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Sangeeta Mehta - One of the best experts on this subject based on the ideXlab platform.
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utilization and effect of neuromuscular blockade in a randomized trial of High Frequency Oscillation
Journal of Critical Care, 2021Co-Authors: Sangeeta Mehta, Francois Lamontagne, Niall D Ferguson, Qi Zhou, Jan O Friedrich, Maureen O Meade, Ruxandra Pinto, Neill K J AdhikariAbstract:Abstract Purpose We evaluated characteristics associated with neuromuscular blockade (NMB) use, center-level variation, and whether NMB mediated excess mortality among patients assigned to High-Frequency oscillatory ventilation (HFOV) in the OSCILLATE trial. Materials and methods NMB exposure was defined as receipt after randomization; the primary outcome was hospital mortality. Descriptive analyses compared NMB-exposed vs unexposed patients. Multivariable analyses included patients not on baseline NMB. Cox regression evaluated associations of patient- and center-level variables with NMB use. A log-normal frailty model evaluated center effects. Mediation analysis examined the effect of NMB in HFOV-assigned patients. Results 376/548 patients (39 centers) received post-randomization NMB, of whom 165 received baseline NMB. Patients receiving post-randomization NMB (vs. not) had worse lung mechanics and gas exchange, received more sedation and vasopressors (p Conclusions In OSCILLATE, receipt of post-randomization NMB was associated with worse outcomes, but NMB use did not mediate HFOV-associated Higher mortality.
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coenrollment in a randomized trial of High Frequency Oscillation prevalence patterns predictors and outcomes
Critical Care Medicine, 2015Co-Authors: Deborah J Cook, Neill K J Adhikari, Niall D Ferguson, Qi Zhou, Lori Hand, Peggy Austin, Andrea Matte, Valerie Danesh, Yaseen M Arabi, Sangeeta MehtaAbstract:Objective: Enrollment of individual patients into more than one study has been poorly evaluated. The objective of this study was to describe the characteristics of patients, researchers and centers involved in coenrollment, studies precluding coenrollment, and the prevalence, patterns, predictors, and outcomes of coenrollment in a randomized clinical trial. Design, Setting, Methods: We conducted an observational study nested within the Oscillation for Acute Respiratory Distress Syndrome Treated Early Trial, which compared High-Frequency oscillatory ventilation to conventional ventilation. We collected patient, center, and study data on coenrollment in randomized patients. Multilevel regression examined factors independently associated with coenrollment, considering clustering within centers. We examined the effect of coenrollment on safety and the trial outcome. Interventions None. Measurements and Main Results: Overall, 127 of 548 randomized patients (23.2%) were coenrolled in 25 unique studies. Coenrollment was reported in 17 of 39 centers (43.6%). Patients were most commonly coenrolled in one additional randomized clinical trial (76; 59.8%). Coenrollment was less likely in older patients (odds ratio, 0.87; 95% CI, 0.76–0.997), and in ICUs with greater than 26 beds (odds ratio, 0.56; 95% CI, 0.34–0.94), and more likely by investigators with more than 11 years of experience (odds ratio, 1.73; 95% CI, 1.06–2.82), by research coordinators with more than 8 years of experience (odds ratio, 1.87; 95% CI, 1.11–3.18) and in Canada (odds ratio, 4.66; 95% CI, 1.43–15.15). Serious adverse events were similar between coenrolled High-Frequency oscillatory ventilation and control patients. Coenrollment did not modify the treatment effect of High-Frequency oscillatory ventilation on hospital mortality. Conclusions: Coenrollment occurred in 23% of patients, commonly in younger patients, in smaller centers with more research infrastructure, and in Canada. Coenrollment did not influence patient safety or trial results.
