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Bersezio C, Martín J, Mayer C, Rivera O, Estay J, Vernal R, Haidar ZS, Angel P, Oliveira OB, Fernández E. Quality of life and stability of tooth color change at three months after dental bleaching. Qual Life Res 2018; 27:3199-3207. [PMID: 30132252 DOI: 10.1007/s11136-018-1972-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE Intracoronary bleaching is a minimally invasive, alternative treatment that addresses aesthetic concerns related to non-vital teeth discoloration. However, to the best of our knowledge, no studies have assessed the psychosocial impacts of such procedures on patients' aesthetic perceptions. The aim of this study was to evaluate aesthetic perceptions and the psychosocial impact of patients up to 3 months after their teeth had been bleached with hydrogen peroxide (35%) and carbamide peroxide (37%) using the walking bleach technique. METHODS The patients were randomly divided into two groups according to the bleaching agent used: G1 = hydrogen peroxide 35% (n = 25) and G2 = carbamide peroxide 37% (n = 25). Non-vital bleaching was performed in four sessions. Color was objectively (ΔE) and subjectively (ΔSGU) evaluated. Aesthetic perception and psychosocial factors were evaluated before, 1 week and 1 month after the bleaching using the Oral Health Impact Profile (OHIP) and Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) questionnaires. RESULTS The color change (ΔE) values at 1 month were G1 = 16.80 ± 6.07 and G2 = 14.09 ± 4.83. These values remained stable until the third month after treatment (p > 0.05). There was a decrease in the values of OHIP-aesthetics and PIDAQ after treatment versus baseline (p < 0.05). This status was maintained through the third month after treatment. CONCLUSIONS Both agents were highly effective and had a positive impact on the aesthetic perception and psychosocial impact of patients, values that also remained stable over time. Non-vital bleaching yields positive and stable impacts on aesthetic perception and psychosocial factors. ClinicalTrials.gov identifier NCT02718183.
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Affiliation(s)
- Cristian Bersezio
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
- Department of Restorative Dentistry, School of Dentistry, University Estadual Paulista-UNESP, Araraquara, CEP 14801-903, Brazil
| | - Javier Martín
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
| | - Carla Mayer
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
| | - Oriana Rivera
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
| | - Juan Estay
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
| | - Rolando Vernal
- Departament of Conservative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Av. Pedro de Valdivia 425, Providencia, Santiago, Chile
| | - Ziyad S Haidar
- BioMAT'X, Centro de Investigación Biomédica, Facultad de Medicina, Universidad de los Andes, Av. Mons. Álvaro del Portillo, 12.455, Las Condes, Santiago, Chile
- Faculty of Dentistry, Universidad Los Andes, Av. Mons. Álvaro del Portillo, 12.455, Las Condes, Santiago, Chile
| | - Pablo Angel
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile
| | - Osmir B Oliveira
- Department of Restorative Dentistry, School of Dentistry, University Estadual Paulista-UNESP, Araraquara, CEP 14801-903, Brazil
| | - Eduardo Fernández
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Independencia, Santiago, Chile.
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Av. Pedro de Valdivia 425, Providencia, Santiago, Chile.
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Bersezio C, Ledezma P, Estay J, Mayer C, Rivera O, Fernández E. Color Regression and Maintenance Effect of Intracoronal Whitening on the Quality of Life: RCT-A One-year Follow-up Study. Oper Dent 2018; 44:24-33. [PMID: 30059269 DOI: 10.2341/17-288-c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE: This randomized clinical study evaluated two parameters: 1) the clinical color rebound of whitening patients' tooth discoloration using the walking bleaching technique and 2) the impact on psychological and aesthetic self-perception at the one-year follow-up of patients who underwent bleaching of nonvital teeth. METHODS AND MATERIALS: Fifty study participants with nonvital tooth discoloration were recruited. Teeth were assigned randomly into one of two groups: 1) 35% hydrogen peroxide (n=25) and 2) 37% carbamide peroxide (n=25). Intracoronal bleaching was carried out over the course of four sessions using the walking bleach technique. Tooth color was evaluated after each session in order to measure the total color variation (ΔE). The guide was arranged from highest (B1) to lowest values (C4) for evaluating color, and color changes using Vita Classical Shade (ΔSGUs) units were calculated. Subjective and objective assessments were compared with the counterpart of the tooth. Aesthetic perception and psychosocial factors were evaluated before and after treatment by the Oral Health Impact Profile (OHIP) and Psychological Impact of Dental Impact Questionnaire (PIDAQ) surveys. RESULTS: Color changes (ΔE) were 15.48 ± 5.17 and 14.02 ± 4.85 for carbamide and hydrogen peroxide groups, respectively. There were no significant differences ( p>0.05) between these two groups at the one-year follow-up. There was a decrease in the PIDAQ scores after treatment compared to baseline values ( p<0.05). The majority of OHIP values regressed to baseline values. CONCLUSION: The technique of walking bleaching was highly effective and showed minimal color rebound in nonvital teeth and had a positive effect on patients' psychological impact at the one-year follow-up.
