Browsing by Author "Gajardo, Abraham I. J."
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- ItemContinuous prolonged prone positioning in COVID-19-related ARDS: a multicenter cohort study from Chile(2022) Cornejo, Rodrigo A.; Montoya, Jorge; Gajardo, Abraham I. J.; Graf, Jerónimo; Alegría Vargas, Leyla; Baghetti, Romyna; Irarrázaval, Anita; Santis, César; Pavez, Nicolás; Leighton, Sofía; Tomicic, Vinko; Morales, Daniel; Ruiz Balart, Carolina; Navarrete, Pablo; Vargas, Patricio; Gálvez, Roberto; Espinosa, Victoria; Lazo, Marioli; Pérez-Araos, Rodrigo A.; Garay, Osvaldo; Sepúlveda, Patrick; Martinez, Edgardo; Bruhn, Alejandro; The SOCHIMI Prone-COVID-19 Group; Pontificia Universidad Católica de Chile. Escuela de MedicinaBackground Prone positioning is currently applied in time-limited daily sessions up to 24 h which determines that most patients require several sessions. Although longer prone sessions have been reported, there is scarce evidence about the feasibility and safety of such approach. We analyzed feasibility and safety of a continuous prolonged prone positioning strategy implemented nationwide, in a large cohort of COVID-19 patients in Chile. Methods: Retrospective cohort study of mechanically ventilated COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS), conducted in 15 Intensive Care Units, which adhered to a national protocol of continuous prone sessions ≥ 48 h and until PaO2:FiO2 increased above 200 mm Hg. The number and extension of prone sessions were registered, along with relevant physiologic data and adverse events related to prone positioning. The cohort was stratified according to the first prone session duration: Group A, 2–3 days; Group B, 4–5 days; and Group C, > 5 days. Multivariable regression analyses were performed to assess whether the duration of prone sessions could impact safety. Results: We included 417 patients who required a first prone session of 4 (3–5) days of whom 318 (76.3%) received only one session. During the first prone session the main adverse event was grade 1–2 pressure sores in 97 (23.9%) patients; severe adverse events were infrequent with 17 non-scheduled extubations (4.2%). 90-day mortality was 36.2%. Ninety-eight patients (24%) were classified as group C; they exhibited a more severe ARDS at baseline, as reflected by lower PaO2:FiO2 ratio and higher ventilatory ratio, and had a higher rate of pressure sores (44%) and higher 90-day mortality (48%). However, after adjustment for severity and several relevant confounders, prone session duration was not associated with mortality or pressure sores. Conclusions: Nationwide implementation of a continuous prolonged prone positioning strategy for COVID-19 ARDS patients was feasible. Minor pressure sores were frequent but within the ranges previously described, while severe adverse events were infrequent. The duration of prone session did not have an adverse effect on safety.
- ItemDouble cycling with breath-stacking during partial support ventilation in ARDS: Just a feature of natural variability?(2025) Brito, Roberto; Morais, Caio C. A.; Arellano, Daniel H.; Gajardo, Abraham I. J.; Bruhn, Alejandro; Brochard, L.; Amato, Marcelo B. P.; Cornejo, Rodrigo A.Background Double cycling with breath-stacking (DC/BS) during controlled mechanical ventilation is considered potentially injurious, reflecting a high respiratory drive. During partial ventilatory support, its occurrence might be attributable to physiological variability of breathing patterns, reflecting the response of the mode without carrying specific risks. Methods This secondary analysis of a crossover study evaluated DC/BS events in hypoxemic patients resuming spontaneous breathing in cross-over under neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV +), and pressure support ventilation (PSV). DC/BS was defined as two inspiratory cycles with incomplete exhalation. Measurements included electrical impedance signal, airway pressure, esophageal and gastric pressures, and flow. Breathing variability, dynamic compliance (CLdyn), and end-expiratory lung impedance (EELI) were analyzed. Results Twenty patients under assisted breathing, with a median of 9 [5–14] days on mechanical ventilation, were included. DC/BS was attributed to either a single (42%) or two apparent consecutive inspiratory efforts (58%). The median [IQR] incidence of DC/BS was low: 0.6 [0.1–2.6] % in NAVA, 0.0 [0.0–0.4] % in PAV + , and 0.1 [0.0–0.4] % in PSV (p = 0.06). DC/BS events were associated with patient’s coefficient of variability for tidal volume (p = 0.014) and respiratory rate (p = 0.011). DC/BS breaths exhibited higher tidal volume, muscular pressure and regional stretch compared to regular breaths. Post-DC/BS cycles frequently exhibited improved EELI and CLdyn, with no evidence of expiratory muscle activation in 63% of cases. Conclusions DC/BS events during partial ventilatory support were infrequent and linked to breathing variability. Their frequency and physiological effects on lung compliance and EELI resemble spontaneous sighs and may not be considered a priori as harmful.