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High Frequency Oscillation in early acute respiratory distress syndrome
Critical Care, 2013Co-Authors: Niall D Ferguson, Francois Lamontagne, Sangeeta Mehta, Qi Zhou, Deborah J Cook, Gordon H Guyatt, Peggy Austin, Andrea Matte, Stephen D Walter, John GrantonAbstract:Background Previous trials suggesting that High-Frequency oscillatory ventilation (HFOV) reduced mortality among adults with the acute respiratory distress syndrome (ARDS) were limited by the use of outdated comparator ventilation strategies and small sample sizes. Methods In a multicenter, randomized, controlled trial conducted at 39 intensive care units in five countries, we randomly assigned adults with new-onset, moderate-to-severe ARDS to HFOV targeting lung recruitment or to a control ventilation strategy targeting lung recruitment with the use of low tidal volumes and High positive end-expiratory pressure. The primary outcome was the rate of in-hospital death from any cause. Results On the recommendation of the data monitoring committee, we stopped the trial after 548 of a planned 1200 patients had undergone randomization. The two study groups were well matched at baseline. The HFOV group underwent HFOV for a median of 3 days (interquartile range, 2 to 8); in addition, 34 of 273 patients (12%) in the control group received HFOV for refractory hypoxemia. In-hospital mortality was 47% in the HFOV group, as compared with 35% in the control group (relative risk of death with HFOV, 1.33; 95% confidence interval, 1.09 to 1.64; P = 0.005). This finding was independent of baseline abnormalities in oxygenation or respiratory compliance. Patients in the HFOV group received Higher doses of midazolam than did patients in the control group (199 mg per day [interquartile range, 100 to 382] vs. 141 mg per day [interquartile range, 68 to 240], P<0.001), and more patients in the HFOV group than in the control group received neuromuscular blockers (83% vs. 68%, P<0.001). In addition, more patients in the HFOV group received vasoactive drugs (91% vs. 84%, P = 0.01) and received them for a longer period than did patients in the control group (5 days vs. 3 days, P = 0.01). Conclusions In adults with moderate-to-severe ARDS, early application of HFOV, as compared with a ventilation strategy of low tidal volume and High positive end-expiratory pressure, does not reduce, and may increase, in-hospital mortality. (Funded by the Canadian Institutes of Health Research; Current Controlled Trials numbers, ISRCTN42992782 and ISRCTN87124254, and ClinicalTrials.gov numbers, NCT00474656 and NCT01506401.)
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High Frequency Oscillation in adults a utilization review
Critical Care Medicine, 2011Co-Authors: Neill K J Adhikari, Abdel Bashir, Francois Lamontagne, Sangeeta Mehta, Niall D Ferguson, Qi Zhou, Lori Hand, Kasia Czarnecka, Deborah J Cook, John GrantonAbstract:Objectives High-Frequency Oscillation is used for adults with acute lung injury/acute respiratory distress syndrome. Given the uncertain benefits, our objective was to describe contemporary patient selection, High-Frequency Oscillation utilization, and outcomes. Design Utilization review. Setting Ten academic centers (Ontario, Canada; January 1, 2005-January 31, 2007). Patients We included 190 consecutive adults treated with High-Frequency Oscillation and retrospectively abstracted data on patient demographics, gas exchange, hemodynamics, settings during conventional ventilation and High-Frequency Oscillation, adjunctive therapies, and outcomes. We used logistic regression to explore associations with oxygenation response and hemodynamic and ventilatory complications (2 hrs after High-Frequency Oscillation initiation) and mortality. Continuous data are reported as mean (sd) or median (quartile 1, quartile 3). Interventions None. Measurements and main results Patients (60.0% male; mean age, 52; sd 17) had predominantly acute lung injury/acute respiratory distress syndrome (89.8%) and were severely ill (mean Acute Physiology and Chronic Health Evaluation II score, 28; sd, 9) and hypoxemic (mean Pao2/Fio2, 80; sd, 42). High-Frequency Oscillation was started a median of 2 (1, 8) days after intubation and continued for a median of 3 (2, 7) days. During High-Frequency Oscillation, adjunctive treatments (neuromuscular blockade, 75.6%; recruitment maneuvers, 49.5%; nitric oxide, 34.0%; steroids, 63.1%) and new barotrauma or chest tube placement (23.5%) were common. Ten patients (5.3%) had technical complications; five required a new ventilator. Reasons for stopping High-Frequency Oscillation included death or withdrawal of life support (39.1%), significant improvement in respiratory failure (37.6%), and inadequate improvement (23.3%). One hundred and twenty-eight of 189 patients died in hospital. Most (62.5%) had a positive oxygenation response after 2 hrs of High-Frequency Oscillation (mean absolute increase in PaO₂/FiO₂, 22 [SD, 54]; 95% confidence interval of mean 14-31). A minority had lower PaO₂/FiO₂ (32.5%) or a hemodynamic (27.5%) or ventilatory (30.5%) complication. Older age, Acute Physiology and Chronic Health Evaluation II score, and Paco2 before High-Frequency Oscillation were independently associated with mortality. Conclusions Most patients treated with High-Frequency Oscillation have acute respiratory distress syndrome and severe hypoxemia that modestly improves 2 hrs after High-Frequency Oscillation application. However, oxygenation worsens in some patients, complications are common, and mortality is High.