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Bersezio C, Ledezma P, Mayer C, Rivera O, Junior OBO, Fernández E. Effectiveness and effect of non-vital bleaching on the quality of life of patients up to 6 months post-treatment: a randomized clinical trial. Clin Oral Investig 2018; 22:3013-3019. [PMID: 29455372 DOI: 10.1007/s00784-018-2389-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 02/09/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the esthetic perception of patients at 6 months after bleaching of non-vital teeth with 35% of hydrogen peroxide and 37% of carbamide peroxide using a walking bleach technique. We also assessed psychosocial impacts as well as the clinical effectiveness and stability of the color change. MATERIALS AND METHODS The teeth bleaching treatment was randomly assigned to two groups according to the bleaching agent used: G1 HP = 35% of hydrogen peroxide (n = 25) and G2 CP = 37% of carbamide peroxide (n = 25). The non-vital bleaching was performed in four sessions using the walking bleach technique. The color was objectively (ΔE) and subjectively (ΔSGU) evaluated. The esthetic perception and psychosocial factors were evaluated before treatment as well as one and 6 months post-treatment using Oral Health Impact Profile (OHIP) esthetics and Psychosocial Impact of Dental Esthetics Questionnaire (PIDAQ). RESULTS The color change (ΔE) at 6 months (G1 = 14.53 ± 5.07 and G2 = 14.09 ± 6.61) for both color groups remained stable until the 6-month post-treatment (p > 0.05). There was a decrease in the values of OHIP esthetics and PIDAQ after treatment compared to the baseline (p < 0.05), and this effect was maintained 6 months post-treatment. CONCLUSIONS Both agents were highly effective and maintained the color stability at 6 months; this positively affected the esthetic perception and psychosocial impact of patients who also remained stable over time. CLINICAL RELEVANCE Non-vital bleaching produces a positive and stable impact on the esthetic perception and psychosocial factors at medium-term follow-ups.
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Affiliation(s)
- Cristian Bersezio
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile.,Universidad Andres Bello, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile
| | - Paulina Ledezma
- Department of Conservative Dentistry, Faculty of Dentistry, University of Chile, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile
| | - Carla Mayer
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile
| | - Oriana Rivera
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile
| | - Osmir Batista Oliveira Junior
- University Estadual Paulista-Unesp., School of Dentistry, Rua Humaitá, 1680-Centro-CEP: 14801-903, Araraquara, Brazil
| | - Eduardo Fernández
- Department of Restorative Dentistry, Faculty of Dentistry, University of Chile, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile. .,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Providencia, Chile.
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Said MM, Rivera O, Mikesell GT, Rais-Bahrami K. Influence of central hemodynamics on VV ECMO oxygen delivery in neonatal animal model. J Neonatal Perinatal Med 2017; 10:139-145. [PMID: 28409759 DOI: 10.3233/npm-171692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
BACKGROUND Recirculation of oxygenated blood in venovenous extracorporeal membrane oxygenation (VV ECMO) can decrease the oxygen delivery provided by the ECMO support. This study investigated the influence of central hemodynamics and catheter position on the amount of recirculation and oxygen delivery during VV ECMO. METHODS Recirculation was measured in seven newborn lambs (mean weight 4.7 kg) during VV ECMO using the ELSA Monitor (Transonic Systems, Inc., Ithaca, NY) and using the central venous line (CVL) method. The ECMO pump was set at the prescribed flow of 110-120 mL/kg/min for a targeted oxygen delivery rate of 6cc/kg/min without recirculation. Hemodynamic status before and during ECMO was also measured by the COstatus Monitor (Transonic Systems, Inc.,Ithaca, NY). RESULTS Lambs with a higher cardiac index (>160 ml/min/kg), had a tendency to have higher percent oxygen delivery (65-94%, at prescribed flow) while lambs with lower cardiac index (<150 ml/min/kg), tended to have lower percent oxygen delivery (39-62%, at prescribed flow). ELSA recirculation measurements had a squared correlation coefficient R2 = 0.8 with the CVL method. CONCLUSIONS The ELSA monitor provides an easy to use, non-invasive method to measure recirculation in VV ECMO. The data suggests that cardiac function may play an important prognostic role in achieving effective VV ECMO support.
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Affiliation(s)
- M M Said
- Departments of Neonatology, Children's National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - O Rivera
- Biomedical Engineering, Children's National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - G T Mikesell
- Cardiovascular Surgery, Children's National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - K Rais-Bahrami
- Departments of Neonatology, Children's National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
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Realpe T, Correa N, Rozo JC, Ferro BE, Gomez V, Zapata E, Ribon W, Puerto G, Castro C, Nieto LM, Diaz ML, Rivera O, Couvin D, Rastogi N, Arbelaez MP, Robledo J. Population structure among mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Colombia. PLoS One 2014; 9:e93848. [PMID: 24747767 PMCID: PMC3991582 DOI: 10.1371/journal.pone.0093848] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 03/08/2014] [Indexed: 11/30/2022] Open
Abstract
Background Phylogeographic composition of M. tuberculosis populations reveals associations between lineages and human populations that might have implications for the development of strategies to control the disease. In Latin America, lineage 4 or the Euro-American, is predominant with considerable variations among and within countries. In Colombia, although few studies from specific localities have revealed differences in M. tuberculosis populations, there are still areas of the country where this information is lacking, as is a comparison of Colombian isolates with those from the rest of the world. Principal Findings A total of 414 M. tuberculosis isolates from adult pulmonary tuberculosis cases from three Colombian states were studied. Isolates were genotyped using IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, and 24-locus Mycobacterial interspersed repetitive units variable number tandem repeats (MIRU-VNTRs). SIT42 (LAM9) and SIT62 (H1) represented 53.3% of isolates, followed by 8.21% SIT50 (H3), 5.07% SIT53 (T1), and 3.14% SIT727 (H1). Composite spoligotyping and 24-locus MIRU- VNTR minimum spanning tree analysis suggest a recent expansion of SIT42 and SIT62 evolved originally from SIT53 (T1). The proportion of Haarlem sublineage (44.3%) was significantly higher than that in neighboring countries. Associations were found between M. tuberculosis MDR and SIT45 (H1), as well as HIV-positive serology with SIT727 (H1) and SIT53 (T1). Conclusions This study showed the population structure of M. tuberculosis in several regions from Colombia with a dominance of the LAM and Haarlem sublineages, particularly in two major urban settings (Medellín and Cali). Dominant spoligotypes were LAM9 (SIT 42) and Haarlem (SIT62). The proportion of the Haarlem sublineage was higher in Colombia compared to that in neighboring countries, suggesting particular conditions of co-evolution with the corresponding human population that favor the success of this sublineage.
