Browsing by Author "Damiani L.F."
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- ItemPatient-ventilator dyssynchronies: Are they all the same? A clinical classification to guide actions(W.B. Saunders, 2020) Damiani L.F.; Damiani L.F.; Bruhn A.; Retamal J.; Bugedo G.© 2020 Elsevier Inc.Patient ventilatory dyssynchrony (PVD) is a mismatch between the respiratory drive of the patient and ventilatory assistance. It is a complex event seen in almost all ventilated patients and at any ventilator mode, with uncertain significance and prognosis. Due to its different pathophysiological mechanisms, there is still not consensual classification to guide us in selecting the best treatment. In the present review we aimed to summarize some clinical data on PVD, and to propose a clinical classification based on the type of PVD, from potentially innocuous to clearly harmful PVD, which could help clinicians in the decision-making process from adjusting ventilator settings to deeply sedate or paralyze the patient. Clearly, further studies are needed addressing risk factors, physiologic mechanisms and direct consequences of PVD in order to help clinicians to design effective and proven strategies at the bedside.
- ItemPhysiological and inflammatory consequences of high and low respiratory rate in acute respiratory distress syndrome(John Wiley and Sons Inc, 2021) Retamal J.; Damiani L.F.; Basoalto R.; Bruhn A.; Bugedo G.; Damiani L.F.; Benites M.H.; Larsson A.© 2021 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons LtdUsing protective mechanical ventilation strategies with low tidal volume is usually accompanied by an increment of respiratory rate to maintain adequate alveolar ventilation. However, there is no robust data that support the safety of a high respiratory rate concerning ventilator-induced lung injury. Several experimental animal studies have explored the effects of respiratory rate over lung physiology, using a wide range of frequencies and different models. Clinical evidence is scarce and restricted to the physiological impact of increased respiratory rate. Undoubtedly, the respiratory rate can influence respiratory mechanics in various ways as a factor of multiplication of the power of ventilation, and gas exchange, and also on alveolar dynamics. In this narrative review, we present our point of view over the main experimental and clinical evidence available regarding the effect of respiratory rate on ventilator-induced lung injury development.
- ItemPositive end-expiratory pressure, pleural pressure, and regional compliance during Pronation An Experimental Study(American Thoracic Society, 2021) Katira B.H.; Osada K.; Engelberts D.; Bastia L.; Damiani L.F.; Li X.; Chan H.; Yoshida T.; Post M.; Kavanagh B.P.; Katira B.H.; Osada K.; Bastia L.; Damiani L.F.; Li X.; Chan H.; Yoshida T.; Ferguson N.D.; Kavanagh B.P.; Brochard L.J.; Katira B.H.; Post M.; Kavanagh B.P.; Katira B.H.; Ferguson N.D.; Post M.; Kavanagh B.P.; Ferguson N.D.; Ferguson N.D.; Kavanagh B.P.; Kavanagh B.P.; Katira B.H.; Bastia L.; Damiani L.F.; Li X.; Li X.; Chan H.; Yoshida T.; Amato M.B.P.; Ferguson N.D.; Ferguson N.D.; Brochard L.J.© 2021 American Thoracic Society. All rights reserved.Rationale: The physiological basis of lung protection and the impact of positive end-expiratory pressure (PEEP) during pronation in acute respiratory distress syndrome are not fully elucidated. Objectives: To compare pleural pressure (Ppl) gradient, ventilation distribution, and regional compliance between dependent and nondependent lungs, and investigate the effect of PEEP during supination and pronation. Methods: We used a two-hit model of lung injury (saline lavage and high-volume ventilation) in 14 mechanically ventilated pigs and studied supine and prone positions. Global and regional lung mechanics including Ppl and distribution of ventilation (electrical impedance tomography) were analyzed across PEEP steps from 20 to 3 cm H2O. Two pigs underwent computed tomography scans: Tidal recruitment and hyperinflation were calculated. Measurements and Main Results: Pronation improved oxygenation, increased Ppl, thus decreasing transpulmonary pressure for any PEEP, and reduced the dorsal ventral pleural pressure gradient at PEEP,10 cm H2O. The distribution of ventilation was homogenized between dependent and nondependent while prone and was less dependent on the PEEP level than while supine. The highest regional compliance was achieved at different PEEP levels in dependent and nondependent regions in supine position (15 and 8 cm H2O), but for similar values in prone position (13 and 12 cm H2O). Tidal recruitment was more evenly distributed (dependent and nondependent), hyperinflation lower, and lungs cephalocaudally longer in the prone position. Conclusions: In this lung injury model, pronation reduces the vertical pleural pressure gradient and homogenizes regional ventilation and compliance between the dependent and nondependent regions. Homogenization is much less dependent on the PEEP level in prone than in supine positon.
- ItemReverse Triggering Dyssynchrony 24 h after Initiation of Mechanical Ventilation(Lippincott Williams and Wilkins, 2021) Mellado Artigas R.; Damiani L.F.; Pham T.; Chen L.; Rauseo M.; Telias I.; Soliman I.; Junhasavasdikul D.; Santis C.; Smith O.M.; Comtois N.; Sinderby C.; Heunks L.; Brochard L.; Piraino T.; Telias I.; Mellado Artigas R.; Damiani L.F.; Pham T.; Chen L.; Rauseo M.; Telias I.; Soliman I.; Junhasavasdikul D.; Santis C.; Goligher E.; Brochard L.; Smith O.M.; Mellado Artigas R.; Mellado Artigas R.; Comtois N.; Damiani L.F.; Goligher E.; Goligher E.; Heunks L.; Junhasavasdikul D.; Pham T.; Pham T.; Pham T.© 2021 Lippincott Williams and Wilkins. All rights reserved.Background: Reverse triggering is a delayed asynchronous contraction of the diaphragm triggered by passive insufflation by the ventilator in sedated mechanically ventilated patients. The incidence of reverse triggering is unknown. This study aimed at determining the incidence of reverse triggering in critically ill patients under controlled ventilation. Methods: In this ancillary study, patients were continuously monitored with a catheter measuring the electrical activity of the diaphragm. A method for automatic detection of reverse triggering using electrical activity of the diaphragm was developed in a derivation sample and validated in a subsequent sample. The authors assessed the predictive value of the software. In 39 recently intubated patients under assist-control ventilation, a 1-h recording obtained 24 h after intubation was used to determine the primary outcome of the study. The authors also compared patients' demographics, sedation depth, ventilation settings, and time to transition to assisted ventilation or extubation according to the median rate of reverse triggering. Results: The positive and negative predictive value of the software for detecting reverse triggering were 0.74 (95% CI, 0.67 to 0.81) and 0.97 (95% CI, 0.96 to 0.98). Using a threshold of 1 μV of electrical activity to define diaphragm activation, median reverse triggering rate was 8% (range, 0.1 to 75), with 44% (17 of 39) of patients having greater than or equal to 10% of breaths with reverse triggering. Using a threshold of 3 μV, 26% (10 of 39) of patients had greater than or equal to 10% reverse triggering. Patients with more reverse triggering were more likely to progress to an assisted mode or extubation within the following 24 h (12 of 39 [68%]) vs. 7 of 20 [35%]; P = 0.039). Conclusions: Reverse triggering detection based on electrical activity of the diaphragm suggests that this asynchrony is highly prevalent at 24 h after intubation under assist-control ventilation. Reverse triggering seems to occur during the transition phase between deep sedation and the onset of patient triggering.