Browsing by Author "Lema, Guillermo"

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Aortic Stenosis and Acquired von Willebrand Disease: Lack of Association
    (W B SAUNDERS CO-ELSEVIER INC, 2011) Carrasco, Esperanza; Lopez, Rodrigo; Rattalino, Marcos; Lema, Guillermo; Pereira, Jaime; Canessa, Roberto; Zalaquett, Ricardo; Carvajal, Claudia; Carrasco, Paulo
    Objectives: The association between aortic stenosis (AS) and acquired von Willebrand disease type 2A has been described. It may be present in up to 90% of patients with AS. Shear stress has been proposed as the underlying mechanism; however, the physiopathology of this condition is not completely understood. No specific treatment has been studied in this specific population besides aortic valve replacement (AVR). As a coadjuvant therapy, some cardiac surgery centers use desmopressin routinely. The authors report the first stage of an ongoing study designed to compare the effects of desmopressin versus placebo in patients with severe AS scheduled for AVR. Because of the different incidences of the acquired von Willebrand type 2A reported in the literature, the first stage was conducted to describe the incidence of this clinical association in the present population, allowing the sample size for the second stage of the study to be obtained.
  • Thumbnail Image
    Item
    Biomarkers as predictors of renal damage in neonates undergoing cardiac surgery
    (SAGE PUBLICATIONS LTD, 2020) Borchert, Evelyn; de la Fuente, Rene; Guzman, Ana Maria; Gonzalez, Katia; Rolle, Augusto; Morales, Karina; Gonzalez, Rodrigo; Jalil, Roberto; Lema, Guillermo
    Background:
  • Thumbnail Image
    Item
    Decreased Nitric Oxide Products in the Urine of Patients Undergoing Cardiac Surgery
    (W B SAUNDERS CO-ELSEVIER INC, 2009) Lema, Guillermo; Urzua, Jorge; Jalil, Roberto; Canessa, Roberto; Vogel, Andrea; Moran, Sergio; Fajuri, Alejandro; Carvajal, Claudia; Aeschlimann, Nicolas; Jaque, Maria P.
    Objective: Renal vasoconstriction has been blamed as a cause of perioperative renal dysfunction after cardiac surgery. Endothelial function is a critical determinant of vascular tonus, including vasoconstriction. The objective of this study was to establish whether the release of the endothelial vasodilator nitric oxide (NO) or NO products is altered in patients undergoing surgery with cardiopulmonary bypass in 3 different clinical conditions.
  • Thumbnail Image
    Item
    Heterogeneity Among Countries in the Subspecialty of Cardiovascular Anesthesia in Latin America: Survey Results
    (2024) Riva, Juan; Calvino, Jimena; Bouchacourt, Juan Pablo; Turconi, Leticia; Cavalleri, Fiorella; Caetano, Nigro Neto; Enriquez, Luis; Tonelotto, Bruno; Lema, Guillermo; Motta, Pablo
    Objectives: To evaluate demographics, workload, training, facilities, and equipment in cardiovascular anesthesia (CVA) in Latin America (LA). Design: A descriptive cross-sectional study with data collected through a survey. Setting: A multicenter, international web -based questionnaire that included 37 multiple-choice questions. Participants: Physicians and specialists in anesthesiology who regularly participated in cardiovascular surgeries and were members of the scientific societies of the Latin American Confederation of Anesthesiology. Interventions: None Measurements and Main Results: A total of 484 completed questionnaires were collected. A total of 97.8% of the respondents had a university degree in anesthesiology. Most did not receive formal training in CVA, and only 41.5% received formal training. Moreover, most of them were trained in their own country, and a smaller percentage were trained abroad. Half of the respondents reported receiving <12 months of training. A third part of the respondents had received training in transesophageal echocardiography. Only 5.8% of the respondents worked exclusively in CVA, and a high percentage dedicated <60% of their weekly work hours to this subspecialty. A total of 80.6% of the centers had <3 cardiac surgery operating rooms. Only one-third of the centers performed heart/lung transplantation, venoarterial extracorporeal membrane oxygenation, venovenous extracorporeal membrane oxygenation, and ventricular assist device implantation. Conclusions: A significant lack of training programs in anesthesiology practice and complex procedures in medical centers in LA are evident. Thus, basic accredited programs should be developed in medical centers in LA. (c) 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY -NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
  • No Thumbnail Available
    Item
    Renal function and cardiopulmonary bypass in pediatric cardiac surgical patients
    (2006) Lema, Guillermo; Vogel, Andrea; Canessa, Roberto; Jalil, Roberto; Carvajal, Claudia; Becker, Pedro; Jaque, Maria Paz; Fajardo, Christian; Urzua, Jorge
    We studied prospectively the perioperative changes of renal function in nine children undergoing cardiac surgery with cardiopulmonary bypass (CPB). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and I-131-hippuran clearances before CPB, during hypo and normothermic CPB, following sternal closure and 1 h postoperatively. Urinary alpha glutathione S-transferase (alpha GS-T) was measured pre- and postoperatively as a marker for tubular cellular damage. Plasma and urine creatinine and electrolytes were measured. Free water, osmolal and creatinine clearances, as well as fractional excretion of sodium (FeNa) and potassium transtubular gradient (TTKG) were calculated. GFR was normal before and after surgery. ERPF was low before and after surgery; it increased significantly immediately after CPB. Filtration fraction (FF) was abnormally elevated before and after surgery; however, a significant decrease during normothermic CPB and sternal closure was found. Alpha GS-T presented a moderate, but nonsignificant increase postoperatively. FeNa also increased in this period, but not significantly. Creatinine, osmolal, free water clearances, as well as TTKG, were normal in all patients pre- and postoperatively. We conclude that there is no evidence of clinically significant deterioration of renal function in children undergoing repair of cardiac lesions under CPB. Minor increases of alpha GS-T in urine postoperatively did not confirm cellular tubular damage. There was no tubular dysfunction at that time.