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Affiliation(s)
- Teresa Realpe
- Corporación para Investigaciones Biológicas, CIB, Medellín, Colombia
- Universidad Pontificia Bolivariana, Medellín, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Nidia Correa
- Corporación para Investigaciones Biológicas, CIB, Medellín, Colombia
- Universidad Pontificia Bolivariana, Medellín, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Juan Carlos Rozo
- Centro Internacional de Entrenamiento e Investigaciones Médicas, CIDEIM, Cali, Colombia
- Instituto Nacional de Salud, Bogotá, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Beatriz Elena Ferro
- Centro Internacional de Entrenamiento e Investigaciones Médicas, CIDEIM, Cali, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Verónica Gomez
- Corporación para Investigaciones Biológicas, CIB, Medellín, Colombia
| | - Elsa Zapata
- Corporación para Investigaciones Biológicas, CIB, Medellín, Colombia
| | - Wellman Ribon
- Instituto Nacional de Salud, Bogotá, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
- Universidad Industrial de Santander, Bucaramanga, Colombia
| | - Gloria Puerto
- Instituto Nacional de Salud, Bogotá, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Claudia Castro
- Instituto Nacional de Salud, Bogotá, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Luisa María Nieto
- Centro Internacional de Entrenamiento e Investigaciones Médicas, CIDEIM, Cali, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Maria Lilia Diaz
- Universidad del Cauca, Popayán, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Oriana Rivera
- Universidad del Cauca, Popayán, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - David Couvin
- WHO Supranational TB Reference Laboratory, TB & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, Abymes Guadeloupe, France
| | - Nalin Rastogi
- WHO Supranational TB Reference Laboratory, TB & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, Abymes Guadeloupe, France
| | - Maria Patricia Arbelaez
- Universidad de Antioquia, Medellín, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
| | - Jaime Robledo
- Corporación para Investigaciones Biológicas, CIB, Medellín, Colombia
- Universidad Pontificia Bolivariana, Medellín, Colombia
- Centro Colombiano de Investigación en Tuberculosis, CCITB, Medellín, Colombia
- * E-mail:
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Abstract
Objectives: The purpose of this study was to compare the newly designed dual-lumen venovenous catheter (VR13, OriGen Biomedical, Austin, TX) with the current dual-lumen catheter (VV12, OriGen Biomedical). Methods: Five newborn lambs, 1 to 5 days old and weighing 4.2 ± 0.5 kg, were cannulated with the VV13 OriGen catheter and placed on extracorporeal membrane oxygenation (ECMO). ECMO flows were increased from 200 to 600 ml/min, with measurements taken after the changes. The experiment was then repeated using the VV12 catheter. Results: Recirculation values were equal for both catheters. The pressure drop at the reinfusion port was equal for both catheters at 200 ml/min, increasing to 275 mmHg at 500 ml/min for the VR13 vs. 240 mmHg for the VV12 catheter. Conclusion: These findings indicate that the VR13 catheter resulted in levels of recirculation equal to the VV12. Based on resistance measurements, we do not recommend the use of this new catheter beyond 400 ml/min until minor design changes are made.
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Affiliation(s)
- MM Said
- Department of Neonatology, Children’s National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - O Rivera
- Department of Biomedical Engineering, Children’s National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - GT Mikesell
- Department of Cardiovascular Surgery, Children’s National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
| | - K Rais-Bahrami
- Department of Neonatology, Children’s National Medical Center and The George Washington University School of Medicine, Washington, DC, USA
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Dutzan N, Rivas C, García-Sesnich J, Henríquez L, Rivera O, Dezerega A, Hernández M, Silva N, Aguillón JC, Puente J, Vernal R, Gamonal J. Levels of Interleukin-21 in Patients With Untreated Chronic Periodontitis. J Periodontol 2011; 82:1483-9. [DOI: 10.1902/jop.2011.100449] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Hernández M, Gamonal J, Tervahartiala T, Mäntylä P, Rivera O, Dezerega A, Dutzan N, Sorsa T. Associations Between Matrix Metalloproteinase-8 and -14 and Myeloperoxidase in Gingival Crevicular Fluid From Subjects With Progressive Chronic Periodontitis: A Longitudinal Study. J Periodontol 2010; 81:1644-52. [DOI: 10.1902/jop.2010.100196] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Dezerega A, Pozo P, Hernández M, Oyarzún A, Rivera O, Dutzan N, Gutiérrez-Fernández A, Overall CM, Garrido M, Alcota M, Ortiz E, Gamonal J. Chemokine Monocyte Chemoattractant Protein-3 in Progressive Periodontal Lesions in Patients With Chronic Periodontitis. J Periodontol 2010; 81:267-76. [DOI: 10.1902/jop.2009.090406] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Dutzan N, Vernal R, Hernandez M, Dezerega A, Rivera O, Silva N, Aguillon JC, Puente J, Pozo P, Gamonal J. Levels of Interferon-Gamma and Transcription Factor T-Bet in Progressive Periodontal Lesions in Patients With Chronic Periodontitis. J Periodontol 2009; 80:290-6. [DOI: 10.1902/jop.2009.080287] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Silva N, Dutzan N, Hernandez M, Dezerega A, Rivera O, Aguillon JC, Aravena O, Lastres P, Pozo P, Vernal R, Gamonal J. Characterization of progressive periodontal lesions in chronic periodontitis patients: levels of chemokines, cytokines, matrix metalloproteinase-13, periodontal pathogens and inflammatory cells. J Clin Periodontol 2008; 35:206-14. [DOI: 10.1111/j.1600-051x.2007.01190.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zeiser S, Rivera O, Kuttler C, Hense B, Lasser R, Winkler G. Oscillations of Hes7 caused by negative autoregulation and ubiquitination. Comput Biol Chem 2008; 32:47-51. [DOI: 10.1016/j.compbiolchem.2007.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 08/21/2007] [Accepted: 09/09/2007] [Indexed: 11/16/2022]
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Abstract
INTRODUCTION Cerebral Oximetry is an optical technique that allows for noninvasive and continuous monitoring of brain oxygenation by determining tissue oxygen saturation (SctO2). In conjunction with pulse oximetry, cerebral oximetry offers a promising method to estimate cerebral venous oxygen saturation (SvO2). OBJECTIVE The aim of this study was to validate the cerebral oximetry measurements with the cerebral oxygen saturation measured from blood drawn in neonates on veno-venous ECMO with existing cephalad catheter with a prototype neonatal cerebral oximeter developed by CAS Medical Systems (Branford, CT, USA). STUDY DESIGN After obtaining informed consent, neonates undergoing VV-ECMO with cephalad catheterization were monitored by the CAS cerebral oximeter. Cephalad blood samples were periodically obtained to validate the monitor's accuracy. RESULTS Seventeen neonates were studied with 1718 h of cerebral oximetry data collected. Compared to the reference values, the bias+/-precision for cerebral oximetry SctO2 was 0.4+/-5.1% and derived SvO2 was 0.6+/-7.3%. CONCLUSION We recommend the use of this noninvasive method as an alternative to blood draws for cerebral venous saturation measurements in neonates requiring extracorporeal life support.
