine-HFOV group than in the prone-CV group. CONCLUSIONS: Although HFOV in the supine position does not improve oxygenation or lung inflammation, the prone position increases oxygenation and reduces lung inflammation in ARDS patients. Prone-HFOV produced similar improvement in oxygenation like prone-CV but was associated with higher BALF indexes of inflammation. In contrast, supine-HFOV did not improve gas exchange and was associated with enhanced lung inflammation.

Adult↗