- ItemEstimation of changes in cyclic lung strain by electrical impedance tomography: Proof-of-concept study(2021) Cornejo, Rodrigo; Iturrieta, Pablo Cristián; Olegári, Tayran M. M.; Hurtado Sepúlveda, Daniel; Kajiyama, Carolina; Arellan, Daniel; Bruhn, Alejandro; Guiñez, Dannette; Cerda, María A.; Brito, Roberto; Gajardo, Abraham I. J.; Lazo, Marioli; López, Lorena; Morais, Caio C. A.; Gonzále, Sedric; Zavala, Miguel; Rojas, Verónica; Medel, Juan N.; Ramos, Cristóbal; Estuardo, Nivia
- ItemExtracorporeal Membrane Oxygenation for COVID-19-associated Severe Acute Respiratory Distress Syndrome in Chile A Nationwide Incidence and Cohort Study(2021) Diaz, Rodrigo A.; Graf, Jeronimo; Zambrano, Jose M.; Ruiz, Carolina; Espinoza, Juan A.; Bravo, Sebastian, I; Salazar, Pablo A.; Bahamondes, Juan C.; Castillo, Luis B.; Gajardo, Abraham I. J.; Kursbaum, Andres; Ferreira, Leonila L.; Valenzuela, Josefa; Castillo, Roberto E.; Perez-Araos, Rodrigo A.; Bravo, Marcela; Aquevedo, Andres F.; Gonzalez, Mauricio G.; Pereira, Rodrigo; Ortega, Leandro; Santis, Cesar; Fernandez, Paula A.; Cortes, Vilma; Cornejo, Rodrigo A.Rationale: The role of and needs for extracorporeal membrane oxygenation (ECMO) at a population level during the coronavirus disease (COVID-19) pandemic have not been completely established.
- ItemInflammatory biomarkers and pendelluft magnitude in ards patients transitioning from controlled to partial support ventilation(2022) Cornejo, Rodrigo A.; Arellano, Daniel H.; Ruiz-Rudolph, Pablo; Guinez, Dannette, V; Morais, Caio C. A.; Gajardo, Abraham I. J.; Lazo, Marioli T.; Brito, Roberto E.; Cerda, Maria A.; Gonzalez, Sedric J.; Rojas, Veronica A.; Diaz, Gonzalo A.; Lopez, Lorena D. M.; Medel, Juan N.; Soto, Dagoberto, I; Bruhn, Alejandro R.; Amato, Marcelo B. P.; Estuardo, Nivia R.The transition from controlled to partial support ventilation is a challenge in acute respiratory distress syndrome (ARDS) patients due to the risks of patient-self-inflicted lung injury. The magnitude of tidal volume (V-T) and intrapulmonary dyssynchrony (pendelluft) are suggested mechanisms of lung injury. We conducted a prospective, observational, physiological study in a tertiary academic intensive care unit. ARDS patients transitioning from controlled to partial support ventilation were included. On these, we evaluated the association between changes in inflammatory biomarkers and esophageal pressure swing (Delta P-es), transpulmonary driving pressure (Delta P-L), V-T, and pendelluft. Pendelluft was defined as the percentage of the tidal volume that moves from the non-dependent to the dependent lung region during inspiration, and its frequency at different thresholds (- 15, - 20 and - 25%) was also registered. Blood concentrations of inflammatory biomarkers (IL-6, IL-8, TNF-alpha, ANGPT2, RAGE, IL-18, Caspase-1) were measured before (T-0) and after 4-h (T-4) of partial support ventilation. Pendelluft, Delta P-es, Delta P-L and V-T were recorded. Nine out of twenty-four patients (37.5%) showed a pendelluft mean >= 10%. The mean values of Delta P-es, Delta P-L, and V-T were - 8.4 [- 6.7; - 10.2] cmH(2)O, 15.2 [12.3-16.5] cmH(2)O and 8.1 [7.3-8.9] m/kg PBW, respectively. Significant associations were observed between the frequency of high-magnitude pendelluft and IL-8, IL-18, and Caspase-1 changes (T-0/T-4 ratio). These results suggest that the frequency of high magnitude pendelluft may be a potential determinant of inflammatory response related to inspiratory efforts in ARDS patients transitioning to partial support ventilation. Future studies are needed to confirm these results.