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Affiliation(s)
- K Rais-Bahrami
- Department of Neonatology, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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Abstract
OBJECTIVE To test the hypothesis that inhaled nitric oxide, when combined with high-frequency oscillatory ventilation, is an effective therapeutic agent in meconium aspiration syndrome. DESIGN Prospective, interventional study. SETTING The animal research laboratory at The Children's National Medical Center. SUBJECTS Five newborn piglets, 1-2 wks old, weighing 3.6 +/- 0.2 kg. INTERVENTION Animals were anesthetized, paralyzed, intubated, and ventilated. Catheters were placed in the femoral vein and artery and the pulmonary artery. After 1 hr of recovery, 10 mL/kg of 20% meconium in normal saline solution was insufflated into the lungs. Animals were ventilated with a SensorMedics oscillator to maintain arterial blood gases in a normal range (pH, 7.35-7.45; Paco2, 40-45 mm Hg [5.3-6.0 kPa]; Pao2, 70-90 mm Hg [9.3-12.0 kPa]). Ventilator settings were increased as needed until maximum settings as follows: Fio2, 1.00; proximal oscillatory pressure amplitude, 36 cm H2O; mean airway pressure, 25 cm H2O; frequency, 10 Hz. After a short period of stabilization, inhaled nitric oxide was administered. Concentrations of 40, 20, and 10 ppm were given and measurements were taken after each exposure to inhaled nitric oxide and after its discontinuation. To assure that there was no additive effect of inhaled nitric oxide, each dose was given for 20 mins followed by a 15-min normalization period at 0 ppm. MEASUREMENTS AND MAIN RESULTS Physiologic measurements, ventilatory settings, arterial blood gases, and methemoglobin were recorded at each study period. Measurements were taken after each exposure to inhaled nitric oxide and after its discontinuation. Arterial saturation and partial pressure of arterial oxygen (Pao2) were significantly lower after meconium aspiration when compared with baseline. Administration of inhaled nitric oxide improved oxygenation without a significant decrease in pulmonary artery pressure. CONCLUSION In this model of meconium aspiration syndrome, short-term exposure to inhaled nitric oxide when combined with high-frequency oscillatory ventilation improved oxygenation secondary to better distribution of inhaled nitric oxide. The increase in oxygenation may be secondary to improved ventilation perfusion mismatch, as the primary etiology of hypoxia in this model may be a combination of parenchymal lung disease and pulmonary hypertension.
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Affiliation(s)
- K Rais-Bahrami
- Department of Neonatology, Children's National Medical Center and George Washington University School of Medicine, Washington, DC 20010, USA
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Velarde CA, Short BL, Rivera O, Seale W, Howard R, Kolobow T, Rais-Bahrami K. A comparison of intratracheal pulmonary ventilation to conventional ventilation in a surfactant deficient animal model. Crit Care Med 2000; 28:1455-8. [PMID: 10834695 DOI: 10.1097/00003246-200005000-00033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare intratracheal pulmonary ventilation (ITPV) with conventional ventilation in a rabbit model of surfactant deficiency. DESIGN A prospective randomized animal study. SETTING The Children's National Medical Center Research Animal Facility in Washington, DC. SUBJECTS Adult male New Zealand white rabbits (n = 20), weighing 1.4-4.2 kg. INTERVENTIONS After anesthesia and catheter placement, rabbits were tracheotomized, paralyzed, and placed on the conventional ventilator. We determined pulmonary functions at baseline. We washed surfactant out of the lungs by using serial bronchoalveolar lavages. Pulmonary function studies were determined after completion of the bronchoalveolar lavages and were used as an indication of severity of lung injury. Animals were randomized into two groups: We placed ten animals on ITPV, using the ITPV reverse thruster catheter designed by Kolobow and a prototype ITPV ventilator designed at Children's National Medical Center; we placed ten animals on conventional ventilation using the Sechrist iv-100 ventilator. Arterial blood gases were drawn every 15 mins, and the ventilator settings were adjusted to the minimal level that would maintain arterial blood gases in the following ranges: pH 7.35-7.45, PaCO2 30-40 torr (3.995.33 kPa), PaO2 50-70 torr (6.66-9.33 kPa). Animals were ventilated with the randomized ventilation techniques for 4 hrs. MEASUREMENTS AND MAIN RESULTS Peak inspiratory pressure, mean airway pressure, and positive end-expiratory pressure were measured at the distal end of the endotracheal tube. We recorded these variables plus respiratory rate at baseline and every 30 mins for a total of 4 hrs of ventilation. Lung compliance did not differ between groups at the postlavage study period (ITPV, 0.56+/-0.13 mL/cm H2O/kg; conventional 0.49+/-0.15 mL/cm H2O/kg). At the end of the 4 hr study period, peak inspiratory pressure (ITPV, 26.2+/-4.6 cm H2O; conventional, 32.4+/-5.04 cm H2O, p = .007) and positive end-expiratory pressure (ITPV, 3.9+/-1.96 cm H2O; conventional, 6.3+/-1.42 cm H2O, p = .005) were lower in the ITPV ventilation group. Peak inspiratory pressure was significantly lower in the ITPV group by 2 hrs into the study. CONCLUSION In this model of surfactant deficiency lung injury, ventilation and oxygenation were achieved at significantly lower ventilator settings using ITPV compared with conventional ventilation. Long-term studies are needed to determine whether this reduction in ventilation is maintained, and if so, if lung injury is reduced.
