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Hemodynamic and Pulmonary Permeability Characterization of Hantavirus Cardiopulmonary Syndrome by Transpulmonary Thermodilution

2019 , LOPEZ HERNANDEZ, RENE RAMON , Rodrigo Pérez-Araos , Álvaro Salazar , Ana L. Ulloa , VIAL COX, MARIA CECILIA , VIAL CLARO, PABLO AGUSTIN , GRAF SANTOS, JERÓNIMO

Hantavirus cardiopulmonary syndrome (HCPS) is characterized by capillary leak, pulmonary edema (PE), and shock, which leads to death in up to 40% of patients. Treatment is supportive, including mechanical ventilation (MV) and extracorporeal membrane oxygenation (ECMO). Hemodynamic monitoring is critical to titrate therapy and to decide ECMO support. Transpulmonary thermodilution (TPTD) provides hemodynamic and PE data that have not been systematically used to understand HCPS pathophysiology. We identified 11 HCPS patients monitored with TPTD: eight on MV, three required ECMO. We analyzed 133 measurements to describe the hemodynamic pattern and its association with PE. The main findings were reduced stroke volume, global ejection fraction (GEF), and preload parameters associated with increased extravascular lung water and pulmonary vascular permeability compatible with hypovolemia, myocardial dysfunction, and increased permeability PE. Lung water correlated positively with heart rate (HR, r = 0.20) and negatively with mean arterial pressure (r = −0.27) and GEF (r = −0.36), suggesting that PE is linked to hemodynamic impairment. Pulmonary vascular permeability correlated positively with HR (r = 0.31) and negatively with cardiac index (r = −0.49), end-diastolic volume (r = −0.48), and GEF (r = −0.40), suggesting that capillary leak contributes to hypovolemia and systolic dysfunction. In conclusion, TPTD data suggest that in HCPS patients, increased permeability leads to PE, hypovolemia, and circulatory impairment.

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Survival of Critically Ill Oncologic Patients Requiring Invasive Ventilatory Support: A Prospective Comparative Cohort Study With Nononcologic Patients

2019 , Rene López , Suraj Rajesh Samtani , Jose Miguel Montes , PEREZ ARAOS, RODRIGO ALEJANDRO , Maria Jose Martin , Alvaro Salazar , Jeronimo Graf

PURPOSE Cancer is in the process of changing to become a chronic disease; therefore, an increasing number of oncologic patients (OPs) are being admitted to intensive care units (ICUs) for supportive care of disease or therapy-related complications. We compare the short- and long-term outcomes of critically ill mechanically ventilated OPs with those of their nononcologic counterparts. PATIENTS AND METHODS We performed a prospective study of patients admitted to our ICU between October 2017 and February 2019. Demographic, physiologic, laboratory, clinical, and treatment data were obtained. The primary outcome was survival at 28 days and at the end of the follow-up period. Secondary outcomes were survival according to acute severity scoring (Acute Physiology and Chronic Health Evaluation II score), Eastern Cooperative Oncology Group (ECOG) performance status, and Charlson comorbidity index. RESULTS A total of 1,490 patients were admitted during the study period; 358 patients (24%) were OPs, and 100 of these OPs were supported with mechanical ventilation. Seventy-three percent of OPs had an ECOG performances status of 0 or 1, and 90% had solid tumors. Reason for admission to the ICU was postoperative admission in 44 patients and neutropenic infection in 10 patients. The follow-up period was 148 days (range, 42 to 363 days). Survival at 28 days was similar between OPs and nononcologic patients and associated with the Acute Physiology and Chronic Health Evaluation II score. However, long-term survival was lower in OPs compared with nononcologic patients (52% v 76%, respectively; P < .001) and associated with poor ECOG performance status. CONCLUSION Short-term survival of critically ill, mechanically ventilated OPs is similar to that of their nononcologic counterparts and is determined by the severity of the critical illness.

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Platelet Count in Patients with Mild Disease at Admission is Associated with Progression to Severe Hantavirus Cardiopulmonary Syndrome

2019 , LOPEZ HERNANDEZ, RENE RAMON , Mario Calvo , VIAL COX, MARIA CECILIA , Marcela Ferrés , GRAF SANTOS, JERÓNIMO , Gregory Mertz , Analía Cuiza , Begonia Agüero , Dante Aguilera , Diego Araya , Ignacia Pailamilla , Flavia Paratori , Víctor Torres-Torres , VIAL CLARO, PABLO AGUSTIN , DELGADO BECERRA, OROZIMBA IRIS

Background: Hantavirus cardiopulmonary syndrome (HCPS) has a mortality up to 35–40% and its treatment is mainly supportive. A variable to predict progression from mild to severe disease is unavailable. This study was performed in patients with documented infection by Andes orthohantavirus, and the aim was to find a simple variable to predict progression to moderate/severe HCPS in patients with mild disease at admission. Methods: We performed a retrospective analysis of 175 patients between 2001 and 2018. Patients were categorized into mild, moderate, and severe disease according to organ failure and advanced support need at hospital admission (e.g., mechanical ventilation, vasopressors). Progression to moderate/severe disease was defined accordingly. Clinical and laboratory variables associated with progression were explored. Results: Forty patients with mild disease were identified; 14 of them progressed to moderate/severe disease. Only platelet count was different between those who progressed versus those that did not (37 (34–58) vs. 83 (64–177) K/mm3, p < 0.001). A ROC curve analysis showed an AUC = 0.889 (0.78–1.0) p < 0.001, with a platelet count greater than 115K /mm3 ruling out progression to moderate/severe disease. Conclusions: In patients with mild disease at presentation, platelet count could help to define priority of evacuation to tertiary care centers.