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open the lung with High Frequency Oscillation ventilation or conventional mechanical ventilation it may not matter
Critical Care, 2010Co-Authors: Sangeeta Mehta, Vito FanelliAbstract:The ‘open lung’ approach has been proposed as a reasonable ventilation strategy to mitigate ventilatorinduced lung injury (VILI) and possibly reduce acute respiratory distress syndrome (ARDS)-related mortality. However, several randomized clinical trials have failed to show any signifi cant clinical benefi t of a ventilation strategy applying Higher positive end-expiratory pressure (PEEP) and low tidal volume. Dispute regarding the optimal levels of PEEP in ARDS patients represents the substrate for a translational research eff ort from the bedside to the bench, driving animal studies aimed at elucidating which ventilation strategies reduce biotrauma, considered one of the most important driving forces of VILI and ARDS-related multi-organ failure and mortality. Inappropriate values for end-inspiratory or end-expiratory pressure have clear potential to damage a lung predisposed to VILI. In the heterogeneous environment of the ARDS ‘baby lung’, lung recruitment and the avoidance of tidal overstretch with High-Frequency Oscillation ventilation or conventional mechanical ventilation, guided by respiratory mechanics, appears to reduce VILI.
Peter C Rimensberger - One of the best experts on this subject based on the ideXlab platform.
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lung recruitment and lung volume maintenance a strategy for improving oxygenation and preventing lung injury during both conventional mechanical ventilation and High Frequency Oscillation
Intensive Care Medicine, 2000Co-Authors: Peter C Rimensberger, Jeanclaude Pache, Colin Mckerlie, Helena FrndovaAbstract:Objective: To determine whether using a small tidal volume (5 ml/kg) ventilation following sustained inflation with positive end-expiratory pressure (PEEP) set above the critical closing pressure (CCP) allows oxygenation equally well and induces as little lung damage as High-Frequency Oscillation following sustained inflation with a continuous distending pressure (CDP) slightly above the CCP of the lung.¶Material and methods: Twelve surfactant-depleted adult New Zealand rabbits were ventilated for 4 h after being randomly assigned to one of two groups: group 1, conventional mechanical ventilation, tidal volume 5 ml/kg, sustained inflation followed by PEEP > CCP; group 2, High-Frequency Oscillation, sustained inflation followed by CDP > CCP.¶Results: In both groups oxygenation improved substantially after sustained inflation (P < 0.05) and remained stable over 4 h of ventilation without any differences between the groups. Histologically, both groups showed only little airway injury to bronchioles, alveolar ducts, and alveolar airspace, with no difference between the two groups. Myleoperoxidase content in homogenized lung tissue, as a marker of leukocyte infiltration, was equivalent in the two groups.¶Conclusions: We conclude that a volume recruitment strategy during small tidal volume ventilation and maintaining lung volumes above lung closing is as protective as that of High-Frequency Oscillation at similar lung volumes in this model of lung injury
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first intention High Frequency Oscillation with early lung volume optimization improves pulmonary outcome in very low birth weight infants with respiratory distress syndrome
Pediatrics, 2000Co-Authors: Peter C Rimensberger, Maurice Beghetti, Silviane Hanquinet, Michel BernerAbstract:The lack of decline in chronic lung disease of prematurity despite the generalized use of surfactant and alternative modes of ventilation such as High-Frequency Oscillation (HFO) has been attributed to some misunderstanding of how HFO has to be used. We used a new ventilatory strategy in very low birth weight (VLBW) infants, by initiating HFO immediately after intubation and attempting early lung volume optimization before surfactant was administered.