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Affiliation(s)
- C A Velarde
- George Washington University School of Medicine and Health Sciences, Department of Pediatrics, Washington, DC, USA
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Viswanathan M, Rivera O, Short BL. Heat shock protein 90 is involved in pulsatile flow-induced dilation of rat middle cerebral artery. J Vasc Res 1999; 36:524-7. [PMID: 10629429 DOI: 10.1159/000025696] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- M Viswanathan
- Center for Applied Physiology Research, Children's Research Institute, Children's National Medical Center, George Washington University School of Medicine, Washington, DC 20010-2970, USA.
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Rais-Bahrami K, Mikesell G, Seale WR, Rivera O, Hearty JP, Short BL. In vitro evaluation of the Mera Silox-S 0.5 and 0.8 m 2 silicone hollow-fibre membrane oxygenator for use in neonatal ECMO. Perfusion 1999; 7:315-20. [PMID: 10148027 DOI: 10.1177/026765919200700411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Mera Silox-S is a silicone hollow-fibre membrane oxygenator made up of thousands of fibres in a clear polycarbonate housing. Being a silicone membrane it does not have the plasma leakage problem associated with conventional microporous hollow fibres when used in a long-term application. This device (Mera Senko Medical Instrument Co., Japan) is made in three sizes: 0.3, 0.5 and 0.8 m 2. The performance of the 0.5 m 2 and 0.8 m 2 Silox-S membrane oxygenators was tested in vitro using filtered ovine blood and a customized test circuit designed to provide a continuous source of de-oxygenated, CO 2-laden blood, according to the AAMI standard for oxygenator performance. The 0.8 m 2 membrane provided excellent oxygenation, with a transfer rate of 13.0-43.5 ml/min for blood flows of 200-800 ml/min. CO 2 transfer over the same range of flows measured 32.3-40.8 ml/min. Flow rates of 100-500 ml/min for the 0.5 m 2 membrane provided an oxygen transfer of 6.8-28.3 ml/min and would probably not be suited for the existing neonatal ECMO population. A matter of concern with both oxygenators was an increased pressure drop for blood flow through the devices. The delta P for the 0.5 m 2 for flows of 100-500 ml/min ranged from 155 +/- 7 mmHg to 516 +/- 6 mmHg. For the 0.8 m 2, delta P was 194 +/- 39 mmHg to 492 +/- 53 mmHg for flows of 200-800 ml/min. Overall, favourable results support further long-term evaluation for potential use in neonatal ECMO.
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Affiliation(s)
- K Rais-Bahrami
- Children's National Medical Center, Washington, DC 20010
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Sokol GM, Van Meurs KP, Wright LL, Rivera O, Thorn WJ, Chu PM, Sams RL. Nitrogen dioxide formation during inhaled nitric oxide therapy. Clin Chem 1999; 45:382-7. [PMID: 10053039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
BACKGROUND Nitrogen dioxide (NO2) is a toxic by-product of inhalation therapy with nitric oxide (NO). The rate of NO2 formation during NO therapy is controversial. METHODS The formation of NO2 was studied under dynamic flows emulating a base case NO ventilator mixture containing 80 ppm NO in a 90% oxygen matrix. The difficulty in measuring NO2 concentrations below 2 ppm accurately was overcome by the use of tunable diode laser absorption spectroscopy. RESULTS Using a second-order model, the rate constant, k, for NO2 formation was determined to be (1.19 +/- 0.11) x 10(-11) ppm-2s-1, which is in basic agreement with evaluated data from atmospheric literature. CONCLUSIONS Inhaled NO can be delivered safely in a well-designed, continuous flow neonatal ventilatory circuit, and NO2 formation can be calculated reliably using the rate constant and circuit dwell time.
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Affiliation(s)
- G M Sokol
- Department of Pediatrics, Indiana University, Indianapolis, IN 46202,
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Fernandez-Martorell P, Rais-Bahrami K, Rivera O, Seale WR, Short BL. Use of nitric oxide in meconium aspiration syndrome: lack of response. Scand J Clin Lab Invest 1998; 58:177-81. [PMID: 9670340 DOI: 10.1080/00365519850186553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE To test the hypothesis that inhaled nitric oxide (INO) may not be an effective therapeutic agent in meconium aspiration syndrome (MAS). DESIGN Prospective, interventional study. SETTING The animal research laboratory at The Children's National Medical Center. SUBJECTS Seven newborn pigs, 2-7 days old, weighing 2.8 +/- 0.17 kg were used for the study. MATERIALS AND METHODS Animals were anaesthetized, paralysed, intubated and ventilated. Catheters were placed in the jugular vein, carotid artery, and pulmonary artery. After 1 h of recovery 10 ml/kg of 20% meconium in normal saline solution was insufflated into the lungs. Animals were ventilated to maintain ABGs in a normal range, i.e. pH = 7.35-7.45, PaCO2 = 40-45, and PaO2 = 70-90 torr. Ventilator settings were increased as needed until maximum settings of: FiO2 = 1.00, PIP = 40, IMV = 60. After 2 h of conventional ventilation or demonstration of significant lung disease by failure to maintain desired blood gases on maximum ventilator settings, INO was administered for 20 min in concentrations of 10, 20 and 40 ppm. To ensure that there was no additive effect of INO, a 15-min normalization period at 0 ppm was allowed between each dose of INO. Physiologic measurements, ventilatory settings, arterial blood gases, and methemoglobin were recorded at each study period. Measurements were taken after each exposure to INO and after its discontinuation. RESULTS Arterial saturation (SaO2) and PaO2 were significantly lower ([81 +/- 18] and [54 +/- 14], respectively) and PAP was significantly higher [24 +/- 3] after MAS when compared with baseline. Administration of INO did not improve oxygenation nor decrease PAP at any of the study doses. CONCLUSION In this model of MAS, short-term exposure to INO did not decrease PAP nor improve oxygenation. It may be postulated that poor distribution of INO caused by the obstructive nature of this disease may be responsible for the lack of response in this disease state, or that the primary etiology for hypoxia is parenchymal lung disease and not pulmonary hypertension.