- ItemPendelluft in hypoxemic patients resuming spontaneous breathing: proportional modes versus pressure support ventilation(2023) Arellano, Daniel H.; Brito, Roberto; Morais, Caio C. A.; Ruiz-Rudolph, Pablo; Gajardo, Abraham I. J.; Guiñez, Dannette V.; Lazo, Marioli T.; Ramirez, Ivan; Rojas, Verónica A.; Bruhn, Alejandro; Cerda, María A.; Medel, Juan N.; Illanes, Victor; Estuardo, Nivia R.; Brochard, Laurent J.; Amato, Marcelo B. P.; Cornejo, Rodrigo A.Background: Internal redistribution of gas, referred to as pendelluft, is a new potential mechanism of effort-dependent lung injury. Neurally-adjusted ventilatory assist (NAVA) and proportional assist ventilation (PAV +) follow the patient’s respiratory effort and improve synchrony compared with pressure support ventilation (PSV). Whether these modes could prevent the development of pendelluft compared with PSV is unknown. We aimed to compare pendelluft magnitude during PAV + and NAVA versus PSV in patients with resolving acute respiratory distress syndrome (ARDS). Methods: Patients received either NAVA, PAV + , or PSV in a crossover trial for 20-min using comparable assistance levels after controlled ventilation (> 72 h). We assessed pendelluft (the percentage of lost volume from the non-dependent lung region displaced to the dependent region during inspiration), drive (as the delta esophageal swing of the first 100 ms [ΔPes 100 ms]) and inspiratory effort (as the esophageal pressure–time product per minute [PTPmin]). We performed repeated measures analysis with post-hoc tests and mixed-effects models. Results: Twenty patients mechanically ventilated for 9 [5–14] days were monitored. Despite matching for a similar tidal volume, respiratory drive and inspiratory effort were slightly higher with NAVA and PAV + compared with PSV (ΔPes 100 ms of –2.8 [−3.8–−1.9] cm H2O, −3.6 [−3.9–−2.4] cm H2O and −2.1 [−2.5–−1.1] cm H2O, respectively, p < 0.001 for both comparisons; PTPmin of 155 [118–209] cm H2O s/min, 197 [145–269] cm H2O s/min, and 134 [93–169] cm H2O s/min, respectively, p < 0.001 for both comparisons). Pendelluft magnitude was higher in NAVA (12 ± 7%) and PAV + (13 ± 7%) compared with PSV (8 ± 6%), p < 0.001. Pendelluft magnitude was strongly associated with respiratory drive (β = -2.771, p-value < 0.001) and inspiratory effort (β = 0.026, p < 0.001), independent of the ventilatory mode. A higher magnitude of pendelluft in proportional modes compared with PSV existed after adjusting for PTPmin (β = 2.606, p = 0.010 for NAVA, and β = 3.360, p = 0.004 for PAV +), and only for PAV + when adjusted for respiratory drive (β = 2.643, p = 0.009 for PAV +). Conclusions: Pendelluft magnitude is associated with respiratory drive and inspiratory effort. Proportional modes do not prevent its occurrence in resolving ARDS compared with PSV.