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first intention High Frequency Oscillation with early lung volume optimization improves pulmonary outcome in very low birth weight infants with respiratory distress syndrome
Pediatrics, 2000Co-Authors: Peter C Rimensberger, Maurice Beghetti, Silviane Hanquinet, Michel BernerAbstract:Objectives. The lack of decline in chronic lung disease of prematurity despite the generalized use of surfactant and alternative modes of ventilation such as High-Frequency Oscillation (HFO) has been attributed to some misunderstanding of how HFO has to be used. We used a new ventilatory strategy in very low birth weight (VLBW) infants, by initiating HFO immediately after intubation and attempting early lung volume optimization before surfactant was administered. Study Design. The outcome of 32 VLBW infants, managed with first intention HFO over a period of 24 months (September 1, 1996 and August 31, 1998) was compared by chart review with 39 historical controls, consecutively managed with conventional mechanical ventilation (CMV) over a period of 24 months (January 1, 1994 and December 31, 1995). Setting. An 11-bed tertiary care pediatric and neonatal intensive care unit of a university teaching hospital. Results. The 2 groups of patients were similar in demographic distribution of birth weight, gestational age, race, and gender. Patients on first intention HFO were ventilator-dependent (median [95% confidence interval]: 5 [3–6] vs 14 [6–23] days) and oxygen-dependent (12 [4–17] vs 51 [20–60] days) for a shorter time than patients on CMV. The incidence of chronic lung disease at 36 weeks of gestational age was significantly lower in the HFO group compared with the CMV group (0% vs 34%). Conclusions. First intention HFO with early lung volume optimization shortened the need for respiratory support and improved pulmonary outcome of VLBW infants with respiratory distress syndrome significantly.
Robert M. Kacmarek - One of the best experts on this subject based on the ideXlab platform.
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open lung protective ventilation with pressure control ventilation High Frequency Oscillation and intratracheal pulmonary ventilation results in similar gas exchange hemodynamics and lung mechanics
Anesthesiology, 2003Co-Authors: Khaled Sedeek, Klaudiusz Suchodolski, Muneyuki Takeuchi, Sara O Vargas, Motomu Shimaoka, Jay J Schnitzer, Robert M. KacmarekAbstract:Background: Pressure control ventilation (PCV), High-Frequency Oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Methods: Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of PaO 2 /FIO 2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H 2 O. Animals were then ventilated for 4 h. Results: There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 ± 2.1 ml/kg; ITPV, 2.7 ± 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 ± 2.6 cm H 2 O; ITPV, 22.3 ± 4.8 cm H 2 O; HFO, approximately 24.3 cm H 2 O) were Higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. Conclusion: These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.
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determinants of tidal volume during High Frequency Oscillation
Critical Care Medicine, 2003Co-Authors: Khaled Sedeek, Klaudiusz Suchodolski, Muneyuki Takeuchi, Robert M. KacmarekAbstract:OBJECTIVE: High-Frequency Oscillation has been proposed for use in adult acute respiratory distress syndrome. However, limited data are available on the effect of pressure amplitude and rate (Hz) on tidal volumes delivered during High-Frequency Oscillation in adults. DESIGN: Prospective, animal model, lung injury study. SETTING: Large-animal laboratory of a university-affiliated medical center. SUBJECTS: Nine sheep (29.2 +/- 2.4 kg). INTERVENTIONS: Severe lung injury was induced by repeated saline lung lavage. After stabilization, High-Frequency Oscillation was initiated at a mean airway pressure equal to the point of maximum curvature on the deflation limb of the pressure-volume curve (26 +/- 1.9 cm H2O). Tidal volume at all combinations of rates of 4, 6, 8, and 10 Hz, pressure amplitudes of 30, 40, 50, and 60 cm H2O, and inspiratory/expiratory ratios of 1:1 and 1:2 (using the Sensormedics 3100B oscillator) were measured. Flow was measured by a pneumotachometer, amplified and digitized at 1000 Hz. Three breaths were analyzed at each setting. MEASUREMENTS AND MAIN RESULTS: At both inspiratory/expiratory ratios, tidal volume was directly proportional to pressure amplitude and inversely proportional to Frequency. During an inspiratory/expiratory ratio of 1:1, at 60 cm H2O pressure amplitude and 4 Hz, a tidal volume of 129.1 +/- 34.8 mL (4.4 +/- 1.2 mL/kg) was delivered. CONCLUSIONS: At low rates and High-pressure amplitudes in this model, tidal volumes approaching conventional mechanical ventilation can be delivered during High-Frequency Oscillation.