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Affiliation(s)
- P Fernandez-Martorell
- Department of Neonatology, George Washington University School of Medicine, Washington, DC, USA
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Handman H, Rais-Bahrami K, Rivera O, Seale WR, Short BL. Use of intratracheal pulmonary ventilation versus conventional ventilation in meconium aspiration syndrome in a newborn pig model. Crit Care Med 1997; 25:2025-30. [PMID: 9403753 DOI: 10.1097/00003246-199712000-00020] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine whether intratracheal pulmonary ventilation (ITPV) allows for effective oxygenation and ventilation at lower mean airway pressures and peak inspiratory pressures than conventional ventilation in a piglet model of meconium aspiration syndrome. DESIGN Prospective, interventional study. SETTING The animal research laboratory at Children's National Medical Center, Washington, DC. SUBJECTS Twenty newborn piglets, 2 to 7 days of age, weighing 1.8 to 2.8 kg. INTERVENTION Animals were anesthetized, paralyzed, intubated, and ventilated. Femoral arterial and venous catheters were inserted; 5 mL/kg of 20% meconium in normal saline was instilled into the endotracheal tube. Animals were randomized to either ITPV or conventional ventilation, and settings were adjusted to maintain ideal blood gases, i.e., pH 7.35 to 7.45, PCO2 40 to 45 torr (5.3 to 6 kPa), PO2 80 to 100 torr (10.7 to 13.3 kPa), and SaO2 > or = 90%. Ventilatory settings were adjusted as needed to a maximum of: FIO2 1.0, peak inspiratory pressure 40 cm H2O, positive end-expiratory pressure 5 cm H2O, and respiratory rate 80 breaths/min. MEASUREMENTS AND MAIN RESULTS Arterial blood gases were taken every 30 mins for 4 hrs and ventilatory settings were adjusted to maintain optimal blood gases. Heart rate, mean arterial blood pressure, and arterial saturation were monitored continuously. The animals in the ITPV group had significantly lower peak inspiratory pressure at 1, 2, 3, and 4 hrs after meconium instillation (p < .018) and significantly lower mean airway pressure at 2, 3, and 4 hrs after meconium instillation (p < .03). The mean peak inspiratory pressure in the ITPV animals ranged from 17 +/- 2.7 cm H2O at baseline to 16.6 +/- 5.7 cm H2O at 4 hrs compared with 16.5 +/- 2.7 cm H2O at baseline to 31.8 +/- 9.1 cm H2O at 4 hrs in the conventionally ventilated animals (p < .04). The mean airway pressure ranged from 6.3 +/- 1.1 mm Hg at baseline to 6.8 +/- 2.5 mm Hg at 4 hrs in the ITPV group compared with 5.5 +/- 1.2 mm Hg at baseline to 10.7 +/- 3.4 mm Hg at 4 hrs in the conventional ventilation group (p < .03). The lungs of the ITPV animals were less hemorrhagic and had less pathologic evidence of injury than the lungs of the conventionally ventilated animals. CONCLUSIONS These results indicate that ITPV can be used to effectively ventilate and oxygenate piglets with meconium aspiration syndrome at lower mean airway pressures and peak inspiratory pressures than conventional ventilation. This lower pressure causes less injury to the lungs of the animals.
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Affiliation(s)
- H Handman
- George Washington University School of Medicine, Washington, DC, USA
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Abstract
OBJECTIVE To test the hypothesis that inhaled nitric oxide may be an effective therapeutic agent in meconium aspiration syndrome and may improve oxygenation after pretreatment with surfactant. DESIGN Prospective, interventional study. SETTING The animal research laboratory at The Children's National Medical Center. SUBJECTS Eight newborn pigs, 1 to 2 wks of age, 4.1 +/- 0.4 kg, were used for the study. INTERVENTIONS Animals were anesthetized, paralyzed, intubated, and mechanically ventilated. Catheters were placed in the femoral vein and artery, and in the pulmonary artery. After 1 hr of recovery, 10 mL/kg of 20% meconium in normal saline solution was insufflated into the lungs. Animals were ventilated to maintain arterial blood gases in a normal range (i.e., pH of 7.35 to 7.45, Paco2 of 40 to 45 torr [5.3 to 6.0 kPa], and Pao2 of 70 to 90 torr [9.3 to 12.0 kPa]). Ventilatory settings were increased, as needed, until the following maximum settings were reached: FIO2 of 1.0; peak inspiratory pressure of 40 cm H2O; and intermittent mandatory ventilation of 60 breaths/min. After 2 hrs of conventional ventilation or demonstration of clinically important lung disease by failure to maintain desired blood gases on the maximum ventilatory settings, 4 mL/kg of beractant was given intratracheally. After a short period of stabilization following surfactant therapy, inhaled nitric oxide was administered. Concentrations of 40, 20, and 10 parts per million were given. To assure that there was no additive effect of inhaled nitric oxide, each dose was given for 20 mins, followed by a 15-min normalization period at 0 parts per million. MEASUREMENTS AND MAIN RESULTS Physiologic measurements, ventilatory settings, arterial blood gases, and methemoglobin were recorded at each study period. Measurements were taken after each exposure to inhaled nitric oxide and after its discontinuation. Arterial oxygen saturation and Pao2 were significantly lower after meconium aspiration when compared with baseline values. After treatment with surfactant, administration of inhaled nitric oxide improved oxygenation without a significant decrease in pulmonary arterial pressure. CONCLUSIONS In this model of meconium aspiration syndrome, short-term exposure to inhaled nitric oxide after treatment with surfactant improved oxygenation secondary to better distribution of inhaled nitric oxide. The increase in oxygenation may be secondary to an improved ventilation/perfusion mismatch, since the primary etiology of hypoxia in this model may be a combination of parenchymal lung disease and pulmonary hypertension.
