Browsing by Author "Daniel Valenzuela, Emilio"

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    Critical care echocardiography in prone position patients during COVID-19 pandemic: a feasibility study
    (2022) Ugalde, Diego; Nicolas Medel, Juan; Mercado, Pablo; Pairumani, Ronald; Eisen, Daniela; Petruska, Edward; Montoya, Jorge; Morales, Felipe; Araya, Carla; Daniel Valenzuela, Emilio
    Purpose Critical care echocardiography is a fundamental tool in the hemodynamic evaluation of critically ill patients and prone position ventilation might limit its application. We aim to evaluate the feasibility of transthoracic echocardiography to assess different measurements performed in prone vs supine position in patients during COVID-19 pandemic to answer our research question: What is the feasibility of classic echocardiographic measurements in COVID-19 patients in prone position ventilation? Methods Patients with covid-19 admitted to ICUs in four academic hospitals with respiratory failure and on mechanical ventilation were evaluated with critical care echocardiography. The first ultrasound assessment was compared between prone and supine patients recording feasibility of several echocardiographic measurements, using Fisher's exact test complementing with Crombach's Alpha. Results 139 patients were included. Sixty-eight (49%) were evaluated in prone position and seventy one (51%) in supine position. Most variables were highly feasible, left ventricular volumes and ejection fraction were more possible to obtain in prone position, while cardiac output was in supine position. Tricuspid regurgitation was the least feasible overall measurement. Conclusion Prone position ultrasound achieved a high feasibility of measurements compared with supine ultrasound in critically ill patients with COVID-19 respiratory failure and on mechanical ventilation. Registration Post hoc analysis of Echo-COVID study (NTC04628195, registered November 13, 2020, retrospectively registered).
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    Exploring the relationship between capillary refill time, skin blood flow and microcirculatory reactivity during early resuscitation of patients with septic shock: a pilot study
    (2023) Contreras, Roberto; Hernandez, Glenn; Daniel Valenzuela, Emilio; Gonzalez, Cecilia; Ulloa, Rodrigo; Soto, Dagoberto; Castro, Ricardo; Guzman, Camila; Oviedo, Vanessa; Alegria, Leyla; Vidal, Diego; Morales, Sebastian; Adolfo Ospina-Tascon, Gustavo; Bakker, Jan; Kattan, Eduardo
    Capillary refill time (CRT), a costless and widely available tool, has emerged as a promising target to guide septic shock resuscitation. However, it has yet to gain universal acceptance due to its potential inter-observer variability. Standardization of CRT assessment may minimize this problem, but few studies have compared this approach with techniques that directly assess skin blood flow (SBF). Our objective was to determine if an abnormal CRT is associated with impaired SBF and microvascular reactivity in early septic shock patients. Twelve septic shock patients were subjected to multimodal perfusion and hemodynamic monitoring for 24 h. Three time-points (0, 1, and 24 h) were registered for each patient. SBF was measured by laser doppler. We performed a baseline SBF measurement and two microvascular reactivity tests: one with a thermal challenge at 44 & DEG;C and other with a vascular occlusion test. Ten healthy volunteers were evaluated to obtain reference values. The patients (median age 70 years) exhibited a 28-day mortality of 50%. Baseline CRT was 3.3 [2.7-7.3] seconds. In pooled data analysis, abnormal CRT presented a significantly lower SBF when compared to normal CRT [44 (13.3-80.3) vs 193.2 (99.4-285) APU, p = 0.0001]. CRT was strongly associated with SBF (R-2 0.76, p < 0.0001). An abnormal CRT also was associated with impaired thermal challenge and vascular occlusion tests. Abnormal CRT values observed during early septic shock resuscitation are associated with impaired skin blood flow, and abnormal skin microvascular reactivity. Future studies should confirm these results.
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    Hypoxia-related parameters during septic shock resuscitation: Pathophysiological determinants and potential clinical implications
    (AME PUBL CO, 2020) Pavez, Nicolas; Kattan, Eduardo; Vera, Magdalena; Ferri, Giorgio; Daniel Valenzuela, Emilio; Alegria, Leyla; Bravo, Sebastian; Pairumani, Ronald; Santis, Cesar; Oviedo, Vanessa; Soto, Dagoberto; Ospina Tascon, Gustavo; Bakker, Jan; Hernandez, Glenn; Castro, Ricardo
    Background: Assessment of tissue hypoxia at the bedside has yet to be translated into daily clinical practice in septic shock patients. Perfusion markers are surrogates of deeper physiological phenomena. Lactate-to-pyruvate ratio ( LPR) and the ratio between veno-arterial PCO2 difference and Ca-vO(2) (Delta PCO2/Ca-vO(2)) have been proposed as markers of tissue hypoxia, but they have not been compared in the clinical scenario. We studied acute septic shock patients under resuscitation. We wanted to evaluate the relationship of these hypoxia markers with clinical and biochemical markers of hypoperfusion during septic shock resuscitation.