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optimal mean airway pressure during High Frequency Oscillation predicted by the pressure volume curve
Anesthesiology, 2001Co-Authors: Sven Goddon, Jonathan Hromi, Yuji Fujino, Robert M. KacmarekAbstract:Background: A number of groups have recommended setting positive end-expiratory pressure during conventional mechanical ventilation in adults at 2 cm H 2 O above the lower corner pressure (P CL ) of the inspiratory pressure-volume (P-V) curve of the respiratory system. No equivalent recommendations for the setting of the mean airway pressure (P aw ) during High-Frequency Oscillation (HFO) exist. The authors questioned if the P aw resulting in the best oxygenation without hemodynamic compromise during HFO is related to the static P-V curve in a large animal model of acute respiratory distress syndrome. Methods: Saline lung lavage was performed in seven sheep (28 ± 5 kg, mean ± SD) until the arterial oxygen partial pressure/fraction of inspired oxygen ratio decreased to 85 ± 27 mmHg at a positive end-expiratory pressure of 5 cm H 2 O (initial injury). The P CL (20 ± 1 cm H 2 O) on the inflation limb and the point of maximum curvature change (PMC; 26 ± 1 cm H 2 O) on the deflation limb of the static P-V curve were determined. The sheep were subjected to four 1-h cycles of HFO at different levels of P aw (P CL + 2, + 6, + 10, + 14 cm H 2 O), applied in random order. Each cycle was preceded by a recruitment maneuver at a sustained P aw of 50 cm H 2 O for 60 s. Results: High-Frequency Oscillation with a P aw of 6 cm H 2 O above P CL (P CL + 6) resulted in a significant improvement in oxygenation (P < 0.01 vs. initial injury). No further improvement in oxygenation was observed with Higher P aw , but cardiac output decreased, pulmonary vascular resistance increased, and oxygen delivery decreased at P aw greater than P CL + 6. The PMC on the deflation limb of the P-V curve was equal to the P CL + 6 (r = 0.77, P < 0.05). Conclusion: In this model of acute respiratory distress syndrome, optimal P aw during HFO is equal to P CL + 6, which correlates with the PMC.
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optimal mean airway pressure during High Frequency Oscillation predicted by the pressure volume curve
Anesthesiology, 2001Co-Authors: Sven Goddon, Jonathan Hromi, Yuji Fujino, Robert M. KacmarekAbstract:Background: A number of groups have recommended setting positive end-expiratory pressure during conventional mechanical ventilation in adults at 2 cm H 2 O above the lower corner pressure (P CL ) of the inspiratory pressure-volume (P-V) curve of the respiratory system. No equivalent recommendations for the setting of the mean airway pressure (P aw ) during High-Frequency Oscillation (HFO) exist. The authors questioned if the P aw resulting in the best oxygenation without hemodynamic compromise during HFO is related to the static P-V curve in a large animal model of acute respiratory distress syndrome. Methods: Saline lung lavage was performed in seven sheep (28 ± 5 kg, mean ± SD) until the arterial oxygen partial pressure/fraction of inspired oxygen ratio decreased to 85 ± 27 mmHg at a positive end-expiratory pressure of 5 cm H 2 O (initial injury). The P CL (20 ± 1 cm H 2 O) on the inflation limb and the point of maximum curvature change (PMC; 26 ± 1 cm H 2 O) on the deflation limb of the static P-V curve were determined. The sheep were subjected to four 1-h cycles of HFO at different levels of P aw (P CL + 2, + 6, + 10, + 14 cm H 2 O), applied in random order. Each cycle was preceded by a recruitment maneuver at a sustained P aw of 50 cm H 2 O for 60 s. Results: High-Frequency Oscillation with a P aw of 6 cm H 2 O above P CL (P CL + 6) resulted in a significant improvement in oxygenation (P < 0.01 vs. initial injury). No further improvement in oxygenation was observed with Higher P aw , but cardiac output decreased, pulmonary vascular resistance increased, and oxygen delivery decreased at P aw greater than P CL + 6. The PMC on the deflation limb of the P-V curve was equal to the P CL + 6 (r = 0.77, P < 0.05). Conclusion: In this model of acute respiratory distress syndrome, optimal P aw during HFO is equal to P CL + 6, which correlates with the PMC.