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Affiliation(s)
- K Rais-Bahrami
- George Washington University School of Medicine, Washington, DC, USA
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Abstract
PURPOSE To determine in-line pressures generated in small-bore central venous catheters during power injection of computed tomographic (CT) contrast media. MATERIALS AND METHODS Five 3.0-7.0-F central venous catheters for pediatric patients were tested at full and half lengths in vitro. In-line pressures were measured during power injection of three contrast media. Rates of injection were increased in steps from 0.1 to 5.0 mL/sec or until a peak pressure of 100 psi (700 kPa) was achieved. The maximum tolerated flow rate was determined with reference to the manufacturer's suggested operating pressure limit for each catheter. RESULTS At full length, the maximum tolerated flow rates were as follows: 2-3 mL/sec for the large lumen and 1-1.4 mL/sec for the small lumen of the 7.0-F double-lumen catheter; 0.2-0.4 and 0.8-1.2 mL/sec for the 3.0- and 4.0-F peripherally inserted central catheters, respectively; 0.7-1.2 mL/sec for the 6.6-F catheter; and only 0.2 mL/sec for the 4.2-F catheter, which ruptured during testing at higher flow rates. CONCLUSION Flow rates were documented at which certain small-bore central venous catheters should tolerate power injection of CT contrast media with peak pressures remaining below the manufacturer's recommended operating pressure limits. These data may serve as a guide for clinical use.
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Affiliation(s)
- L Ruess
- Department of Diagnostic Imaging, Children's National Medical Center, Washington, DC 20010, USA
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Velarde CA, Short BL, Rivera O, Seale W, Howard R, Kolobow T. Reduced airway resistance and work of breathing during mechanical ventilation with an ultra-thin, two-stage polyurethane endotracheal tube (the Kolobow tube). Crit Care Med 1997; 25:276-9. [PMID: 9034264 DOI: 10.1097/00003246-199702000-00014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES To compare dynamic pulmonary function studies using the ultrathin walled Kolobow endotracheal tube, with conventional endotracheal tubes of similar external diameter on rabbits during mechanical ventilation. To test the hypothesis that the increased internal diameter of the Kolobow tube will result in decreased airway resistance and work of breathing. DESIGN Controlled animal study. SETTING Institutional animal research facility. SUBJECTS Adult female Dutch Belted rabbits (n = 6), weighing 1.4 to 1.6 kg. INTERVENTIONS The animals were initially intubated with a conventional endotracheal tube (2.5-mm internal diameter; 3.6-mm outer diameter); they were paralyzed and placed on a mechanical ventilator. Ventilatory settings were adjusted to obtain standard arterial blood gases: pH of 7.35 to 7.45; PaCO2 of 35 to 40 torr (4.7 to 5.3 kPa), and PaO2 of 90 to 100 torr (12.0 to 13.3 kPa). After the stabilization period, pulmonary function tests (PFTs) were measured (period 1), the conventional endotracheal tube was replaced with a Kolobow tube, and PFTs were measured again and recorded (period 2). While continuously monitoring tidal volume, the peak inspiratory pressure was decreased to match the tidal volume measured during ventilation with the conventional endotracheal tube. Once the desired tidal volume was reached, PFTs were recorded (period 3). Flows were unchanged during the experiment and the length of the endotracheal tubes was the same for both the conventional and the Kolobow tube. MEASUREMENTS AND MAIN RESULTS Mean values of the airway resistance and work of breathing from periods 1 and 3 were compared using the Student's t-test. There was a 59% decrease in total airway resistance (p = .001) and 45% decrease in the work of breathing (p = .0006). CONCLUSIONS The use of the ultrathin walled Kolobow endotracheal tube resulted in significant decreases in airway resistance and work of breathing, which has the potential for improving the ventilatory mechanics in very small premature newborns.
