GRAF SANTOS, JERÓNIMO
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GRAF SANTOS, JERÓNIMO
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jgraf@udd.cl
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7102778326

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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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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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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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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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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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Mechanical ventilatory parameters guided by the low flow pressure-volume curve in patients with acute lung injury/acute respiratory distress syndrome

2007-03-01 , Tomicic Flores, Vinko , Molina B, Jorge , GRAF SANTOS, JERÓNIMO , Espinoza R, Mauricio , Antúnez R, Miguel , Errázuriz C, Isabel , Aguilera F, Pablo , Izquierdo M, Francisco , López, Tania , Canals L, Claudio

Background: Mechanical ventilation may contribute to lung injury and then enhance systemic inflammation. Optimal ventilatory parameters such as tidal volume (VT) and positive end expiratory pressure (PEEP) can be determined using different methods. Low flow pressure volume (P/V-LF) curve is a useful tool to assess the respiratory system mechanics and set ventilatory parameters. Aim: To set VT and PEEP according P/V-LF curve analysis and evaluate its effects on gas exchange and hemodynamic parameters. Materials and methods: Twenty seven patients underwent P/V-LF within the first 72 hours of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). P/V-LF curves were obtained from the ventilator and both lower and upper inflexion points determined. Gas exchange and hemodynamic parameters were measured before and after modifying ventilator settings guided by P/V-LF curves. Results: Ventilatory parameters set according P/V-LF curve, led to a rise of PEEP and reduction of VT: 11.6 ±2.8 to 14.1±2.1 cm H 2O, and 9.7±2.4 to 8.8±2.2 mL/kg (p<0.01). Arterial to inspired oxygen fraction ratio increased from 158.0±66 to 188.5±68.5 (p <0.01), and oxygenation index was reduced, 13.7±8.2 to 12.3±7.2 (p <0.05). Cardiac output and oxygen delivery index (IDO2) were not modified. Demographic data, gas exchange improvement and respiratory system mechanics showed no significant difference between patients with extra-pulmonary and pulmonary ALI/ARDS. There was no evidence of significant adverse events related with this technique. Conclusion: P/V-LF curves information allowed us to adjust ventilatory parameters and optimize gas exchange without detrimental effects on oxygen delivery in mechanically ventilated ALI/ARDS patients.

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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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Respiratory Support Adjustments and Monitoring of Mechanically Ventilated Patients Performing Early Mobilization: A Scoping Review

2021 , GONZALEZ SEGUEL, FELIPE ANDRES , CAMUS MOLINA, AGUSTIN , Anita Jasmén , Jorge Molina , PEREZ ARAOS, RODRIGO ALEJANDRO , GRAF SANTOS, JERÓNIMO

Objectives: This scoping review is aimed to summarize current knowledge on respiratory support adjustments and monitoring of metabolic and respiratory variables in mechanically ventilated adult patients performing early mobilization. Data Sources: Eight electronic databases were searched from inception to February 2021, using a predefined search strategy. Study Selection: Two blinded reviewers performed document selection by title, abstract, and full text according to the following criteria: mechanically ventilated adult patients performing any mobilization intervention, respiratory support adjustments, and/or monitoring of metabolic/respiratory real-time variables. Data Extraction: Four physiotherapists extracted relevant information using a prespecified template. Data Synthesis: From 1,208 references screened, 35 documents were selected for analysis, where 20 (57%) were published between 2016 and 2020. Respiratory support settings (ventilatory modes or respiratory variables) were reported in 21 documents (60%). Reported modes were assisted (n = 11) and assist-control (n = 9). Adjustment of variables and modes were identified in only seven documents (20%). The most frequent respiratory variable was the Fio 2, and only four studies modified the level of ventilatory support. Mechanical ventilator brand/model used was not specified in 26 documents (74%). Monitoring of respiratory, metabolic, and both variables were reported in 22 documents (63%), four documents (11%) and 10 documents (29%), respectively. These variables were reported to assess the physiologic response (n = 21) or safety (n = 13). Monitored variables were mostly respiratory rate (n = 26), pulse oximetry (n = 22), and oxygen consumption (n = 9). Remarkably, no study assessed the work of breathing or effort during mobilization. Conclusions: Little information on respiratory support adjustments during mobilization of mechanically ventilated patients was identified. Monitoring of metabolic and respiratory variables is also scant. More studies on the effects of adjustments of the level/mode of ventilatory support on exercise performance and respiratory muscle activity monitoring for safe and efficient implementation of early mobilization in mechanically ventilated patients are needed.

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The ventilatory inefficiency measured as VE/VCO2 slope is increased in patients who fail to spontaneous breathing trial

2018 , LOPEZ HERNANDEZ, RENE RAMON , PEREZ ARAOS, RODRIGO ALEJANDRO , CAVIEDES SOTO, IVAN RICARDO , GRAF SANTOS, JERÓNIMO

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