Michel Berner - One of the best experts on this subject based on the ideXlab platform.
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first intention High Frequency Oscillation with early lung volume optimization improves pulmonary outcome in very low birth weight infants with respiratory distress syndrome
Pediatrics, 2000Co-Authors: Peter C Rimensberger, Maurice Beghetti, Silviane Hanquinet, Michel BernerAbstract:The lack of decline in chronic lung disease of prematurity despite the generalized use of surfactant and alternative modes of ventilation such as High-Frequency Oscillation (HFO) has been attributed to some misunderstanding of how HFO has to be used. We used a new ventilatory strategy in very low birth weight (VLBW) infants, by initiating HFO immediately after intubation and attempting early lung volume optimization before surfactant was administered.
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first intention High Frequency Oscillation with early lung volume optimization improves pulmonary outcome in very low birth weight infants with respiratory distress syndrome
Pediatrics, 2000Co-Authors: Peter C Rimensberger, Maurice Beghetti, Silviane Hanquinet, Michel BernerAbstract:Objectives. The lack of decline in chronic lung disease of prematurity despite the generalized use of surfactant and alternative modes of ventilation such as High-Frequency Oscillation (HFO) has been attributed to some misunderstanding of how HFO has to be used. We used a new ventilatory strategy in very low birth weight (VLBW) infants, by initiating HFO immediately after intubation and attempting early lung volume optimization before surfactant was administered. Study Design. The outcome of 32 VLBW infants, managed with first intention HFO over a period of 24 months (September 1, 1996 and August 31, 1998) was compared by chart review with 39 historical controls, consecutively managed with conventional mechanical ventilation (CMV) over a period of 24 months (January 1, 1994 and December 31, 1995). Setting. An 11-bed tertiary care pediatric and neonatal intensive care unit of a university teaching hospital. Results. The 2 groups of patients were similar in demographic distribution of birth weight, gestational age, race, and gender. Patients on first intention HFO were ventilator-dependent (median [95% confidence interval]: 5 [3–6] vs 14 [6–23] days) and oxygen-dependent (12 [4–17] vs 51 [20–60] days) for a shorter time than patients on CMV. The incidence of chronic lung disease at 36 weeks of gestational age was significantly lower in the HFO group compared with the CMV group (0% vs 34%). Conclusions. First intention HFO with early lung volume optimization shortened the need for respiratory support and improved pulmonary outcome of VLBW infants with respiratory distress syndrome significantly.
Spyros Zakynthinos - One of the best experts on this subject based on the ideXlab platform.
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intermittent recruitment with High Frequency Oscillation tracheal gas insufflation in acute respiratory distress syndrome
European Respiratory Journal, 2012Co-Authors: Spyros D Mentzelopoulos, Sotiris Malachias, Stelios Kokkoris, Charis Roussos, Elias Zintzaras, E Zakynthinos, Demosthenes Makris, Eleni Magira, V Markaki, Spyros ZakynthinosAbstract:In acute respiratory distress syndrome (ARDS), recruitment sessions of High-Frequency Oscillation (HFO) and tracheal gas insufflation (TGI) with short-lasting recruitment manoeuvres (RMs) may improve oxygenation and enable reduction of subsequent conventional mechanical ventilation (CMV) pressures. We determined the effect of adding HFO-TGI sessions to lung-protective CMV on early/severe ARDS outcome. We conducted a prospective clinical trial, subdivided into a first single-centre period and a second two-centre period. We enrolled 125 (first period, n = 54) patients with arterial oxygen tension (P(a,O(2)))/inspiratory oxygen fraction (F(I,O(2))) of 12 consecutive hours at an end-expiratory pressure of ≥ 8 cmH(2)O. Patients were randomly assigned to an HFO-TGI group (receiving HFO-TGI sessions with RMs, interspersed with lung-protective CMV; n = 61) or CMV group (receiving lung-protective CMV and RMs; n = 64). The primary outcome was survival to hospital discharge. Pre-enrolment ventilation duration was variable. During days 1-10 post-randomisation, P(a,O(2))/F(I,O(2))), oxygenation index, plateau pressure and respiratory compliance were improved in the HFO-TGI group versus the CMV group (p < 0.001 for group × time). Within days 1-60, the HFO-TGI group had more ventilator-free days versus the CMV group (median (interquartile range) 31.0 (0.0-42.0) versus 0.0 (0.0-23.0) days; p < 0.001), and more days without respiratory, circulatory, renal, coagulation and liver failure (p ≤ 0.003). Survival to hospital discharge was Higher in the HFO-TGI group versus the CMV group (38 (62.3%) out of 61 versus 23 (35.9%) out of 64 subjects; p = 0.004). Intermittent recruitment with HFO-TGI and RMs may improve survival in early/severe ARDS.