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Affiliation(s)
- C A Velarde
- Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Children's National Medical Center, Washington, DC 20010-2970, USA
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Raïs-Bahrami K, Rivera O, Mikesell GT, Seale WR, Sell JE, Short BL. Improved oxygenation with reduced recirculation during venovenous extracorporeal membrane oxygenation: evaluation of a test catheter. Crit Care Med 1995; 23:1722-5. [PMID: 7587238 DOI: 10.1097/00003246-199510000-00017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To determine whether modifications of the original design of a double-lumen, venovenous, extracorporeal membrane oxygenation (ECMO) catheter would reduce recirculation and improve oxygenation during venovenous ECMO. DESIGN Prospective, interventional study. SETTING The animal research laboratory at The Children's National Medical Center. SUBJECTS Six newborn lambs, 1 to 7 days old and weighing 4.7 +/- 0.9 kg. INTERVENTIONS Animals were anesthetized, intubated and ventilated. The ductus arteriosus was ligated. Femoral artery and vein, cephalic jugular vein, and pulmonary artery catheters were placed. After systemic heparinization, the test catheter (with venous drainage holes moved away from the arterial return holes) was placed in the right internal jugular vein and advanced into the right atrium. The animal was placed on ECMO and stabilized, with the ventilator settings decreased to a peak inspiratory pressure of 15 cm H2O, peak positive end-expiratory pressure of 5 cm H2O, respiratory rate of 15 breaths/min, and an FIO2 of 0.21. ECMO flows were increased in 100-mL increments from 200 to 600 mL/min, with measurements taken 15 mins after each change. The test catheter was removed, the double-lumen, venovenous ECMO catheter was placed, and the studies were repeated. MEASUREMENTS AND MAIN RESULTS Heart rate, mean arterial pressure, PaO2, jugular cerebral oxygen saturation, pulmonary artery oxygen saturation, mixed venous oxygen saturation, and postmembrane circuit pressures were measured at each study period. The test catheter improved oxygenation significantly, with higher systemic PaO2, higher pulmonary artery and cerebral oxygen saturations, and lower mixed venous oxygen saturations (indicating less recirculation). With the test catheter, PaO2 levels ranged from 62 +/- 6 torr (8.3 +/- 0.8 kPa) to 112 +/- 12 torr (14.9 +/- 1.6 kPa), compared with 46 +/- 4 torr (6.1 +/- 0.5 kPa) to 59 +/- 2 torr (7.9 +/- 0.3 kPa) for the double-lumen, venovenous ECMO catheter (p < or = .001). These findings indicate that at all flow rates studied, less recirculation occurred with the test catheter than with the double-lumen, venovenous ECMO catheter. CONCLUSIONS These findings indicate that the redesign of the double-lumen, venovenous ECMO catheter, as outlined in this study, resulted in a significant reduction of recirculation, thereby resulting in a significant improvement in oxygenation while on venovenous ECMO. This newly designed catheter makes venovenous ECMO more effective, and represents a design that could be used for pediatric and/or adult ECMO.
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Affiliation(s)
- K Raïs-Bahrami
- Department of Neonatology, Children's National Medical Center, Washington, DC 20010, USA
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Jung H, Rivera O, Reguero MT, Rodríguez JM, Moreno-Esparza R. Influence of liquids (coffee and orange juice) on the bioavailability of tetracycline. Biopharm Drug Dispos 1990; 11:729-34. [PMID: 2271748 DOI: 10.1002/bdd.2510110808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- H Jung
- Departamento de Farmacia y Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México
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Van Meurs KP, Mikesell GT, Seale WR, Short BL, Rivera O. Maximum blood flow rates for arterial cannulae used in neonatal ECMO. ASAIO Trans 1990; 36:M679-81. [PMID: 2252781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The arterial cannulae used in neonatal ECMO cause hemolysis and red blood cell damage at elevated blood flows. Hemolysis in extracorporeal circuits has been found to occur with shear stress greater than 132 dynes/cm2, turbulence as measured by Reynold's number greater than 1,000, and velocity greater than 120 to 200 cm/sec. These parameters need to be considered when sizing the proper arterial cannula for a required flow rate. In-vitro measurements of the pressure drop across six arterial cannulae at varying flow rates were performed using human blood with a hematocrit of 43%. Shear stress, Reynold's number, velocity, and pressure drop were calculated for each catheter at flow rates from 50 to 1,000 cc/min. The maximum mean flow rate to maintain the shear stress, Reynold's number, velocity, and pressure drop within the accepted range, was determined for each cannula. Recommended maximum blood flow rates for each of the six cannulae are given. Internal diameter, length, and cannula geometry appear to be the factors most affecting the flow achievable without causing red blood cell damage and hemolysis. Ten French Biomedicus, 10 French Cook, and 10 French Elecath arterial cannulae appear best suited to deliver the range of blood flow rates used in neonatal ECMO.
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Affiliation(s)
- K P Van Meurs
- Department of Neonatology, Children's National Medical Center, Washington, D.C
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Galioto FM, Brudno DS, Rivera O, Howard RP. Use of the rebreathing method in the differential diagnosis of congenital heart disease and persistent fetal circulation. Am J Cardiol 1984; 54:1305-9. [PMID: 6507303 DOI: 10.1016/s0002-9149(84)80087-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The differential diagnosis of congenital heart disease from persistent fetal circulation is clinically difficult and cardiac catheterization is often needed. The development of a safe, new technique for use of the rebreathing method has allowed the determination of effective pulmonary blood flow, lung tissue volume, lung diffusion capacity and functional residual capacity in 7 critically ill, ventilator-dependent infants at the bedside. Analysis of the data revealed highly significant differences for lung tissue volume and diffusion capacity, a minimally significant difference for effective pulmonary blood flow and no difference for functional residual capacity between the groups. Use of this method allows not only attainment of clinically useful information but also permits better insight into the pathophysiology of the disease state.
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Abstract
The differential arrangement of two pneumotachographs in a gas blow-by system, upstream and downstream from the patient connection port, permits accurate measurement of the tracheal air flow without introduction of flowmeter dead-space. The method does not require but will accept a constant background gas flow rate and permits humidification and easy switching of the inhalant gases. The admissible background flow rates limiting measurement errors below 5% in the range of tidal volumes relevant for newborns for two sizes of commercially available pneumotachographs were found to be -3 L/min and 0-12 L/min, respectively. The lack of restrictions imposed on the properties of the background flow source makes the differential system especially suitable for measurement of ventilation and pulmonary mechanics in spontaneously breathing or mechanically ventilated newborn infants.
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Abstract
An automated method of obtaining a time-weighted average of nitrous oxide levels in an operating room was compared with a standard method. The automated method consisted of electronic integration of the voltage output of a nitrous oxide analyzer using a multimeter-microprocessor. The standard method utilized a bag and pump to collect a room air sample, which was subsequently analyzed with a nitrous oxide analyzer. There was a high degree of correlation (r = 0.99) between the two methods. It is concluded that the automated method is an accurate alternative and offers institutions a simple, cost-effective method of monitoring and documenting results of pollution control programs in anesthetizing locations.
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Hoffmann AJ, Riveros F, Araya S, Rivera O, Avila G, Montenegro G, Aljaro ME. [Identification and counting of atmospheric pollen in Santiago downtown, (1976-77)]. Rev Med Chil 1978; 106:595-600. [PMID: 725380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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