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Increased respiratory dead space could associate with coagulation activation and poor outcomes in COVID-19 ARDS

2022 , GRAF SANTOS, JERÓNIMO , Rodrigo Pérez , René López

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Bedside lung volume measurement for estimation of alveolar recruitment

2012 , GRAF SANTOS, JERÓNIMO

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Comment on Tusman et al.: Validation of Bohr dead space measured by volumetric capnography

2011 , GRAF SANTOS, JERÓNIMO

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Transpulmonary pressure targets for open lung and protective ventilation: one size does not fit all

2012 , GRAF SANTOS, JERÓNIMO

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Minute ventilation to carbon dioxide production ratio is a simple and non-invasive index of ventilatory inefficiency in mechanically ventilated patients: proof of concept

2017 , René López , CAVIEDES SOTO, IVAN RICARDO , Jerónimo Graf

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Intrathoracic blood volume versus pulmonary artery occlusion pressure as estimators of cardiac preload in critically ill patients

2005-01-01 , Tomicic F, Vinko , GRAF SANTOS, JERÓNIMO , Echevarría O, Ghislaine , Espinoza R, Mauricio , Abarca Z, Juan , Montes S, José Miguel , Torres M, Javier , Núñez U, Gastón , Guerrero P, Julia , Luppi N, Mario , Canals L, Claudio

Background: Monitoring of cardiac preload by determination of pulmonary artery occlusion pressure (PAOP) has been traditionally used to guide fluid therapy to optimize cardiac output (CO). Since factors such as intrathoracic pressure and ventricular compliance may modify PAOP, volumetric estimators of preload have been developed. The PiCCO system is able to measure CO and intrathoracic blood volume (ITBV) by transpulmonary thermodilution. Aim: To compare a volumetric (ITBV) versus a pressure (PAOP) determination to accurately estimate cardiac preload in severely ill patients. Patients and Methods: From June 2001 to October 2003, 22 mechanically ventilated patients with hemodynamic instability underwent hemodynamic monitoring with pulmonary artery catheter (PAC) and PiCCO system. ITBV index (ITBVI), PAOP and CI were measured simultaneously by both methods. One hundred thirty eight deltas (Δ) were obtained from the difference of ITBVI, PAOP, CI-PAC and CI-PiCCO between 6-12 am and 6-12 pm. Linear regression analysis of Δ ITBVI versus Δ CI-PiCCO and Δ PAOP versus Δ CI-PAC were made. Results: Mean age of patients was 60.8 ± 19.4 years. APACHE II was 23.9 ± 7. Fifteen patients met criteria for acute respiratory distress syndrome (ARDS). Delta ITBVI significantly correlated with Δ CI-PiCCO (r=0.54; 95% confidence interval = 0.41-0.65; p <0.01). There was no correlation between Δ PAOP and Δ CI-PAC. Conclusion: ITBVI correlated better with CI than PAOP, and therefore it seems to be a more accurate estimator of preload in unstable, mechanically ventilated patients.

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Continuous prolonged prone positioning in COVID-19-related ARDS: a multicenter cohort study from Chile

2022 , Rodrigo A. Cornejo , Jorge Montoya , Abraham I. J. Gajardo , GRAF SANTOS, JERÓNIMO , Leyla Alegría , Romyna Baghetti , Anita Irarrázaval , César Santis , Nicolás Pavez , Sofía Leighton , Vinko Tomicic , Daniel Morales , Carolina Ruiz , Pablo Navarrete , Patricio Vargas , Roberto Gálvez , Victoria Espinosa , Marioli Lazo , Rodrigo A. Pérez-Araos , Osvaldo Garay , Patrick Sepúlveda , Edgardo Martinez , Alejandro Bruhn , Nicole Rossel , María José Martin , Juan Nicolás Medel , Vanessa Oviedo , Magdalena Vera , Vicente Torres , José Miguel Montes , Álvaro Salazar , Carla Muñoz , Francisca Tala , Mariana Migueles , Claudia Ortiz , Felipe Gómez , Luis Contreras , Itzia Daviu , Yurimar Rodriguez , Carol Ortiz , Andrés Aquevedo , Rodrigo Parada , Cristián Vargas , Miguel Gatica , Dalia Guerrero , Araceli Valenzuela , Diego Torrejón

Abstract Background 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.