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comparison of High Frequency Oscillation and tracheal gas insufflation versus standard High Frequency Oscillation at two levels of tracheal pressure
Intensive Care Medicine, 2010Co-Authors: Spyros D Mentzelopoulos, Sotiris Malachias, Stelios Kokkoris, Charis Roussos, Spyros ZakynthinosAbstract:Purpose In acute respiratory distress syndrome (ARDS), combined High-Frequency Oscillation (HFO) and tracheal gas insufflation (TGI) may improve oxygenation through a TGI-induced increase in mean tracheal pressure (Ptr). We compared standard HFO and HFO-TGI matched for Ptr, in order to determine whether TGI affects gas exchange independently from Ptr.
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acute effects of combined High Frequency Oscillation and tracheal gas insufflation in severe acute respiratory distress syndrome
Critical Care Medicine, 2007Co-Authors: Spyros D Mentzelopoulos, Sotiris Malachias, Charis Roussos, Antonia Koutsoukou, Sotiris Sourlas, Alexandra Lachana, Spyros ZakynthinosAbstract:OBJECTIVE In acute respiratory distress syndrome (ARDS), High-Frequency Oscillation (HFO) improves oxygenation relative to conventional mechanical ventilation (CMV). Alveolar ventilation is improved by adding tracheal gas insufflation (TGI) to CMV. We hypothesized that combined HFO and TGI (HFO-TGI) might result in improved gas exchange relative to both standard HFO and CMV according to the ARDS Network protocol. DESIGN Prospective, randomized, crossover study. SETTING A 30-bed university intensive care unit. PATIENTS A total of 14 patients with early (<72 hrs in duration), severe (PaO2/FiO2 of <150 mm Hg and prerecruitment oxygenation index of 22.8 +/- 1.9 [mean +/- SEM]), primary ARDS. INTERVENTIONS Patients were ventilated with HFO without (60 mins) and combined with TGI (6.1 +/- 0.1 L/min, 60 mins) in random order. HFO sessions were repeated in inverse order within 24 hrs. HFO sessions were preceded and followed by ARDS Network CMV. Four recruitment maneuvers were performed during the study period. During HFO sessions, mean airway pressure was set at 1 cm H2O above the point of maximal curvature of the respiratory system expiratory pressure-volume curve. MEASUREMENTS AND MAIN RESULTS Gas exchange and hemodynamics were determined before, during, and after HFO sessions. HFO-TGI improved PaO2/FiO2 relative to HFO and CMV (174.5 +/- 10.4 vs. 136.0 +/- 10.0 and 105.0 +/- 3.7 mm Hg, respectively, p < .05 for both) and oxygenation index relative to HFO (17.1 +/- 1.3 vs. 22.3 +/- 1.7, respectively p < .05). PaO2/FiO2 returned to baseline within 3 hrs after HFO. During HFO-TGI, shunt fraction and mixed venous oxygen saturation improved relative to CMV (0.36 +/- 0.01 vs. 0.45 +/- 0.01 and 77.8% +/- 1.2% vs. 71.8% +/- 1.3%, respectively, p < .05 for both). PaCO2 and hemodynamics were unaffected by HFO sessions. Respiratory mechanics remained unchanged throughout the study period. CONCLUSIONS In early onset, primary, severe ARDS, short-term HFO-TGI improves oxygenation relative to standard HFO and ARDS Network CMV.